Re: LMC With Regard To Surge Test Cable Length
Eric, To make your nice input more informative, please allow me to add what clause 3.6 reads: Long distance lines: Lines within a building which are longer than 30m, or which leave the building (including lines of outdoor instalations). BM -- On Wed, 20 December 2000, eric.lif...@ni.com wrote: EN 61326-1 Product Family, Laboratory, measurement, and control equipment within the scope of EN 61326-1 does not require surge testing until reaching the definition of Long Lines (see clause 3.6) which is NOT 10 meters, but does include lines that can leave the building. . [clipped by BM] --- Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUhttp://www.anritsu.com Morgan Hill, CA 95037 Find the best deals on the web at AltaVista Shopping! http://www.shopping.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: ESD Floor waxing
Michael, The ESD Association seems to be at http://www.esda.org/. Regards, -Barry --- On Mon, 11 December 2000, michael.garret...@radisys.com wrote: The ESD Association (http://www.eosesd.org) in the US and the The British Electrostatic Control Association (http://www.beca.co.uk) appear to be the best sources of information and would likely be a better point to begin your inquiry. Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUhttp://www.anritsu.com Morgan Hill, CA 95037 Find the best deals on the web at AltaVista Shopping! http://www.shopping.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN55024
Hi Chris, I agree with 99.9% of your convincing opinions with a tiny question. You said: I believe its because the scope of EN 55024 is geared toward the residential, commercial and light industrial environment. If I were producing a piece of ITE equipment intended for a truly industrial environment, I would consider Class A emissions (yes Class A) from EN 55022 (assuming it's ITE). I would then look for the best fit of an immunity standard for industrial environments. Either a generic immunity standard such as EN 50082-2 or another whose scope is directed at an industrial environment. I respect the due diligence to find a best-fit immunity standard for industrial environment, especially when customers want to do so. Please allow me to ask a question when customer dont care: Is there any conflict with written statement in relevant standards if we simply follow EN55024 for ITE used in industrial environment? Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUhttp://www.anritsu.com Morgan Hill, CA 95037 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: ITE Emissions above 1 GHz
Dick, The standard ETS 300-683 is for Radio Equipment used in short range. Is the unit described by Richard falls under this category? Richard, A question raised by you about how to regulate ITE (Information Technology Equipment) device in compliance with Telecom standards is of very important and practical interest. Telecom industry is developing so fast that many other equipment which fall under categories of ITE or Test equipment are involved in the Telecom environment. ... If customers in Telecom industry really want us to test devices of other categories in compliance with Telecom standards, should we raise our price for the extra cost? :-) Barry - On Thu, 16 November 2000, Dick Grobner wrote: Short range device? Look at ETSI 300-683, EMC Std for Short Range Devices - operating freq. 9kHz to 25GHz. Chapter 8 deals with emissions. Hope this helps! -Original Message- From: wo...@sensormatic.com [mailto:wo...@sensormatic.com] Sent: Wednesday, November 15, 2000 3:10 PM To: emc-p...@majordomo.ieee.org Subject: ITE Emissions above 1 GHz I have an Information Technology device that intentionally generates and uses 2.45 GHz signals. EN55022 does not provide limits above 1 GHz. Is there another harmonized EN that can be applied for spurious emissions above 1 GHz? If not, will this product have to be submitted to a Competent Body? Richard Woods --- Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: New Edition of EN 61010-1
Paul, Would it be possible for you or anybody else to summarize main points of modifications made in the new edition of IEC61010-1? Regards, Barry -- On Wed, 15 November 2000, O'Shaughnessy, Paul wrote: Dear List, I've received word of an Edition 2 for IEC 61010-1 which was recently approved in a vote within the IEC. Does anyone have any information on when or if this will be published by the EC (a DOP), or when an ultimate DOW might be set? Many thanks, Paul O'Shaughnessy Affymetrix, Inc. ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
DoC in Website
Hi, More and more people are talking about putting Declaration of Conformity onto internet web site. Can anybody refer me to URL addresses showing real DoC on websites of some manufacturers. -Barry Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: A1 of EN61000-4-3
Larry, Thank you very much for the clarification! Can we try to conclude that (1) The modulation parameters of A1 are the same as original EN61000-4-3. (2) If both EN 61000-4-3 and A1 are stipulated at the same test amplitude, say 3 V/m, we don't have to retest 800-960 MHz of A1 after passing EN61000-4-3. If there is a special concern with the interference from cell phones, we may raise the test amplitude of A1 to say 10 V/m. Then we have to retest 800-960 MHz of A1 after EN61000-4-3. (3) The frequency range of 1.4-2.0 GHz in A1 would not be affected anyhow. Please correct me. Best Regards, Barry Ma On Wed, 25 October 2000, stillin...@aol.com wrote: Barry, I have the copy of A1 and do verify that it states 80% AM from 800 to 960. Appendix A in the Amendment provides the rational why 80% AM was chosen. Appendix A in a nutshell: Sine Wave AM, Square Wave AM and Pulsed RF signals were compared on a variety of products. It was concluded in Section A.4 that: In summary, sine wave modulation has the following advantages - narrow band detection response in analogue systems reducing background noise problems; - universal applicability, i.e. no attempt to simulate the behavior of the disturbing source; same modulation at all frequencies; - always at least as severe as pulse modulation. For the reasons stated above, the modulation method defined in this standard is 80% AM sine wave. Larry Stillings Compliance Worldwide, Inc. www.cw-inc.com ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: A1 of EN61000-4-3
Sorry, there's a typo in my quotation that I just sent: The requirement for 9005 MHz pulse modulation in ENV 50204 was replaced by 800-960 MHz and 1.4-2.0 GHz, 80% amplitude modulation in Amendment 1:1998 of EN61000-4-3. 9005 MHz should have been 900 + - 5 MHz. ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: A1 of EN61000-4-3
Chris, Unfortunately I don't have a copy of A1 at hand. Please allow me to quote a text from an article in EE July 2000, p. S-55: The requirement for 900+/-5 MHz pulse modulation in ENV 50204 was replaced by 800-960 MHz and 1.4-2.0 GHz, 80% amplitude modulation in Amendment 1:1998 of EN61000-4-3. That text inspired my question because I got an impression that the pulse modulation of ENV50204 has been replaced by A1 with 80% AM. Can anybody who has a copy of A1 to verify? Thanks in advance. Barry - On Wed, 25 October 2000, Maxwell, Chris wrote: Do they have the same modulation parameters? I always assumed that the 800-960Mhz tests were pulse modulation tests using 200Hz, 50% duty cycle square waves. If not, then I'm just as confused as you are. ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Beta units and the FCC
On Wed, 25 October 2000, jestuckey wrote: ... [editted by BM] My recommendation would to include the following text (in a conspicuous font and type set) in all documentation sent with an evaluation or test package, regardless of the quantities or receiving agent : This device has not been authorized as required by the rules of the Federal Communications Commission. This device is not, and may not be, offered for sale or lease, or sold or leased, until authorization is obtained. Additionally, I recommend that a label with the following wording be attached to the board itself: PROTOTYPE for EVALUATION ONLY This board has not been tested for conformance to FCC Rules. JOHN E. STUCKEY EMC Engineer Micron Technology, Inc. Integrated Products Group Micron Architectures Lab 8455 West Emerald Boise, ID 83704 Ph. 208.363.5313 Fx. 208.363.5596 jestuc...@micron.com - What John said reminds me of a real story. About 10 years ago a friend of mine was working for a small PC company as an EMC engineer. A marketing person moved that label with the text of This device has not been authorized as required by the rules of the Federal Communications Commission. ... from the conspicuous front to the back of the PC in a computer show. This action was found by FCC and caused a fine to the company. BM Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Beta units and the FCC
In my understanding of FCC rules, your beta unit with a not for sale' sticker on it has no obligation to be compliant with Part 15B limit even if 15 dB above. Barry Ma On Wed, 25 October 2000, Mike Morrow wrote: What are the rules regarding a piece of equipment that is being beta tested (not for sale, not being offered for sale) that does not currently comply with Part 15B limits? Everything I've read (47CFR Part 2.803) revolves around marketing and sales of the equipment, but nothing about equipment that is being given to someone for evaluation. FYI, the unit only has two failing frequencies and it only fails by about 4 db. I am planning on putting a not for sale sticker on the units as well. Thanks in advance. Mike Morrow Senior Compliance Engineer Ucentric Systems 978-897-6482 mi...@ucentric.com www.ucentric.com ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: A1 of EN61000-4-3
Hi group, Thanks for all replies in respond to my question on the Amendment 1 of EN61000-4-3 a few days ago. But there is another unclear issue left with the A1. Please help. I think the intention of A1 is to simulate the interference from near cell phones. That's why A1 has two frequency ranges: 800-960 MHz and 1.4-2.0 GHz. What I'm kind of confused is that the 80-1000 MHz frequency range of original EN1000-4-3 already includes 800-960 MHz of A1. It seems to make no sense to re-test a subset (800-960 MHz) after passing 80-1000 MHz. - They both have the same modulation parameters: 80% AM at 1 KHz. It makes sense, on the other hand, to test another frequency range 1.4-2.0 GHz of A1, which is out of 80-1000 MHz. Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Class D in EN61000-3-2
Gert, Thanks for your clarification. Paul, I also include your nice explanation below. I speculate that the main point of A14 of EN61000-3-2 is to retain Class D requirement only for PC, PC monitor and TV, and replace Class D requirement with Class A for other equipment. Please verify my conjecture. Thanks. Barry Ma -- On Thu, 19 October 2000, CE-test - Gert Gremmen Ing. - CE-mark more ... wrote: You are right Barry, The decision was in favor and there are no other equipment yet defined in Class D. I have sent the list a press release from cenelec a few days ago about this subject. However, this was a compromise between industry fighting against and power companies on the other side. It was said by people witnessing the disc(p)utes that it was the toughest discussion since standardization started. With the next revision this compromise will certainly extend into the direction of other equipment within the power limits fall in Class D as long as it meets the criteria formulated as: having a substantial influence on the power system. Read : all capacitor loaded bridge rectifier applications. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presencehttp://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === -Original Message- From: O'Shaughnessy, Paul [SMTP:paul_oshaughne...@affymetrix.com] Sent: Monday, October 09, 2000 10:28 AM To: 'Nick Rouse'; Friedemann Adt Cc: EMC Subject: RE: EN 61000-3-2/A14 Right - the dop is the first date upon which you MAY employ a new standard for compliance. The dow is the day by which any conflicting (ie the old standard) must be withdrawn and is therefore ineffective. This makes the period between dop and dow a transition period. Typically, the new standard is tougher than the original, so the transition period is used by everyone to ECO their products, retire the dinosaurs, etc. In this case (assuming all the dates are correct and it goes according to the plan), the situation is a bit upside down - A14 makes compliance to EN61000-3-2 easier. The dow for EN61000-3-2 will coincide with the dop of A14, which means on January 1st, you'll need to comply with EN61000-3-2, BUT you'll have the option to use A14 in doing so. For many manufacturers, A14 is the simpler and easier path, so I expect that many will take it once it is available. Paul O'Shaughnessy ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Class D in EN61000-3-2
I read an article about EN61000-3-2 in p2 of http://www.techintl.com/pdfs/newsletters/sd_news2000.pdf titled Deficiencies of EMC Harmonics Standards Are Addressed. It reads: Several national standards organizations have asked the EC and CENELEC for an extension to the date of withdrawal of conflicting standards (1 January 2001). For this reason, Working Group 1 of IEC SC 77A prepared an interim draft to address some of the standards deficiencies. The draft modification proposes to withdraw the special wave-shape test for Class D yet still retains the Class D category and test limits. Equipment will be specified in the standard as being in the Class D category, and therefore have to be tested for compliance. PCs, PC monitors and television receivers with a power consumption of between 75 W and 600 W fall into this category. The vote closing date is 15 September 2000. If adopted, the Common Modification could be ratified before 1 January 2001. Manufacturers would have the option of using only the standard or using the standard with the Common Modification. There is no proposal to delay the date of withdrawal of EN 61000-3-2. Please help me clarify the followings: (1) What is the vote result of 9/15/00? Has the Common Modification been adopted? (2) If adopted, does it mean Class D only pertain to PC, PC monitors and TV? Does it mean there is no Class D category for other equipment? Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: A1 of EN61000-4-3
Richard and Geoff, In test equipment industry, we follow EN61326. A colleague, Norm Provost, just informed me that there is a statement in EN61326 encouraging us to apply all updated Basic standards. In the heading under Clause 2, Normative References, we can read: ... All normative documents are subject to revision, and parties to agreement based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. ... It seems that we don't have to wait for new version of EN61326 when adopting A1 of EN61000-4-3. Barry Ma - On Mon, 16 October 2000, wo...@sensormatic.com wrote: All of the standards that I have seen use the same approach. Richard Woods -- From: Geoff Lister [SMTP:geoff.lis...@motion-media.com] Sent: Monday, October 16, 2000 6:04 AM To: 'wo...@sensormatic.com' Cc: emc-p...@majordomo.ieee.org Subject: RE: A1 of EN61000-4-3 Annex ZA (normative) of EN55024:1998 includes the following phrase at the head of the list of associated specifications. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. It then goes on to list EN61000-4-3 as the 1996 edition. As I read it, there must be a revision of EN55024 before I need to apply a more recent version of EN61000-4-3. This seems nice and logical, so there must be a flaw in it somewhere. Do any of the other Family and Product standards use a different approach? Geoff Lister Senior Engineer Motion Media Technology Ltd. http://www.motion-media.com Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Source for doing MTBF Calculations
I found a very informative website http://rac.iitri.org/. You may try to contact them. Regards, Barry -- On Fri, 13 October 2000, Mike Campi wrote: I hope that someone in this group can help me find this information. I have been asked to find an outside source or company that can do MTBF reports. Any information would be appreciated. Thanks, Mike Campi EMI Engineer Set Engineering, Inc. V(408) 778-6238, F(408) 778-6288 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: ENV standards
Ari, Do you have any idea when ENV 50204 should be totally replaced? Barry - On Fri, 13 October 2000, ari.honk...@nokia.com wrote: ENV 50204 is still alive, the others are not. regards, Ari Honkala -Original Message- From: EXT am...@westin.org [mailto:am...@westin.org] Sent: Friday, October 13, 2000 12:53 PM To: emc-p...@majordomo.ieee.org Subject: ENV standards Dear members, Regarding the European standards in the ENV-series, ENV50140 / 50141 / 50142, are all of them withdrawn or superseeded ? Any of those standards which still are valid ? I've heard different versions across and I'd like to hear your opinion. Personally, I thought all of them was out of date (withdrawn /superseeded). Best regards Amund Westin am...@westin.org -- Get your firstname@lastname email for FREE at http://NamePlanet.com/?su -- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
A1 of EN61000-4-3
Hi, I don't have a copy of A1 of EN61000-4-3 at hand. Please help me. (1) let me know when is the DOW of A1 for EN61000-4-3? (2) confirm the difference of A1 and ENV50204. A1: 800 - 960 MHz, and 1.4 - 2.0 GHz. ENV50204: 900 MHz at 200Hz/50%. Thank you. Best Regards, Barry Ma ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Compliance Global list information
It seems to be www.cbscheme.org, instead of www.cbscheme.com -Barry --- On Tue, 10 October 2000, geor...@lexmark.com wrote: Go to www.cbscheme.com and click on Countries George Dear Group, Where can I get a global agency certification list that showed all coutries accept CB-Scheme or CE marking? Thanks in Advance! Richard Terawave Communications 30680 Huntwood, CA 94544 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: mil-std-461/462 for download
Quoted from http://www.conformity.com/shop/newsbreaks.html#need --- Need Help In Finding Copies Of MIL STD 461? Dont ever say that you get nothing in return for all of your tax dollars. Its now possible to obtain copies of MIL STD 461 E (the latest release) through the Internet at http://astimage.daps.dla.mil/quicksearch. If youre looking for earlier editions of the standards (many programs are still using the earlier release MIL STD 461 D), try http://www-chas.nosc.mil/spawar/pdf/MIL461D.PDF. -- Barry Ma ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: ESD Opportunities
Please allow me to ask a relevant question only for curiosity. We have no idea of what charge (positive or negative) would go to the DUT in ordinary ESD. That's why we have to test two polarities in ESD immunity test. Lightning is a kind of ESD happened between a charged cloud and objects on earth surface. Some figures imply that an electron current flows from the charged cloud to the earth. Is it possible to have an opposite direction - electron flows from earth to cloud? Thanks. Barry Ma ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Fwd: Probing power plane with analyzer
From: Dawson Yee daws...@microsoft.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 28 Sep 2000 14:15:33 -0700 If you are doing A vs B comparisons, then just use some resistors to safely voltage divide the input voltage, present a high enough measurement instrument input impedance (preventing the power plane from seeing 50 ohms!), feed with a coax cable and then use the measurement instrument attenuator if needed. If you use DC blocking caps you have to be concerned about frequency roll-off (the higher frequencies rolls-off, tricking you into thinking that there are no high frequency issues). With this technique you can (sort of) ascertain the Power and Ground plane noises when used with a spectrum analyzer (don't connect the ground lead, but be aware of what potential it is at). I've used this technique for many, many years (despite a lot of skeptics), have not blown out any instruments, and have had a lot of real world, high volume success. Regards, Dawson ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Battery Safety
Scott, Thanks for the nice answer. Barry Ma - On Tue, 26 September 2000, Scott Lacey wrote: Barry, These use magnetic coupling to transfer the charging energy. In essence, the transformer secondary is inside the toothbrush handle, along with the rectifiers and rechargeable batteries. The older models used line-frequency sine waves and tended to get warm (but not hot). Many of the newer models use high-frequency (tens of kilohertz or higher) square waves and do not get warm while in the stand. As for safety, the lack of exposed contacts is a great advantage. Battery chargers can deliver substantial current - enough to cause burns to a curious child probing them with a pair of metal tweezers. Scott Lacey ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Battery Safety
Chris' email reminds me of a relevant question: The charging stand for a battery-driven toothbrush (Sonicare) has no contact with the toothbrush. What is the charging mechanism? Is it safer than other battery? Best Regards, Barry Ma ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: FCC Part 15
Ed, Thanks a lot for the info. I found another one in FCC webside finally: http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/cfr/1999/ Best Regards, Barry ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: HALT/HASS Testing
Sorry, I was pointed out a typo in the email I sent 2 hrs ago this afternoon. MALT should be corrected to HALT in the second insertion with The product is made better, but how much better is not known, at least not by the MALT methods. -BM Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: HALT/HASS Testing
Hi Darrell, By coincidence, I'm reading the book you recommended. I found your descriptions consistent with the book. Please allow me to insert some supplements below. Barry Ma Anritsu Company On Fri, 08 September 2000, Darrell Locke wrote: HALT. Highly Accelerated Stress Testing. This can go by other names. This is where you stress the product (prototype stage typically) using a number of criteria, the most common being temperature extremes and vibration. ... many HALT results have shown that all-axis vibration far surpass the effectiveness of thermal cycling for the broad spectrum of faults found in many types of equipment ... -(quoted from p. 13 of the book) You test first to determine the operational limits of the EUT (fails to operate but recovers when the stresses are removed), then continue until you reach the destruct limits (unit is damaged). The test is of short duration (couple days) and is intended to simulate life expectancy. This can be shown using mathematical analysis with the Arrhenius equation among others. In the process of finding upper and lower operational and destruct limits and pushing them to ... ... a very robust product ... will be generated. ... The product is made better, but how much better is not known, at least not by the MALT methods. However, when results of the MTBF based on field failure rates (the only meaningful MTBF) become known, it will probably be far higher than ever... - (quoted from p. 72 of the book) There has also been a high degree of correlation experimentally. The failures seen in HALT are usually what you see in the field. The idea is to find the weak points in your product, remedy them, such as using a higher rated part, then re-test to find the new limits. The goal is to add lots of margin concerning the reliability of your product. These tests must be done in specially designed chambers (called HALT chambers by most). They start around $130K. If you don't have the money to buy one there several labs that will gladly do the tests. One such lab is Qualmark. Others are popping up all the time. HASS. Highly accelerated Stress Screening. This is a production test designed to find manufacturing defects, engineering changes, etc., that may affect the reliability of the product. You need some kind of environmental or HALT chamber, or you can send all your units to a lab, but that gets expensive real fast. The test is similar to HALT but you don't go to the destruct limits, just high enough to stress the unit and find defects. The limits are usually established during HALT testing Many books are available on the above subject, most notably Accelerated Reliability Engineering. HALT Hass by Greg K. Hobbs distributed by Wiley. Good Luck Darrell Locke Advanced Input Devices -Original Message- From: Dave Wilson [mailto:dwil...@alidian.com] Sent: Friday, September 08, 2000 10:34 AM To: 'emc-p...@ieee.org'; 'n...@world.std.com' Subject: HALT/HASS Testing We make a Metro DWDM product (all fiber) and one of our potential customers mentioned HALT/HASS environmental testing. Has anyone else had to go through this for similar products? Thanks, Dave Wilson Alidian Networks Inc. Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
What safety lesson we may learn from Concord crash?
Hi, What safety lesson we may learn from Concord crash? When having read recent reports on Concord crash the question occurred. - http://www.washingtonpost.com/wp-dyn/articles/A2191-2000Jul29.html reads A preliminary report on Tuesday's crash is due to be published at the end of August, but just three days after the tragedy, a sketchy image of the sequence of events has surfaced. At least one tire exploded, which could have triggered a chain of events, structural damages, a fire and an engine breakdown, the Transport Ministry said Friday. .. In 1981, the U.S. National Transportation Safety Board reported five potentially catastrophic incidents resulting from blown-out tires during Concorde takeoffs between June 1979 and February 1981. -- There are lot of Safety standards in Electronic and Electrical industries. If we strictly follow them we can avoid fatal accidents. Is there any previous example showing that accident still happens although all relevant Safety regulations have been followed and maintained, and then resulting in revision of some safety standard? It looks weird if the maintenance was not required to exclude possibility of tire blown-out, due to what the above article said: FIVE 'potentially catastrophic' incidents resulting from blown-out tires during Concorde takeoffs between June 1979 and February 1981. I have no knowledge of aviation safety aall. It was really sad to the world that the potentially catastrophic danger finally became a real catastrophe. Do we really have to pay so high price to learn the lesson? Barry Ma ANRITSU company ___ Free Unlimited Internet Access! Try it now! http://www.zdnet.com/downloads/altavista/index.html ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
PDF file copy method
Hi, When reading an EMC article in PDF file, I sometimes want to copy a couple of sentences or paragraph to my MS WORD document. Most of times I failed. But a few times I could do it. I don't know why. Do you have the same experience? ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Internet port in test equipment
Hi, Eric Lifsey explains to me in a separate Email today: On page 11 (of EN61326), at the top, the first paragraph seems to be clear about the exception for I/O ports that employ shielded cables. It overrides any discussion of shielded cables in -4-6. Please allow me to quote the paragraph of EN61326 here: For I/O circuits where the manufacturer specifies that shielded cables must be used... the conducted immunity requirements can be omitted within the frequency range 150 KHz to 80 MHz. This is a convincing argument. Therefore EN61326 exempts 1000-4-6 from I/O ports with shielded cables. Thanks Eric. Regards, Barry Ma ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Internet port in test equipment
Hi Eric, Thanks for reminding us of checking Safety issues of Ethernet port. I have a few questions about the Ethernet port: 1. A phone line port has to comply with related regulations in Telecom world. In my recollection, PC industry just added an Immunity requirement to the phone line port. (It is included in EN55024?) But Ethernet can be converted to phone line through an adapter. Is there a similar immunity requirement for the Ethernet port in test equipment? If not, should it be added to EN61326? 2. You are right when saying, shielded network cable will at least direct a significant portion the surge or transient energy to the ground system. But I dont think we are allowed to waive EN61000-4-6 for ports with shielded cable. (We can waive I/O ports with less than 3 meter cable.) The purpose of test method defined in EN61000-4-6 is to induce common-mode RF current flowing through the EUT. The EUT does not have direct grounding points in the test. As a matter of fact, EN61000-4-6 specifies how to test shielded cable. Please refer to Fig. 8b Definition of a common-mode point with screened cables. Regards, Barry Ma On Thu, 13 July 2000, eric.lif...@ni.com wrote: Barry et al, Certainly, we're adding more Ethernet based data acquisition and control products all the time. The applicable EMC standard is still the relatively new product family standard EN 61326-1, with it's counterpart for safety EN 61010-1. The Ethernet port has overvoltage features that should be checked (creapage, clearance, dielectric strength) that I suspect many folks neglect to do. We call for the use of shielded CAT 5 cable for our latest products being tested to EN 61326-1. A desktop computer is not too painful to replace after a damaging surge event enters the enclosure on unshielded cable, an instrument like yours/ours at many times the cost (plus the loss of it's use) is another matter. The hope is that shielded network cable will at least direct a significant portion the surge or transient energy to the ground system; or maybe to a less costly device elsewhere (like the local network hub). And, a hard benefit to ignore is that in EN 61326-1 the 61000-4-6 RF test is waived for I/O ports if you specify to the customer the use of shielded cable. So shielded cable also saves us a lot of test time. (I wonder if this tidbit will provoke another thread denouncing EN 61326-1? Poor EN 55024 guys.) By the way, I think the brain chip has a standard now, they call it BlueSkull :) Best Regards, Eric Lifsey National Instruments Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Implanted IC in brain
Hi, It seems not a pure friction to implant intelligent IC into human brains. Some people made prediction about this new breed of human being. Some are talking about downloading certain virtual sense from Internet. ... Lets put aside the feasibility and focus only on related EMC/Safety concerns. 1. If there going to be a wireless access from human brain to Internet, do we have the same Safety concern as cellular phone? 2. It would also be possible to directly communicate each other via brain ICs. We dont have to exchange thoughts by means of any language (spoken and written) or eye contact. ... Should we have EMC standards to regulate the emission level of brain waves and immunity capability for brain ICs? Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Internet port in test equipment
Hi, I just read an article: Oscilloscopes plug into the Internet - A new breed of scopes adopts an information anywhere approach with open access to applications, interfaces, and network communications http://electronicproducts.com/ShowPage.asp?SECTION=3700PRIMID=FileName=JULTEK1.jul2000 I have a question. It's possible to see more and more test instruments having Internet access. Do we have relevent EMC standard regulating the network connecting port in the test instrument? Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Radiated Immunity
John, You may also try a magnetic (or electric) sniffer probe by using it in an opposite direction. Conventional way using the sniffer is to connect it to a preamplifier and an oscilloscope. The sniffer serves as a receiving antenna. ... The opposite way is to connect it to a signal generator - (caution about the power level), and make it a transmitting antenna. You may pinpoint this small antenna to any suspicious part on the circuit board to see if it brings about the system immunity problem. Regards, Barry Ma Anritsu Co. On Wed, 12 July 2000, Eric Petitpierre wrote: John, Maybe an ESD generator could help you find the problem. Playing with the risetimes may get you an E-field in the 300-320 Mhz range.. Good luck! Eric Petitpierre Pulsecom Herndon,VA eric.petitpie...@pulse.com __ Reply Separator _ Subject: Radiated Immunity Author: jjuh...@fiberoptions.com (John Juhasz) at smtp Date:7/12/00 11:23 AM Having a Radiated Immunity problem (300-320MHz - 3V/M ) that I need to troubleshoot . . . I don't have a screen room to work in . . . I want to troubleshoot down to the circuit or component level . . . is there any type of 'probe' that can be used instead of creating a full-field in a chamber? Any ideas . . . ? Haven't had a problem like this yet . . . John Juhasz Fiber Options Bohemia, NY 631-419-2324 ___ $1 million in prizes! 20 daily instant winners. AltaVista Rewards: Click here to win! http://shopping.altavista.com/e.sdc?e=3 ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Site Attenuation Measurement / Antenna Factors
Hi, Please allow me to take the liberty of fwding this note in another discussion forum. Michael was talking about OATS validation using networm analyzer. -barry ma - From: Michael Foegelle [mailto:michael.foege...@emctest.com] Sent: Friday, June 16, 2000 9:15 AM To: Tim Harrington (AEI); Kefeng Liu Cc: 'patentlaw...@ieee.org' Subject: RE: Site Attenuation Measurement / Antenna Factors Gentlemen: Unfortunately Clifford's response cut off Doug's e-mail address, so hopefully you can forward this or post it to the discussion group. Here at ETS we've used vector network analyzers for antenna calibration and site validation for the past five years. They provide results that are far superior to that possible from a spectrum analyzer/tracking generator configuration due to the excellent dynamic range, linearity, and external signal rejection. If you perform a full two-port calibration, you can also eliminate the necessity of pads since the calibration can correct for mismatch. However, there is one significant limitation and a couple of pitfalls to be aware of. Clifford is quite correct that the first issue is the height scan requirement and the lack of max-hold functionality on network analyzers. I've tried to get HP (Agilent) and others to listen and convince them that there is an untapped market here if they'd just add max-hold to their firmware, but so far I've been unsuccessful. Thus, the only way to use the network analyzer is to perform the max-hold from test automation on the PC. In order to do broadband scans with a large number of points, this also requires height stepping of the tower, since the sweep time becomes too slow to maximize on the fly. An additional danger to be aware of is a limitation (I consider it a defect) in the popular HP line of analyzers (HP 8753, 8720, etc.). If the cable length is too long, the path delay becomes longer than the step period, thus the transmitted signal does not reach the tuner before it steps to the next frequency. Thus, the tuner is not centered on the received signal. In minor cases, this results in a 10 dB error or so, but the inexperienced user is not likely to realize where the problem comes from or even that there is a problem. (Worst case, the receiver sees the noise floor because it's stepped so far that the received signal is outside the bandwidth of the receiver.) For broad span measurements, this will typically be indicated by falling steps in the signal as you sweep to higher frequencies. For narrow span measurements, you'll never notice the effect, since the receiver bandwidth will typically still cover the incoming signal, but it will be recorded at a different frequency point on the display. The result would be that a resonance would appear to be at different frequencies depending on the bandwidth, frequency span, and number of points. The only solution is to forcibly slow the sweep speed (typically by narrowing down to 10-30 Hz bandwidth) which greatly increases the test time. We've pointed this problem out to HP, but they do not seem to be interested in fixing it. We've tested the newest analyzers from Anritsu/Wiltron and they do not seem to suffer from the same problem. I've been told that the new Rhode Schwarz units do not either, but I haven't had the opportunity to test one yet. As far as ANSI testing, the next revision of C63.5 will contain more generalized wording that make it clear that network analyzers and automated measurements are acceptable for performing the calibrations specified in the standard. After all, a network analyzer is really just a high quality signal generator and receiver with a few additional features over a spectrum analyzer/tracking generator combination. It's just that in their current incarnation, none of them have the max-hold automation built in. All-in-all, vector network analyzers are great pieces of equipment to have around, and if you have one that's going unused, I suggest you take a look at it. Chances are, you've only scratched the surface of its potential! (Ok, so I got my Ph.D. using an 8753B! It allowed us to perform measurements and see things that had never been seen before, so I'm definitely a fan! =) Sincerely, Dr. Michael D. Foegelle --- Dr. Michael D. Foegelle | 2205 Kramer Lane Senior Principal Design Engineer | Austin TX, 78758 EMC Test Systems, L.P. |(512) 835-4684 x650 ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe
Re: 61000-4-8 Ground Plane
On Fri, 16 June 2000, rehel...@mmm.com wrote: Can someone explain to me why a ground plane is required in the test setup for EN 61000-4-8 (power frequency magnetic fields)? Thanks, Bob Heller 3M Company --- Bob, Good question! The ground plane is described in the EN 61000-4-8 standard, but not used in many EMC testing labs. People cannot figure out the difference if using it in real test. However, there must be a reason to use it when the standard was written. Thanks. Best Regards, Barry Mab...@anritsu.com ANRITSUwww.anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 x 4465 ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EMC Symposia CD of 1955 to 1995
Jim and David, Yes! the re-setup works. Thank you very much. Barry -- On Wed, 07 June 2000, david_ster...@ademco.com wrote: We were unable to print after upgrading from Win95 to Win98. Changing printer options, changing pritners both were futile. A re-install solved the problem. David Sterner, ADEMCO __ Reply Separator _ Subject: RE: EMC Symposia CD of 1955 to 1995 Author: Knighten; Jim L SMTP:jk100...@exchange.sandiegoca.ncr.com at ADEMCONET Date:6/7/2000 1:10 PM Barry, I AM able to print papers from the EMC Symposia Records CDs 1955-1995 (40 years for $40), although it is a bit tricky. The program is a bit clunky by today's standards. I had difficulty printing the paper and not all the abstracts recovered in a query. It took reading the instructions that came with the CD set to print the paper, itself. Perhaps you need to re-install the program on your computer? Jim Dr. Jim Knighten e-mail: jim.knigh...@ncr.com jim.knigh...@ncr.com Technical Consultant - Design NCR 17095 Via del Campo San Diego, CA 92127 http://www.ncr.com http://www.ncr.com Tel: 858-485-2537 Fax: 858-485-3788 -Original Message- From: Barry Ma [mailto:barry...@altavista.com] Sent: Wednesday, June 07, 2000 9:09 AM To: EMC-PSTC Subject: EMC Symposia CD of 1955 to 1995 Hi list members, I have difficulty to print EMC Symposia CD of 1955 to 1995 that I bought for $40. I have no problem to read them on my PC screen. But when following the instruction to print them from my PC, I can only get blank paper. Do you have the same problem? Thanks. Regards, Barry Ma m...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
EMC Symposia CD of 1955 to 1995
Hi list members, I have difficulty to print EMC Symposia CD of 1955 to 1995 that I bought for $40. I have no problem to read them on my PC screen. But when following the instruction to print them from my PC, I can only get blank paper. Do you have the same problem? Thanks. Regards, Barry Ma m...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Price comparison for EMC/Safety standards
Hi, Do we have any website for price comparison of EMC/Safety standards? If wanting to buy books, we may go some websites below for price comparison: http://www.evenbetter.com/books.html http://www.addall.com/AddBooks/Stores.html http://home.bestedeal.com/cgi-bin/book/book/book.cgi http://www.bestbookbuys.com/ Regards, Barry Ma b...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Fwd: Split Plane
Subject: RE: [SI-LIST] : Split Plane To: si-l...@silab.eng.sun.com From: Barry Ma barry...@altavista.com List-Post: emc-pstc@listserv.ieee.org Date: 24 May 2000 10:51:29 PDT Another reason, I guess, is that you are not confident to use pwr planes as signal return planes. You said: We pulled out all the stops to ensure every signal layer is referenced to a ground plane, rather than a power plane, which I understand should give better EMC performance. I'd like to say it again, it's OK to use pwr planes if you have enough interplane capacitance. Regards, Barry Ma b...@anritsu.com On Wed, 24 May 2000, Brad Crowell wrote: Christoph I agree with your suggestion and we did consider this but the additional cost was the overriding factor. Brad -Original Message- From: owner-si-l...@silab.eng.sun.com Sent: Wednesday, May 24, 2000 10:29 AM To: si-l...@silab.eng.sun.com Subject: RE: [SI-LIST] : Split Plane Brad, Did you think about doing this job using MicroVia technology? In this case you would be able to cover the top and bottom layer with ground, as the Fanout-Vias are in the pad. So the top and bottom ground plane will be real planes over the whole board! Then the stackup could look like this: GND Signal Signal 3.3V GND Signal Signal GND 5V Signal Signal GND Because of the MicroVias, you will be able to route much more effective, as they don't block other layers - perhaps you can even save one or two signal layers. If you are looking for good EMI performance, this would be a good idea. Christoph Hillen Utimaco Safeware AG Germany ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Fwd: [SI-LIST] : Announcement, new book
--- Start of forwarded message --- To: si-l...@silab.eng.sun.com Subject: [SI-LIST] : Announcement, new book From: Doug Brooks d...@eskimo.com List-Post: emc-pstc@listserv.ieee.org Date: Tue, 23 May 2000 16:18:43 -0700 UltraCAD has just published its new book Electrical Engineering for the Non-Degreed Engineer The book is specifically written for people in the PCB design, fabrication and assembly industry and covers the basics of EE up through impedance and RLC phase shifts. Although most of you on this list don't need a book like this, I believe you all work with people who COULD use it. It has already been adopted for class use in one of the Community Colleges in Texas. You can review the book and the table of contents on our web site, http://www.ultracad.com Thanks Doug Brooks . Doug Brooks' book Electrical Engineering for the Non-Degreed Engineer is now available. See our web site for details. . Doug Brooks, President d...@eskimo.com UltraCAD Design, Inc. http://www.ultracad.com --- End of forwarded message --- ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Charge moving from decoupling capacitors
George, I am impressed by your attitude to pursue the correctness, and glad to discuss with you further on How does a decoupling capacitor support an IC? Here is my two cents worth. The decap supplies necessary charge to the IC during Tr through a transmission line. As you mentioned before: The current is an impulse function, although the voltage waveform is a step function. This impulse function, actually a bell-like function on Tr, happens every time period T when the IC gate switches from low to high. The corresponding frequency spectrum contains lots of frequencies. There must be some frequencies making the transmission line a 1/4, 3/4, ... wavelength. It is hard for me to be convinced that currents of those frequencies cannot flow from the decap to the IC. ... Pleas correct me if misunderstood. Thanks. Regards, Barry Ma b...@anritsu.com On Mon, 22 May 2000, george_t...@dell.com wrote: Barry, I need to make a correction. I was rushing to lunch on Thursday, so I did not read over what I wrote. Here is the correction for the 2nd comment below: At 1/4 wavelength, the charges are 180 degrees out of phase, so they are working against the IC current draw. 1/8 wavelength (90 degrees out of phase) is what I consider to be acceptable. Regards, George Tang george_t...@dell.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Charge moving from decoupling capacitors
Ralph, Please be cautious about what you said below: the reason why most power buses on PCBs use several values of decoupling is to ensure that a wide range of frequencies are covered. Several V curves shown in the figure of impedance vs. frequency, which we are all familiar with, would easily convince us the above statement. But those V curves only show the absolute value of impedance around self-resonance frequency of various capacitors. If considering related phase relations, the total impedance of several values of decaps would become not as simple as we expected - having low impedance over wider frequecy range. You may refer to an article by Paul, C. R.: Effectiveness of multiple decoupling capacitors, IEEE EMC Vol. 34, p. 130, May 1992. In my practice of using SMA caps, only the largest value of capacitance available for given SMA size is selected, if I have a PCB with 10 mil or less plane spacing. Regards, Barry Ma b...@anritsu.com On Thu, 18 May 2000, Ralph Cameron wrote: As I read in an article related to bypassing for good decoupling ( in 1971) one can select from a number of EIA values and by cutting the lead lengths correctly ( e.g. from 1/2- less than 1/4 ) the series reonant frequency will drop by a considerable amount so - yes, the reason why most power buses on PCBs use several values of decoupling is to ensure that a wide range of requencies are covered. Perhaps, with surface mount caps, that is easier to predict because they are essentially leadless. I once cured a very severe case of an FM receiver responding to the 7th harmonic of a 14Mhz transmitter because an untuned mixer was used. Placing a 100pf cap with 1/4 leads right across the mixer IC completely cured the problem without degrading mixer sensitivity. Ralph Cameron EMC Consultant for Suppression of Consumer Electronics (After Sale) ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Charge moving from decoupling capacitors
George, Sorry, I forgot to repeat what I wrote to you 5/15/00: It is generally acknowledged that decaps and plane cap are complementary (supposing a 10 mil or less spacing between pwr and gnd planes). Decaps cover low end of frequency range, while the plane cap takes care of high frequencies. I wrote similar words to Steve wei...@atdial.net 5/17/00: If there's a 10 mil or less spacing between pwr and gnd planes, the plane cap is available. The plane cap and the decaps are complementary in whole frequency range. Plane cap takes care of high end, and decaps cover low portion. Then locations of decaps are not critical. And then decaps can be shared by other chips, according to the excellent research conducted by EMC lab at UMR. That's my fault omitting this prerequisite today. In a PCB with 10 mil or less plane spacing, the plane capacitance would work better at 400 MHz than any decaps. Please allow me to put some words about plane cap. Why do we - actually the EMC lab at UMR, insist on 10 mil or less? Three reasons: (1) Utilizable plane capacitor. (2) Low inductance when pwr/gnd serve as a transmission line. (3) Low mutual inductance between vias. I apologize for not phrasing properly. Thank you Best Regards, Barry --- On Thu, 18 May 2000, george_t...@dell.com wrote: Barry, Thanks for the comments. Here are my comments: Ok, you put caps at a certain distance away from the IC because you only want them to work at 100 MHz. But that distance turns out to be the 1/4 wave distance at 400 MHz, and you placed enough caps at the 1/4 wave distance to cause board resonance. Now what? Do you tell the caps not to work at 400 MHz because it's not their frequency? For your 2nd comment: I used the words loosely define for that reason. If you are interested in high frequency decoupling and instantaneous current, you really want to have all your charges moving in phase. At 1/4 wavelength, the charges are 90 degrees out of phase, so they will not do much for your instantaneous current. 1/8 wavelength is what I consider to be acceptable. You can certainly pick a different number. Regards, George Tang george_t...@dell.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Charge moving from decoupling capacitors
George, Thanks for your long input. I'd like to make some comments below. - On Wed, 17 May 2000, george_t...@dell.com wrote: Large parallel plates behave as transmission lines. A quarter wavelength transmission line with a short at the end has infinite impedance, so capacitors placed 1/4 wavelength away are bad. Thats why decaps work on low frequency portion. Lets set 100 MHz and below for decaps to cover. The wavelength at 100 MHz is 3 meters. A quarter of it is 75 cm. Its long enough to ordinary PCB size. (The cap is directly connected to pwr/gnd planes.) This means that we can loosely define the largest usable board area capacitance as 1/8 wavelength radius of copper surrounding the IC power pin. Charges stored on the planes further than 1/8 wavelength away are not very usable due to the time delay. At 500MHz in FR4, 1/8 wavelength is 1.5 inches. Is such a board capacitor good enough for your IC? George, I beg for differentials. How did you jump from capacitors placed 1/4 wavelength away are bad to the largest usable board area capacitance as 1/8 wavelength radius? Can I use the same token to infer from caps placed one wavelength away are good to the largest usable board area capacitance is within 1/2 wavelength radius? And so, and so on. Regards, Barry Ma b...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Charge moving from decoupling capacitors
Hi Yu, Lets begin with the excellent description written by Andrew Ingraham: The voltage sag propagates outward from the chip, consuming charge stored in the intrinsic capacitance of the planes bit by bit (not all of it at once!), and eventually reaching external capacitors which help hold up the voltage. When a chip gate opens, the V (and Q) sag on the metal plane propagates outward from the chip at circle front, consuming charges inside the circle. If the outgoing circle front meets a decap, charge would be moving from the decap to the chip. ... What if the circle does not reach any decap before the end of Tr? The gate has closed, no current loop can be formed. That is the scenario I was interested in. Now an electrical potential imbalance happens in a metallic plane. Charge on the plane would flow toward the circle for regaining eqi-potential. ... Regards, Barry Ma ANRITSU company Morgan Hill, CA 95037 - From: Yu Wang wangy...@yahoo.com, on 5/17/00 7:45 AM: Hi, Barry, I think we all do agree the 1st point you said. But on the 2nd point, I have another opinion. Say, you are right,When an electrical potential imbalance happens in a metallic plane, a current would flow on the plane for regaining the equi-potential. But we regard the metallic plane as a reference plane, then, theoretically, there is no an electrical potential imbalance happens in a metallic plane. In fact, we can never get a ideal reference plane(even the earth is not IDEAL). Based on this, I would say yes on your question Does it need EM field support from the dielectric?. Still but, the need of the support is usually slight if the electical size of the metallic plane is big enough. because we know the metallic plane is a equi-potential plane. regards, Yu Wang, Ph.D U.T. MD Anderson Cancer Center 1100 Holcombe Blvd., Box 217 Houston, TX, 77030 Tel:713-745-1671 ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Charge moving from decoupling capacitors
Steve, Thanks a lot for the very nice hierarchy description below. If there's a 10 mil or less spacing between pwr and gnd planes, the plane cap is available. The plane cap and the decaps are complementary in whole frequency range. Plane cap takes care of high end, and decaps cover low portion. Then the location of decaps are not critical. And then decaps can be shared by other chips, according to the excellent research conducted by EMC lab at UMR. Please allow me to modify a bit your description as follows. The capacitance inside the device supports the chip first, but usually not enough. Charge from the planes also supports the chip and replenishes the device capacitance, Decaps replenish the plane on low frequency portion, while plane cap responds itself on HF end, Bulk capacitors replenish decaps and plane cap, The voltage regulator replenishes the bulk capacitors. Please correct me. Thanks. Regards, Barry b...@anritsu.com - From: sweir wei...@atdial.net, on 5/11/00 9:28 PM: The capacitance inside the device supports the chip, Charge from the planes replenishes the device capacitance, HF capacitors on the board replenish the planes, Bulk capacitors replenish the HF capacitors, The voltage regulator replenishes the bulk capacitors. [edited by bm] ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Charge moving from decoupling capacitors
Hi Andrew, You said: It is just like an ordinary transmission line such as stripline. Please allow me to say something different. (1) When a signal propagates along a transmission line, we could observe a current loop from source to load through the transmission line. The signal velocity is the same as the speed of light in the dielectric. You are right. (2) When an electrical potential imbalance happens in a metallic plane, a current would flow on the plane for regaining the equi-potential. This current looks different from the signal current. There's no current loop here. Does it need EM field support from the dielectric? If not, should it have a different velocity? That is my point. I have no answer, and appreciate any input. Thanks. Bets Regards, Barry Ma b...@anritsu.com Barry Ma wrote: As the speed of digital signals gets faster and faster, people begin being concerned with the distance for electric charge to move on power and ground planes of multilayer PCB during the signal rise time from a decoupling capacitor (cap) to a chip it serves. I would like to raise two questions. (1) The charge is moving in a metalic plane, not inside the dielectric between pwr and gnd planes. Please let me know why you have to use the propagation velocity in the dielectric, instead of that in the metal. -- Ingraham, Andrew wrote: The charge may be moving in the metal, but the energy (which makes the charge keep moving) is primarily in the electro-magnetic field between the planes, in the dielectric. The charge won't move unless there is an E-M field to push it. It is just like an ordinary transmission line such as stripline. The propagation velocity of a trace is that of the dielectric, even though the charge moves only in the metal trace and planes. (Edited by BM) ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Charge moving from decoupling capacitors
Thanks a lot for your inputs. All responses to my second question are only concerned with the inductance due to long distance between chip and decap. Nobody seems to agree imposing another constrain to the distance. My question was Do we really have to limit the distance letting the charge have enough time to move from the cap to the chip during the rise time interval? I doubt it. But I really read an article implying this extra concern. George, you wrote: This is true if you have only DC current. For AC, you may have water in the pipe but no water out of the faucet if the faucet is switching out of phase from the water in the pipe. Thank you for reminding me of Frequency Domain analysis. Yes, I should have described and analyzed a transient problem (charge travel during Tr) in both TD and FD, and then correlate the results. Let me have a try this time: It is generally acknowledged that decaps and plane cap are complementary (supposing a 10 mil or less spacing between pwr and gnd planes). Decaps cover low end of frequency range, while the plane cap takes care of high frequencies. Thus the interplane cap would play more and more important role in high-speed PCB design, as the speed gets faster and faster. On the other hand, nobody objects closer distances from decaps to the chip, if possible. . When a chip drains necessary charges from pwr/gnd planes during Tr, decaps would supply charges to pwr and gnd planes on lower frequencies, while interplane cap can respond itself on higher frequencies. Best Regards, Barry Ma b...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Charge moving from decoupling capacitors
Hi, As the speed of digital signals gets faster and faster, people begin being concerned with the distance for electric charge to move on power and ground planes of multilayer PCB during the signal rise time from a decoupling capacitor (cap) to a chip it serves. I would like to raise two questions. (1) The charge is moving in a metalic plane, not inside the dielectric between pwr and gnd planes. Please let me know why you have to use the propagation velocity in the dielectric, instead of that in the metal. (2) The second question is regarding distance between the cap and the chip. Do we really have to limit the distance letting the charge have enough time to move from the cap to the chip during the rise time interval? I doubt it. Take the running water system for example. When we open, then close the water faucet within one second, does the water we've got in basin come from water tower (or water station, or reservoir)? No, it is the water that resides in the pipe. As a matter of fact, we have a very large pipe - pwr/gnd planes. Well, of cause you know, I did not mean we don't need water tower - the cap. .. Regards, Barry Ma b...@anritsu.com Morgan Hill, CA 95037 Tel. 408-778-2000 ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Chip noise halts Intel 820 motherboard
http://dailynews.yahoo.com/h/zd/2510/tc/chip_noise_halts_intel_820_production_1.html INTEL will replace motherboards using its 820 chip set due to noise caused by simultaneous switching of signals. Can anybody be more specific or just make a speculation by using EMC language? Another question is irrelevant to EMC. I am wondering why it took so long - five months from field failure report to recreating the problem inside INTEL? See quotation below: First noted in November Intel began shipping the MTH last November. The problem was brought to light by an Intel customer who observed the problem Intel followed up on the report and observed the problem in its own tests earlier this month. Barry Ma b...@anritsu.com ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: origin of common-mode currents
Ken, I was impressed by a paper: Common mode current induced on wires attached to multilayer printed wire boards with segmented ground planes, by EMC lab of Univ. of Missouri-Rolla, pp. 116-120, 1994 IEEE EMC Symposium. That was the first article, to my knowledge, for EMC design community to investigate the correlation between CM current on attached cables and PCB layout design both theoretically and experimentally. It deserves being called a milestone, although some EMC design engineers had kind of feelings before the article and the theoretical calculation used by EMC lab of UMR at that time was a rough approximation. Once common mode voltage is established in either ground or power planes, the RF potential would find efficient way to radiate RF energy toward outside space. That is another type of RF loop for CM current to implement its mission :-). Attached cables are good wire antennas. Any traces connected to gnd/pwr planes of the PCB could also become antennas. Barry Ma b...@anritsu.com - On Wed, 03 May 2000, Ken Javor wrote: Lots of books cover this. Clayton Paul comes to mind for signal cable cm CE, and Mark Nave for power-line cm CE. Cable cm CE: Usually dm ground bounce on a PCB converting to a cm potential driving cm currents onto I/O port connected cables. Fixes are better PCB layout, proper grounding/isolation of I/O port. Power-line CM CE: Parasitic capacity developed either from switching transistor to chassis ground and/or across switching transformer primary to secondary. Allows current to be driven into ground. Fixes include reducing the cm capacitance, and filtering: Y-caps to force currents to circulate within EUT, and a cm choke to make Y-caps look like a more attractive path to ground than through the LISN. ___ Why pay when you don't have to? Get AltaVista Free Internet Access now! http://jump.altavista.com/freeaccess4.go ___ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Waste Directive/Lab Equipment
On Wed, 05 April 2000, Barry Ma wrote: A defending opinion to WEEE: http://www.fi.ruu.nl/~wim/schonberg/buda96/msg00093.html An opponent opinion against WEEE: http://www.nema.org/papers/letter.html Barry Ma b...@anritsu.com On Wed, 05 April 2000, marti...@pebio.com wrote: Richard, You can get a copy of the second draft, I think a third draft is almost complete, at the following location www.svtc.org/cleancc/weeedir.htm. Regards Joe Martin For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Waste Directive/Lab Equipment
A different opinion to WEEE: http://www.nema.org/papers/letter.html Barr Ma b...@anritsu.com On Wed, 05 April 2000, marti...@pebio.com wrote: Richard, You can get a copy of the second draft, I think a third draft is almost complete, at the following location www.svtc.org/cleancc/weeedir.htm. Regards Joe Martin -- wo...@sensormatic.com on 04/04/2000 10:19:42 AM To: Joe P Martin/FOS/PEC@PEC Subject: RE: Waste Directive/Lab Equipment Martin, can you supply with the URL for this document? Thanks. Richard Woods -- From: marti...@pebio.com [SMTP:marti...@pebio.com] Sent: Tuesday, April 04, 2000 11:54 AM To: emc-p...@ieee.org Subject: Waste Directive/Lab Equipment Annex 1A and 1B of the Second Draft of the Proposal for a Directive on Waste from Electrical and Electronic Equipment specifies categories and examples of equipment that is covered by the Directive. In the section for Medical Equipment Systems it specifies Laboratory equipment for in-vitro diagnostics, yet does not just specify Laboratory Equipment. Why are they so specific to spell out in-vitro diagnostics? Does this imply that they are not concerned about general laboratory equipment? Does anyone know their intent? All responses are appreciated. regards Joe Martin P.E. Biosystems marti...@pebio.com For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Cell Phone Hazard - follow up
Hi Edward, Thanks for the info. I just visited the website you listed below. The article reads: Which? tested two hands-free sets, from Carphone Warehouse and BT Cellnet. The results were startling: these sets acted as aerials, channelling three times as much radiation from the phones into users' heads. Hands-free kits can be convenient to use, but Which? says that consumers cannot rely on them to reduce health risks. Here is my two cents worth: Do you know what part brought three times as much radiation from the phones into users' heads? It might be the audio cable from the cell phone to users' ears. IF that is the reason the test results of Which? should be forwarded to Carphone Warehouse and BT Cellnet (two manufacturers). And Which? may ask EMC engineers of these two companies to improve their EMC designs. - Say, they did not carefully layout the PCB inside cell phone and let the RF energy leak to audio cable. Best Regards, Barry Ma b...@anritsu.com -- On Wed, 05 April 2000, Edward Fitzgerald wrote: Further to the thread on Cell Phone Hazards and Electromagnetic Field Radiation in February, the UK Consumer Association Which? caused a stir this week by claiming it has tested two hands free kits for Mobile phones and found that they actually increased the radiation levels by three fold The following link takes you to their Press Release on the subject: http://www.which.net/whatsnew/pr/apr00/general/handsfree.html [clipped by bm]... For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Mars Lander EMC problem?
Lou, IMHO, the poor management problem does not only belong to NASA, also to the senate committee. The committee should help NASA improve their Verification and Qualification procedure. Not long ago NASA had a failed mission due to a design mistake omitting transition unit for propelling force in Pound to Kilogram. Pretty soon they had the second failed mission. This time it is because The software ... was not properly implemented (see the NASA report below). Are all these overlook mistakes are forgivable to taxpayers? Barry Ma b...@anritsu.com -- Original Text -- From: Lou Gnecco l...@tempest-inc.com, on 3/30/00 2:20 PM: Sen. McCain is on the committee that oversees NASA. He recently said that the basic problem is poor management. IMHOP he's right. lou -- Scott Lacey Below is an excerpt from the complete NASA report. Premature shutdown of descent engines. PLAUSIBLE. A magnetic sensor is provided in each of the three landing legs to sense touchdown when the lander contacts the surface, initiating the shutdown of the descent engines. Data from MPL engineering development unit deployment tests, MPL flight unit deployment tests, and Mars 2001 deployment tests showed that a spurious touchdown indication occurs in the Hall Effect touchdown sensor during landing leg deployment (while the lander is connected to the parachute). The software logic accepts this transient signal as a valid touchdown event if it persists for two consecutive readings of the sensor. The tests showed that most of the transient signals at leg deployment are indeed long enough to be accepted as valid events, therefore, it is almost a certainty that at least one of the three would have generated a spurious touchdown indication that the software accepted as valid. The software - intended to ignore touchdown indications prior to the enabling of the touchdown sensi! ! ng logic - was not properly implemented, and the spurious touchdown indication was retained. The touchdown sensing logic is enabled at 40 meters altitude, and the software would have issued a descent engine thrust termination at this time in response to a (spurious) touchdown indication. MOST PROBABLE CAUSE OF LOSS OF MISSION For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Fwd: Re: modest proposal
Sorry for bothering those who are not interested in. Rene, Please forgive me Fwding your email to the group. Barry Ma --- Start of forwarded message --- Subject: Re: modest proposal - unl at unu.edu To: Barry Ma barry...@altavista.com From: r...@twn.tuv.com List-Post: emc-pstc@listserv.ieee.org Date: Wed, 29 Mar 2000 08:04:29 +0800 There is already a project running that will address item 1) of the mail shown below: http://www.unl.ias.unu.edu/ As the central concept of this project seems to be about grammar, it will probably not be able to fulfil the requirement of item 2) of the mail shown below. Learning vocabulary is learning facts, that might be done during sleeping (with a tape-machine running under the pillow). Grammar in my opinion is more a concept, a thing of logic. For learning grammar you probably have to be awake. Regards Rene Charton -- Barry Ma barry...@altavista.com on 03/28/2000 08:07:25 AM To: emc-p...@ieee.org cc: Lou Gnecco l...@tempest-inc.com (bcc: Rene Charton/TUV-Twn) Subject: Re: modest proposal Hi Lou, There must be some day in the future, the artificial intelligence has been so well developed that (1) An instant interpreting machine built-in to your PC would automatically transfer any language you input (either typed or voiced) to any languages the other party would like to have. (2) Learning foreign language is a very pleasant process and can be completed in very short period of time even when you are in sleep. ... :-) Best Regards, Barry Ma b...@anritsu.com --- End of forwarded message --- For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN61326-1 Harmonics
Chris, I am impressed by your gentleman discussion manner. We all agree that the committee of EN 61326-1 has very solid reason to exclude 3-2 3-3 for Class A equipment. If we had had the vote right we might have done the same thing. Unfortunately 3-2 3-3 became Product Standards with very broad definition. The rumor I heard is that these two standards were originally drafted as Basic Standards. ... (There must be some esteemed members in the EMC-PSTC group able to tell us what really happened.) If I have a piece of Class A lab equipment (referenced to EN 61326-1) with current 16A, I would rather test it for 3-2 3-3. Because I want to be prudent and conservative for the best interest of my company, the same attitude as you said: I don't want cause my company to be seduced by the dark side of non-compliance. Thank you very much. Best Regards, Barry Ma b...@anritsu.com --- On Tue, 28 March 2000, Maxwell, Chris wrote: Barry, You have a great point. It doesn't just apply to Information Technology Equipment. I apologize for using the term ITE loosely. I feel (don't know) that the lowering of the current limit from 16A per phase (one of the main differences between IEC 555-2, 3 and IEC 1000-3-2,3) was aimed at the proliferation of ITE and consumer products. Someone at IEC realized that there could be a cumulative effect of harmonic currents. However, the scope of the standards is very broad. It can be interpreted to include anything that uses an electron :-) I felt that the commitee that wrote EN 61326-1 actually looked at the difference between Class A and Class B equipment within EN 61326-1 and consciously left the harmonics and flicker limits out of the Class A requirements. This was confirmed by Norm Provost's reply to the thread. He participated in the writing and development of the standard. I think that you have a valid point in that EN 61326-1 treated EN 61000-3-2 and 61000-3-3 as Basic Standards as opposed to Product Standards. I never considered that point of view before your email. But I want to know more. Now that I have conceded that I used ITE incorrectly, could I get an explanation of what makes IEC 1000-3-2 and IEC 1000-3-3 a Product Standard as opposed to a Basic Standard? Thanks, Chris Maxwell, Design Engineer GN Nettest Optical Division 109 N. Genesee St. Utica, NY 13502 PH: 315-797-4449 FAX: 315-797-8024 EMAIL: chr...@gnlp.com -Original Message- From:Barry Ma [SMTP:barry...@altavista.com] Sent:Tuesday, March 28, 2000 12:40 PM To:chr...@gnlp.com Cc:bkundew...@qtm.net; nprov...@foxboro.com; emc-p...@ieee.org Subject:RE: EN61326-1 Harmonics Hi Chris, Would you please prove that two product family standards 3-2 and 3-3 are only applicable to ITE? Thanks. Barry Ma b...@anritsu.com For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: modest proposal
Ed, Thanks. Here is my basic $0.02. Most of time spent learning a foreign language is to remember vocabulary. This is not a creative job. The most precious resource - our brain should be gradually released from downloading burden. Barry Ma b...@anritsu.com -- On Tue, 28 March 2000, Price, Ed wrote: Barry: I've heard that your success rate depends entirely on the quality of the dictionary that you take to bed with you. Ahem grin Ed For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN61326-1 Harmonics
Hi Chris, Would you please prove that two product family standards 3-2 and 3-3 are only applicable to ITE? Thanks. Barry Ma b...@anritsu.com -- On Tue, 28 March 2000, Maxwell, Chris wrote: . My understanding of the scope of EN 61000-3-2 and EN 61000-3-3 is that it is targeting Information Technology Equipment (ITE). Much of the equipment under EN 61326-1 is not ITE. . For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: modest proposal
Hi Lou, There must be some day in the future, the artificial intelligence has been so well developed that (1) An instant interpreting machine built-in to your PC would automatically transfer any language you input (either typed or voiced) to any languages the other party would like to have. (2) Learning foreign language is a very pleasant process and can be completed in very short period of time even when you are in sleep. ... :-) Best Regards, Barry Ma b...@anritsu.com For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Questions about EN61000-4-6
Hi Group, Here are some of my questions and thoughts about EN61000-4-6. Any corrections and comments are greatly appreciated. In discussion of Wisdom behind all these standards, Richard Nute summarized three points raised by Martin Rowe. One of them is reasonableness or appropriateness of the standard. Please allow me to have better understanding of reasonableness or appropriateness of the EN61000-4-6. Both EN61000-4-3 (4-3 in short below) and EN61000-4-6 (4-6) verify the immunity of EUT against induced disturbances caused by incident electromagnetic fields from 150 KHz to 1 GHz. The chamber test approach used in 4-3 is not suitable at lower frequencies (150 KHz to 80 MHz), - not in principle only technically. That's why we need to perform 4-6 differently from 4-3. The methodology of 4-6 is to inject conducted disturbance to cables connected to the EUT by using direct injection or clamp coupling. The injected cable currents are supposed to be the same as induced by incident electromagnetic fields in real world. The methodology of 4-6 also implies that at low frequencies the possible disturbance directly coupled into the EUT from incident electromagnetic fields can be ignored in comparison with the disturbance indirectly coupled to the EUT via attached cables. For many well-shielded EUT that assumption works because it is difficult for low frequency electromagnetic fields to directly get into the EUT through apertures (such as slots, seams, and holes), whose dimensions are small compared to wavelength. But what if the EUT has larger openings or only plastic enclosure? Let's see an extreme example. A component cannot work properly under the illumination of 2.5 V/m incident field at 50 MHz The component would feel 2.5 V/m field when installed if the EUT is illuminated by 3 V/m incident field. But the component could work OK if injecting cable current of 3V into the EUT. The boundary 80 MHz between 4-3 (80 to 1000 MHz) and 4-6 (0.15 to 80 MHz) is not always fixed. It may be adjusted depending on different scenario. That principle is mentioned only in principle. I would like to see a real example to adjust the boundary between 4-3 and 4-6. Does it make more sense to setup a transition region, say 50 to 100 MHz, for both 4-3 and 4-6 to overlap? For the same EUT the test level of 4-3 is 3V/m, and the test level of 4-6 is 3V (80% AM @ 1KHz). Is there any explanation or verification available to show the equivalence (even roughly) between these two levels in interferences with the EUT at boundary frequency? In real world all attached cables would have induced currents at the same time if an incident field illuminates upon the EUT. In 4-6 test procedure, however, all cables are injected one by one in turn. On the other hand, in Radiated Emission test we have to manipulate the placement of all attached cable to maximize the resultant emission from all cables. Is it fair? I mean there seems to be a double standard for Radiated Emission and Conducted Immunity. Best Regards, Barry Ma b...@anritsu.com For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: The wisdom behind all these standrads
Hi Martin and Richard, The world consists of ordinary people and lawmakers. As ordinary people we must comply with laws, and respect the wisdom behind laws. On the other hand, ordinary people also have some ways to express their views on the current laws in modern democratic society. All lawmaker should respect public opinions as well. In EMC/Safety world, compliance engineers are ordinary people, and committees are lawmakers. Can we find some way to improve the communication between lawmakers and ordinary people? I think the EMC-PSTC forum is a good place for lawmakers to listen to public opinions and explain their intentions. Best Regards, Barry Ma b...@anritsu.com -- On Fri, 24 March 2000, Rich Nute wrote: Hi Martin: There are three issues in your message: 1) compliance to the standard; 2) reasonableness or appropriateness of the standard; 3) value added to the product through compliance. You point out that messages posted to this list address compliance to the standard, but not the other two issues. I believe the nature of the issues is such that we can effectively address compliance issues and resolve them but not the other two. A committee addresses the content of standards. Discussion of the value of the limits and of other content of a standard is only effective insofar as members of this listserver are also members of the committee. We have a few committee members as subscribers, but not all committee members are subscribers. So, a broad discussion of standards contents cannot be brought to a conclusion through the subscribers to this listserver. I have often commented on contents of safety standards, but such comments are not effective in changing the standards; to change a standard I must make a very specific input to the committee or to a member of a committee who agrees that the issue should be addressed by the committee. For political reasons, committee members are reluctant to share their views in a public forum such as this. The view may be mistaken as an official interpretation or position of the committee. Official outputs of standards committees are the minutes and the draft standards produced by the committees. For comments on those standards to be considered, the comments on those outputs must be through the official channels for such comments, not in a public forum such as this listserver. So, discussion of the appropriateness of the standard or its contents is largely ineffective in this forum. Its not that we don't have concerns regarding the contents and appropriateness of standards, its that this is not an effective place for such discussions. The same comments can be said for the value added to a product by virtue of compliance to the standard. We all have doubts as to some or all of the requirements being of value. But, expression of those doubts here will not be effective in implementing any change. Of course, the regulatory engineer's place is to question the appropriateness of a standard and its contents. And we do so. Some of us sit on the committees that draft and change the standards. But, we can't all sit on the committees; the committees would be huge and unwieldly. Whether or not safety and EMC standards make this world a better place is an interesting question. I think the EMC standards are effective in doing this. Emission and susceptibility limits establish compatibility that normal equipment operation is assured. I'm not sure safety standards are effective because we don't have a solid engineering basis for the safety standards. Instead, safety standards are based on inversion of bad experiences. This is not a good, systematic approach for predicting injury and providing safeguards -- which is what we SHOULD be doing in product safety. Best regards, Rich For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EN61326-1 Harmonics
Hi Brian, Here is my $0.02. (1) As far as EN61326-1 is concerned, Class A is not required to pass EN61000-3-2 and EN61000-3-3. Because EN61326 committee treated these two standards as basic standards. (2) However, they are not basic standards. They are product standards. If your product falls under their definition the product MUST comply with them no matter whether EN61326 calls for them. (3) Therefore, we found a conflict between 61326 and 61000-3-2/3 (although they are all listed in harmonized standards). How to solve the conflict? There might be two options. (A) Change 61326: Class A is also required to pass EN61000-3-2 and -3. (B) Change 61000-3-2/3: They are basic standards. (the same as 61000-4-X series). Best Regards, Barry Ma b...@anritsu.com -- On Fri, 24 March 2000, Provost,Norm wrote: The exclusion of harmonic test requirements in EN 61326 for equipment which need only meet Class A emission limits was a deliberate decision by the authors. It was not an omission by error. Many outside the committee now view this decision as a mistake. There is no revision in progress. Best Regards, Norm Provost -Original Message- From:Brian Kunde [SMTP:bkundew...@qtm.net] Sent:Friday, March 24, 2000 12:16 PM To:'IEEE EMC/PS Group' Subject:EMC: EN61326-1 Harmonics The EN 61326-1 family standard for laboratory equipment only lists Harmonic testing as a requirement for Class B environments. So Class A products are not required to pass the harmonics tests (flicker too). Is this going to continue as the rule in the future? Will this rule carry over to other family and generic standards? I had heard that omitting harmonic testing in a class A environment was a mistake and that it will be corrected on future versions of the standard. Can anyone validate or invalidate this statement. Thanks, Brian For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Antenna factors to be used for NSA measurement
Hi Paolo, I am interested in this topic, but don't have much available time to participate the discussion. You mentioned the far-field in item 3 of your message below. You might be interested in an article The Fer-Field: How Far is Far Enough? http://www.noblepub.com/archives2/1999/November1999/nov1999-p58.pdf That would support what you said: you can be in the near field even at 3+ meters distance. Thank you. Best Regards and nice weekend, Barry Ma b...@anritsu.com - On Fri, 17 March 2000, paolo.ronc...@compuprint.it wrote: 3. There are substantial difference in the antenna factors (and site attenuation) values at various range distances. I agree that it's always better to calibrate antennas at the test distance. On the other end, within the range of 3-10 m distance my experience with broadband antennas (biconicals and log-periodic) between 30 and 1000 MHz tells me that the error is well within 1 dB, as long as you are in the far-field at 3 m (which is the case most of the times using biconicals). I have not direct experience but my guess is that you may have non-negligible errors for distances 3m and/or highly directional antennas (horns freq. 1GHz), whereby you can be in the near field even at 3+ meters distance. For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: broad band EM noise
The broadband interference from corona and any other high-voltage related sources indicates the problem of power transmission. Those who detected and reported it deserve a reward from the power company for helping them reduce the cost. Barry Ma b...@anritsu.com -- From: wo...@sensormatic.com, on 3/10/00 8:14 AM: Corona on high voltage insulators is a known source of broadband interference. Poor connections can also be a problem. A good wash down of the insulators may temporarily cure or reduce the corona problem. We were able to locate bad connections near our OATS using a directional antenna near the power lines. A persistent complaint to the power company may give the desired results. Richard Woods For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: MIL-STD-285
On Thu, 09 March 2000, Westin, Amund wrote: There is a similar standard: IEEE Standard 299 Standard Method of Measuring the Effectiveness of the Electromagnetic Shielding Enclosures, Approved March 11, 1991 by IEEE Standard Board, Approved July 26, 1991 by American National Standards Institute (ANSI). Barry Ma b...@anritsu.com HI members, I have a copy of the military standard MIL-STD-285 Attenuation measurements for enclosures, electromagnetic shielding, for electronic test purposes, method of , on my desk. This standard was issue 25 June 1956. Has it been revised since '56 or is this still valid ? Best regards Amund Westin Det Norske Veritas (DNV) * amund.wes...@dnv.com For the largest MP3 index on the Web, go to http://mp3.altavista.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: EMC Circuit Board Design
Yes, what Earl Morse said is very important! Always keep in mind we have to carefully take care of BOTH signal trace and return path. If the reference plan is solid, the return path would automatically make it's way to form a least loop area with signal trace. (Why? least loop area - least inductance - least impedance in RF). Barry Ma Anritsu b...@anritsu.com --- On Fri, 21 January 2000, Morse, Earl wrote: The number one problem with PCB board routing that we encounter that can be attributed to the layout personnel is: Routing high speed signal traces without regard for return current paths. Either the signals are routed across splits in the reference plane or the signal switches layers and the new reference plane doesn't have a good path to the old plane. Both problems result in higher emissions and poor signal integrity. Earl Morse Portable Division EMC Design Compaq Computer Corporation Phone: 281.927.3607 Pager: 713.717.0824 Fax: 281.927.3654 Email: earl.mo...@compaq.com mailto:earl.mo...@compaq.com Emissions Control Laboratory 10320 Rodgers Road, EC106 Houston, TX 77070 -Original Message- From:rehel...@mmm.com [mailto:rehel...@mmm.com] Sent:Friday, January 21, 2000 6:48 AM To:emc-p...@majordomo.ieee.org Subject:EMC Circuit Board Design Dear List-Members, I am requesting information/opinions/etc. on the following: When circuit boards are designed, what are the common mistakes that the circuit board designers make regarding EMC (multi-layer boards in particular)? You can respond to me directly but I would prefer a response to the list as I believe that the question is of interest to many on this list-server. In either event I will compile the responses and resend the compilation later. Thanks for your time, Bob Heller 3M Company __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Harmonics Testing
Actually I had the same question as what Randy raised hear. I felt confused when trying to classify my EUT below 50W input power as Class A or Class D. Thanks for the clarification made by Gert. I was wondering why I could not have found the answer in Fig. 2 Flow-chart for classification of equipment in Page 10 of EN 61000-3-2. The current 3-2 is a very bad document,..., Gert Gremmen said. That is the most straitforward comment I've ever heard. Nobody is perfect. Can we extend it to No document is perfect.? But I still feel the law-making process in EMC world like something happened inside a much higher authority far far away from us. Is it possible to expedite the feedback process from ordinary EMC engineers? Barry Ma b...@anritsu.com On Tue, 18 January 2000, cetest wrote: I suppose Randy you are concerned about the EN-61000-3-2 instead of the EN 61000-3-3 which is concerned with Flicker testing. Please Note that the 3-2 is currently under revision and prone to change very soon ! I would select Scenario #1 The 50 watt limit is meant to be used for all equipment, and the current document TC210-169 (in voting right now) has it's clause modified as such. Strictly read you are right about the application of scenario #2. The current 3-2 is a very bad document, f.a. nothing is said about test times and transitory effects. This will all or partly be covered in the new version. BTW Using scenario #2 it will be hard to exceed any limit at all with an active input power 50 watt !!! Gert Gremmen ce-test qualified testing == http://www.cetest.nl Do you know our CE/E mark True type Font ? http://www.cetest.nl/cettf.htm == -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] Sent: Tuesday, January 18, 2000 7:12 PM To: 'emc-pstc' Subject: Harmonics Testing Greetings EMC Professionals! I have a quick question regarding Harmonics testing to EN61000-3-3. We have an ITE product with a switching power supply. The product uses about 38 watts input power. According to the standard, which scenario applies? Scenario #1 The unit does not need to be tested, because it falls below the Class D Input power range of 75(50)W to 600W. Section 7.4 of the standard states that ...No limits apply for equipment with an active input power up to and including 75W Scenario #2 Since the unit does not use more than 75W (or more than 50W for that matter), the unit then defaults to the Class A requirements and therefor must meet the less stringent Class A limits. Section 5 of EN61000-3-3 states: Class A: Balanced 3-phase equipment AND ALL OTHER EQUIPMENT, except that stated [in Classes B-D]... So I guess my question is this: when an ITE product with a switching power supply uses less than 50W (75w), does it become an exempt Class D Device, or doe sit become a Class A device? Your insights would be appreciated. Regards, Randy Flinders Chairman Orange County Chapter IEEE EMC Society r.flind...@ieee.org (714) 513-8012 (714) 513-8265 Fax Note: The opinions expressed herein are personal and in no way represent the position of the IEEE, The EMC Society, or my employer. __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Chamber and OATS Coorelation
Is it possible that the correction factors you got from RefRad* cannot give the same good results when measuring real EUT? In other words, different EUT would probably need different correction factors. I'm just curious. *RefRad is a comb generator produced by EMCo - a part of ETS now. Barry Ma --- On Wed, 12 January 2000, umbdenst...@sensormatic.com wrote: Barry, Thank you for your comment. What we are trying to do is establish better correlation between the chamber and OATS so we minimize our time in the heat, humidity, rain and bugs (South Florida) at the OATS. We are not trying to replace the OATS with the chamber. We have recently been evaluating a REFRAD for correlation purposes. So far the results with the REFRAD factors have been very good. The emission in the chamber was 7 dB off from the OATS value, but this correlated to within 1 dB of what was predicted by the REFRAD. I admit our sample universe is small at this time with only a handful of emissions to compare to. But these first results are promising. Don Umbdenstock Sensormatic -- From: Barry Ma[SMTP:barry...@altavista.com] Reply To: Barry Ma Sent: Tuesday, January 11, 2000 5:55 PM To: mmate...@foxboro.com Cc: emc-p...@majordomo.ieee.org Subject: RE: Chamber and OATS Coorelation Mirko, I happen to have a copy of CISPR 16-1 at hand. Clause 16.6 Open area site validation procedure reads: ... The deviation between a measured NSA value and the theoretical value shall not be used as a correction for a measured EUT field strength. This procedure shall be used only for validating a test site. ... The above statement is not followed by any explanation. What do you think the reason is? My guess is that there are lot of factors causing inaccurate E-field measurement. The collective result of those factors cannot be simply corrected by changing antenna factors. At the end of your message, however, you stressed on for a specific test setup. May we try this illegal correction procedure with caution only for a specific test setup and for a specific frequency range? Hopefully it might be worthwhile to try. Barry Ma Anritsu Company Morgan Hill, CA --- On Tue, 11 January 2000, Matejic, Mirko wrote: Richard, You could improve correlation by adjusting chamber antenna factors for a correlation differences which you can get from NSA measurements one at OATS the other in the chamber with a fixed antenna height. You could also determine correlation differences by comparing measured field strength levels from battery powered comb generator. Fixed vs. 1-4m antenna height among other factors will always create unpredictable correlation for a specific test setup. Mirko Matejic __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Tiger Tail for 27 MHz?
Yes, the coil inductance would reduce the antenna length. Also it would change the antenna impedance. To accommodate all related factors people usually use ferrite bar with two windings - the primary to the monopole antenna, and the secondary to an amplifier. Barry Ma Anrutsu Comany On Tue, 11 January 2000, Mike Hopkins wrote: That will work, but the electrical length of the tail will change due to the inductance of the coil you're winding... This method has been used to produce shorter antenna elements in the HF (3-30MHz) region with some success; however, shorter antenna elements generally also mean loss rather than gain.. Mike Hopkins -Original Message- From:Lacey,Scott [SMTP:sla...@foxboro.com] Sent:Tuesday, January 11, 2000 8:33 AM To:'emc-p...@ieee.org' Cc:'sla...@foxboro.com' Subject:Tiger Tail for 27 MHz? Fellow Listmembers, I have a question regarding tiger tails used to improve transmission characterisics of a hand-held transmitter (HHT). The HHT is basically a dipole, with the chassis as the bottom element. The tiger tail is a quarter-wave length of wire that connects to the shell of the coaxial connector and is allowed to hang downwards, effectively increasing the electrical length of the chassis. They are commonly used with higher frequency HHT's where a quarter wavelength is relatively short compared to a standing man. I want to fabricate one for use with a 27 MHz (CB) HHT. I need a length of wire more than nine feet long. My question is this: If I wind the nine feet of wire spirally around a length of polypropylene rope, will it still work properly? Also, should I use Litz wire? Thanks in advance for any help. Scott Lacey __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Chamber and OATS Coorelation
Mirko, I happen to have a copy of CISPR 16-1 at hand. Clause 16.6 Open area site validation procedure reads: ... The deviation between a measured NSA value and the theoretical value shall not be used as a correction for a measured EUT field strength. This procedure shall be used only for validating a test site. ... The above statement is not followed by any explanation. What do you think the reason is? My guess is that there are lot of factors causing inaccurate E-field measurement. The collective result of those factors cannot be simply corrected by changing antenna factors. At the end of your message, however, you stressed on for a specific test setup. May we try this illegal correction procedure with caution only for a specific test setup and for a specific frequency range? Hopefully it might be worthwhile to try. Barry Ma Anritsu Company Morgan Hill, CA --- On Tue, 11 January 2000, Matejic, Mirko wrote: Richard, You could improve correlation by adjusting chamber antenna factors for a correlation differences which you can get from NSA measurements one at OATS the other in the chamber with a fixed antenna height. You could also determine correlation differences by comparing measured field strength levels from battery powered comb generator. Fixed vs. 1-4m antenna height among other factors will always create unpredictable correlation for a specific test setup. Mirko Matejic __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Radiation levels
David, You may try http://n5xu.ae.utexas.edu/rfsafety/;. Barry Ma Anritsu Company Morgan Hill, CA - Original Message - From: David Monreal To: emc-p...@majordomo.ieee.org Sent: Tuesday, January 11, 2000 5:14 AM Subject: Radiation levels. Hi all! Could anyone tell me the radiation levels (V/m) generated by broadcast antennae? (Radio and TV). I also need the radiation levels for any other emitting devices, machinery, GSM antennae, etc. The more information the better. Thanks a lot :-) David - The V/m guy __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: EN 61326
Lisa, It is July first of 2001. 1/7/2001 is the UK way whereas 7/1/2001 the US way. Barry Happy New Millennium for everybody! On Tue, 04 January 2000, lisa_cef...@mksinst.com wrote: Could someone please clarify the dow for EN 61326? I've heard 1/7/2001 and 7/1/2001. Thank you. Happy New Year! Regards, Lisa __ Free Internet Access from AltaVista: Get it, share it win! http://freeaccess.altavista.com/pika/www/initweb.jsp - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Cell Phone Hazards?
Hi, Introduced by our local EMC chapter (SCVemc.org), I visited http://n5xu.ae.utexas.edu/rfsafety/ and surfed to FCC OET Bulletin 65 Evaluating Compliance with FCC Guidelines for Human Exposure to RF Electromagnetic Fields from there. Those who are concerned may go there. Barry Ma Anritsu __ Open your mind. Close your wallet. Free Internet Access from AltaVista. http://www.altavista.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
re: Article to UL
Chaz, Why do they call UL a non-profit organization? Barry Anritsu Co. From: Grasso, Charles (Chaz) gra...@louisville.stortek.com, on 11/24/99 1:23 PM: Forgive a jaded old man but two things jumped out at me when I read the article. 1. In many other countries, standards are set or approved by a government entity with industry involvement. U.S. safety standards, on the other hand, are set primarily by private industry - either in independent labs such as UL or by industry associations or organizations. The CPSC, an independent regulatory agency charged with protecting consumers from hazardous products, imposes federal regulations only when it believes industry's voluntary efforts are insufficient. Oh Boy. Lets see look like UL is ripe for a government takeover to me!! 2. Many experts interviewed contend that UL's recent problems can be traced to the way the company is organized and funded - with more than nine-tenths of its revenue coming from companies for testing products. UL also sets industry safety standards - which it then measures products against - but does not charge for that. Lets see - if we reorganize and - more importantly - change the funding (a euphemism for taxation) then we'll all be safer!! Sorry - Just could not resist.. __ Open your mind. Close your wallet. Free Internet Access from AltaVista. http://www.altavista.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
MIL-STD-202
Hi, Can anymoby let me know the detail of MLT-STD-202, method 103? Thanks in advance. Barry Ma __ Open your mind. Close your wallet. Free Internet Access from AltaVista. http://www.altavista.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
FW: re: Data acquisition for AST
Hi EMC-PSTC group, Some of Compliance Engineers in this group would be interested in Reliability tests. AST = Accelerated Stress Test. Barry --- From: Bailin Ma b...@anritsu.com, on 11/10/99 4:09 PM: Hi Harry, You said that STRIFE is HP's HALT. Actually there's a slight difference between HALT and STRIFE in my understanding. Please allow me to review three different limits before discussing the difference between HALT and STRIFE: (1) Specs limit, (2) Operating limit, and (3) Destruction limit. Let's take a printer for example. Assuming the operating temperature range of 0 to 50 C degree has been specified in your user's manual. But your printer still works well when raising the environment temperature from 50 all the way to 80 C degree. Then the printer couldn't work from 80 to 110 C degree. But it would go back to normal when reducing the environment temperature to the range of 0 to 50 C. After 110 C degree the printer would be permanently damaged and could not go back to normal any more. Now we may say that Specs limit = 50 C, Operating limit = 80 C, and Destruction limit = 110 C. In typical STRIFE, people test the printer over 50, then 80, and then usually stop somewhere between 80 to 110. In HALT, however, people won't stop until after 110. They have to know where both Operating limit and Destruction limit are. In conclusion, STRIFE is a subset of HALT. They are not the same thing Best Regards, Barry Ma Anritsu Company Morgan Hill, CA 95037 www.anritsu.com P.S. I usually heard of HASS (Highly Accelerated Stress Screening) and HALT (Highly Accelerated Life Test). Is HASA in your Email below the same as HASS, or you just misspelled it? -- Original Text -- From: McLean, Harry harry.mcl...@attws.com, on 11/9/99 1:47 PM: At HP, we used a dedicated test platform on Unix for driving our printers in HASA as well as in STRIFE (HP's HALT). This worked well but required that a dedicated (contract) programmer be allocated every time a new printer was designed. This was a very high volume environment and a new printer was developed about every three months. At ATT we use LabView as the test platform to access on board diags. This si VERY time consuming and at least two individuals are writing LV full time. The results are just as good as the HP results. Our volumes to date are moderate and should reach very high volume early in 2K. We average a HALT every three weeks. I have run a very large number of HALTs in which data acquisition was done manually. The results were just as good as the two cases above but this does require one to pay close attention and to be accurate in data reading and writing. As you can see all three methods work well it just depends on how you want to get there. I understand that QualMark is offering test development as a business to support HALT. You may want to contact Ann Marie (I've included her on the distribution list). Her phone is (303) 254-8800. -- From: Morelli, Mark[SMTP:mark.more...@otis.com] Sent: Tuesday, November 09, 1999 11:10 AM To:'accelerated-stress-test...@majordomo.ieee.org' Subject: Data acquisition for AST The Test Engineering organization at my company is attempting to improve the process used to specify the data acquisition equipment used in design AST such as HALT and temperature/humidity cycling tests. In the past we have primarily used in-house designed/built systems controlled by PCs using custom Visual Basic or Labview software programs and associated hardware depending on the type of signals being recorded. We are finding this approach, which requires significant human resources, can not keep with our test volume, which is about one new HALT and one temp/humidity test per week. I would like to explore all possible options including outsourcing the design/fab of data acquisition systems or performing some of the tests at outside labs. If the members of this e-mail group could suggest the approach that has worked best for you I would appreciate it. In addition, we may want to benchmark organizations to help in the improvement process. Thanks, Mark L. Morelli [mailto:mark.more...@otis.com] Sr. Reliability Engineer Otis Elevator Co. Farmington 860-676-6140 __ Open your mind. Close your wallet. Free Internet Access from AltaVista. http://www.altavista.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RFI Problems with Certified Computers
Hi Ladies/Gentlemen, I have been reading with interest the discussion articles on this subject. Since Mike Violette 04/15/96 presented his opinion on VCC/GND plane layout in multilayer board, the discussion seems to be focused on PCB EMC design. Max Kelson 04/16/96 wrote: [snip] What this ferrite/cap configuration would do is to force the oscillator to draw all transient current from the capacitor. Or, in otherwords, the rest of the caps on the board would be unable to help provide fast-transient current because of the ferrite. This would keep the current loop (power AND GROUND) small and prevent it from infecting the rest of the board. The path for the transient current surges would be from the capacitor to the IC's power pin, out the IC's ground pin and back to the negative side of the capacitor (a relatively small loop). [snip] It might be worthwhile to pay attention to research work done by professors at the Univ. of Missouri-Rolla. In the article Power Bus Decoupling on Multilayer Printed Circuit Board, IEEE Trans. on EMC, vol. 37, pp. 155-166, May 995, they wrote: [snip] VI. Conclusion. Unlike boards without internal power and ground planes, multilayer boards have a built-in capacitance that is a more effective source of current than surface decoupling capacitors at high frequencies. In the time-domain, this means that most of the initial current supplied to a fast switching device is provided by the interplane capacitance. [snip] Regards, Barry Ma
