Re: Exemption from CE for products intended for military or police purposes
I read in !emc-pstc that richhug...@aol.com wrote (in 073F28F0.0F29EB51 .0ba45...@aol.com) about 'Exemption from CE for products intended for military or police purposes' on Tue, 15 Apr 2003: 1) Certain types of military equipment (such as night sights, radios, etc) that was originally sold for solely for military purposes can find its way into civilian hands once it hits the 'army surplus' market. This may not be a concern for the original equipment manufacturer, but it may be of concern to enforcement authorities and other government bodies. After WW2, the authorities feared that government surplus equipment falling into the hands of civilians would cause problems, so much equipment was partially damaged before sale. This, of course, simply acted as a challenge. Later, common sense prevailed, and there was no rush of accidents or illegal transmission. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Russian (GOST) equivalent standards.
I read in !emc-pstc that Barker, Neil neil.bar...@e2vtechnologies.com wrote (in 4f826f960057d4118ec3009027e2453808a52...@whl17.eev.uk) about 'Russian (GOST) equivalent standards.' on Mon, 14 Apr 2003: Although the technical requirements are somewhat similar, you should be using EN 55103-1 EN 55103-2 for EMC as they are the product specific standards for audio, video, and lighting control apparatus for professional use. I would make sure that you meet these first. I don't agree with earlier advice to us EN 55015 as this applies to the luminaires rather than the control equipment. Well, I'm afraid you are wrong in respect of dimmers, as you would know if you had read clause G.2.2.4 of EN 55103-1. The OP's 'dimmer/control equipment' suggested to me that the control was integrated in the dimmer rack, in which case EN 55015 applies to the whole box. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CISPR 22 Ed. 4.0 Published April 10 2003
I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote (in d9223eb959a5d511a98f00508b68c20c12516...@orsmsx108.jf.intel.com) about 'CISPR 22 Ed. 4.0 Published April 10 2003' on Fri, 11 Apr 2003: The 4th Edition differs from the 3rd Edition plus Amendments 1 and 2 by making changes in the telecommunication port conducted emissions tests. The LCL values change for the ISNs, along with other changes. Labs will be needing to have their ISNs re-built or replaced. AIUI, there are big problems in this area, and there is much discussion on what to do about it. Since it won't come into force in Europe for around three years, I would wait and see what happens. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Russian (GOST) equivalent standards.
I read in !emc-pstc that David Sproul david.spr...@alexanderlynn.co.uk wrote (in lnepkcgaigehccdompbbeeafciaa.david.spr...@alexanderlynn.co.uk ) about 'Russian (GOST) equivalent standards.' on Thu, 10 Apr 2003: In Europe we currently use EN 61000-6-1 -3 for EMC, and EN 60439-1, EN 61010-1 and EN 60950 to cover the safety requirements. You should be using EN 55015 for emissions and you do not need to apply EN 61010-1 for safety. I advise you to sort that out before you approach Russia, because they will know. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: EN61326 and deviations
I read in !emc-pstc that charles.mar...@ps.ge.com wrote (in 6BBE5C5603D 0d611a06f0002a5d6556401497...@nyschx22psge.sch.ge.com) about 'EN61326 and deviations' on Mon, 7 Apr 2003: Does this mean I can Pass, for example, a product that meets criteria B for 4-3, Rad Im. at let's say 5.5 V/m just in a few frequencies only. **CriteriON**. Yes, provided the immunity lapses are not too broad in frequency. How broad is 'too broad' depends on what services use the band(s) where the lapses occur. How much highlighting would I have to do in the Test Report and for the product spec, what level of details? Maybe a graph. Would this include the DoC? Not in the DoC. Could I say we meet Criteria A, but in a few frequencies we meet criteria B, call for more details. I don't think that's enough; you should provide the details up-front. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Medical grade PSU and Grounding techniques
I read in !emc-pstc that Chris Chileshe chris.chile...@ultronics.com wrote (in 01c2fd1a.6ef19ba0.chris.chile...@ultronics.com) about 'Medical grade PSU and Grounding techniques' on Mon, 7 Apr 2003: I have been looking at commercially available medical grade PSU's and I find the 5-way DIN connector extensively used. Is this the preferred connector? If so which standard should I be looking at to design the mating part? If not, is there a section of the standard which recommends connector types? I don't know for sure which 'DIN' connector you mean, but maybe IEC 60130-9 is relevant. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CISPR 22 Ed. 4.0 Vote Results
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A04675E3A@flbocexu05) about 'CISPR 22 Ed. 4.0 Vote Results' on Mon, 31 Mar 2003: Voting on CISPR/I/67/FDIS for CISPR 22 Ed. 4.0 ended 2003-03-21. Does anyone know the results? It usually takes a lot longer than 10 days for the result to be put on the IEC web site. However, in this case, the results are there. Approval Criteria Result P-members voting: 29 P-members in favour: 22 = 76 % = 67% APPROVED Total votes cast: 30 Total against: 7 = 23 % = 25% APPROVED Final Decision: APPROVED -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: G5-4 Harmonics Emissions Limits for Industrial Apparatus.
I read in !emc-pstc that David Sproul david.spr...@alexanderlynn.co.uk wrote (in lnepkcgaigehccdompbbgelechaa.david.spr...@alexanderlynn.co.uk ) about 'G5-4 Harmonics Emissions Limits for Industrial Apparatus.' on Tue, 1 Apr 2003: Has anyone heard of G5-4 which is apparently a new standard or amendment to an existing standard within Europe, dealing with the Harmonic Current limits for industrial equipment, presumably meaning equipment rated at more than 16A per phase. I would like to know when is it due to come into force, or when it was ratified, and what exactly it applies to. G%/4 is not a European standard. It is a document produced for the UK electricity suppliers, as guidance on planning levels of voltage harmonics, when supplying fairly large consumers of electricity. It can be obtained (for GBP65) from the Electricity Association, http://www.electricity.org.uk You can sign on to the catalogue pages as 'guest', with password 'guest', but you can't download; you have to pay first. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Stripline design
I read in !emc-pstc that McBurney, Ian [Allen Heath UK] ian.mcbur...@allen-heath.com wrote (in BC4E3DA2E1C8164D9CBE2DF1595DCC 76011...@gandalf.allen-heath.com) about 'Stripline design' on Thu, 29 May 2003: Does anyone have fabrication drawings for a 150mm Stripline they could send me. I am keen to construct one from aluminium sheet. There is a set of drawings in CISPR 20/EN 55020 but there are some fairly obvious mistakes in them concerning the details. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Harmonics and conducted emissions
I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote (in 42050df556283a4d977b111eb7063208138...@orsmsx407.jf.intel.com) about 'Harmonics and conducted emissions' on Tue, 27 May 2003: EN 61000-3-2, by definition, is unhelpful. End of editorial comment. That's a bit harsh. IEC/EN 61000-3-2 expect the use of the measuring device described in IEC/EN 61000-4-7. This does not measure 'conducted emissions' in the CISPR sense. I don't see how 61000-3-2 can be 'helpful' on a subject outside its scope, but if you have a proposal I will suggest how you can get it taken into account for the planned full revision of 61000-3-2. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Harmonics and conducted emissions
I read in !emc-pstc that Neil Helsby nei...@solid-state-logic.com wrote (in 20030527.10334...@mis.configured.host) about 'Harmonics and conducted emissions' on Tue, 27 May 2003: Has anyone else noticed the tendency of modern switch mode power supply designers to save manufacturing costs at the expense of harmonic and conducted emissions measurements? Did you mean to write 'measurements' in that sentence? It doesn't make sense, really. EN 61000-3-2:2000 has introduced the concept of Partial Odd Harmonics for the 21st and above. While this adds extra functions to the spread-sheet results check, I wonder if it also has an unhelpful side effect. I don't see that this is necessarily relevant to the next paragraph, about conducted emissions, which are still mostly measured from 150 kHz upwards. The 'partial odd harmonics' thing deals with harmonics up to the 39th only. That's 1950 Hz in Europe and 2340 Hz in the Americas. Are you measuring conducted emissions down to 9 kHz? With conducted emissions, new power supply designs generate peak emissions at frequencies below 200 KHz that increase in level inversely to the frequency. I don't see anything 'new' in that. It applies to all SMPS, with suitable changes to the '200 kHz'. These out-of-band emissions result in overloading the front-end of a Spectrum Analyser that consequently requires either a pre-selector or calibrated filter to function correctly. There is, of course, the alternative of purchasing a new receiver! This overloading has been around for a very long time. It is one of the disadvantages of using a spectrum analyser instead of a CISPR receiver. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: VG95373 - advice needed
I read in !emc-pstc that Hudson, Alan alan.hud...@amsjv.com wrote (in c432a75247b8f84d86febc5425b6a552087...@amsms01001.jupiterlnk.net) about 'VG95373 - advice needed' on Tue, 27 May 2003: (I suppose I'm asking that if a cabinet meets VG95373 will it pass the EN standard equivalent(s) and I can just say so in my Technical Construction file) I suspect that it is irrelevant for the TCF. The conformity applies to the cabinet before you have pierced any holes in it, or modified it in any way. There is absolutely no guarantee that the modified cabinet still meets the requirements of the VG. The same applies to the EN. I don't know how much consistency there is between the VG and the EN. The EN standard is: Pub Id : BS EN 61000-5-7:2001 Status : Current Title : Electromagnetic compatibility (EMC). Installation and mitigation guidelines. Installation and mitigation guidelines. Degrees of protection by enclosures against electromagnetic disturbances (EM code) Int Relationships : EN 61000-5-7:2001 IDT; IEC 61000-5-7:2001 IDT ICS Classification : 33.100.10 Committee Ref : GEL/210;GEL/210/12 ISBN : 0 580 38031 9 Form : A4 Pages : 30 Price : £70.00 Non-member Price -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Bad Fuse vs. Good Fuse
I read in !emc-pstc that richhug...@aol.com wrote (in 095A00F3.5FF82361 .0ba45...@aol.com) about 'Bad Fuse vs. Good Fuse' on Mon, 26 May 2003: It could be that the faulty components that John Woodgate mentioned fall into this category. The epidemic failures were undoubtedly due to manufacturing defects, not counterfeiting - unless the manufacturer was shipping the counterfeits to us! We weren't buying from distributors. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Bad Fuse vs. Good Fuse
I read in !emc-pstc that douglas_beckw...@mitel.com wrote (in ofaba67a95.7e85c2b8-on85256d32.004d2778-85256d32.00519...@mitel.com) about 'Bad Fuse vs. Good Fuse' on Mon, 26 May 2003: You can be almost certain that it was not caused by a bad fuse. No, that is not true, or at least it wasn't when we were putting 20 x 5 mm fuses in television sets. Periodically, one or other of our five fuse suppliers would run into manufacturing problems and we would get a batch of fuses with a short-term failure rate of 20% or even more. They would usually hold up long enough to pass soak and final test, and let go a few days after purchase. The failure modes were open-circuit for no external reason and high resistance. Occasionally, we would get one that produced cracking on sound, indicating a poor internal connection. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Use of Voltage Probe
I read in !emc-pstc that ITL-EMC User Group itl-...@itl.co.il wrote (in 2D1037012914D4118DB8204C4F4F5020275AD1@ITLLTD01) about 'Use of Voltage Probe' on Sun, 25 May 2003: According to Section 4.1.3 Voltage probes of ANSI C63.4, A voltage probe may be used for radio-noise voltage measurements when measurements are made at a user's installation (see 5.6) or when the ac current level exceeds the current-carrying capability of commercially available LISNs. For such measurements, the method shown on Figure 4 may be used. Special precautions shall be taken to establish a reference ground for the measurements. This is an example of useless wording in a standard. What 'special precautions' did the authors have in mind? To achieve or avoid what? They don't tell us, and coyness is definitely not a virtue in such a case. All it does is create confusion, as we see here. Accord to Section 5.6 Testing at manufacturer's location or user's installation, The voltage probe (see 4.1.3) shall be used for ac powerline conducted emission measurements. (See IEEE Std 13-1988 for additional information.) Neither a reference groundplane nor an LISN shall be installed for user's installation testing unless one or both are to be a permanent part of the installation. The above sections seem to me to contradict one another regarding the reference groundplane. No, because you have no 'grounds' (ouch!) for assuming that the 'special precautions' imply 'use a ground plane'. Can we interpret the above (Section 4.1.3 Special precautions shall be taken to establish a reference ground for the measurements.) to be applicable only when testing in the laboratory and the ac current level exceeds the current-carrying capability of commercially available LISNs? Please comment. No, it is reasonable and technically correct to pay attention to where you ground the voltmeter connected to the probe, wherever the measurements are carried out. It would be logical to connect it to the enclosure of the EUT, if it is metal, with the shortest practicable lead. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: AC shut-down
I read in !emc-pstc that simon_...@emc.com wrote (in 277DD60FB639D511AC 0400b0d068b71e0b435...@corpmx14.corp.emc.com) about 'AC shut-down' on Fri, 23 May 2003: I wonder if anybody can substantiate or debunk a rumor that in New York City, and maybe in New York State, there is a new requirement to shut off air conditioning systems in buildings in case of emergency, a post 9/11 measure. It is an important issue: Since the computer systems can continue to function, the computer room temperature can quickly shoot up to as high as 140F (60C), there maybe no risk of fire, but a multimillion system can overheat and self-destruct. It sounds like 'military intelligence' to me. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety testing after equipment repair
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200305231749.kaa15...@epgc264.sdd.hp.com) about 'Safety testing after equipment repair' on Fri, 23 May 2003: I stand by my statements. You added a lot more information. In the light of that, I agree that your results are likely to be more representative than your first description suggested. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: harmonics testing
I read in !emc-pstc that Brian Epstein brian.epst...@veeco.com wrote (in 41c71af75675d54bb97c2fadcae7f994260...@exchange.di.com) about 'harmonics testing' on Fri, 23 May 2003: That raises and interesting question. The components are not in a rack or case, they are tabletop mounted. I would think that systems on a tabletop would be less in need of being tested as a whole, but para 6.3 doesn't say that. Once again, you need to refer to the definition of 'system'. If the components are marketed as one item of commerce, they are tested together and one CE mark (in theory), and one DOC are required. If they are marketed as separate items, each requires a DOC and a CE mark, and they are tested separately. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: harmonics testing
I read in !emc-pstc that ssel...@yorkemc.co.uk wrote (in E19J8TQ- 000cv7...@anchor-post-31.mail.demon.net) about 'harmonics testing' on Fri, 23 May 2003: Brian/John I notice that EN61000-3-2(2000) para 6.3 says Where individual self contained items are installed in a rack or case, they are regarded as being individually connected to the mains supply. The rack or case need not be tested as a whole. So, is it a rackfull of systems, or a system in a rack?! :) The implication of 'individual, self-contained items' is that they are marketed individually (and are therefore each CE-marked). Unfortunately, we could not get agreement on more specific wording. These items may be supplied by one or more than one manufacturer, and are often racked-up on-site; thus the rack is an 'installation' as defined in the Directive and Guidelines. If a manufacturer sells as a single item of commerce a rack of physically-separable items which are not marketed individually, then that is a 'system' as defined in the Directive and the Guidelines and is tested and CE-marked as a whole. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety testing after equipment repair
I read in !emc-pstc that richhug...@aol.com wrote (in 014C7BA9.2FB45A16 .0ba45...@aol.com) about 'Safety testing after equipment repair' on Thu, 22 May 2003: For earth bond test we suggested that only a low current would normally be required because the equipment would have been type tested at a higher current anyway and the intention of these Regulations is to show up deterioration of products in the workplace caused by normal wear and tear. There is a justification for a high-current test **where it won't cause any new damage**. The justification is that it will find bad joints in the PEC path, and stranded PEC and bond wires that have only one or two strands still intact. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety testing after equipment repair
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200305230123.saa09...@epgc264.sdd.hp.com) about 'Safety testing after equipment repair' on Thu, 22 May 2003: Some years ago, I undertook a test to determine when an insulation would fail if subjected to a continuous hi-pot voltage. I connected several units to the hi-pot voltage for 8 hours/day. The units started failing after about 10 days. That would be about 48,000 minutes. I don't think you can draw universal conclusions from just one experiment. In addition, the rate of increase of voltage is limited in the test procedures. In your experiment, there was only one increase of voltage, whereas in repeated testing, there are many. At best, we don't know if that matters or not. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: harmonics testing
I read in !emc-pstc that Brian Epstein brian.epst...@veeco.com wrote (in 41c71af75675d54bb97c2fadcae7f994260...@exchange.di.com) about 'harmonics testing' on Thu, 22 May 2003: We make a product that has several components that plug into the power mains including a computer, two monitors, and two units that we manufacture ourselves. When all these components are tested for power current harmonic emissions together, they fail. When tested separately, they pass. Is it reasonable to assume that if we ship the system to Europe with a power strip that we have to test all components together, but if we do not include a power strip, we can test each component for harmonics separately? It doesn't work quite like that. You need to look at the special definitions of 'system' and 'installation' in the Directive and the Guidelines. You may be surprised at the following, but I believe it is true and no- one has specifically said that it is not: If the whole kit is catalogued, priced and invoiced at a single inclusive price, then it is a 'system', as defined in the Directive and the Guidelines, and must be tested as a single entity. If you have to go down this route, consider that you can buy off-the- shelf power supplies with active PFC now for only a few dollars more, and these meet the limits with a wide margin. You may find that just changing the power supplies in the units that you make is sufficient. If the items are catalogued, priced and invoiced as separate items, and purchasers can choose which items to buy, then there is no one kit that the manufacturer can test; instead each item is tested separately. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety testing after equipment repair
I read in !emc-pstc that Peter L. Tarver peter.tar...@sanmina-sci.com wrote (in nebbkemlgllmjofmoplekemhegaa.peter.tar...@sanmina-sci.com) about 'Safety testing after equipment repair' on Thu, 22 May 2003: Or a lower potential test for mains connected equipment, such as insulation resistance. No, an IR test is not a substitute for a hi-pot test, and has a can of worms all its own. Pass values of leakage resistance are in the megohm range, but much modern equipment starts off in the 100 megohm or even gigohm range. So a degradation to 1 or 2 megohms could well be a sign of seriously-damaged insulation, but the equipment is regarded as OK. In my opinion, a value less than one-third of the initial value (preferably specified by the manufacturer) is a cause for concern. More complicated, but less deleterious, tests could include an earth leakage current test or a touch current test. Earth leakage is often appropriate but it is necessary to distinguish between resistive leakage and capacitive current. I don't know of any snags with touch current testing IF the IEC 60999 meter is used. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety testing after equipment repair
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote (in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about 'Safety testing after equipment repair' on Thu, 22 May 2003: My last (3) employers have required all repaired or modified units to be hi-potted. If a unit has been repaired, then the cover was removed, and the unit is no longer controlled by the oroginal production hi-pot. I think this is too stringent. Repeated hi-pot tests must be *minimised*, because of the possibility of progressive degradation of insulation. A possible solution is to say that a hi-pot test is required if a visual inspection by a supervisor indicates that it is necessary. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ENV 50204
I read in !emc-pstc that Carpentier Kristiaan Kristiaan.Carpentier@thom son.net wrote (in 421CB3B9B2D2F645B548D213C0A90E550159FB84@edgmsmsg01. eu.thmulti.com) about 'ENV 50204' on Thu, 22 May 2003: Some small remark on your statement: EN 50082-1:1997 is being replaced by EN 61000-6-1:2001. EN 50082-1:1997 can still be used as harmonised standard up to July 1rst, 2004. That's why I wrote 'is being replaced' rather than 'has been replaced'. For old products, the old standard is still valid. For new products, the new standard should be applied if the product will continue in production after July 2004. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ENV 50204
I read in !emc-pstc that Joe P Martin marti...@appliedbiosystems.com wrote (in of4e88fbab.7b257c61-on88256d2d.000c6...@pe-c.com) about 'ENV 50204' on Tue, 20 May 2003: ENV 50204 is titled Radiated Electromagnetic Fields from Digital Radio Telephones-Immunity Test Please refresh my memory on what exactly is an ENV Standard? An experimental or trial standard. Are there any requirements for testing to ENV's? Not any more: they are all superseded AFAIK. For EN 50204, see EN 61000-4-3 latest edition. For what type of products would ENV 50204 be applicable? Nothing, now. We normally test to EN 61326. It has been some time since I looked at EN 50082-1 Generic Immunity. Could someone be so kind as to list what immunity standards are in the latest version of EN 50082-1. Replaced by EN 61000-6-4:2001. Does the latest version still state that if there is a product specific standard then that standard takes precedence over the generic standard? Yes. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: RTTE DoC languages
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A04675F9D@flbocexu05) about 'RTTE DoC languages' on Tue, 20 May 2003: Anything the group can provide would be appreciated, but I would ask that persons refrain from offering translations if they are not sufficiently competent in the language. I recommend that you ask the professional translators on sci.lang.translation because there are legal implications if a translation is defective. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ATEX Directive
I read in !emc-pstc that lisa_cef...@mksinst.com wrote (in OF9E3924EC.C 5f3fe92-on85256d2b.00665f16-85256d2b.00677...@mksinternal.com) about 'ATEX Directive' on Mon, 19 May 2003: Does anyone have any information on the relationship between the ATEX directive and CENELEC? There isn't any. Is it a replacement for CENELEC? How could it be? ATEX is a Directive and CENELEC is a standards-making body. Does compliance with one insure compliance with the other? No answer is possible. Are they mutually exclusive? No answer is possible. Any help or direction as to where to look would be appreciated. I think you need to try to explain more clearly what you are really asking. For example, what products do you have in mind, and I suspect you are writing 'CENELEC' when you really mean specific CENELEC standards. If so, which ones? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Standards applicable for Speaker
I read in !emc-pstc that Koh koh...@singnet.com.sg wrote (in 3ec8cf1e.80...@singnet.com.sg) about 'Standards applicable for Speaker' on Mon, 19 May 2003: Complying to EN55013/55020, will we be violating the EMC requirement/directive if we sell/target the speakers as multimedia speaker (say in PC show)? No. There is an IEC Guide on this subject, but it isn't worth getting a copy. This subject has been raised thousands of times over the last few years and no-one has ever reported any problem with the regulatory authorities, AFAIK. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Heat Sink Colour.
I read in !emc-pstc that Chris Maxwell chris.maxw...@nettest.com wrote (in 83d652574e7af740873674f9fc12dbaaf7e...@utexh1w2.gnnettest.com) about 'Heat Sink Colour.' on Mon, 12 May 2003: We radiate heat through our skin, not our clothes. We don't cool by radiation much, but by evaporation of perspiration. Dark skin radiates better, hence the dark coloring of people with African ancestry. The dark skin is more for protection against UV. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Standards applicable for Speaker
I read in !emc-pstc that Koh koh...@singnet.com.sg wrote (in 3ec2aca5.1080...@singnet.com.sg) about 'Standards applicable for Speaker' on Thu, 15 May 2003: For this speaker products, what is the EN standard to comply? EN55022/24 or EN55013/20? To test to EN55022/24 but there's no digital circuitry to classify as ITE.. But we do allow users to connect the speaker as multimedia speaker, i.e. connected to PC. Like to hear your view of this dilemma that we're in. EN 55013/55020 apply. Such products are 'household and similar electronic equipment'. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: NEW EMC DIRECTIVE
I read in !emc-pstc that Gordon,Ian ian.gor...@bocedwards.com wrote (in E1BA0362B28ED211A1E80008C71EA3060206FBEA@EXC_EAS01) about 'NEW EMC DIRECTIVE' on Fri, 9 May 2003: How can the authors of the directive reconcile the concept of benign equipment (which are outside the scope of the directive) with the requirement to include, for example, a mains lead? Does this mean that if leads are sold separately they must have a D of C? It appears so. I suppose the standards one would cite for EMC and safety are those which apply to the products the cable is intended to be used with. For general-purpose mains leads, I suppose one would cite the Generics for EMC, and they would pass by default. I assume that a lead provided with a piece of equipment would be covered by the D of C for that equipment. I think the DOC had better say 'the Model XYZ, including the cables supplied with it'. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Field trial requirements
I read in !emc-pstc that Jon Jones jon.jo...@atltelecom.com wrote (in D1D4A262894FD511A65900902707BB246122B5@CARDIFF-NT-MAIL) about 'Field trial requirements' on Fri, 9 May 2003: Are there any EU legal requirements regarding the supply of products for field trials that have not yet completed the CE process. Is it legal to do so provided the products are labelled accordingly, (Evaluation sample etc), installed in restricted locations and are still the property of the manufacturer (thus in effect not being made available as defined in the new / global approach) If the products are not 'placed on the market', they are not 'in free circulation'. But there may well be difficulties in shipping them across national borders in Europe. The approach of the regulatory authorities differs from country to country. If you designate each item as being for use at a named site only, you may be able to use the provisions for 'one-offs' in the new Directive. But this is a matter which has already been raised as an objection to the current draft, AIUI. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Acoustic Noise Level
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A04675F30@flbocexu05) about 'Acoustic Noise Level' on Wed, 7 May 2003: Does anyone know of a recommended maximum acoustic noise level for a laboratory? I'm not looking for a regulatory level, but a recommended maximum level that will allow employees in the lab to carry out normal activities without the noise causing undue problems with their productivity. It depends what the activities are, but in general, the quieter the better, down to the 'library' level (about 40 dBA), but not below, because sensory deprivation occurs in 'deathly hush' conditions. If the noise level is rather high, say 60 to 65 dBA, the critical factor is whether the sound is 'tonal' (has an identifiable pitch, as opposed to simply noise) and, above all, if it has a rhythmic component. The latter can drive people made even if it's more than 10 dB below the total noise level. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: NEW EMC DIRECTIVE
I read in !emc-pstc that Gordon,Ian ian.gor...@bocedwards.com wrote (in E1BA0362B28ED211A1E80008C71EA3060206FBE3@EXC_EAS01) about 'NEW EMC DIRECTIVE' on Thu, 8 May 2003: Does anyone know what a ready-made connection device is? A cable with connectors attached, offered for general sale. A special cable, made for a particular site, comes under the new provisions for 'one-offs' (a term not used in the Directive, of course). I'm sure there are valuable prizes offered within the Commission, for 'the most obscure text of the month'. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD gun verification
I read in !emc-pstc that Jim Ericson jde...@nas.com wrote (in 004001c31052$499e9c40$83663fce@pavilion) about 'ESD gun verification' on Thu, 1 May 2003: Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the shape of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. I strongly endorse that. It's not a 'ground strap', it's an open-wire transmission line in most cases. There is one product that has a more technically-defensible arrangement. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD gun verification
I read in !emc-pstc that John Harrington jharring...@f2labs.com wrote (in 5777c7d14a69d411be4200a0cc746898493...@exchange.f2labs.com) about 'ESD gun verification' on Thu, 1 May 2003: Does any one have a quick and dirty (and hopefully cheap) way to verify the performance of an ESD gun. It's a major bugbear with that standard (and any ESD standard, I think). Any QD method will only give you very dirty answers. You might just as well not bother. No-one, AFAIK, really knows how the discharge current gets back to the gun. Even for an 'electrostatic' discharge, there must be a closed current path. Now think about those nanosecond pulses travelling along a metre or more of return cable. Inductance? What's that? (;-) Please, no one suggest building the current sensing system described in the back of IEC 61000-4-2. I don't understand the drawings let alone have the workshop or materials to consider it. Although, I may pay someone to build it for me... Don't. The amount of black magic you need even to make the official method work is immense, and you certainly can't qualify the current- sensing system without a lot of VERY costly test equipment. I am desperate enough to consider buying something off the shelf (if I could find said shelf). I'm not sure that you can even do that at a sensible cost, but I understand that there are a few specialist companies who will verify your gun for you. I don't have any names or URLs, though. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD failure
I read in !emc-pstc that Ravinder Ajmani ajm...@us.ibm.com wrote (in of3726dba3.c9d3514a-on88256d19.007dd66b-88256d19.00802...@us.ibm.com) about 'ESD failure' on Thu, 1 May 2003: Any suggestions on what I should I try next. A grounded shield over the ASIC? It's being zapped by radiated energy, after all. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: D of C again
I read in !emc-pstc that Wagner, John P (John) johnwag...@avaya.com wrote (in 4203D61676D0AE468AA5CEA90A891C130288F018@cof110avexu4.global. avaya.com) about 'D of C again' on Thu, 1 May 2003: I agree with Paul. It is usually very difficult to print the DoC in the users manual. Ordinarily, the manual is approved and goes to print before the final testing of the product and certainly before the DOC is signed. Is that a new law of nature? It seems that the system is running you, rather than the other way round. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD gun verification
I read in !emc-pstc that drcuthb...@micron.com wrote (in CFEFA50C9BCAD2 1197470001fa7eba6b14121...@ntexchange05.micron.com) about 'ESD gun verification' on Thu, 1 May 2003: to verify the waveform and charge you will need a Tektronix CT-1 current transformer, a 500 MHz digital oscilloscope, and a 500 ohm high voltage resistor. A 1/4 watt or larger carbon comp will work. Be aware that it has a voltage coefficient. This will allow you to view the rise time, the decay time, and calculate the total charge in coulombs (amps X seconds). I have been working on this subject myself for the past couple of days. I have been view actual human discharges, an ESD gun, and have built my own miniature ESD generator. The generator and SPICE model are amazingly close when using component models that incorporate the parasitics. If that is true, I wonder why the people who investigated the previous version of the calibrator found a need for a 6 GHz scope among other exotica. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: D of C again
I read in !emc-pstc that Wagner, John P (John) johnwag...@avaya.com wrote (in 4203D61676D0AE468AA5CEA90A891C1302A014D6@cof110avexu4.global. avaya.com) about 'D of C again' on Thu, 1 May 2003: Quite the opposite. Compliance testing can only be done on the final production model. This obviously places compliance testing at the end of the pipeline. It is questionable, to say the least, to issue a DOC prior to final testing, You aren't 'issuing' it until you ship the product. You can't ship it (legally) until the DoC is validated by compliance testing. So you could prepare and sign it the day the development project starts - it is just a scrap of paper until you ship the product. so the DOC is not available till after final compliance testing. There is normally a several month lead time for publication of manuals, so the product introduction will be delayed by the amount of time necessary to get the manuals published. I don't understand a 'several month lead-time'. When I was producing copy for manuals, we had the proofs in a couple of weeks, and that was when computer-aided publishing was a new thing. Besides, if it's a big and complex manual, you can leave a space on page 299 to drop the DoC in at a late stage. Even Caxton could have done that. (;-) Manufacturers have very agressive (and often optomistic) development cycles. There is no extra time in the cycle to add a few weeks or months for publication and still meet introduction dates. These things have to run in parallel. I would not be daft enough to suggest a procedure that added even a week to time-to-market. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: D of C again
I read in !emc-pstc that Didcott Paul pdidc...@sendo.com wrote (in 83224DA0036BD511BD93001083FD8899030A3BE1@SENDOAPP2) about 'D of C again' on Thu, 1 May 2003: This is the position in the EU under the RTTE Directive, as well as LVD/EMC. (The RTTED replaces these directives for equipment within it's scope.) Well, sort of. In fact, for most equipment, the manufacturer can choose whether to apply the RTTE Directive OR the LVD and EMC. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: D of C again
I read in !emc-pstc that Mazzola, Santo santo.mazz...@baesystems.com wrote (in d63659cefebdd511b8670050da7facfe03560...@edison.hazeltine.com ) about 'D of C again' on Wed, 30 Apr 2003: Just a question. If you are not going to put the D of C in the users manual to satisfy the RTTE directive requirement of having a D of C with the product, is there another more elegant place to put it. Printing it in the manual costs next to nothing, ensures that it is shipped and impresses the purchaser. I recommend doing this even if the applicable Directives don't require it. Any other suggestions would be interesting to note. How about the idea of putting an online link to where the DOC could be found. Do you think that would meet the RTTE requirement of D of c with product. About 2 years ago, I heard that some countries will NOT accept this solution. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Do you realize how annoying it is?
I read in !emc-pstc that Grasso, Charles charles.gra...@echostar.com wrote (in DEDA59C30D344E4182D1A4DAB86C5B780434B36D@riv- exch2.echostar.com) about 'Do you realize how annoying it is?' on Mon, 30 Jun 2003: Any reasonable email software can set rules that automatically files email replies. For example the OOF replies?..they are automatically routed to my Deleted Items. Not too much of a hassle.. ... unless you inadvertently set your mailer to **reject** them, in which case you may set up an endless loop, and your ISP will kill you. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The transformer screen/shield conundrum
I read in !emc-pstc that richhug...@aol.com wrote (in 6C87B93E.0C9D7087 .0ba45...@aol.com) about 'The transformer screen/shield conundrum' on Sat, 28 Jun 2003: [R_Hughes ] I know it as prospective short-circuit current, but maybe I go boldly whereas you boldly go? Do we know what the current values are in various countries, for equipment connected to wall-sockets? Assuming that the mains lead has the resistance that can be deduced from the maximum permissible resistance of its PEC. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The transformer screen/shield conundrum
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200306271743.kaa29...@epgc264.sdd.hp.com) about 'The transformer screen/shield conundrum' on Fri, 27 Jun 2003: The screen/shield must be capable of carrying the full fault current and is often tested using the 25-amp test. C.2 of Annex C of IEC/EN 60950-1:2001 says, in the Notes: ' an overload device [should be 'protective device', I think] will open the circuit before the screen is destroyed.' If the product is fitted with an internal fuse, say 5 A, I don't see any need for the screen to withstand 25 A. I certainly would not want to design a transformer with a screen that would withstand 25 A unless the cost and difficulty of manufacture were amply justified. At 25 A, the current divergence from the fault point and convergence to the lead out could well have significant effects. There are ways of dealing with that, but it's bothersome. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The transformer screen/shield conundrum
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200306271956.maa00...@epgc264.sdd.hp.com) about 'The transformer screen/shield conundrum' on Fri, 27 Jun 2003: I would agree that this current, at a very small contact area, is the driver for the hole in the screen/shield. OK, the trade secret is to use two layers of foil. Only the first one gets the hole. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CE without LVD?
I read in !emc-pstc that drcuthb...@micron.com wrote (in E6F64B42266D6 54b80a0f7f4b98212a50ec...@ntxboimbx03.micron.com) about 'CE without LVD?' on Fri, 27 Jun 2003: Yes I once had a device that was SELV and this caused some confusion. We designed it to meet EN61010 as it was a piece of lab equipment. It was powered by a 5 volt, 40 amp power supply. We designed/tested for single component faults, temperature, etc. In the end, a large safety testing company informed us that no testing was required at all since it was SELV. I still do not agree with their assessment. 200 W input under normal operating conditions! You could have arranged to have one burn up in their CEO's office to prove your point! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Czech medical grounding?
I read in !emc-pstc that brent.dew...@us.datex-ohmeda.com wrote (in OF8C92B488.05E195FF-ON87256D52.006A403E-87256D52.006AC7C7@us.datex- ohmeda.com) about 'Czech medical grounding?' on Fri, 27 Jun 2003: I got some weird feedback from one of our sales people in the Czech republic. One of the local folks said they were concerned that a metal cased piece of medical electrical equipment didn't have a separate ground for when it was used on internal batteries. I'm an EMC guy so I was wondering if any of the safety experts out there could tell me if this makes any sense from a regulatory standpoint. I don't know about regulatory issues, but the equipment could accumulate a static charge, unless earthed (or bonded, anyway, to everything else in the area) and zap a patient in a sensitive spot. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CE without LVD?
I read in !emc-pstc that David Gelfand david.gelf...@memotec.com wrote (in db3b83f22a576e41983ea8bfa15af2f30577d...@mtlex01.nexxlink.int) about 'CE without LVD?' on Fri, 27 Jun 2003: A ITE product (not ours!) is powered by an CE marked external ac-dc power supply and has only SELV ports. I believe this product must be tested to EN 60950, and that in the CE Declaration of Conformity it must declare conformity to the LVD via EN 60590. It is being suggested that this product does not need safety testing and does not need to include the reference to EN 60950 and the LVD in the CE DoC, since it is SELV circuits only. Can you provide me with references to back my point of view? Not really. If the *product* is SELV, can you find any tests in 60950 that are applicable? I suspect not, unless it contains a battery of sufficient beef that a short-circuit could create a fire hazard. In that case, even though the LVD does not apply, the manufacturer should control his product liability under the GPSD by applying the standard as far as it is relevant. The same applies if there is a high voltage generated internally in a product supplied at SELV, FELV or PELV (or any other xLV that may have been invented). HOWEVER, if the product and the external power supply are marketed together, the that is a 'system' under the EMC Directive. While there is no such concept under the Low Voltage Directive, the DOC needs to apply to both parts of the 'system', so indeed it should declare conformity to EN 60950. There is also a need to put the CE mark on the product, for the EMC Directive. The comments about the GPSD are correct, but they don't actually indicate what the manufacturer needs to do physically in order to comply with all the rules. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Dielectric withstand voltage for power supplies
I read in !emc-pstc that richhug...@aol.com wrote (in 6D8B5870.6AD0B19A .0ba45...@aol.com) about 'Dielectric withstand voltage for power supplies' on Fri, 27 Jun 2003: John, What you highlight is one of the differences between traditional ICT equipment and traditional radio equipment. ICT equipment tends to use switch mode power supplies where any inter-winding screen is connected to the neutral for EMC purposes. From what you say, radio equipment tends to use 50 Hz transformers where connection to PE has the benefits you outline. Yes, that is correct. Please do not fall into the trap of thinking that Notes contain requirements, they should not and in this case do not. After 30 years experience with IEC standards, and more with British standards, I am very well aware of that. There is a general requirement that any Protective Earth path must 'out-live' the over-current device in the supply line, clause 2.6 of IEC 60950-1 has lots of requirements on various aspects of this. The note you are referring to in C.2 is just a reminder of these requirements. It particularly applies to foils that may be much thinner than the adjacent primary winding (otherwise the transformer would be difficult to make) since it is important that any short from winding to screen causes the up-stream fuse to blow rather than causing the screen to locally melt. I did not suggest otherwise. My comments were about using a *winding* as the screen, a practice which has been frowned on by the 60065 community, but it can be OK for equipment up to about 200 VA. There is another difficulty with foil screens in that the transformer manufacturers sometimes add insulating tape over the top and bottom of the screen (for manufacturing reasons) The sharp edge is a cut hazard, to operators as well as to insulation. which then means that the creepage path is effectively longer from primary to PE than it is from primary to secondary. Presumably, the wire screens you refer to in radio equipment are simply bare wire (not enamelled?) No, enamelled wire. The normal practice was to put on an extra layer of primary winding wire. So it can be quite thin. None of my transformer designs used this technique: I always called for foil. I'll certainly take your word for what is common practice in the radio industry, Well, it was once, These days radios run from wall-warts. but when it comes to safety I'll check it out for myself. That's precisely my advice. [snip most of my quoted message] But don't take my word for it! There you are! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Dielectric withstand voltage for power supplies
I read in !emc-pstc that Reginald Henry rhe...@vicon-cctv.com wrote (in 8FACEFD20E5BD311BA5200E018C14B4401A2C30C@VICONMAIL) about 'Dielectric withstand voltage for power supplies' on Fri, 27 Jun 2003: So, if there should be some looking up of information by the questioner, point him or her in the direction as to where to find it without the negative comments. Well, the OP obviously knew where to find the information, but unwisely chose not to do that. I don't think we can emphasise too much that: If your equipment must meet a standard, you must have that standard freely accessible to you so that you can read, and indeed learn, its provisions. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Dielectric withstand voltage for power supplies
I read in !emc-pstc that richhug...@aol.com wrote (in 44E75E95.7A170092 .0ba45...@aol.com) about 'Dielectric withstand voltage for power supplies' on Thu, 26 Jun 2003: [R_Hughes ] Technically incorrect: it is also possible to have a design where the secondary circuit is floating from earth and where you have a double-wound transformer with a screen connected to protective earth. It's called 'Method 2' and the requirements are in IEC/EN 60950-1 clause 2.2.3.2. In this case, breakdown from primary to secondary is rendered unlikely because breakdown from primary to protective earth is made to be more likely. It is also permissible to construct PCBs or other components this way. Admittedly in practice this is seldom done because by the time you have made the protective screen 'meaty' enough you may as well have provided insulation. Actually, it's often done like that in professional audio equipment, to which IEC/EN 60065 applies. I am more familiar with that standard, in which there is no special mention of the technique, and I'd forgotten that EN60950 goes into the method more formally, in 2.2.3.2 of IEC/EN 60950-1:2001. The technique stems from traditional a.m. radio receivers, where the interwinding screen provides greatly increased immunity to conducted disturbances entering from the mains supply. The implications of it for safety were realised when IEC/EN 60065 began to be applied in earnest to professional audio equipment, around 30 years ago. It allows the signal circuits of individual pieces of equipment to be optionally connected to the PEC or not, which is particularly useful for outside broadcast equipment, to prevent earth currents flowing in the screens of signal cables. For the EMC purpose, a single layer of winding, which the winding machines can put on automatically, has been found effective, but the current-carrying capacity of such a layer of thin wire might have insufficient current-carrying capacity for the safety purpose, and this is dealt with in Annex C of IEC/EN 60950-1. However, in the NOTE to C.2, there is, despite a disclaimer, an implication that a foil screen is necessary. The same note says that the requirement is that an overload device operates in the event of a fault before the screen is damaged, and this may be satisfied by a screen of quite thin wire if the operating current of the overload device is less than 1 A or so. But don't take my word for it! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Fuel cell product and EMC
I read in !emc-pstc that Wani, Vijay (V) vw...@dow.com wrote (in 2f39688ca531604abd535e8f857d54d32bb...@usmdlmdowm051.dow.com) about 'Fuel cell product and EMC' on Thu, 26 Jun 2003: is there any special EMC related requirement specific to fuel cell products? Not yet! Is there anything special about fuel cells that would justify a product-family standard? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD - not applicable ?
I read in !emc-pstc that Chris Maxwell chris.maxw...@nettest.com wrote (in 83d652574e7af740873674f9fc12dbaa0189d...@utexh1w2.gnnettest.com) about 'ESD - not applicable ?' on Tue, 24 Jun 2003: The problem here is: the product still can be touched; and I see no specific guidelines in any standard that says a product higher than x meters off of the floor is not accessible. IEC 60364-41, clause 2.5, I think. It specifically mentions 2.5 m. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD - not applicable ?
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F 84BA2B6045BBF7E9A6A0467608A@flbocexu05) about 'ESD - not applicable ?' on Mon, 23 Jun 2003: Clause 8.3.1 of EN 61000-4-2 says The static electricity discharges shall be applied only to such points and surfaces of the EUT which are acessible to personnel during normal usage. And it also says The application of discharges to any point of the equipment which is assessible only for maintenance purposes, excluding customer's maintenance, is not allowed unless different prescription is given in the dedicated product specification. So, unless the product or family spec says otherwise, no testing is required if a product is touched only during maintenance other than customer maintenance. OK, it seems that a majority of people here don't agree with that. So, will anyone propose an amendment to the standard? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ESD - not applicable ?
I read in !emc-pstc that Pettit, Ghery ghery.pet...@intel.com wrote (in 42050df556283a4d977b111eb7063208139...@orsmsx407.jf.intel.com) about 'ESD - not applicable ?' on Mon, 23 Jun 2003: Did the lab explain how the equipment would be installed, if not touched by human hands? By partly-trained monkeys, like most installations. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: another OATS question
I read in !emc-pstc that drcuthb...@micron.com wrote (in E6F64B42266D6 54b80a0f7f4b98212a50f3...@ntxboimbx03.micron.com) about 'another OATS question' on Mon, 23 Jun 2003: This method makes a DUT look hotter than it really is and makes the site uncertainty appear larger. Yes, well, for some people that's the Holy Grail. For them, the purpose of testing is to fail products, not to pass them. While their influence has declined in recent years, there are still traces of their earlier achievements. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: (mis)spelling humor
I read in !emc-pstc that garymcintu...@aol.com wrote (in 1e9.b587fca.2 c248...@aol.com) about '(mis)spelling humor' on Fri, 20 Jun 2003: Once let spell check do its thing while having my brain on empty and not paying to much attention to what it was suggesting. So I sent a company wide memo that changed a name from Hugh Hagel to Huge Bagel. Gary I won't tell you what Word97 spelling checker suggests for the initials of my firm - JMWA. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Transverse Balance Limitations 68.310_On Hook
I read in !emc-pstc that gr...@test4safety.com wrote (in 006f01c3366b$a 3375960$cf00a8c0@menhaden) about 'Transverse Balance Limitations 68.310_On Hook' on Thu, 19 Jun 2003: I have also noted that the Earth Leakage current can vary significantly. My worst experience was connecting a LAN between two systems (with individual ELC3.5 mA) and watching the ELC rise to more than 8 mA. Even powering them both from the same isolating transformer made little difference - Some you loose: some you loose badly. Do you have an explanation for this effect? Were you using an IEC 60990 meter? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: New EU Member States
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A0467606F@flbocexu05) about 'New EU Member States' on Thu, 19 Jun 2003: Thanks to those who responded. I found and searched the whole treaty concerning the assession of the new members states. There is mention of some other directives such auto, medical and packaing waste, but not the LV, EMC and RTTE Directives. Thus, it appears that the requirements for those three directives are in effect upon entry into the EU. At least some of the acceding states have already implemented those three Directives, or something very like them, in their national legislation. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Transverse Balance Limitations 68.310_On Hook
I read in !emc-pstc that Alex McNeil alex.mcn...@ingenicofortronic.com wrote (in 5685ADDE2285D511925200508BB9F5031EC502@fort2) about 'Transverse Balance Limitations 68.310_On Hook' on Thu, 19 Jun 2003: Hi All, Thanks to all who responded to my query. I will inform you of my findings as soon as I have a solution. Kind Regards ALEX -Original Message- From: Alex McNeil Sent: Tuesday, June 17, 2003 10:09 AM To: 't...@world.std.com' Subject: Transverse Balance Limitations 68.310_On Hook Hi Group, Can you help here. I pass the above FCC Part 68 specification when my product uses a Linear Power Supply but fail when I use my alternate Switch Mode Power Supply. Why should this be? I didn't see your original message. In Germany, it has been found that the conducted emissions on the mains lead, due to an SMPS in a computer, vary according to whether the modem is connected to a phone line with good balance or poor balance! This seems to be something of an opposite effect to the one you are finding. I think the first question you need to answer by measurement is whether emissions (possibly out-of-band) from the SMPS are causing the apparent lack of balance. The on-hook balance is presumably determined by measurements that effectively (or indirectly) compare the impedances from each leg to ground. If there are spurious emission voltages on the legs, and the measurement equipment responds to them, this must make the impedance determinations inaccurate. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: IEC 60664-4 concerns
I read in !emc-pstc that POWELL, DOUG doug.pow...@aei.com wrote (in c00d8c6f890dcd488840ec9c5d2b2cc057a...@ftcexc01.aei.com) about 'IEC 60664-4 concerns' on Fri, 13 Jun 2003: I've been studying IEC 60664-4, Insulation coordination for equipment within low-voltage systems - Part 4: Consideration of high-frequency stress. My intent is to determine reasonable safety spacings for air gaps, insulators and thin film insulators at high frequencies. So far, the standard does not seem to be very helpful. It presents limited empirical data on a selection of insulating materials but really does not offer any practical application, in general. In addition, it appears there is no information for frequencies above 100 MHz. Exactly. There is a notable lack of research results on this subject. The standards committee cannot work without input data. I am interested in characterizing a number of material types and factor in frequencies up to 300 MHz and higher. You may well need to get some original applied research done on your specific project. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Argicultural machines
I read in !emc-pstc that Kim Boll Jensen k...@bolls.dk wrote (in 3ee04490.62d5c...@bolls.dk) about 'Argicultural machines' on Fri, 6 Jun 2003: Does any one know of other EMC requirements or other coming requirements for agricultural machines than EN ISO 14982. Check on the IEC web site. I think CISPR 25/EN 55025(?) will apply to agricultural machines, or perhaps only some. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CENELEC Harmonisation Documents
I read in !emc-pstc that John Allen ja014d7...@blueyonder.co.uk wrote (in 001f01c32a08$b6facaa0$0200a8c0@HOME2) about 'CENELEC Harmonisation Documents' on Tue, 3 Jun 2003: The reason is that I am trying to trace some older national regulations which were typically listed in the HD's as the reasons for national deviations to the base standards. These regulations were often more clearly called out than in the superceeding EN's. It wasn't the reason that you wanted the information that wasn't clear, it was precisely what you wanted. Has Rich Nute steered you to it? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CENELEC Harmonisation Documents
I read in !emc-pstc that John Allen john.al...@era.co.uk wrote (in BFE68AB0084CD311B4FB00508B014C8704D229A2@MERCURY) about 'CENELEC Harmonisation Documents' on Tue, 3 Jun 2003: Does anyone have, or know of, a list of HD's, including the cancelled ones? I am particularly interested in those relating to domestic appliances (CEE 10/11, IEC 335/60335), audio-visual equipment (CEE 1, IEC 65/60065) and portable tools (CEE ??, IEC 745/60745). It's not clear to me exactly what you want. In the history of EN 60065, for example, IEC 65 4th edition was adopted as HD 195 S3 but later the 5th edition with amendments was adopted as EN 60065. The situation with IEC/EN 60335 is immensely complex, since the Parts and Sections were re-numbered 'on the fly' some years ago, with considerable confusion for those not involved in the committee work. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The Universal Plug Adapter!???
I read in !emc-pstc that Enci emc-p...@cinepower.com wrote (in 5.1.1.6.2.20030603003016.00ba4...@mail.cinepower.com) about 'The Universal Plug Adapter!???' on Tue, 3 Jun 2003: but it has a large CE mark I get in response. It would be interesting to learn from the DOC which standards are cited. AFAIK, there IS no safety standard for 'universal adapters', so a Notified Body should have been involved. I hope the product has been brought to the attention of the appropriate authority. Maybe I am missing something, but does having CE Marking somehow extend an invisible shield around the product, akin to one or more levels of protection?!? Yes. of course. It's very powerful juju. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The Universal Plug Adapter!???
I read in !emc-pstc that Lou Aiken ai...@gulftel.com wrote (in 003301c3297b$a60ea640$868166d1@default) about 'The Universal Plug Adapter!???' on Mon, 2 Jun 2003: If my understanding is correct, that is the CE mark means the manufacturer believes the product complies with the applicable harmonized European standards, or exhibits an equivalent degree of safety and/or EMC if the 'Technical File Routes' are followed instead of applying standards. I conclude the sole purpose of the CE marking on these adapters is to lead the layperson to believe there ARE applicable standards, and that the thing complies with those standards. Quite. There are no harmonized standards for plugs or socket outlets - they are all CEE or national standards. So it is impossible for the manufacturer to claim compliance with a harmonized standard. The status of the old CEE standards is a bit uncertain. Industry is certainly still working to them on a large scale, of course. I have even heard the term CE Approved from time to time. Yes, well, people try to justify it as a 'shorthand' expression, but it's seriously misleading. But, on the otherhand, maybe I don't understand the correct use of the CE marking. I think you understand it very well. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Surge Suppressors on a UPS
I read in !emc-pstc that michael.sundst...@nokia.com wrote (in 57a26d272f67a743952f6b4371b8f81101e42...@daebe007.americas.nokia.com) about 'Surge Suppressors on a UPS' on Mon, 2 Jun 2003: I also don't understand the prohibition of an extension cord. Maybe this is a legal issue, as I can't see any valid safety or regulation issues here. We regularly put a UPS in the bottom of a rack system, and then wire a stripline outlet set for the height of the rack. Isn't that the electrical equivalent of an extension cord? What am I missing? I think you are right. The advice is a cop-out. A surge suppressor on the output of a UPS should, in theory, never be activated. But something outside the spec of the UPS, such as a close lighting strike, might activate it and perhaps damage the UPS. Banning extension cords (without surge suppressors) is bizarre and inexplicable. I see the leaden hand of the corporate attorney there. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Number of Terminations on a Ground Stud?
I read in !emc-pstc that Momcilovic, Nick nick.momcilo...@qtiworld.com wrote (in 139803a793e0d311aff60050da2bc54005297...@qtiexch1.qgraph.com ) about 'Number of Terminations on a Ground Stud?' on Wed, 30 Jul 2003: Is anyone familiar with any requirement that limits the number of ground terminations on a single stud? I heard that the limit is two per stud but I was not able to confirm this with any of the standards we have. Many IEC product safety standards require a separate stud for the PEC connection to the supply. and some have requirements for other grounding points. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Carton box dimension and gross weight to EU
I read in !emc-pstc that Paul Chan ncc...@tuvps.com.hk wrote (in 003d01c355a4$e1e22e80$3608670a@pcv0115) about 'Carton box dimension and gross weight to EU' on Tue, 29 Jul 2003: I have been asked for the max. dimension and weight of the carton box [loaded with product]. Do you know any requirements/guidelines? I don't know of any maximum dimensions or weight, but there are marking and other requirements under the Manual Handling Directive (is it still called that?) for cartons over 5 kg and cartons whose centre-of-gravity is displaced from an approximately central position (such as those containing TV sets). -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Q on Correlation of Votage ripple with a Spectrum Analyser
I read in !emc-pstc that Charles Grasso cgrassospri...@earthlink.net wrote (in ekeeipjkkmpklafoobmcaelkcfaa.cgrassospri...@earthlink.net) about 'Q on Correlation of Votage ripple with a Spectrum Analyser' on Sat, 26 Jul 2003: I first calibrated myslef using a known source - a sine wave. Really? You calibrated yourself? The amplitudes fell in just as theory predicted. Encouraged, I then probed the Vcc plane on a product I was working on and was not so happy!! You really must write more clearly, and give much more information, if you want useful answers. What did you find that made you unhappy? Maybe we can tell you where it came from. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Q on Correlation of Votage ripple with a Spectrum Analyser
I read in !emc-pstc that Charles Grasso cgrassospri...@earthlink.net wrote (in ekeeipjkkmpklafoobmcoelhcfaa.cgrassospri...@earthlink.net) about 'Q on Correlation of Votage ripple with a Spectrum Analyser' on Sat, 26 Jul 2003: Has anyone tried correlating the voltage ripple as seen on a scope with the amplitudes measured on a Spectrum Analyser? More information, please. What voltage is it that has ripple on it? Do you mean the ripple voltage across a rectifier filter capacitor? I tried doing that the other day with ..umm. minimal success. I think that due to the comples convoltions that would have to occur when FFT'ing an irregular voltage shape. It's really no more difficult to FFT one waveform than another. The FFT doesn't 'know' whether the waveform looks regular or irregular to a human. If it is power supply ripple that you are considering, the waveform is approximately a sawtooth, but the short rising branch is a small section of the crest of a sine wave. If the ripple voltage is very small compared with the d.c. voltage and the ESR of the filter capacitor is very low, the spectrum of the ripple is often quite close to that of a sawtooth. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: pulse modulation in reverb chambers
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb48596e.36a1%ken.ja...@emccompliance.com) about 'pulse modulation in reverb chambers' on Sat, 26 Jul 2003: What is the limitation on minimum pulse width in reverberation chambers? I expect it relates to room size, but does anyone have either a functional relation or a rough order of magnitude? Light travels 300 meters per microsecond, so I would think a 1 microsecond pulse width would work just fine, but nanosecond rise-times would be lost. Judging by what happens a million times slower in acoustics, I think 1 microsecond could be quite a bit short. Obviously it depends on the size of the chamber. If there is a paddle, it might be necessary to allow several turns of it to establish a cyclically stable field pattern. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The transformer screen/shield conundrum
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200306302129.oaa24...@epgc264.sdd.hp.com) about 'The transformer screen/shield conundrum' on Mon, 30 Jun 2003: I disagree that the same power is distributed at 230 V and 120 V. We have a certain amount of misunderstanding. If the breakers are 230 V/16 A and 120 V/15 A, then the power distributed at 230 V is roughly twice that at 120 V. But your '120 V' is also '240 V' for some equipment. Besides, I think I was being 'generous'; electrical energy consumption per head in USA is probably greater than in Europe. My subject was *not* supply voltage tolerance, but system *design* goal for percent voltage drop at max rated load (the circuit-breaker rating). OK, that's clear now. I really believe that EEs in Europe design supply systems to 3% voltage drop at rated current, 16 A, just as they do in North America. The reason I so believe is that the wire sizes for 15 A (NA) or 16 A (Euro) circuits are nearly the same. The same size wire at (nearly) the same current would give (nearly) the same percent voltage drop. Yes, well, it's actually 3.3% for the worst case, see the amendment to IEC/EN 61000-3-3. But 3% normally. (If the system source impedance is 0.47 ohms, then, at 230 V, the system voltage drop would be slightly more than 6% at maximum rated load.) Yes, but that 0.47 ohms is the source impedance at the point of common coupling (PCC), which you weren't addressing, AIUI. Your 3% is the drop from the PCC to the wall socket? We really weren't talking about voltage, but about the maximum current into a fault in cord-connected equipment. The voltage tolerance can be ignored for this purpose. Yes, but the voltage tolerance provides information on the impedance, which is itself not specified, and the impedance is what determines the prospective fault current. That still gives 490 A, which would be embarrassingly big, but it apples at the 'point of common connection', not at the wall socket and still less at the equipment. My comments were for the current available at the wall socket. In North America, building wiring is designed for maximum 3% voltage drop at maximum rated current. Yes, OK, that works in Europe as well. In NA, at the point of common connection between the building and the electicity supplier, the electricity supplier maintains a nearly constant voltage. He does so not only by his system design, but also by dynamically adjusting the voltage of the source. Two points there: 1. Yes, in Europe the voltage may be 'nearly constant', but it is only the 'declared voltage' for some customers. Those nearer the substation transformer get more, and those further away get less, but within legal limits. Typically, one transformer feeds 200 to 500 residential customers. 2. It is possible to adjust the LV voltage but only by adjusting the MV supply to the transformers. On-load tap-changing at LV is extremely rare. In the Americas, this adjustment is not so easy, because of the very large number of transformers, some of which are likely at a given time to be lightly loaded, and some heavily loaded. Most of the source impedance of the LV network is in the transformer, so those that are heavily loaded will deliver fewer volts, and if the MV were increased to compensate, the lightly-loaded transformers would deliver too many volts. Of course, seasonal load variations tend to affect each transformer equally, so MV adjustment does work in this case. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CE for components?
I read in !emc-pstc that Neil Helsby nei...@solid-state-logic.com wrote (in 20030701.13220...@mis.configured.host) about 'CE for components?' on Tue, 1 Jul 2003: These requirements are now generally available from psu manufacturers but it shows how customers can demand and expect more testing of components or modules than may strictly be required by the Directives. Indeed, but this is a separate issue from the matter of CE marking -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: RTTE Directive Member States Notification
I read in !emc-pstc that Jan Heffken jheff...@core.com wrote (in 200307011403.h61e3n69098...@mail4.mx.voyager.net) about 'RTTE Directive Member States Notification' on Tue, 1 Jul 2003: Since paragraph 31 uses should and not shall do I have to do it all? The text you cite is in the 'whereases' part, which is not about requirements; it's an archaic form of rationale, still preserved by the legal eagles. The 'shoulds' refer to what the Commission *hopes* (but does not mandate) member states will do; they do not refer to what manufacturers have to do. You will find what manufacturers have to do later in the Directive. I don't have access to a copy at present so I can't say exactly where you will find the information you want. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CE marking for professional audio equip
I read in !emc-pstc that j...@aol.com wrote (in 8f.2f0e1107.2c333535@ao l.com) about 'CE marking for professional audio equip' on Tue, 1 Jul 2003: Sorry to ask what will be an obvious question to some of you, but what standards apply for CE marking of professional audio equipment? I'm a telecom guy, but I have been asked about professional audio equipment and do not know the answers. The product in question is a digital reverb processor that is typically used in a professional recording studio. For those who have been following the recent LVD discussion on the list, I should note that this product is basically a SELV device that uses a CE marked wall wart power supply. The wall supply is connected to the SELV unit with a hardwired cable. I am interested to know what safety standard applies to this product, and whether additional testing is required beyond the existing power supply approval. That depends on which standard has been applied to the wall wart. If the product and the wall wart are sold together, the combination must conform to EN 60065. I am also interested in what EMC requirements apply, and whether the emissions classification would class A or class B. The safety standard is EN 60065 and the EMC standards are EN 55103-1 and EN 55103-2. There is no 'Class A' or 'Class B' in EN 55103-1. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: The transformer screen/shield conundrum
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200307011612.jaa01...@epgc264.sdd.hp.com) about 'The transformer screen/shield conundrum' on Tue, 1 Jul 2003: So, you can't really consider North American 240 V mains circuits in this discussion. We don't. * I think that's debatable, but probably doesn't need any further debate at this point. I do agree that electricity consumption per head in North America is probably greater than in Europe. Having lived in Spain, I believe that North American appliances are bigger and therefore consume more electricity. It depends indirectly on where you lived in Spain. Some rural supplies are rated at only 6 kVA per household. Naturally, they don't have too many 3 kW appliances in those households. [snip] Neither of these topics has anything to do with the current available into a fault before the circuit breaker operates. They are about matters which you raised in your responses, and indirectly refer to the crucial matter of supply impedance. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: CE for components?
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote (in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about 'CE for components?' on Thu, 3 Jul 2003: Pre-compliance EMC testing of component power supplies is problematic. My employer has directed a lot of resources helping customers fix their noise problems. And occasionally, some of our (more clever) customers give us EMC test reports that indicate much better performance than when the installed power supply was tested as stand-alone device... There is a reason that I cannot list any EMC standards for component power supplies on the D of C; because the test has no meaning until the unit is installed in the end-use device. There is a product EMC standard for power supplies - IEC 61204-3. I'm not sure of its status in Europe. Conversely, there are valid reasons that I can list Product Safety standards on the D of C; because LVD standards define re-producible tests that clearly indicate performance upon end-use abuse. There was a CTL meeting report (Helsinki, October 2000) that indicated EMC test data was re-producible internally, but much less so from one lab to another. This variation of EMC test data seems to be expected, but is never acceptable for Product Safety test data. Go figure It's very simple, really. Tests for product safety are not accepted into standards unless they give reproducible results. The limitations imposed by the laws of physics are such that many EMC tests, especially those involving radiate energy, have poor reproducibility of results. But better tests are simply not available. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Source of noise
I read in !emc-pstc that lfresea...@aol.com wrote (in 136.21721a07.2c34 9...@aol.com) about 'Source of noise' on Wed, 2 Jul 2003: In messing around, at about 40 MHz, the PC noise is showing up on the power cord. I guess noone worries because CE stops at 30 MHz. Where did you get the idea that 'CE stops at 30 MHz'? The test for *conducted emissions on the mains lead* goes up to 30 MHz. Emissions at higher frequencies are controlled by the requirements for radiated emissions. The lead is long enough to radiate reasonably efficiently above 30 MHz. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: High Power Transorb
I read in !emc-pstc that lfresea...@aol.com wrote (in 70.300239f4.2c3b4 b...@aol.com) about 'High Power Transorb' on Mon, 7 Jul 2003: Transorb power rating is specified normalised to a 1 mS pulse, otherwise you would be right. Well, I might be sort-of right anyway, if the OP didn't have a 1 ms pulse and had not already taken the time into account -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: cable maximization - do you or don't you??
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb2f7186.2be2%ken.ja...@emccompliance.com) about 'cable maximization - do you or don't you??' on Mon, 7 Jul 2003: I don't think it is at all complicated, at least in principle. Maybe a devil will emerge out of some details I am missing... It's a point worth discussing. I don't see how an end-driven wire can radiate more efficiently than a tuned half-wave dipole. That model can be used to convert from field intensity at X meters to peak current on the cable. Agreed that it can't be more efficient, but it can be less efficient to a nearly unlimited extent, so making that assumption can be very pessimistic indeed. For the case of multiple cables one could make various assumptions about the additive effect of emissions at X meters: A worst case assumption is that the same spectrum could appear on each cable and add in phase at the measurement point. This would require subtracting from the previously determined single cable current limit the factor: 20*log (number of cables). I think this is unreasonable, that the summing would be of random phase and the factor to be subtracted from the single cable current limit ought to be 10*log (number of cables). Agreed, as a first approximation. I am not trying to say that this approach is precisely correct and should be implemented as is. I do think it would be interesting to make some cable measurements using an absorbing clamp and compare to the corresponding OATS profile and draw some conclusions. Yes, I think that is justified, now that you have raised the subject. Unfortunately, many such proposals are never investigated because no-one has the time, even if the costs can be handled. I think we all look forward to your report of the first results. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: High Power Transorb
I read in !emc-pstc that lfresea...@aol.com wrote (in 196.1cf48d62.2c3a f...@aol.com) about 'High Power Transorb' on Mon, 7 Jul 2003: I'm looking for a high power transorb ( NOT MOV ). Currently the biggest I can find is 5kW. Can anyone point me to a higher power device? 5 kW for how long? Isn't it the total energy that is critical, not the power? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: cable maximization - do you or don't you??
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb2efbe8.2b77%ken.ja...@emccompliance.com) about 'cable maximization - do you or don't you??' on Mon, 7 Jul 2003: Why not calculate the cable conducted emission that would result in radiated spec level compliance, and levy a cable conducted emission requirement? Such a calculation would be extremely difficult, wouldn't it? Even if you could calculate for one cable, dealing with many cables interacting would be hard. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: cable maximization - do you or don't you??
I read in !emc-pstc that lfresea...@aol.com wrote (in 7a.439a5e0a.2c3ad c...@aol.com) about 'cable maximization - do you or don't you??' on Mon, 7 Jul 2003: I've often wondered what would happen if the FCC ( for example ) had under cover engineers that took products barely passing to test labs. Specifically, what the results would be :-) The repeatability of many EMC tests is such that if they took products that passed by a fair margin to another lab, they might not pass. This is particularly relevant to cable maximization. Unless you lay out the cables in EXACTLY the same way for each test (within a centimetre or so in some cases), the results WILL be different - maybe better, maybe worse. The proof of that is a case of 'res ipsa'. If moving the cables had little effect, no-one would bother about maximization or the converse. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Conducted emissions--green wire?
I read in !emc-pstc that Boris Yost y...@rainbowdisplays.com wrote (in cmecjbngiaaelbblloingeomjaaa.y...@rainbowdisplays.com) about 'Conducted emissions--green wire?' on Mon, 14 Jul 2003: I recently watched a conducted emissions test. Which standard was being applied? They don't all require the same things. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Professional Lighting Control Console - the Americas
I read in !emc-pstc that Kevin Richardson kevin.richard...@ieee.org wrote (in nebbihdflagbliikmlbkoeplebaa.kevin.richard...@ieee.org) about 'Professional Lighting Control Console - the Americas' on Mon, 14 Jul 2003: John, thank you for the confirmation for Europe. Have you had any experience with certification requirements for equipment of this type in the USA or Canada? Would you agree UL1950 or UL60950 for the USA and C22.2 No 14-M91 for Canada appropriate as Peter Tarver suggests? Well, no, not really. For Europe, EN 60065 applies, not EN 60950, so, as I indicated before, I would suggest the UL and CSA equivalents to EN 60065. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Equipment I need
I read in !emc-pstc that Tony Rayman tray...@acstestlab.com wrote (in 002c01c34656$e1e949c0$0e010...@iad3754atl.atl0.cbeyond.net) about 'Equipment I need' on Wed, 9 Jul 2003: Loop Sensor: Field Strength Loop Sensor with 36 turns and 13.3 cm diameter Must comply with Standards EN55103-1 and MIL-461D Emissions requirements 50 Hz ? 50 KHz You could get a local engineering shop to make up the former, and either wind the coil yourselves or get a coil-winding shop to do it. I made my own in my not very well-equipped workshop, and checked it out against a proprietary product later (not that it should be necessary; the point about the device is that if it's made correctly, the characteristics are calculable). -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Professional Lighting Control Console - the Americas
I read in !emc-pstc that Kevin Richardson kevin.richard...@ieee.org wrote (in nebbihdflagbliikmlbkoeoiebaa.kevin.richard...@ieee.org) about 'Professional Lighting Control Console - the Americas' on Thu, 10 Jul 2003: From a standard applicability point of view therefore, for Australia and Europe at least, it is felt the appropriate standards are as follows: - Safety - AS/NZS 60065 and EN 60065 (both including vibration test of IEC/EN 60068-2-6) - EMC emissions - EN 55103-1 - EMC immunity - EN 55103-2 - Harmonics - EN 61000-3-2 (harmonic current emissions for equip with rated current = to or less than 16A) - Voltage Fluctuation/Flicker - EN 61000-3-3 (voltage fluctuation and flicker for equip with rated current = to or less than 16A) Those are the correct standards for Europe. There are no US or Canadian equivalents or parallels to any of those, except to IEC/EN 60065. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Generic industrial EMC standards
I read in !emc-pstc that Nick Williams nick.willi...@conformance.co.uk wrote (in p05210611bb444ab1ee90@[192.168.1.22]) about 'Generic industrial EMC standards' on Wed, 23 Jul 2003: Could someone please explain the relationship between EN 50081-2 and EN 50082-2, and the newer standards EN 61000-6-2 and EN 61000-6-4? In particular, how is it that the OJ listing published on 26 of March of this year (and the one before) lists EN 50081-2:1993 and gives no details of a superseding standard, Well, that what is technically known as a 'mistake'. yet the same list also contains EN 61000-6-4 against which EN 50081-2:1993 is listed as the superseded standard with a DOCOPOCOSS of 1.7.2004. That is so. For practical purposes, are the any differences between these standards, Yes: immunity requirements are introduced above 1 GHz. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Additivity of Conducted Emission
I read in !emc-pstc that francesco.campede...@transport.alstom.com wrote (in of3e02755c.a4628162-onc1256d6c.002b4...@transport.alstom.com) about 'Additivity of Conducted Emission' on Wed, 23 Jul 2003: If I measure the emission for one driver, would it be possible to derive the emission level when two or more drivers are present (at least a worst case)? If yes, how to do it? Does the noise add up linearly (so that I have to add 6 dB for two driver, 20 dB for ten in the worst case - the noise from each driver has the same frequency and phase) ? Yes, the worst case is probably arithmetic addition. 'Probably', because there might be some subtle effect that gives a better or worse result. But the *expected* situation is probably root-sum-square addition, i.e. 10 dB for ten units. Of course, if these units are self-contained and marketed as individual items of commerce, with each being CE marked, there is no requirement to add up the emissions for regulatory purposes. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: NEW EMC Standards
I read in !emc-pstc that Gordon,Ian ian.gor...@bocedwards.com wrote (in E1BA0362B28ED211A1E80008C71EA3060206FD03@EXC_EAS01) about 'NEW EMC Standards' on Wed, 23 Jul 2003: I had a look at the OJ link you sent to check that I had the latest versions of the standards I use. However, the document doesn't include the 61000-4-x EMC immunity standards. Are they listed elsewhere? They are not 'notified' under the EMC Directive, because they are only about methods of measurement, and compliance with the Directive does NOT require that you have to use those methods, despite what some people will tell you. All that is required for the 'standards route' is that the limits in the standards that set limits are met. In addition, for either route, the practical requirements of Article 4 of the Directive must be met. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: voltage dips
I read in !emc-pstc that Paolo Peruzzi paolo.peru...@esaote.com wrote (in ofce6b2c1c.06aec745-onc1256d6b.00371...@esaote.com) about 'voltage dips' on Tue, 22 Jul 2003: Is there any basic standard concerning voltage dips and short interruptions immunity for equipment with input current larger than 16 amps per phase? Not at present. The omission has been noted in UK, but not drawn to the attention of IEC, AFAIK. IIRC, there seems to be no particular reason why the scope of this standard is limited to 16 A per phase and below. Most of the text seems to be applicable only to *single-phase or interphase* equipment, though. Clause 7 and clause 8.2.1 differ in their statements about simultaneous and differential disturbances on 3-phase supplies. And more: can a product standard prescribe such test for equipment with more than 16 amps per phase and still refer to 61000-4-11 as basic standard? Well, sort of. It could say, 'The test methods specified in IEC 61000-4-11 shall be applied.' But the product standard would have to say something about the specification of the test equipment to be used, because clause 6 doesn't apply. Annex C appears independent of the current. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: pulse modulation in reverb chambers
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb4987fa.372a%ken.ja...@emccompliance.com) about 'pulse modulation in reverb chambers' on Sun, 27 Jul 2003: As long as those delays are much shorter than 1 us (path difference much less than 300 meters), the original modulation is received. Not really. If a reflection arrives with a delay of 10 us, the received pulse is 1.01 us long. Some 'rays' suffer multiple reflections, which increases the delay considerably, and the reflections in a reverberation chamber must be low-loss. How much stretching can you accept? But if delays are too long, then the pulse smears. Yes. How long is 'too long' for you? If you can find someone who has ray-tracing software for either electromagnetic **or acoustic** applications, you can run some simulations. Just remember if you use acoustic to treat seconds as microseconds. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Last day of manufacture EN60950: A4, A11
I read in !emc-pstc that Ilan Cohen ico...@itl.co.il wrote (in 2D1037012914D4118DB8204C4F4F502045FE06@ITLLTD01) about 'Last day of manufacture EN60950: A4, A11' on Sun, 27 Jul 2003: Can anyone point me to the specified last day of manufacture for products tested under EN60950: A4 and A11. (In the official Journal you may find the date of 1/08/03 as the last date for modifications, but the last date for manufacture is not listed) I will be very thankful if any one actually points to the official document that specifies the date. The DOCOPOCOSS for a specific standard is given (normally) in the next edition, in this case that is EN 60950:2000. The 'dow' given there is 2005-01-01, and the Commission has not, AFAIK, notified a different DOCOPOCOSS. BUT, there is also EN60950-1:2002, which can be used now and in which the 'dow' of EN 60950:2000 is given as 2006-07-01. You may find it advantageous to use this standard rather than the 2000 edition. DOCOPOCOSS - date of cessation of presumption of compliance of the superseded standard. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: pulse modulation in reverb chambers
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb49768d.3717%ken.ja...@emccompliance.com) about 'pulse modulation in reverb chambers' on Sun, 27 Jul 2003: So if I am worried whether the 1 us pulse width can be sustained, and I don't know how to determine it analytically, my plan is as follows: I put a wire probe in the room, run it to a spectrum analyzer tuned to the transmit frequency, put the analyzer in zero span mode with a 1 or 3 MHz bandwidth and look at the modulation waveform. If it is significantly longer than 1 us, I know my constructive interference path delays are smearing the modulation away. I originally thought you wanted to establish a reverberant field with a 1 us pulse. Now I'm not so sure. By 'modulation', you mean the envelope of the 1 us pulse? Isn't the idea of a reverberation chamber that once it is excited the energy takes a long time to die away? That means that the original pulse will be s t r e t c h e d, dying away exponentially if the room is a good one. A too-short pule would almost certainly produce a delay that was not exponential. You can only 'sustain' the 1 us pulse if your receiver is in the 'direct field' of the antenna, i.e. the field strength due to the direct propagation path from sending antenna to receiving antenna is at least 3 dB above the combined field strength due to all indirect paths. You can easily see this if you consider just a few simple specular reflections, which appear at the receiver as a series of overlapping (since their path lengths are less than 300 m) 1 us pulses of varying level. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: self blinking LEDs as EMI sources WAS: LED lamps
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in bb480cc1.366c%ken.ja...@emccompliance.com) about 'self blinking LEDs as EMI sources WAS: LED lamps' on Sat, 26 Jul 2003: I agree with most of Mr. Woodgate's commentary, but I wonder if the presence of even an rf emission (as contrasted to 50 Hz) should cause any problem to a land-line phone with a wired handset. It wouldn't seem likely that the power available from a couple AA batteries would be sufficient for that. It's maybe a question of proximity, but I agree that I was reaching for an explanation. Now if it were a cordless phone and there were an rf emission in band to the cordless link, that would be much more credible. The OP didn't mention that: if it is, it reminds me of the story of the sailor who reported to a newspaper that his broken leg had been cured in three days by wrapping it in oakum and tarring it. After many protestations of disbelief, he disclosed that the leg was made of wood. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: self blinking LEDs as EMI sources WAS: LED lamps
I read in !emc-pstc that Wan Juang Foo f...@np.edu.sg wrote (in of7340f59a.f0a87124-on48256d6f.000df921-48256d6f.0013d...@np.edu.sg) about 'self blinking LEDs as EMI sources WAS: LED lamps' on Sat, 26 Jul 2003: These circuits were found to (well at any rate, seems to) emit interference that cause a telephone to pick up (50Hz) hum! Up to that point, your treatment of the phenomenon was quite scientific. It looks like the mains hum was pick up and modulated by the 'device' and reradiated or broadcasted... I think that is improbable. For such a small circuit to pick up significant mains hum, the magnetic field would have to be very strong, but in that case, why did not the circuits in the telephone, which are much larger in area, pick up the hum directly? Then again, such a small circuit as you describe for the LEDs would not re-radiate significantly at 50 Hz. And the presence of a flashing LED would seem to play no part in any re-radiation. You don't say that the hum was modulated on/off or in level in time with the flashing of the LED, and if there were no such modulation, that would seem to confirm that the LED circuit was not causing the hum. The situation might be different if the LED circuit included a precision timer, based on a high-frequency clock. This might radiate over short distances, and the radiation *might* be modulated by quite a small voltage induced by a weak 50 Hz magnetic field. In that case, you should be able to find the high-frequency emission with a spectrum analyser and sniffer loop, or a scanning receiver, whether or not the 50 Hz field is present. But the induced hum would be modulated at the flash rate. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Russian Translation for Battery Disposal Marking
I read in !emc-pstc that simon_...@emc.com wrote (in 277DD60FB639D511AC 0400b0d068b71e0c606...@corpmx14.us.dg.com) about 'Russian Translation for Battery Disposal Marking' on Thu, 24 Jul 2003: I would strongly advise you against this translator - I tried and the translation was really poor and grammatically incorrect. I will try to do it for you later from home, where I have a Russian keyboard, and will post for everybody on the list. However, to read it you will need to have Russian fonts installed on you PC. Leo Simon EMC Corp. From: Ablewisp - Compliance Consultants [mailto:s...@ablewisp.com] Sent: Thursday, July 24, 2003 5:27 AM To: peter merguerian; emc-p...@majordomo.ieee.org Subject: RE: Russian Translation for Battery Disposal Marking Peter Try this site for Russian translation: http://www.translate.ru/text.asp?lang=en NO machine translators available free on the web are reliable. They should NEVER be used to translate INTO a language you do not know. In some cases, they can be used to translate FROM a language you do not know into one that you do. But, unless you are very lucky, you will get an 'English as she is spoke' type of translation. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
