RE: UL - marking - gentle warning not to extrapolate.
Hi Rich - I know what is says - but I just picked up my LAN cable and it reads:"ETL VERIFIED TO EIA/TIA TSD-40 CATEGORY 5 E111018 TYPE CM 24 AWG (UL)LL92833 CSA TYPE FCC FT4" 'nuff said... Best regards Gregg -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Rich Nute Sent: Wednesday, October 17, 2001 8:14 PM To: gkerv...@eu-link.com Cc: chris.maxw...@nettest.com; am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: Re: UL - marking - gentle warning not to extrapolate. Hi Gregg: > The File number 'may' be used on things like cable (it is common to see UL > and CSA file numbers) and other components - Control numbers (I forget the > correct terminology) is required on some UR components but not all Listed > products. UL Listed wire: According to the UL Yellow Book, UL-certified Appliance Wiring Material must bear the UR mark. If the wire bears the UL file number, then it is either in lieu of the manufacturer's name or is in addition to the manufacturer's name; the file number is NOT required. UL Listed products: The UL 4-character control number is ALWAYS required on a Listed product. UR Recognized Components: There is no control number for UL Recognized Components (UR). The usual UL component certification mark is the manufacturer's name and model number. For some components, e.g., connectors, the UR mark either is not required or is optional. For some components, the UR mark is required. The UL Yellow Book identifies the required markings for components, including those components that must bear the UR mark. I hope this answers your question. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: duty cycle correction factors
This appears to be the missing piece . . . > -- > From: Ken Javor[SMTP:ken.ja...@emccompliance.com] > Sent: Thursday, October 18, 2001 4:39 PM > To: umbdenst...@sensormatic.com; emc-p...@majordomo.ieee.org; > stu...@timcoengr.com > Subject: FW: duty cycle correction factors > > There is another issue which is different which may be what the FCC is > after > (I didn't read the referenced part 15 paragraph). FCC calls it pulse > desensitization. It was what the mil and aerospace world used to call a > broadband signal. If a signal is in the passband of a receiver for less > time than it takes to charge the IF bandpass filter, then the filter > output > is the average of the input. For instance, if the signal lasted one tenth > of a filter time constant, then the potential (Volts) that the filter > charges to is one tenth of the peak level that was fed into the filter. > This is very important when the test instrumentation uses a different > bandwidth than the real world victim protected by the requirement. Take > broadcast TV as an example. FCC/CISPR requires a 120 kHz bandwidth, but > TV > uses 6 MHz. An interference signal lasting 1 us with a 10% duty cycle (on > 1 > us, off 9 us) would be averaged by the CISPR measurement and would appear > at roughly 10% the level it would present to the TV receiver. In this > case, > the pulse desensitization factor is calculated as 20 log (duty cycle), > because we are talking about a coherent signal where the voltage is > proportional to the duty cycle, There is one last very important concept > here and that is duty cycle itself. Duty cycle is not an absolute but is > relative to the filter time constant. We could imagine a signal lasting > 10 > us and having a 10% duty cycle (10 us on, 90 us off) and the CISPR > receiver > and the TV would report exactly the same level. Duty cycle is relative to > receiver bandwidth. > > -- > From: "Ken Javor" > To: umbdenst...@sensormatic.com , emc-p...@majordomo.ieee.org , > stu...@timcoengr.com > Subject: Re: duty cycle correction factors > Date: Thu, Oct 18, 2001, 2:37 PM > > > I wasn't going to weigh in on this but... what was presented by Mr. > Umbdenstock is equivalent to saying that since 2 + 2 = 4, then 2 x 2 = 4. > It is tautological. The decibel scale is a power ratio. If a signal has > a > particular duty cycle then it is the total power that is affected by the > duty cycle ratio. If something is on 100% and then you reduce the on-time > to 50%, clearly you consume half the previous POWER. > > dB = 10 log (P1/P2) > > Let "a" be the duty cycle ratio, with 0 > Then dB = 10 log (aP2/P2) = 10 log (a). QED. > > -- > >From: umbdenst...@sensormatic.com > >To: emc-p...@majordomo.ieee.org, stu...@timcoengr.com > >Subject: RE: duty cycle correction factors > >Date: Thu, Oct 18, 2001, 12:26 PM > > > > > > > Stuart, > > > > Duty cycle in 15.231 is related to a voltage ratio, therefore 20 > log(duty > > cycle) will provide the correct factor. > > > > Demonstrate it to yourself. Start with a given value (say 100V), > multiply > > this by some duty cycle (say 15% or .15). Convert the result to dB. > This > > is your reference result. Now take 20 log of a duty cycle (.15). > Convert > > your given value (100V) to dB. Add the numbers together, duty cycle dBs > to > > the given value dBs, and behold -- the same answer as the reference > result. > > > > Best regards, > > > > Don > > > >> -- > >> From: Stuart Lopata[SMTP:stu...@timcoengr.com] > >> Reply To: Stuart Lopata > >> Sent: Thursday, October 18, 2001 12:00 PM > >> To: emc > >> Subject: duty cycle correction factors > >> > >> > >> Part 15.231 devices use a duty cycle correction factor to adjust peak > >> readings. The duty cycle represents the fractional on-time over a > given > >> period of time (that must be under some limit). Anyways, given this > >> fractional time, d, how do you make the conversion to dB? > >> > >> 10log(d) or 20log(d)? > >> > >> There have been some misinterpretations, since the readings are made at > a > >> span of zero hertz (voltage readings). Normally, a reduction in > voltage > >> would use the 20log scale. However, since the duty cycle does not > >> represent > >> a scale down (it represents the off-time versus on-time), the 10log > scale > >> seems more appropriate. > >> > >> I have seen conflicting documents, so would like your professional > >> opinions! > >> > >> Thanks, > >> > >> Stuart Lopata > >> > >> > >> --- > >> 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: > >> Michael Garrets
RE: duty cycle correction factors
Perhaps I oversimplified.
The definitions may be conditioned by what the FCC is looking for. And in
general, I have always tested my understandings for a sanity check, not as a
proof.
So, going back to the origins of the question, in some sections the FCC
refers to an averaging detector, and a preference to use duty cycle with
peak detection to provide the "averaging detector" reading. The FCC
commented that they preferred math over averaging detectors due to linearity
issues (per comments on a submission).
So let's test the understanding:
Given a 100uV signal measured by the peak detector in my spectrum analyzer.
Given a 15 % duty cycle.
The FCC would call this a signal equivalent to an averaging detector output
of 15uV, 100 x .15 = 15 uV.
If I wanted to simplify the handling of factors, I would apply the formula
10 log (P1/P2) or 10 log (V1^2/V2^2) = 10 log (V1/V2)^2 = 2*10 log (V1/V2)
or in general,
20 log ("V").
The signal converted to dB would be 20 log (15) or 23.5dB
If I want to simplify the handling of factors, I would apply the formula to
the given value, 20 log (100) or 40 dB.
If I apply the test to Ken's formula 10 log (a) = 10 log (.15) we have
-8.2dB.
As we are multiplying in linear terms, that means we are adding in log
terms.
40 + (-8.2) = 31.8 dB
If we apply the formula 20 log (.15) we have -16.5 dB.
40 + (-16.5) = 23.5 dB, which compares to 23.5 dB above.
There is a piece missing somewhere as demonstrated when a test is applied.
Don Umbdenstock
> --
> From: Ken Javor[SMTP:ken.ja...@emccompliance.com]
> Sent: Thursday, October 18, 2001 3:37 PM
> To: umbdenst...@sensormatic.com; emc-p...@majordomo.ieee.org;
> stu...@timcoengr.com
> Subject: Re: duty cycle correction factors
>
> I wasn't going to weigh in on this but... what was presented by Mr.
> Umbdenstock is equivalent to saying that since 2 + 2 = 4, then 2 x 2 = 4.
> It is tautological. The decibel scale is a power ratio. If a signal has
> a
> particular duty cycle then it is the total power that is affected by the
> duty cycle ratio. If something is on 100% and then you reduce the on-time
> to 50%, clearly you consume half the previous POWER.
>
> dB = 10 log (P1/P2)
>
> Let "a" be the duty cycle ratio, with 0
> Then dB = 10 log (aP2/P2) = 10 log (a). QED.
>
> --
> >From: umbdenst...@sensormatic.com
> >To: emc-p...@majordomo.ieee.org, stu...@timcoengr.com
> >Subject: RE: duty cycle correction factors
> >Date: Thu, Oct 18, 2001, 12:26 PM
> >
>
> >
> > Stuart,
> >
> > Duty cycle in 15.231 is related to a voltage ratio, therefore 20
> log(duty
> > cycle) will provide the correct factor.
> >
> > Demonstrate it to yourself. Start with a given value (say 100V),
> multiply
> > this by some duty cycle (say 15% or .15). Convert the result to dB.
> This
> > is your reference result. Now take 20 log of a duty cycle (.15).
> Convert
> > your given value (100V) to dB. Add the numbers together, duty cycle dBs
> to
> > the given value dBs, and behold -- the same answer as the reference
> result.
> >
> > Best regards,
> >
> > Don
> >
> >> --
> >> From: Stuart Lopata[SMTP:stu...@timcoengr.com]
> >> Reply To: Stuart Lopata
> >> Sent: Thursday, October 18, 2001 12:00 PM
> >> To: emc
> >> Subject: duty cycle correction factors
> >>
> >>
> >> Part 15.231 devices use a duty cycle correction factor to adjust peak
> >> readings. The duty cycle represents the fractional on-time over a
> given
> >> period of time (that must be under some limit). Anyways, given this
> >> fractional time, d, how do you make the conversion to dB?
> >>
> >> 10log(d) or 20log(d)?
> >>
> >> There have been some misinterpretations, since the readings are made at
> a
> >> span of zero hertz (voltage readings). Normally, a reduction in
> voltage
> >> would use the 20log scale. However, since the duty cycle does not
> >> represent
> >> a scale down (it represents the off-time versus on-time), the 10log
> scale
> >> seems more appropriate.
> >>
> >> I have seen conflicting documents, so would like your professional
> >> opinions!
> >>
> >> Thanks,
> >>
> >> Stuart Lopata
> >>
> >>
> >> ---
> >> 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:
> >> Michael Garretson:pstc_ad...@garretson.org
> >> Dave Healddavehe...@mediaone.net
> >>
> >> For policy questions, send mail to:
> >> Richard Nute: ri...@ieee.org
> >> Jim Bacher: j.bac...@ieee.org
> >>
> >> All emc-pstc postings are archived and searchable on the web at:
> >> No longer online until our new server is bro
Re: purchasing IEC standards
Stuart, I think you were asking about bulk-quantity discounts. I have bought single-copies from the IEC website (needs a credit card): www.iec.ch. You might find some info on the same site, apologies if you tried already. If you only want IEC _EMC_ standards, I think they have a package of those, used to be on CD-ROM and was quite a good deal. I also attach a list I sent out a while back, probably not completely up to date (last updated in April). "Where to buy "electronic" (PDF) copies of standards: ISO, IEC, UL, ANSI, CSA, SEMI, EN" best regards, glyn Glyn R. Garside (mailto:ggars...@us.tuv.com) Senior Engineer, Industrial Machinery Division TUV Rheinland of North America, Inc. (Chicago Office) 1945 Techny Rd, Unit 4, NORTHBROOK, IL 60062-5357, USA http://www.us.tuv.com Text: mailto:8476121...@mobile.att.net TEL 847-562-9888 ext 25 FAX 847-562-0688 MOBILE 847-612-1574 Nationally Recognized Test Laboratory -- ANSI, UL, CSA, SEMI EU Notified & Competent Body -- CE, EN, IEC, ISO, CB-scheme Safety, EMC, Machinery, Pressure, Quality, Ergonomics, Automotive, Medical, Telecom. Where to buy "electronic" (PDF) copies of standards: ISO, IEC, UL, ANSI, CSA, SEMI, EN FYI: This might be of interest, I have been compiling it for a while (last updated Apr 2001). See also s.e.e.c FAQ "Sources of EMC & Safety Compliance Information": http://users.metro2000.net/~purwinc/compliance_faq.html - Where to buy "electronic" (PDF) copies of standards: ISO, IEC, UL, ANSI, CSA, SEMI, EN - All IEC, all ISO, & some ANSI and EN standards can be bought online from ANSI: http://webstore.ansi.org. Click on "Standards Search" Or, go direct to http://webstore.ansi.org/ansidocstore/find.asp HINT: try typing in just the number, without the letter prefix. In some cases it helps to omit the "dash numbers" (e.g. -5-4 too). IEC corrigenda (corrections to published standards): FREE downloads: http://www.iec.ch/catlg-e.htm Select the last option (corrigenda) on the search form. HINT: If you have problems opening a PDF file in your browser, try "refresh". There were recently 271 corrigenda, incl. IEC 60204, IEC 60947-xx, IEC 60068-x, IEC 60950, IEC 61010, etc. IEC (alternative source): http://www.iec.ch/webstore Very easy, up-to-date, all IEC stds available. Give major credit card number, download Acrobat PDF. Most files are full-text searchable. Prices are very competitive (in Swiss Francs). ISO Buy from ANSI, see above. (ISO plan to sell downloads "soon".) (ISO catalogue and some free background papers are online at: http://www.iso.ch/ ) UL Buy online at: http://www.comm-2000.com/ULmain.htm All UL stds available. (To check latest revision, etc., go to http://ulstandardsinfonet.ul.com/) SEMI Buy online: http://www.semi.org/standards Or, subscribe to CD (excellent value, IMHO !) CSA http://www.csa-intl.org Non-Canadians should click on "US & International Customers" under the heading "Catalogue". Or try this direct link: http:// www.csa-intl.org/onlinestore/getcatalogdrilldown.asp?Parent=0&k=3&l=1 Type the complete standard number, for example "C22.2 No. 94" into the SEARCH box. Or browse the Sections, for example click "Electrical/Electronic" then click "Industrial Devices", etc.) CAUTION: -You can buy English or French, hardcopy, CDROM or PDF editions of most CSA standards, on the same website. Be sure to order the "PDF" version, in English, if that is what you want. -CSA stds are often quoted thus, "C22.2-94". But you must search using format "C22.2 No. 94", with spaces. -If you type a partial reference for a large multi-part standard, say "C22.2" into the SEARCH box, you will see a maximum of 50 parts listed. NFPA http://catalog.nfpa.org/ National Fire Protection Association (USA). ANSI/NFPA 70: National Electrical Code (NEC); ANSI/NFPA 79, etc. EN Not so easy. The standards are issued, but not sold, by Cenelec, http://www.cenelec.org/ then republished by the National standards bodies in each EU country: BSI, SS, DIN etc. Sometimes they are translated into the respective national language. Option 1: Most EN standards are similar (sometimes identical) to an equivalent IEC or ISO standard. (Example: EN 60204-1 is almost the same as IEC 60204-1.) So, it is often easier & sometimes cheaper to buy the IEC edition, see above (http://www.iec.ch). To research equivalence, look at a hardcopy, or an old edition, or go to http://www.cenelec.org/ then click on "Standardisation Activities" (CENELEC has a useful, but s-l-o-w site!) Or, http://europa.eu.int/comm/enterprise/newapproach/standardization/harmstds/reflist.html (Click on the relevant Directive: EMC, Low-voltage, Machinery, etc. In some cases, an IEC or ISO document is listed next to the EN number
FW: duty cycle correction factors
There is another issue which is different which may be what the FCC is after (I didn't read the referenced part 15 paragraph). FCC calls it pulse desensitization. It was what the mil and aerospace world used to call a broadband signal. If a signal is in the passband of a receiver for less time than it takes to charge the IF bandpass filter, then the filter output is the average of the input. For instance, if the signal lasted one tenth of a filter time constant, then the potential (Volts) that the filter charges to is one tenth of the peak level that was fed into the filter. This is very important when the test instrumentation uses a different bandwidth than the real world victim protected by the requirement. Take broadcast TV as an example. FCC/CISPR requires a 120 kHz bandwidth, but TV uses 6 MHz. An interference signal lasting 1 us with a 10% duty cycle (on 1 us, off 9 us) would be averaged by the CISPR measurement and would appear at roughly 10% the level it would present to the TV receiver. In this case, the pulse desensitization factor is calculated as 20 log (duty cycle), because we are talking about a coherent signal where the voltage is proportional to the duty cycle, There is one last very important concept here and that is duty cycle itself. Duty cycle is not an absolute but is relative to the filter time constant. We could imagine a signal lasting 10 us and having a 10% duty cycle (10 us on, 90 us off) and the CISPR receiver and the TV would report exactly the same level. Duty cycle is relative to receiver bandwidth. -- From: "Ken Javor" To: umbdenst...@sensormatic.com , emc-p...@majordomo.ieee.org , stu...@timcoengr.com Subject: Re: duty cycle correction factors List-Post: emc-pstc@listserv.ieee.org Date: Thu, Oct 18, 2001, 2:37 PM I wasn't going to weigh in on this but... what was presented by Mr. Umbdenstock is equivalent to saying that since 2 + 2 = 4, then 2 x 2 = 4. It is tautological. The decibel scale is a power ratio. If a signal has a particular duty cycle then it is the total power that is affected by the duty cycle ratio. If something is on 100% and then you reduce the on-time to 50%, clearly you consume half the previous POWER. dB = 10 log (P1/P2) Let "a" be the duty cycle ratio, with 0From: umbdenst...@sensormatic.com >To: emc-p...@majordomo.ieee.org, stu...@timcoengr.com >Subject: RE: duty cycle correction factors >Date: Thu, Oct 18, 2001, 12:26 PM > > > Stuart, > > Duty cycle in 15.231 is related to a voltage ratio, therefore 20 log(duty > cycle) will provide the correct factor. > > Demonstrate it to yourself. Start with a given value (say 100V), multiply > this by some duty cycle (say 15% or .15). Convert the result to dB. This > is your reference result. Now take 20 log of a duty cycle (.15). Convert > your given value (100V) to dB. Add the numbers together, duty cycle dBs to > the given value dBs, and behold -- the same answer as the reference result. > > Best regards, > > Don > >> -- >> From: Stuart Lopata[SMTP:stu...@timcoengr.com] >> Reply To: Stuart Lopata >> Sent: Thursday, October 18, 2001 12:00 PM >> To: emc >> Subject: duty cycle correction factors >> >> >> Part 15.231 devices use a duty cycle correction factor to adjust peak >> readings. The duty cycle represents the fractional on-time over a given >> period of time (that must be under some limit). Anyways, given this >> fractional time, d, how do you make the conversion to dB? >> >> 10log(d) or 20log(d)? >> >> There have been some misinterpretations, since the readings are made at a >> span of zero hertz (voltage readings). Normally, a reduction in voltage >> would use the 20log scale. However, since the duty cycle does not >> represent >> a scale down (it represents the off-time versus on-time), the 10log scale >> seems more appropriate. >> >> I have seen conflicting documents, so would like your professional >> opinions! >> >> Thanks, >> >> Stuart Lopata >> >> >> --- >> 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: >> Michael Garretson:pstc_ad...@garretson.org >> Dave Healddavehe...@mediaone.net >> >> For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >> All emc-pstc postings are archived and searchable on the web at: >> No longer online until our new server is brought online and the old >> messages are imported into the new server. >> > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > >
Re: duty cycle correction factors
I wasn't going to weigh in on this but... what was presented by Mr. Umbdenstock is equivalent to saying that since 2 + 2 = 4, then 2 x 2 = 4. It is tautological. The decibel scale is a power ratio. If a signal has a particular duty cycle then it is the total power that is affected by the duty cycle ratio. If something is on 100% and then you reduce the on-time to 50%, clearly you consume half the previous POWER. dB = 10 log (P1/P2) Let "a" be the duty cycle ratio, with 0From: umbdenst...@sensormatic.com >To: emc-p...@majordomo.ieee.org, stu...@timcoengr.com >Subject: RE: duty cycle correction factors >Date: Thu, Oct 18, 2001, 12:26 PM > > > Stuart, > > Duty cycle in 15.231 is related to a voltage ratio, therefore 20 log(duty > cycle) will provide the correct factor. > > Demonstrate it to yourself. Start with a given value (say 100V), multiply > this by some duty cycle (say 15% or .15). Convert the result to dB. This > is your reference result. Now take 20 log of a duty cycle (.15). Convert > your given value (100V) to dB. Add the numbers together, duty cycle dBs to > the given value dBs, and behold -- the same answer as the reference result. > > Best regards, > > Don > >> -- >> From: Stuart Lopata[SMTP:stu...@timcoengr.com] >> Reply To: Stuart Lopata >> Sent: Thursday, October 18, 2001 12:00 PM >> To: emc >> Subject: duty cycle correction factors >> >> >> Part 15.231 devices use a duty cycle correction factor to adjust peak >> readings. The duty cycle represents the fractional on-time over a given >> period of time (that must be under some limit). Anyways, given this >> fractional time, d, how do you make the conversion to dB? >> >> 10log(d) or 20log(d)? >> >> There have been some misinterpretations, since the readings are made at a >> span of zero hertz (voltage readings). Normally, a reduction in voltage >> would use the 20log scale. However, since the duty cycle does not >> represent >> a scale down (it represents the off-time versus on-time), the 10log scale >> seems more appropriate. >> >> I have seen conflicting documents, so would like your professional >> opinions! >> >> Thanks, >> >> Stuart Lopata >> >> >> --- >> 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: >> Michael Garretson:pstc_ad...@garretson.org >> Dave Healddavehe...@mediaone.net >> >> For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >> All emc-pstc postings are archived and searchable on the web at: >> No longer online until our new server is brought online and the old >> messages are imported into the new server. >> > > --- > 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: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Air Filter Material
When i worked for my last company we also used Universal and found them to be very knowledgable and responsive. They were able to supply us with a UL 94 HF-1 flame class filter that was also met the Telcordia requirements for flammability - which I cannot remember now off the top of my head. They also made up an aluminium holder for the filter which meant we were able to easily slot it in/out of the (telecoms) equipment chassis for cleaning and/or replacement. Brian McAuliffe MCA Compliance Consulting 13 Silver Grove, Ennis, Co.Clare, Ireland Tel: +353.65.6823452 Mobile: +353.87.2352554 email: i...@mcac.ie -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Andrews, Kurt Sent: 16 October 2001 16:29 To: 'Chris Maxwell'; EMC-PSTC Internet Forum Subject: RE: Air Filter Material Chris, We have used filter material from Universal Air Filter for quite some time and have been very happy with it. I can not give you a specific part number or material type without doing a lot of research that I don't have time to do. However if you contact them I'm pretty sure that they would have what you need. I have included their contact information below. Universal Air Filter Company 1624 Sauget Industrial Parkway P.O. Box 5006 Sauget, IL 62206 Ph: 800-541-3478 Fax: 618-271-8808 www.uaf.com Hope this helps, Kurt Andrews Compliance Engineer Tracewell Systems, Inc. 567 Enterprise Drive Westerville, Ohio 43081 voice: 614.846.6175 toll free: 800.848.4525 fax: 614.846.7791 http://www.tracewellsystems.com/ -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Tuesday, October 16, 2001 10:39 AM To: EMC-PSTC Internet Forum Subject:Air Filter Material Hi All, We are looking to find a "safe" material to use to filter dust/lint ... from fan openings in a product chassis. I have talked to our mechanical engineer, the ideal material would: 1. Serve to filter dust/lint from air coming into our chassis. (I don't have an exact spec for particle size.) 2. The material would be die cuttable so that we could have a shop cut different configurations of it in large quantities. 3. About 1/8" to 1/16" thick. 4. Non hygroscopic (won't absorb water) 5. Non-flammable. 6. Slightly compressible (We would want to deflect the material possibly 10% or so just to hold it in place. I would assume a maximum desired deflection of 25%.) 7. Strong (i.e. we don't want it to rip or tear) Does anybody know of a material that comes close to what we want? AdTHANKSvance for your help. Best Regards, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard
RE: Air Filter Material
When i worked for my last company we also used Universal and found them to be very knowledgable and responsive. They were able to supply us with a UL 94 HF-1 flame class filter that was also met the Telcordia requirements for flammability - which I cannot remember now off the top of my head. They also made up an aluminium holder for the filter which meant we were able to easily slot it in/out of the (telecoms) equipment chassis for cleaning and/or replacement. Brian McAuliffe MCA Compliance Consulting 13 Silver Grove, Ennis, Co.Clare, Ireland Tel: +353.65.6823452 Mobile: +353.87.2352554 email: i...@mcac.ie -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Andrews, Kurt Sent: 16 October 2001 16:29 To: 'Chris Maxwell'; EMC-PSTC Internet Forum Subject: RE: Air Filter Material Chris, We have used filter material from Universal Air Filter for quite some time and have been very happy with it. I can not give you a specific part number or material type without doing a lot of research that I don't have time to do. However if you contact them I'm pretty sure that they would have what you need. I have included their contact information below. Universal Air Filter Company 1624 Sauget Industrial Parkway P.O. Box 5006 Sauget, IL 62206 Ph: 800-541-3478 Fax: 618-271-8808 www.uaf.com Hope this helps, Kurt Andrews Compliance Engineer Tracewell Systems, Inc. 567 Enterprise Drive Westerville, Ohio 43081 voice: 614.846.6175 toll free: 800.848.4525 fax: 614.846.7791 http://www.tracewellsystems.com/ -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Tuesday, October 16, 2001 10:39 AM To: EMC-PSTC Internet Forum Subject:Air Filter Material Hi All, We are looking to find a "safe" material to use to filter dust/lint ... from fan openings in a product chassis. I have talked to our mechanical engineer, the ideal material would: 1. Serve to filter dust/lint from air coming into our chassis. (I don't have an exact spec for particle size.) 2. The material would be die cuttable so that we could have a shop cut different configurations of it in large quantities. 3. About 1/8" to 1/16" thick. 4. Non hygroscopic (won't absorb water) 5. Non-flammable. 6. Slightly compressible (We would want to deflect the material possibly 10% or so just to hold it in place. I would assume a maximum desired deflection of 25%.) 7. Strong (i.e. we don't want it to rip or tear) Does anybody know of a material that comes close to what we want? AdTHANKSvance for your help. Best Regards, Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard
rms power versus average power for duty cycle
The difference in duty cycle factors seems to be based on taking the power based on the average voltage (rms power) versus converting voltage to power and then taking the average. Thus, the average power is half of the rms power. It is as simple as that, just do the math. The question is, which one do we use in the standard? P(Vave) ~ 20log() Pave ~ 10log() Sincerely, Stuart Lopata --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Agreed, and if it weren't for the unscrupulous we wouldn't need follow-up inspections, or laser embossed UL logos etc. A certain large country had so many bogus UL marks on power supplies that they have recently instituted a holographic mark on some recognized supplies. (That didn't work for Microsoft on their software - but at least it makes them work harder) Gary -Original Message- From: Peter Tarver [mailto:peter.tar...@sanmina.com] Sent: Thursday, October 18, 2001 7:36 AM To: emc-p...@majordomo.ieee.org Subject: RE: UL - marking - gentle warning not to extrapolate. Gary - Or for the less scrupulous than careless, to remove the certification mark from a product and place it one that is not safety certified. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com > From: Gary McInturff > > The Product identity may be omitted if the > Mark is directly and > permanently applied to the product, stamping, > molding, ink-stamping > I assume that is because you can't > mistakenly put and ITE label on a > medical device or something during manufacture. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
another way of looking at duty cycle..
I understand the responses to my first question. But what if we took the original time domain display (voltages) and converted it to power vs time? Now if you take the average power reading based on the conversion, you get 10log() and not 20log(). Something just doesn't seem right. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
purchasing IEC standards
Does anyone know where the best deals are for purchasing the IEC standards? I think there is one deal for IEC members that gives them all of the standards via download. The membership fee is --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Guys, I think that we've found the rub. UL is different than CSA in this regard (marking). UL can certify products for "dual" listing in US and Canada. CSA can also certify for dual listing in US and Canada. However, there is a difference in the marking requirements. We have used CSA ourselves, so I went and looked at our latest product report. In the marking section it mentions that the CSA logo with the "C US" subscript is required. However, all of the other markings are manufacturer, model number, ... All information that we put on our existing serial/model tags. There is no requirement for file number, listing number ... (Specific information required by UL, see Kurt Andrews reply attached below) It appears to me that CSA (unlike UL) marking lends itself to using a generic label. So, I'm trying to find an approved source for a label with the CSA logo along with the "C US" subscript. Some of the replies that I have received have pointed me toward some vendors which I am going to check out. Stay compliant guys... and as always...if I've said anything wrong I only have myself to blame and I'm sure that one of my learned colleagues will set the record straight. Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -Original Message- > From: Andrews, Kurt [SMTP:kandr...@tracewell.com] > Sent: Thursday, October 18, 2001 9:35 AM > To: 'Peter Merguerian'; 'Rich Nute'; rpick...@hypercom.com > Cc: Chris Maxwell; emc-p...@ieee.org > Subject: RE: UL - marking - gentle warning not to extrapolate. > > Rich and others, > > Here is what the Listing Mark Data Page says in one of our FUS books > for a > piece of Listed ITE equipment that was Listed to UL 1950. Note number > 3 > below stating that you can use the File Number or the Control Number. > By the > way we create our own Listing Mark labels using the downloadable > Listing > Marks from the UL website and a label maker and software combination > manufactured by Brady. > > PROCUREMENT > > All Listing Marks shall be obtained from a supplier authorized by > Underwriters Laboratories Inc. unless the Listing Mark is molded, > cast, > die-stamped, rubber stamped, silk screened or reproduced by the > manufacturer. > > COMPOSITION AND ELEMENTS > > 1. UL in circle symbol > 2. The word "LISTED" > 3. The assigned control number(s) or the Applicant/Listee's File > Number > 4. Product identity. Consists of the following: > > "UL 1950", "NWGQ", "INFORMATION TECHNOLOGY EQUIPMENT", INFO. TECH. > EQUIP.", > or "I.T.E." In addition, the name or the specific type of product as > shown > on the individual Listing (i.e. 'ADDING MACHINE", "CALCULATOR", > "PRINTER", > "PERSONAL COMPUTER", etc.) may also be noted. > > If the first three elements are directly applied to the product by > die-stamping, ink-stamping, silk screening, molding, etching, or > similar > processes, or if they are part of a nameplate which includes either > the > electrical rating or the catalog or model designation, the product > identity > may appear elsewhere on the product. > > Minimum size is not specified as long as the Listing Mark is legible. > The > first three elements shall be in close proximity. > > SEPARABLE LISTING MARK > > If separable Listing Marks are employed, all four elements are > required to > be part of the sticker, label, decal, etc. (A separable Listing Mark > is one > which bears only the Listing Mark information and is separately > applied.) > > Kurt Andrews > Compliance Engineer > > Tracewell Systems, Inc. > 567 Enterprise Drive > Westerville, Ohio 43081 > voice: 614.846.6175 > toll free: 800.848.4525 > fax: 614.846.7791 > > http://www.tracewellsystems.com/ > > > --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: duty cycle correction factors
Stuart, Duty cycle in 15.231 is related to a voltage ratio, therefore 20 log(duty cycle) will provide the correct factor. Demonstrate it to yourself. Start with a given value (say 100V), multiply this by some duty cycle (say 15% or .15). Convert the result to dB. This is your reference result. Now take 20 log of a duty cycle (.15). Convert your given value (100V) to dB. Add the numbers together, duty cycle dBs to the given value dBs, and behold -- the same answer as the reference result. Best regards, Don > -- > From: Stuart Lopata[SMTP:stu...@timcoengr.com] > Reply To: Stuart Lopata > Sent: Thursday, October 18, 2001 12:00 PM > To: emc > Subject: duty cycle correction factors > > > Part 15.231 devices use a duty cycle correction factor to adjust peak > readings. The duty cycle represents the fractional on-time over a given > period of time (that must be under some limit). Anyways, given this > fractional time, d, how do you make the conversion to dB? > > 10log(d) or 20log(d)? > > There have been some misinterpretations, since the readings are made at a > span of zero hertz (voltage readings). Normally, a reduction in voltage > would use the 20log scale. However, since the duty cycle does not > represent > a scale down (it represents the off-time versus on-time), the 10log scale > seems more appropriate. > > I have seen conflicting documents, so would like your professional > opinions! > > Thanks, > > Stuart Lopata > > > --- > 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: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Motor Drive Grounding Scheme
Greetings All, I work for a product safety consulting firm/test lab/agent. I am currently having some difficulties with UL relating to one of our customer's products. The grounding scheme of the products has become a barrier which has halted the planned testing. In our opinion, the engineering rationale behind this position is not very strong or clear. The products are small open-type stepper and servo motor drives (rated up to 6 A) which are intended to be used within another enclosure. They are powered by an 18 - 74 V dc external source which is supplied by the user. The drive output is a DC pulse width modulated waveform. UL 508C and UL 840 are the standards being used. The main issue is the fact that the DC - (common) input supply lead is connected internally to the input ground (PE) lead. UL has referenced UL 508C requirements (not really applicable to these particular products since we have agreed to use UL 840 for spacings) that indicate that spacings are required within the product between these two leads. This implies that this grounding scheme cannot be used. The manufacturer has indicated that the drives will not operate properly without this grounding connection. The product designers made this connection internally to prevent the common from floating above/below ground potential and for EMI purposes. The customer and my company do not agree with UL's position. One possible hazard UL stated was that the heatsink was connected to the grounded DC - (common) internal bus and could be electrically "live". Since the heatsink is referenced to ground potential, it is not "live" during normal operation. If an internal fault does occur, the circuitry is designed such that the fault current will flow through the ground, as intended. In addition, a "hint" of possibly increasing the risk of shock was also mentioned. No one involved has been able to identify any real safety issues resulting from this grounding scheme. In order to address all potential safety hazards, we have recommended that testing be conducted to confirm compliance with the intent of the standards. This would hopefully show that the products are "safe" and that all foreseeable safety hazards (during normal and fault conditions) have been identified and minimized/eliminated. After weeks of research and discussions, we have not been able to convince UL that this grounding scheme should be allowed and that we should proceed with the testing. Does anyone know of any similar UL certified motor drives (or other similar DC powered products) that employ this grounding scheme? The closest examples we could find were AC powered products with DC ground referenced secondary circuits. However, this is not the same since a transformer usually provides the required isolation. Does anyone have any comments/information on this grounding scheme that might be helpful in building a stronger case either way? The closest thing we could reference was a grounded DC distribution system in the 1999 National Electrical Code (NEC - NFPA 70). Please respond at your earliest convenience. Thanks in advance for your assistance, Mark A. Haynes Senior Product Safety Engineer D.L.S. Conformity Assessment, Inc. 1250 Peterson Drive Wheeling, IL 60090-6454 (847) 537-6400 (Ext. 157) Fax (847) 537-6488 mhay...@dlsemc.com --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: UL - marking - gentle warning not to extrapolate.
Hi Peter: Thanks for sending the UL letter and UL Listing Mark page. I stand corrected. For Information Technology Equipment, UL's letter of March 31, 1995, authorizes the optional use of the file number as the control number. Apparently, this option is not available for non-ITE products. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: duty cycle correction factors
20log(d) time is linear, like voltage not the square, like power, thus the 20log - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Stuart Lopata To: emc List-Post: emc-pstc@listserv.ieee.org Date: Thursday, October 18, 2001 9:45 AM Subject: duty cycle correction factors > >Part 15.231 devices use a duty cycle correction factor to adjust peak >readings. The duty cycle represents the fractional on-time over a given >period of time (that must be under some limit). Anyways, given this >fractional time, d, how do you make the conversion to dB? > >10log(d) or 20log(d)? > >There have been some misinterpretations, since the readings are made at a >span of zero hertz (voltage readings). Normally, a reduction in voltage >would use the 20log scale. However, since the duty cycle does not represent >a scale down (it represents the off-time versus on-time), the 10log scale >seems more appropriate. > >I have seen conflicting documents, so would like your professional opinions! > >Thanks, > >Stuart Lopata > > >--- >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: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > >For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > >All emc-pstc postings are archived and searchable on the web at: >No longer online until our new server is brought online and the old messages are imported into the new server. > --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: IEC 61508
At the IEC website but only at a price. I'm afraid IEC standards don't come for free. Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com > -Original Message- > From: lisa_cef...@mksinst.com [SMTP:lisa_cef...@mksinst.com] > Sent: 18 October 2001 13:50 > To: emc-p...@majordomo.ieee.org > Subject: IEC 61508 > > > Hi all, > Does anyone know where I can download a copy of IEC 61508? > > Thanks, > > Regards, > > Lisa > > Lisa A. Cefalo, CRE > Manager, Reliability and Design Services > MKS Instruments > (978)-975-2350 X 5669 > lisa_cef...@mksinst.com > > > --- > 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: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. ** Please visit us at www.tagmclaren.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159) ** Please visit us at www.tagmclaren.com ** --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: UL - marking - gentle warning not to extrapolate.
Hi Rich, >> 1. UL in a circle (the famous UL Listing mark symbol), >> 2. The word "LISTED" in capital letters, >> 3. The assigned control number*, and >> 4. Product identity (e.g., NWGQ, I.T.E., etc.) >> >> * The assigned control number is a designation that UL assigns to a >> manufacturer, or manufacuring >> location (I have also seen UL file numbers used here, although I'm not >> sure that UL objects to >> that). >The file number cannot replace the control number. >The control number is always required. > >The file number can replace the manufacturer's name, >or can be used in addition to the manufacturer's >name. I agree with you on what is spelled out. However, the reason that I said what I did was that I have seen more than a few UL Listing marks over the years on products with only the UL in a circle and a UL file number. I was just reflecting on past observations. Best regards, Ron Pickard rpick...@hypercom.com --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 10/100 base interface in a plastic box
Gary, About 50% of our 100BASE-Tx cards require an additional 4-line common-mode choke between the transformer-filter and the RJ-45 connector, to meet Radiated Emissions limits with enough margin to satisfy our electromagnetic compatibility (EMC) folks. So we snuggle all three components as close together as our manufacturing guidlines will allow, usually within 0.025" of one another pad-to-pad or pad-to-body. Since the transformers and filters in the transformer-filter are symmetrical between the + and - sides, and the transmit and receive sides often are the same, we shuffle the pin numbers in the common-mode choke and transformer-filter so that the traces run almost parallel (no crossovers) in the critical area between the RJ-45 connector and the transformer filter: RJ-45 ++common- transformer- !!modefilter ! O !choke +--+ ! O! +--+ /-! ! ! O--! !--/ ! ! ! O! ! ! /-! ! ! O ! /-! !--/ ! ! ! O-/ ! ! ! ! ! O--! !--\ ! ! ! O-\ ! ! \-! ! !! \-! !--\ ! ! ++ +--+ \-! ! +--+ This forces vias and crossovers in the RXD+, RXD-, TXD+, and TXD- lines to the zone between the transformer-filter and the PHY or MAC/PHY, where they are much less critical. We also try to get the PHY or MAC/PHY as close as we can to the transformer-filter, no more than 1 inch away and preferable within 0.5 inch, with the trace lengths closely matched. Depending on how bold the engineer is, on our first engineering cards we will short the pads of the common-mode choke together with traces or with 0-ohm surface-mount resistors paralleling the windings of the common-mode choke. I personally prefer the resistors, because if we ever discover that we need the common-mode choke, all I have to do is no pop the four resistors and put the common-mode choke in their place. I've considered using a 0-ohm 4-resistor resistor network, but didn't feel comfortable with the coupling that might cause between the receive and transmit signals on pins 2 and 3. Since my most recent card had over 1000 components crammed onto a 12.5" x 7.9" card, including a 350MHz X86 processor, six large ball-grid array (BGA) parts, and provisions for 512MB of SDRAM, I wasn't willing to take any risks that I didn't have to. (We started production two months ago using the second spin of my card...) John Barnes Advisory Engineer Lexmark International --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
duty cycle correction factors
Part 15.231 devices use a duty cycle correction factor to adjust peak readings. The duty cycle represents the fractional on-time over a given period of time (that must be under some limit). Anyways, given this fractional time, d, how do you make the conversion to dB? 10log(d) or 20log(d)? There have been some misinterpretations, since the readings are made at a span of zero hertz (voltage readings). Normally, a reduction in voltage would use the 20log scale. However, since the duty cycle does not represent a scale down (it represents the off-time versus on-time), the 10log scale seems more appropriate. I have seen conflicting documents, so would like your professional opinions! Thanks, Stuart Lopata --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
SAE J1113-13 and ISO 10605
An ESD question or two... For SAE J1113-13 and ISO 10605: Are air discharges directed to non-metal surfaces only as in IEC 61000-4-2? Or are both air and contact discharges directed to metal contact locations? (This may sound like a silly question, but the SAE/ISO specifications are not clear on this point ) Regards, Ron Chernus Compliance Engineer, DENSO --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Printable calendar for 2002 sent by request
Ok, ok. For all those whose virus scanners spit up when seeing files with my mnemonic names - upon request I'll send to you an unzipped version (about 60K total) with every file renamed with the extension *.txt. For example, PRINT_02.BAT will be PRINT_02.BAT.TXT etc Then you can do with it what you want. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Rich - Regarding UL Recognized Component Appliance Wiring Material, the yellow book states that the marking must be on a tag, the reel or smallest unit container, not surface marked on the wire insulation, as referred to by Greg. Very few UL FUS folks will accept surface marking, though I had seen some loosening up in recent years. The message is, don't rely on the wire surface making and keep the reel handy at the factory's work station. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com > From: Rich Nute > >Hi Gregg: > > > The File number 'may' be used on things like cable (it is common to see UL > > and CSA file numbers) and other components - Control numbers (I forget the > > correct terminology) is required on some UR components but not all Listed > > products. > > UL Listed wire: > > According to the UL Yellow Book, UL-certified > Appliance Wiring Material must bear the UR mark. > > If the wire bears the UL file number, then it is > either in lieu of the manufacturer's name or is > in addition to the manufacturer's name; the file > number is NOT required. > > > Best regards, > Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Gary - Or for the less scrupulous than careless, to remove the certification mark from a product and place it one that is not safety certified. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com > From: Gary McInturff > > The Product identity may be omitted if the > Mark is directly and > permanently applied to the product, stamping, > molding, ink-stamping > I assume that is because you can't > mistakenly put and ITE label on a > medical device or something during manufacture. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Peter - If you have such a memo, please do provide a copy. I my years working at UL and working with them since, it was ever abundantly and adamantly maintained (by UL's FUS Label Services group) that the Control Number is a required part of the Listing Mark and there is no substitution for it. The UL File No. may be used as a substitution the for company identification, in the ilk of a trademark or tradename. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com > From: Peter Merguerian > > Rich, > > For ITE, the file number may be used in lieu of > control number. I will be > glad to provide a memo from UL Labels Department > regarding this issue. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Rich is quite right, in general. There are UL Listing Marks available, but they won't have the other three required elements that make up the complete marking (some may include the word "Listed"). The page Rich referred to in a UL Follow-Up Services Procedure, though, is separate from the Section General and is called the Listing Mark Data Page. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina Homologation Services peter.tar...@sanmina.com > From: Rich Nute > > > A generic UL label is not possible. Section General of > your UL FUS Procedure identifies 4 elements that comprise > the UL certification mark: > > Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: IEC 61508
Can be obtained from http://www.iec.ch/seatop-e.htm if you pay for it. Don't know if it is downloadable - updates are in pdf format. Also try http://www.bsi-global.com/group.html but again you'll have to pay. Chris -Original Message- From: lisa_cef...@mksinst.com [mailto:lisa_cef...@mksinst.com] Sent: 18 October 2001 13:50 To: emc-p...@majordomo.ieee.org Subject: IEC 61508 Hi all, Does anyone know where I can download a copy of IEC 61508? Thanks, Regards, Lisa Lisa A. Cefalo, CRE Manager, Reliability and Design Services MKS Instruments (978)-975-2350 X 5669 lisa_cef...@mksinst.com --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Rich and others, Here is what the Listing Mark Data Page says in one of our FUS books for a piece of Listed ITE equipment that was Listed to UL 1950. Note number 3 below stating that you can use the File Number or the Control Number. By the way we create our own Listing Mark labels using the downloadable Listing Marks from the UL website and a label maker and software combination manufactured by Brady. PROCUREMENT All Listing Marks shall be obtained from a supplier authorized by Underwriters Laboratories Inc. unless the Listing Mark is molded, cast, die-stamped, rubber stamped, silk screened or reproduced by the manufacturer. COMPOSITION AND ELEMENTS 1. UL in circle symbol 2. The word "LISTED" 3. The assigned control number(s) or the Applicant/Listee's File Number 4. Product identity. Consists of the following: "UL 1950", "NWGQ", "INFORMATION TECHNOLOGY EQUIPMENT", INFO. TECH. EQUIP.", or "I.T.E." In addition, the name or the specific type of product as shown on the individual Listing (i.e. 'ADDING MACHINE", "CALCULATOR", "PRINTER", "PERSONAL COMPUTER", etc.) may also be noted. If the first three elements are directly applied to the product by die-stamping, ink-stamping, silk screening, molding, etching, or similar processes, or if they are part of a nameplate which includes either the electrical rating or the catalog or model designation, the product identity may appear elsewhere on the product. Minimum size is not specified as long as the Listing Mark is legible. The first three elements shall be in close proximity. SEPARABLE LISTING MARK If separable Listing Marks are employed, all four elements are required to be part of the sticker, label, decal, etc. (A separable Listing Mark is one which bears only the Listing Mark information and is separately applied.) Kurt Andrews Compliance Engineer Tracewell Systems, Inc. 567 Enterprise Drive Westerville, Ohio 43081 voice: 614.846.6175 toll free: 800.848.4525 fax: 614.846.7791 http://www.tracewellsystems.com/ -Original Message- From: Peter Merguerian [mailto:pmerguer...@itl.co.il] Sent: Thursday, October 18, 2001 3:41 AM To: 'Rich Nute'; rpick...@hypercom.com Cc: chris.maxw...@nettest.com; emc-p...@ieee.org Subject:RE: UL - marking - gentle warning not to extrapolate. Rich, For ITE, the file number may be used in lieu of control number. I will be glad to provide a memo from UL Labels Department regarding this issue. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Thursday, October 18, 2001 1:09 AM To: rpick...@hypercom.com Cc: chris.maxw...@nettest.com; emc-p...@ieee.org Subject: Re: UL - marking - gentle warning not to extrapolate. Hi Ron: > 1. UL in a circle (the famous UL Listing mark symbol), > 2. The word "LISTED" in capital letters, > 3. The assigned control number*, and > 4. Product identity (e.g., NWGQ, I.T.E., etc.) > > * The assigned control number is a designation that UL assigns to a manufacturer, or manufacuring > location (I have also seen UL file numbers used here, although I'm not sure that UL objects to > that). The file number cannot replace the control number. The control number is always required. The file number can replace the manufacturer's name, or can be used in addition to the manufacturer's name. > So, given the above and IMHO, I would say that just a generic UL Listing mark would neither be > acceptable nor authorized by UL. However, I recommend contacting UL for their official position on > the use of their Listing mark. The generic UL mark (the UL in a circle -- without the other three items) may be used in advertising or on the product carton. I believe UL has some guidelines for this use. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and search
RE: IEC 61508
http://www.iec.ch/webstore/ Respectfully yours, Constantin Constantin Bolintineanu P.Eng. DIGITAL SECURITY CONTROLS LTD. 3301 LANGSTAFF Road, L4K 4L2 CONCORD, ONTARIO, CANADA e-mail: bolin...@dscltd.com telephone: 905 760 3000 ext 2568 Visit our web site at www.dscgrp.com -Original Message- From: lisa_cef...@mksinst.com [mailto:lisa_cef...@mksinst.com] Sent: Thursday, October 18, 2001 8:50 AM To: emc-p...@majordomo.ieee.org Subject: IEC 61508 Hi all, Does anyone know where I can download a copy of IEC 61508? Thanks, Regards, Lisa Lisa A. Cefalo, CRE Manager, Reliability and Design Services MKS Instruments (978)-975-2350 X 5669 lisa_cef...@mksinst.com --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
IEC 61508
Hi all, Does anyone know where I can download a copy of IEC 61508? Thanks, Regards, Lisa Lisa A. Cefalo, CRE Manager, Reliability and Design Services MKS Instruments (978)-975-2350 X 5669 lisa_cef...@mksinst.com --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
National EMF Exposure Regulations
This message is addressed to members affected by national regulations for EMF exposure of workers and the general public, especially in Europe. I am attempting to learn at an early stage when national regulations are being developed or revised, but I am having great difficulty in finding persons, publications or web sites that have that information. Specifically, I am creating a list of knowledgeable persons (agency contacts, consultants, and other persons), agencies (government and private), web sites, professional organizations, and publications. I am aware of the following developments: * Italy: three decrees are to be written to support the new law * Germany: BGV B11 is a worker exposure regulation that is now in effect and equipment is being tested by the BG lab * Germany: the 26th Ordinance covering public exposure is going to be revised. The SSK has provided the Ministry of Environment with recommendations I would like to hear from others on how they manage this process and if they know of any other developments. Richard Woods Sensormatic Electronics --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Fw: SLIM Survey Findings
- Original Message - From: Alan E Hutley To: emc-pstc Sent: Thursday, October 18, 2001 10:15 AM Subject: SLIM Survey Findings Hello All The findings of the European Commission survey for proposals to modify the EMC directive can now be found in a 15 page word document on the home page of our web site www.compliance-club.com it makes for interesting reading. Cheers Alan E Hutley EMC Compliance Journal
SLIM Survey Findings
Hello All The findings of the European Commission survey for proposals to modify the EMC directive can now be found in a 15 page word document on the home page of our web site www.compliance-club.com it makes for interesting reading. Cheers Alan E Hutley EMC Compliance Journal
What Approvals required for Japan
Hi all, Can anyone tell me what if any EMC/Safety Certification is required for Military Equipment supplied to Japan. It should be noted that in one application the equipment can be connected to the electrical utility. Regards Andrew Price BAE SYSTEMS Avionics email This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Rich, For ITE, the file number may be used in lieu of control number. I will be glad to provide a memo from UL Labels Department regarding this issue. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Thursday, October 18, 2001 1:09 AM To: rpick...@hypercom.com Cc: chris.maxw...@nettest.com; emc-p...@ieee.org Subject: Re: UL - marking - gentle warning not to extrapolate. Hi Ron: > 1. UL in a circle (the famous UL Listing mark symbol), > 2. The word "LISTED" in capital letters, > 3. The assigned control number*, and > 4. Product identity (e.g., NWGQ, I.T.E., etc.) > > * The assigned control number is a designation that UL assigns to a manufacturer, or manufacuring > location (I have also seen UL file numbers used here, although I'm not sure that UL objects to > that). The file number cannot replace the control number. The control number is always required. The file number can replace the manufacturer's name, or can be used in addition to the manufacturer's name. > So, given the above and IMHO, I would say that just a generic UL Listing mark would neither be > acceptable nor authorized by UL. However, I recommend contacting UL for their official position on > the use of their Listing mark. The generic UL mark (the UL in a circle -- without the other three items) may be used in advertising or on the product carton. I believe UL has some guidelines for this use. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: World Wide EMC requirements Singapore TAS
Cecil, For Singapore the following are some excerpts from the requirements as given in TAS (Telecommunication Authority of Singapore) specification - TAS TS EMC, issue 1, May 1999: EMISSION STANDARDS (Mandatory) CISPR 22 Limits and Methods of Measurement of Radio Disturbance Characteristics of Information Technology Equipment; ITE EN 55022 Limits and Methods of Measurement of Radio Disturbance Amended Characteristics of Information Technology Equipment; ITE SS IEC CISPR 22: 1993Limits and Methods of Measurement of Radio Disturbance Characteristics of Information Technology Equipment (Adopted in 1995) Amendment No. 1, November 1996 IMMUNITY STANDARDS (Voluntary) IEC 1000-4-1 Overview of EMC Immunity Tests IEC 1000-4-2 Electro-static Discharge Immunity; ESD IEC 1000-4-3 Immunity to Radio Frequency EM-Fields; RF Radiated Field IEC 1000-4-4 Electrical Fast Transient / Burst Immunity IEC 1000-4-5 Surge (Mains) Immunity IEC 1000-4-6 Immunity to Conducted Disturbances Induced by Radio Frequency Fields; RF Conducted Conformity Requirements EMC emission requirements will be mandatory while the immunity requirements are voluntary. However, TAS may subject the immunity requirements to regulation at a later date when deemed necessary. Suppliers must ensure that the telecommunications equipment intended for use in Singapore has been successfully tested for conformity with the mandatory EMC requirements. :-) Tim Foo, (or just call me 'Tim') E-mail: f...@np.edu.sg ECE, School of Engineering, http://www.np.edu.sg/ece/ Tel: + 65 460 6143 Ngee Ann Polytechnic, Fax: + 65 467 1730 535 Clementi Road, Singapore 599489 cecil.gitt...@kodak.com Sent by: To: emc-p...@majordomo.ieee.org owner-emc-pstc@majordomcc: (bcc: Wan Juang Foo/ece/staff/npnet) o.ieee.org Subject: World Wide EMC requirements 10/17/01 10:31 PM Please respond to cecil.gittens From: Cecil A. Gittens What are the EMC requirements for ITE products that are marketed in the Southwest region of Russia, Eastern Mediterrian countries, Asia, South Africa, Israel, Indonesia, Saudi Arabia, Singapore. Cecil --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Printable calendar for 2002
Hi Robert: > I got two NAV (Norton Antivirus) msgs back from the ieee.org that said my > attachment had a virus in it. > > If so, please let me know, because there is nothing but text files (that I > know of) and a simple batch program in that attachment. The IEEE listserver checks all messages for viruses before sending them to our subscribers. Your files that were sent to subscribers were zipped. I checked both the zipped and unzipped files for viruses (with up-to-date Norton AV, 7.03, scan engine 4.1.0.2, virus definition file 31017e) and found no viruses. So, the file distributed by the IEEE server seems to be clean. So, it may be that the IEEE server removed the virus, forwarded the message to our subscribers, and notified you of the virus. Good luck, and best regards, Rich Richard Nute Administrator, IEEE emc-pstc listserver c/o Hewlett-Packard Company San Diego Tel:1-858-655-3329 FAX:1-858-655-4374 e-mail: ri...@ieee.org --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: UL - marking - gentle warning not to extrapolate.
Hi Gregg: > The File number 'may' be used on things like cable (it is common to see UL > and CSA file numbers) and other components - Control numbers (I forget the > correct terminology) is required on some UR components but not all Listed > products. UL Listed wire: According to the UL Yellow Book, UL-certified Appliance Wiring Material must bear the UR mark. If the wire bears the UL file number, then it is either in lieu of the manufacturer's name or is in addition to the manufacturer's name; the file number is NOT required. UL Listed products: The UL 4-character control number is ALWAYS required on a Listed product. UR Recognized Components: There is no control number for UL Recognized Components (UR). The usual UL component certification mark is the manufacturer's name and model number. For some components, e.g., connectors, the UR mark either is not required or is optional. For some components, the UR mark is required. The UL Yellow Book identifies the required markings for components, including those components that must bear the UR mark. I hope this answers your question. Best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Shrunk-die power MOSFET's and compliance
I'm curious what others in the compliance community have experienced over the last year or so in regards to re-designed power MOSFET's that the big FET manufacturers are pushing on us. These next generation "trench" style FET's have smaller dies, resulting in lower on-resistance but higher thermal impedance to their cases, and in lower gate capacitances and faster rise times. At first glance it seems obvious these changes could impact the compliance of power conversion products in the areas of emissions (increase due to faster rise times), susceptibility to surges, and perhaps temperatures (not that agencies care about FET temperatures, but if they're hotter neighbouring components may be too). The FET's involved are some of the highest volume parts these mfr's make (to achieve maximum savings), and are widely used in power electronics. Since most products either are, use, or contain power electronics these days, I'd expect this issue to be affecting almost all of us. I'd be glad to hear of any experiences the forum has had with this issue. Thanks, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power web: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: UL - marking - gentle warning not to extrapolate.
Just happen to be looking this up when you e-mail arrived. I noticed something interesting buried in the Listing Mark data page. Paragraph 5 in our UL report. I think they are generic pages so likely you would find it in the same place in your reports/procedures. The Product identity may be omitted if the Mark is directly and permanently applied to the product, stamping, molding, ink-stamping I assume that is because you can't mistakenly put and ITE label on a medical device or something during manufacture. -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Wednesday, October 17, 2001 1:57 PM To: chris.maxw...@nettest.com Cc: gkerv...@eu-link.com; am...@westin-emission.no; emc-p...@majordomo.ieee.org Subject: Re: UL - marking - gentle warning not to extrapolate. Hi Chris: > Does the file number need to be on the label? Can the manufacturer > leave the file number off of the label and simply put a generic UL (or > CSA) mark on the product along with their nameplate identifying the > manufacturer, model and serial number? In my response to Amund, I indicated that UL requires a manufacturer identifier, which is usually the manufacturer's name, but alternatively can be the UL file number. UL also requires a product identifier such as the model number, but does not require a serial number. A generic UL label is not possible. Section General of your UL FUS Procedure identifies 4 elements that comprise the UL certification mark: 1. The copyrighted UL mark itself (UL in a circle). 2. The word "Listed." 3. The category of equipment, e.g., "ITE" or "PRINTER." 4. The UL control number assigned to the manufacturer for this specific category of equipment. While you may be able to buy Item 1, or even Items 1 and 2, on a "generic" pre-printed label, you must necessarily provide Item 3 because it describes your equipment, and you must necessarily provide Item 4 because it is unique to you. All of these elements must be in reasonable proximity of each other. I don't believe CSA has the same four requirements for its mark. So, I believe you can buy the generic CSA mark. Be sure to verify this statement with CSA before taking any action. Good luck, and best regards, Rich --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: 10/100 base interface in a plastic box
Question: The Ethernet magnetics from Pulse and others are a combination of common mode choke along and isolation windings input-to-output. The isolation is the reason the moat is effective. Are you saying that you put additional common mode chokes in the signal line? I am assuming that you are putting them between on the connector side of the Ethernet magnetics? Gary -Original Message- From: Cook, Jack [mailto:jack.c...@cax.usa.xerox.com] Sent: Wednesday, October 17, 2001 1:58 PM To: 'jrbar...@lexmark.com'; Jon Keeble; emc-p...@majordomo.ieee.org Cc: Cook, Jack Subject: RE: 10/100 base interface in a plastic box John, Really good information there regarding treatment of chassis ground & evacuation of other layers. I'd add the comment that the layout of the signal etch between the transformer & the RJ45 connector (UTP) is also important. Keep the +/- pairs as short, tightly coupled and as symmetrical as possible. We usually do use discrete CM chokes and have never tried backing them out. Regards, Jack Cook Xerox EMC Engineer -Original Message- From: jrbar...@lexmark.com [mailto:jrbar...@lexmark.com] Sent: Wednesday, October 17, 2001 12:57 PM To: Jon Keeble; emc-p...@majordomo.ieee.org Subject: Re: 10/100 base interface in a plastic box Jon, My department has developed ten generations of Ethernet adapters (10BASE2, 10BASE-T, 100BASE-Tx) for IBM/Lexmark printers since 1990. We have looked at, but so far have not used, integrated-magnetics connectors because we like having the option of putting a common-mode choke in between the Ethernet magnetics (transformer-filter) and the connector. In our card layouts we: 1. Define a FRAME_GROUND to connect the metal bodies/shields of all connectors going to the outside world. 2. Connect FRAME_GROUND to GROUND with 4-or-more "ground ties", 0.025-inch wide traces on the topside and bottomside of the card. We use at least one pair of ground ties for every 3 inches of "beach front" with connectors going to the outside world. 3. For the Ethernet interfaces, put a void in all layers stretching from the center of the transformer-filter to the farthest pins of the RJ-45 connector, 0.2" wider than the transformer-filter, common-mode choke, and RJ-45 connectors. The *only* wires permitted in this area are the Ethernet transmit/receive signals. 4. Run FRAME_GROUND down the edge of the card, as wide as we can make it, ending in mounting pads for a metal bracket or the chassis. These pads have non-plated-through holes for the mounting screws circled by eight vias, and are plated with tin or tin-lead on the topside and bottomside. FRAME_GROUND has the same outline in all copper layers, although we sometimes have to leave it as a void in ground planes because of a quirk in Mentor Graphics.Put a via about every 1/2 inch along FRAME_GROUND to connect the layers together. 5. Place a ground tie at each mounting pad topside and bottomside, with additional topside and bottomside ground ties roughly equally spaced in between the mounting pads. During development testing, these groundties can be easily cut with an X-acto knife if it looks like separating FRAME_GROUND from GROUND, or having them connected at only one end, might improve radiated emissions and electrostatic discharge (ESD) immunity. Make sure that solder does not get onto the mounting pads during manufacturing. The mounting pads sit right on the lugs of the metal bracket/chassis. These contact points on the metal bracket/chassis must be bare metal. We recently discovered that a transparent phosphate wash applied to a chassis before powder coating, as a priming step, seriously affected radiated emissions and the ESD immunity. We now require these contact points to be masked off before the chassis goes through any cleaning/painting steps. A machine screw with a built-in belleville washer, and a nut with a captive star washer, hold the card and the metal bracket/chassis in tight metal-to-metal contact despite temperature changes, vibration, creeping of the plating, etc. For our External Network Adapters, the metal bracket is bent into L, and extends all the way under the card. This bracket ties the faces of metal connectors together, connects to FRAME_GROUND, and provides a ground plane all the way under the card to reduce radiated emissions and reduce our susceptibility to tabletop ESD (an IBM test). From the side the card, connectors, and bracket look like this: ! !+--+ !! ! !! ! ! + ! <-- insulating spacer, or tab bent up to support card + here-- experiment to see whether having the card and bracket isolated or connected gives the best EMC/ESD results
