Re: Radiated Immunity Testing
The biggest chamber effect in radiated immunity testing is reflections. The reflections off the walls, ceiling, and especially the floor in semi-anechoic chambers will add or subtract from the field generated via the direct path. The main effect is to make the 16 point uniform field calibration difficult or impossible, since the phase length of the reflection path changes with position, thus adding to or subtracting from the direct path power (reducing uniformity). Reflections have a big effect on the necessary forward power. When the reflections subtract from the field generated via the direct path, additional forward power is needed. Reflections back to the antenna do increase the VSWR. Increased VSWR is usually viewed as a loss of power being radiated by the antenna, since part of it is reflected back by the mismatch. In the case of an antenna in a chamber and the resulting increase in VSWR, power is still effectively radiated by the antenna, but part of the power is reflected back to the antenna by the chamber, and then back to the source. Generally, one wants the absorber to be as absorbant as possible so that the direct path is the only one delivering power to the DUT, simulating free space. Don Borowski Schweitzer Engineering Labs Pullman, WA richwo...@tycoint.com on 09/26/2002 09:34:41 AM Please respond to richwo...@tycoint.com To: emc-p...@majordomo.ieee.org cc:(bcc: Don Borowski/SEL) Subject: Radiated Immunity Testing What types of chamber effects, if any, should one consider when determining the extra factor to be applied to determine the forward power applied to the transmit antenna. Potential effects might include loading of the antenna by the anechoic materials or the chamber itself and resonance's. If there are such effects, what factor should be applied to these effects in order to determine the required forward power to the antenna? And before someone mentions the other factors to consider, I am aware of the need to account for VSWR and loss in the directional coupler and cable. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list This e-mail may contain SEL confidential information. The opinions expressed are not necessarily those of SEL. Any unauthorized disclosure, distribution or other use is prohibited. If you received this e-mail in error, please notify the sender, permanently delete it, and destroy any printout. Thank you. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Hot surfaces
Neil, easy UK source of safety labels www.rswww.com look under 'health and safety' 'vinyl labels on a roll' --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: FW: EMC Prosecution in UK
I read in !emc-pstc that Jim Eichner jim.eich...@xantrex.com wrote (in 67C475A5ECE7D4118AEC0002B325CAB603510EDA@BCMAIL1) about 'FW: EMC Prosecution in UK' on Thu, 26 Sep 2002: I read this article with some consternation, since in my mind it challenges not the manufacturer or importer, but the concept of Presumption of Conformity (I'll use PofC...). Quote: If the standard in question only covers some of the EM phenomena, or is limited in its scope, then full compliance cannot be guaranteed. The products thus failed the essential protection requirements and were incorrectly CE marked. I am in strong disagreement with that statement. If the standard in question only covers some of the EM phenomena, then the standard in question does NOT provide PofC and should NOT have been published in the OJ or on the Europa site as a harmonized standard under the EMC Directive. It is not the manufacturer's fault if the EU incorrectly publishes references in the OJ implying PofC where there are essential requirements not covered. In my mind, the CE Mark was correctly applied by the mfr, and the fault lies with EN55014 (which I have always thought is flawed) and with the EU/CEN Neither EU or CEN, but CENELEC, adopting CISPR 14. This is the umpteenth edition of CISPR 14 and, AFAIK, it's never been found inadequate before. for issuing a standard that fails to provide PofC. Am I right or am I delusional, naive, misinformed, an idealist, or all of the above?!?!? No, you are right, and I intend to expand on that point in my column in 'EMC and Compliance Journal'. At the very least, it seems to me that the EU has an obligation to provide more information. If a standard is listed as applicable to the EMC Directive and does not provide PofC, then the standard's preamble and the Europa listing should say so, and should point out which essential requirements are not addressed, and which standards should be used to cover the missing requirements. I am getting extremely tired of the let the mfr figure it out approach used by the EU. The obligation is the other way round, actually, on the member states, not the Commission. A national authority that doesn't think an EMC standard is adequate should take action under Article 8 of the Directive. There is a similar provision in the Low Voltage Directive, and the French government used it last year to block the notification of an EN in the Official Journal. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
FW: EMC Prosecution in UK
I read this article with some consternation, since in my mind it challenges not the manufacturer or importer, but the concept of Presumption of Conformity (I'll use PofC...). Quote: If the standard in question only covers some of the EM phenomena, or is limited in its scope, then full compliance cannot be guaranteed. The products thus failed the essential protection requirements and were incorrectly CE marked. I am in strong disagreement with that statement. If the standard in question only covers some of the EM phenomena, then the standard in question does NOT provide PofC and should NOT have been published in the OJ or on the Europa site as a harmonized standard under the EMC Directive. It is not the manufacturer's fault if the EU incorrectly publishes references in the OJ implying PofC where there are essential requirements not covered. In my mind, the CE Mark was correctly applied by the mfr, and the fault lies with EN55014 (which I have always thought is flawed) and with the EU/CEN for issuing a standard that fails to provide PofC. Am I right or am I delusional, naive, misinformed, an idealist, or all of the above?!?!? At the very least, it seems to me that the EU has an obligation to provide more information. If a standard is listed as applicable to the EMC Directive and does not provide PofC, then the standard's preamble and the Europa listing should say so, and should point out which essential requirements are not addressed, and which standards should be used to cover the missing requirements. I am getting extremely tired of the let the mfr figure it out approach used by the EU. Ok, I'll stop whining now. Jim Eichner, P.Eng. Regulatory Compliance Manager Xantrex Technology Inc. e-mail: jim.eich...@xantrex.com web: www.xantrex.com http://www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. No really. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -Original Message- From: Alan E Hutley [mailto:nutwoo...@nutwood.eu.com] Sent: Wednesday, September 25, 2002 11:43 PM To: Emc-Pstc Discussion Group Subject: EMC Prosecution in UK EMC Prosecution, the company mentioned in the report Hot UK Ltd is owned by Helen of Troy based in El Paso Texas. For full story go click below http://www.compliance-club.com/TS%20Prosecution.doc http://www.compliance-club.com/TS%20Prosecution.doc Alan E Hutley EMC Compliance Journal www.compliance-club.com http://www.compliance-club.com
Re: EMC Prosecution in UK
I read in !emc-pstc that Price, Ed ed.pr...@cubic.com wrote (in b78135310217d511907c0090273f5190d0b...@curly.ds.cubic.com) about 'EMC Prosecution in UK' on Thu, 26 Sep 2002: HOT was fined $9,000 by the British magistrates. Not the point: if reports are true, part of the prosecution case was ill-founded and if not challenged could result in very serious trouble for just ANY manufacturer at random. A challenge has been mounted. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Radiated Immunity Testing
What types of chamber effects, if any, should one consider when determining the extra factor to be applied to determine the forward power applied to the transmit antenna. Potential effects might include loading of the antenna by the anechoic materials or the chamber itself and resonance's. If there are such effects, what factor should be applied to these effects in order to determine the required forward power to the antenna? And before someone mentions the other factors to consider, I am aware of the need to account for VSWR and loss in the directional coupler and cable. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
Ian, All, With the equipment you have it is possible to get some measure of SWR or match of devices. I am not claiming it is accurate but with care should provide some useful information. Apart from your equipment you will need two good-quality attenuators -probably 20dB will be suitable, a good quality 50 Ohm load, a T piece and 2 bits of good co-ax of the shortest suitable length. For best accuracy you might need an attenuator at the signal source and the measurement receiver. Place the T piece on the device to be measured. Set any input attenuation on the device to whatever range you need to check the SWR.. Put the two attenuators on the other 2 legs of the T. Feed one attenuator (att1) with a signal source. Measure the output of the other attenuator (att2). Sweep 1 - across the range in suitable steps, making amplitude measurements at each step. Record amplitude vs. frequency.(1) Disconnect the T from the device Sweep 2 across the range in same steps, making amplitude measurements at each step. Record amplitude vs. frequency.(2) Connect 50 Ohm load to T where device had been. Sweep 3 across the range in same steps, making amplitude measurements at each step. Record amplitude vs. frequency.(3) The theory behind it is this. You have a known source level (measurement 2 + att2) at the center of the T When you compare the level with the device in place (measurement 1 +att2), since att2 is common and if the device is a perfectly flat 50 Ohms, you should see a loss of 1.765dB on measurement 1 compared with measurement 2. You can check the system out by terminating the T with the 50 ohm load and this will indicate the quality of the set up. By examining the delta amplitude change with frequency (measurement1-measurement2)F1 to (measurement1-measurement2)F2 you might be able to draw some conclusion regarding any reactive components (its unlikely that a pure resistance will actually change value with frequency). The attenuators are to reduce the effects of mismatched source / cable / measurement receiver. One error that may creep in, is if the device leg of the T is extended with co-ax or is relatively long (lambda/20) e-mail me direct if you want any more info Regards Tim Haynes tim.hay...@baesystems.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
Everybody I need to assess the uncertainty of radiated emission and immunity measurements and thus need to measure the mismatch between components in the systems. The frequency range of interest is 30MHz-1GHz) Is there a way in which I can measure the VSWR of a cable-antenna-receiver/amplifier combination without having to purchase a directional coupler or network analyser? The equipment I have at my disposal is: two power amplifiers (150kHz-30MHz 80MHz-1GHz), a spectrum analyser with tracking generator (9kHz-2.6GHz), signal generator (150kHz-1GHz), RF power meter (9kHz-1GHz) and a receiver (9kHz-2.6GHz). Any suggestions would be appreciated. Thanks Ian Gordon Ian: It's a request that may be intellectually stimulating, but for a real-world answer, go get a directional coupler. Since you already have invested multiple thousands in equipment, there's no excuse to not buy a directional coupler. Check out eBay, go to your closest electronics surplus store, check out Pasternack Mini Circuits Werlatone, or try a rental company. Regards, Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: subcontracted parts - compliance with EN's
I read in !emc-pstc that Brian O'Connell boconn...@t-yuden.com wrote (in f7e9180f6f7f5840858d3db815e4f7ad1f2...@cms21.t-yuden.com) about 'subcontracted parts - compliance with EN's' on Thu, 26 Sep 2002: I can think of no reason to ever build in a component power supply, that is connected to mains, or a safety-related TNV source, that does not have an existing CB report and/or a major agency approval. We don't have 'approval', in the sense you mean, in Europe any more. We do have 'certification', but it is purely a civil matter between manufacturer and test-house - it has no legal status in itself. There is no way that you can demonstrate control of the construction of a power supply unless the vendor is subject to FUS audits by the applicable agency(s). Yes, that is so. Any reputable supplier of OEM power supply units has his range already vetted for safety. **as far as the standard can be applied**: if the unit is not enclosed, no tests on the enclosure are possible, of course. EMC is another matter; loads on the supply unit may considerably change the conducted emissions on the supply cable, for example. A (CE-type) declaration of conformity does not prove anything. Well you can only have a DOC on a finished product, and it must be issued by the manufacturer, no-one else. Whether it proves anything depends on the probity of the manufacturer. You do not need construction details for a recognized power supply, your agency engineer will be the escrow agent for the CB report. My complany routinely provides copies of our CB report to agency engineers. This is not applicable in Europe. US-based test houses may operate such a scheme even for products intended for Europe, but we don't have 'agency engineers'. We seldom provide detailed construction data to a customer, unless it is a custom power supply. Get a copy of the installation instructions, a copy of the CB and safety agency certs, and you are done... Yes, that should be sufficient. IT ISN'T if there is no CB or other similar certification. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
Unfortunately, this method doesn't work in general. Take, for example, a source and load, both mismatched to (say) a 50 ohm system. One could measure the output power of the source delivered to a 50 ohm load (power meter). One could then drive the load with a 50 ohm source (signal generator, with output power equal to that measured in the previous step) and measure the load response. Then the source and load could be connected together. The response at the load could indicate lower, higher, or exactly the same power as measured with the 50 ohm power meter, depending on the relative phase of the mismatch between the source and load, and the electrical length of the transmission line between them. In the case where the response was the same, a zero electrical length 10 dB attenuator could be inserted, and the response at the load would be exactly 10 dB lower, even though both the source and the load are mismatched. The mismatch error is bounded by 20log(1 ± |rho1*rho2|). Doing the experiment can only set a lower bound on |rho1*rho2|, where rho1 is the reflection coefficient of the source, and rho2 is the reflection coefficient of the load (0 = |rho| = 1, any phase angle). And only the magnitude of the product of the two rho values is know, not the individual rho values. Don Borowski Schweitzer Engineering Labs Pullman, WA Ken Javor ken.ja...@emccompliance.com on 09/26/2002 06:56:44 AM Please respond to Ken Javor ken.ja...@emccompliance.com To: Gordon,Ian ian.gor...@edwards.boc.com, 'IEEE EMC SAFETY PSTC' emc-p...@majordomo.ieee.org cc:(bcc: Don Borowski/SEL) Subject: Re: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER I am putting this out not as the best solution necessarily, but as a solution. It will be interesting to get several different techniques and see whose is most accurate, fastest, requires least equipment. I would install a 10 dB pad at each discontinuity (consecutively, not simultaneously) and measure the difference each time. If you measure precisely 10 dB less, there was no vswr. Anything different from 10 dB means there was a reflection. There is a way to get from the reflected amount to what the vswr actually is, but in your case you don't need a vswr reading as much as you want to bound the errors. The biggest mismatch is from 30 - 80 MHz between the antenna and the attached coax. Another source of reflections is if no internal attenuation is selected and the spectrum analyzer mixer is a poor match to 50 Ohms. HP used to warn about this. Along those lines I recall Don White (does anyone hear from him anymore?) critiquing a paper at the 1989 EMC Symposium in Denver. The paper was something about how accurate this facility was in making RE measurements. Don asked the speaker if they used a pad to match the antennas to the coax when making NSA measurements, and the speaker said of course. Then he asked if they took the pads out in order to get usable sensitivity for RE testing. Again the answer was in the affirmative. Don didn't have to say another word. The sneer on his face said it all. on 9/26/02 6:01 AM, Gordon,Ian at ian.gor...@edwards.boc.com wrote: Everybody I need to assess the uncertainty of radiated emission and immunity measurements and thus need to measure the mismatch between components in the systems. The frequency range of interest is 30MHz-1GHz) Is there a way in which I can measure the VSWR of a cable-antenna-receiver/amplifier combination without having to purchase a directional coupler or network analyser? The equipment I have at my disposal is: two power amplifiers (150kHz-30MHz 80MHz-1GHz), a spectrum analyser with tracking generator (9kHz-2.6GHz), signal generator (150kHz-1GHz), RF power meter (9kHz-1GHz) and a receiver (9kHz-2.6GHz). Any suggestions would be appreciated. Thanks Ian Gordon _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 --- This message is from the IEEE EMC Society
Re: subcontracted parts - compliance with EN's
I read in !emc-pstc that Gert Gremmen g.grem...@cetest.nl wrote (in mpeeiccjhhndekobpnnbaejacgaa.g.grem...@cetest.nl) about 'subcontracted parts - compliance with EN's' on Thu, 26 Sep 2002: Now for safety you will need a declaration of conformity according to a EN/IEC standard compatible WITH YOUR END PRODUCT, probably issued by an European test house such as VDE NEMKO KEMA or other. Careful with the terminology there! A test house CANNOT issue a Declaration of Conformity; only the manufacturer can do that. A test-house can issue a 'certificate of conformity', but that is a private document between test-house and manufacturer and relates only to the actual sample(s) tested. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: EMC Prosecution in UK
-Original Message- From: Alan E Hutley [mailto:nutwoo...@nutwood.eu.com] Sent: Wednesday, September 25, 2002 11:43 PM To: Emc-Pstc Discussion Group Subject: EMC Prosecution in UK EMC Prosecution, the company mentioned in the report Hot UK Ltd is owned by Helen of Troy based in El Paso Texas. For full story go click below http://www.compliance-club.com/TS%20Prosecution.doc http://www.compliance-club.com/TS%20Prosecution.doc Alan E Hutley EMC Compliance Journal www.compliance-club.com http://www.compliance-club.com HOT was fined $9,000 by the British magistrates. HOY FY 2001 sales were $361M. Hair dryers are a hot market! http://www.helenoftroylp.com/index.htm http://www.helenoftroylp.com/index.htm Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis
RE: Safety Symbol / Hot surfaces
Hello David / Neil, I wasn't sure if either of you were in the UK or on the other side of the pond. In the UK I have been supplied with these labels from a company called HTE Controls. Their phone number is +44 (0) 1355 238641. They have many different labels in different sizes , printed on self adhesive plastic. I have no connection with this company other than to occasionally buy labels from them. Best regards, David Sproul, Alexander Lynn Approvals Management Services -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Neil Helsby Sent: 26 September 2002 08:34 To: emc-p...@majordomo.ieee.org Subject: Hot surfaces The hot symbol is also found at ISO 7000 pattern 0535 and BS 6217 pattern 5041. We have recently introduced this symbol on some of our products. The problem with this, and other safety required symbols, is that we have been unable to locate a source that supplies these as standard off the shelf items. It has therefore been necessary to pay for artworks to be designed and this adds considerable cost to the product. Once the artwork has been paid for, the cost between printing 100 and 1000 labels s generally minimal in comparison so our batch of labels should last a long time. Does anyone know of a source of these types of labels or is this a business opening for someone? Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
If you want to make measurements, you will need to invest in some sort of equipment. To measure VSWR, you need some sort of equipment that can either measure forward and reverse waves, measure voltage along a transmission line, or can vary phase and possibly magnitude of impedance. The first is a directional coupler or network analyzer, the second would be a slotted line or open wire transmission line, and the third would be things like line stretchers or a large selection of slightly different length transmission lines, and various sorts of tuners (LC or transmission line tuners such as the double stub variety). A directional coupler is certainly the easiest to use. The tuner option is often used when measuring the output impedance of non-linear devices (e.g., class C amplifiers). Open transmission lines are not often used for measurements, but are excellent tools to demonstrate standing waves. Don Borowski Schweitzer Engineering Labs Pullman, WA Gordon,Ian ian.gor...@edwards.boc.com on 09/26/2002 03:01:02 AM Please respond to Gordon,Ian ian.gor...@edwards.boc.com To: 'IEEE EMC SAFETY PSTC' emc-p...@majordomo.ieee.org cc:(bcc: Don Borowski/SEL) Subject: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER Everybody I need to assess the uncertainty of radiated emission and immunity measurements and thus need to measure the mismatch between components in the systems. The frequency range of interest is 30MHz-1GHz) Is there a way in which I can measure the VSWR of a cable-antenna-receiver/amplifier combination without having to purchase a directional coupler or network analyser? The equipment I have at my disposal is: two power amplifiers (150kHz-30MHz 80MHz-1GHz), a spectrum analyser with tracking generator (9kHz-2.6GHz), signal generator (150kHz-1GHz), RF power meter (9kHz-1GHz) and a receiver (9kHz-2.6GHz). Any suggestions would be appreciated. Thanks Ian Gordon _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list This e-mail may contain SEL confidential information. The opinions expressed are not necessarily those of SEL. Any unauthorized disclosure, distribution or other use is prohibited. If you received this e-mail in error, please notify the sender, permanently delete it, and destroy any printout. Thank you. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Safety Symbol
Hello Dave, IEC 417, Symbol 5041 is for hot surfaces.. Check this link for a picture: http://w3.hike.te.chiba-u.ac.jp/iec417/html/doc/5041f.html Robert Mavis -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Cereceres, David Sent: Wednesday, September 25, 2002 4:13 PM To: 'emc-p...@majordomo.ieee.org' Subject: Safety Symbol Hello Group, Does anyone know if there is a specific symbol for hot surfaces? I looked in IEC 417, but have been unable to locate anything specific. Thanks, David Cereceres Pelco --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
I am putting this out not as the best solution necessarily, but as a solution. It will be interesting to get several different techniques and see whose is most accurate, fastest, requires least equipment. I would install a 10 dB pad at each discontinuity (consecutively, not simultaneously) and measure the difference each time. If you measure precisely 10 dB less, there was no vswr. Anything different from 10 dB means there was a reflection. There is a way to get from the reflected amount to what the vswr actually is, but in your case you don't need a vswr reading as much as you want to bound the errors. The biggest mismatch is from 30 - 80 MHz between the antenna and the attached coax. Another source of reflections is if no internal attenuation is selected and the spectrum analyzer mixer is a poor match to 50 Ohms. HP used to warn about this. Along those lines I recall Don White (does anyone hear from him anymore?) critiquing a paper at the 1989 EMC Symposium in Denver. The paper was something about how accurate this facility was in making RE measurements. Don asked the speaker if they used a pad to match the antennas to the coax when making NSA measurements, and the speaker said of course. Then he asked if they took the pads out in order to get usable sensitivity for RE testing. Again the answer was in the affirmative. Don didn't have to say another word. The sneer on his face said it all. on 9/26/02 6:01 AM, Gordon,Ian at ian.gor...@edwards.boc.com wrote: Everybody I need to assess the uncertainty of radiated emission and immunity measurements and thus need to measure the mismatch between components in the systems. The frequency range of interest is 30MHz-1GHz) Is there a way in which I can measure the VSWR of a cable-antenna-receiver/amplifier combination without having to purchase a directional coupler or network analyser? The equipment I have at my disposal is: two power amplifiers (150kHz-30MHz 80MHz-1GHz), a spectrum analyser with tracking generator (9kHz-2.6GHz), signal generator (150kHz-1GHz), RF power meter (9kHz-1GHz) and a receiver (9kHz-2.6GHz). Any suggestions would be appreciated. Thanks Ian Gordon _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: subcontracted parts - compliance with EN's
CONFLICT OF INTEREST NOTICE: My employer makes componet power supplies (almost all types). I was waiting for someone (Mr Woodgate?) to jump on this... I can think of no reason to ever build in a component power supply, that is connected to mains, or a safety-related TNV source, that does not have an existing CB report and/or a major agency approval. There is no way that you can demonstrate control of the construction of a power supply unless the vendor is subject to FUS audits by the applicable agency(s). A (CE-type) declaration of conformity does not prove anything. You do not need construction details for a recognized power supply, your agency engineer will be the escrow agent for the CB report. My complany routinely provides copies of our CB report to agency engineers. We seldom provide detailed construction data to a customer, unless it is a custom power supply. Get a copy of the installation instructions, a copy of the CB and safety agency certs, and you are done... I do not speak for my employer. R/S, Brian -Original Message- From: Gert Gremmen [mailto:g.grem...@cetest.nl] Sent: Thursday, September 26, 2002 12:33 AM To: Alexandru Guidea; emc-p...@majordomo.ieee.org Subject: RE: subcontracted parts - compliance with EN's Hi Alkexandru, There are several spects to this. I will elaborate on the specifications for a power supply (SMPS). Components and power supplies used to be incorporated into equipment are not subject to ce marking. This you concluded yourself. Now for safety you will need a declaration of conformity according to a EN/IEC standard compatible WITH YOUR END PRODUCT, probably issued by an European test house such as VDE NEMKO KEMA or other. For a PC supply you will need a EN 60950 compliance statement and for medical equipment you will need a EN 60601 compliant supply. Ask your manufacturer for a (partial)copy of the test report that list out the conditions under what the supply needs to be incorporated to fulfill safety requirements. This is very important as an open Frame power supply could NEVER meet the full requirements of EN 60950 f.a. , but incorperated in an open end product may inhibit approval of your end product. If your equipment enclosure fulfills fire enclosure requirements, then that would be no problem. Pay especially attention to terminals , open/closed enclosures en insulation class between mains and secondary. It needs to be compatible with your end product. It will not be easy to obtain such a copy as manufacturers are reluctant to give them. Now for EMC, the supply needs to be compatible with the EMC directive itself. This is what you will find in general in the datasheets. of course , here compatibility of the specs with your end product is required too. Most of the time a compliant power supply will not produce problems in itself for the approval of your end product (by it's proper emissions f.a.) The attenuation however, for emission currents originating from your proper electronics and transferred by the power supply to the mains supply may however, be unspecified as there exist no requirement for such. Most of the time they ARE unspecified, and may varie widely among supplies having virtually the same approval data. May even vary among different batches of the same product. Now what you really need is statements of compatibility (liability) with suitable standards (compatible with your end product). Most of the time these are IEC standard possibly in an EN variant. These statements are civil liability statements between you and the manufacturer and have no legal meaning in (EC) public right and are therefore (within national limitations) valuable all over the world. Then you will have to create THE Declaration of Conformity according to public law for Europe, based on the TCF for your product. Note the differences between civil and public legal aspects. if you are not familiar with it, ask a specialist. Due to the arguments earlier mentioned a private compatibility statement with suitable standards needs to be completed with additional purchase requirements, such as not modifying the product in such a way that it might impact the compliance of your end product (or at least don't allow to do that without notice) For this you need to specify what properties of the supply you are relying on for compliance of the end product. In order to correctly design the implementation you will probably need a copy of the test reports. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail
Re: Hot surfaces
Dear Neil: Hazard Communication Systems, LLC has the Hot Surface symbol on an ISO-style yellow triangle heat-resistant sticker as its catalog No. '6043_-ISO AL'. The catalog number for a sticker that is not heat-resistant is '6043_-ISO'. The stickers are available in A, B, C and D sizes (3.8, 2.25, 1.3 and .69 inch base lengths) by substituting the size letter (A, B, C or D) for the underscore. Hazard Communication Systems, LLC Routes 6 209 Post Office Box 1174 Milford, Pennsylvania 18337 800.748.0241 or +1 570.296.5686 Telephone 800.748.0536 or +1 570.296.5656 Facsimile http://www.hazcomsys.com I am not affiliated with this company in any way, but know that it is experienced in the development of many types of safety warning labels, particularly paying attention to conformity with the relevant ANSI and ISO standards. Regards, Chuck Seyboldt (207) 893-0352 (207) 838-4026 Cellular (586) 461-6096 Facsimile At 07:33 (-) on 02.09.26, Neil Helsby wrote: The hot symbol is also found at ISO 7000 pattern 0535 and BS 6217 pattern 5041. We have recently introduced this symbol on some of our products. The problem with this, and other safety required symbols, is that we have been unable to locate a source that supplies these as standard off the shelf items. It has therefore been necessary to pay for artworks to be designed and this adds considerable cost to the product. Once the artwork has been paid for, the cost between printing 100 and 1000 labels s generally minimal in comparison so our batch of labels should last a long time. Does anyone know of a source of these types of labels or is this a business opening for someone? Regards, Neil Helsby --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Safety Symbol
Horizontal bar with three (vertical) wavy lines/ G -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Cereceres, David Sent: Wednesday, September 25, 2002 7:13 PM To: 'emc-p...@majordomo.ieee.org' Subject: Safety Symbol Hello Group, Does anyone know if there is a specific symbol for hot surfaces? I looked in IEC 417, but have been unable to locate anything specific. Thanks, David Cereceres Pelco --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
MEASURING VSWR WITHOUT A DIRECTIONAL COUPLER
Everybody I need to assess the uncertainty of radiated emission and immunity measurements and thus need to measure the mismatch between components in the systems. The frequency range of interest is 30MHz-1GHz) Is there a way in which I can measure the VSWR of a cable-antenna-receiver/amplifier combination without having to purchase a directional coupler or network analyser? The equipment I have at my disposal is: two power amplifiers (150kHz-30MHz 80MHz-1GHz), a spectrum analyser with tracking generator (9kHz-2.6GHz), signal generator (150kHz-1GHz), RF power meter (9kHz-1GHz) and a receiver (9kHz-2.6GHz). Any suggestions would be appreciated. Thanks Ian Gordon _ This e-mail has been scanned for viruses by the WorldCom Internet Managed Scanning Service - powered by MessageLabs. For further information visit http://www.worldcom.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Safety Symbol
David, Do a search on google as follows: 417-IEC-5041 and the symbol you're looking for will appear. Regards This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 http://www.itl.co.il http://www.i-spec.com -Original Message- From: Cereceres, David [mailto:dcerece...@pelco.com] Sent: Thursday, September 26, 2002 1:13 AM To: 'emc-p...@majordomo.ieee.org' Subject: Safety Symbol Hello Group, Does anyone know if there is a specific symbol for hot surfaces? I looked in IEC 417, but have been unable to locate anything specific. Thanks, David Cereceres Pelco --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
FCC rules
Thanks again everyone for your helpful responses. The group is certainly a source of valuable help and expertise. Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Hot surfaces
The hot symbol is also found at ISO 7000 pattern 0535 and BS 6217 pattern 5041. We have recently introduced this symbol on some of our products. The problem with this, and other safety required symbols, is that we have been unable to locate a source that supplies these as standard off the shelf items. It has therefore been necessary to pay for artworks to be designed and this adds considerable cost to the product. Once the artwork has been paid for, the cost between printing 100 and 1000 labels s generally minimal in comparison so our batch of labels should last a long time. Does anyone know of a source of these types of labels or is this a business opening for someone? Regards, Neil Helsby ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: subcontracted parts - compliance with EN's
Hi Alkexandru, There are several spects to this. I will elaborate on the specifications for a power supply (SMPS). Components and power supplies used to be incorporated into equipment are not subject to ce marking. This you concluded yourself. Now for safety you will need a declaration of conformity according to a EN/IEC standard compatible WITH YOUR END PRODUCT, probably issued by an European test house such as VDE NEMKO KEMA or other. For a PC supply you will need a EN 60950 compliance statement and for medical equipment you will need a EN 60601 compliant supply. Ask your manufacturer for a (partial)copy of the test report that list out the conditions under what the supply needs to be incorporated to fulfill safety requirements. This is very important as an open Frame power supply could NEVER meet the full requirements of EN 60950 f.a. , but incorperated in an open end product may inhibit approval of your end product. If your equipment enclosure fulfills fire enclosure requirements, then that would be no problem. Pay especially attention to terminals , open/closed enclosures en insulation class between mains and secondary. It needs to be compatible with your end product. It will not be easy to obtain such a copy as manufacturers are reluctant to give them. Now for EMC, the supply needs to be compatible with the EMC directive itself. This is what you will find in general in the datasheets. of course , here compatibility of the specs with your end product is required too. Most of the time a compliant power supply will not produce problems in itself for the approval of your end product (by it's proper emissions f.a.) The attenuation however, for emission currents originating from your proper electronics and transferred by the power supply to the mains supply may however, be unspecified as there exist no requirement for such. Most of the time they ARE unspecified, and may varie widely among supplies having virtually the same approval data. May even vary among different batches of the same product. Now what you really need is statements of compatibility (liability) with suitable standards (compatible with your end product). Most of the time these are IEC standard possibly in an EN variant. These statements are civil liability statements between you and the manufacturer and have no legal meaning in (EC) public right and are therefore (within national limitations) valuable all over the world. Then you will have to create THE Declaration of Conformity according to public law for Europe, based on the TCF for your product. Note the differences between civil and public legal aspects. if you are not familiar with it, ask a specialist. Due to the arguments earlier mentioned a private compatibility statement with suitable standards needs to be completed with additional purchase requirements, such as not modifying the product in such a way that it might impact the compliance of your end product (or at least don't allow to do that without notice) For this you need to specify what properties of the supply you are relying on for compliance of the end product. In order to correctly design the implementation you will probably need a copy of the test reports. Other OEM products may be easier to specify, however. Gert Gremmen ce-test, qualified testing -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Alexandru Guidea Sent: Wednesday, September 25, 2002 9:56 PM To: emc-p...@majordomo.ieee.org Subject: subcontracted parts - compliance with EN's Importance: Low Dear colleagues, This questions might have been asked before. Still looking for answers... Our company purchases power distribution equipment designed per our specs. This equipment is not put on the market, but integrated in our products, and does safety/EMC functions(EMI filtering, protection, emergency stop) among other things, in accordance to the EC Directives applicable to our product. We believe there is no point to have it CE marked but only compliant with the standards we need. The text of the EMC Directive reads the manufacturer may subcontract certain operations, e.g., apparatus design or production, provided that he retains overall control and responsibility for the apparatus as a whole. By the same token, he may use ready-made items or components, CE marked or not, to produce the apparatus without losing his status as a manufacturer. We follow the Technical Construction File route for CE marking. What's the documentation required from our sub-contractors that proves compliance with the EN standards we indicate? Do we need complete copies of test reports, technical description, analysis, or just a statement of compliance would do the job? What's the legal value of such a paper in North-America? As we don't control their production (parts, quality, etc,) what's the documentation we shall request to ensure all production units are compliant? What's the industry/your
EMC Prosecution in UK
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RE: Current from Car 12V cigarette lighter socket
Hi Forum, Just a clarification for me on this topic. Some vehicles have negative and some have positive chassis. Some ITE equipment is hard wired in a vehicle i.e. not always via the cigarette lighter. Am I correct in saying that this hard wired harness would be better if both lines are fused in order to meet all conditions of installation? Regards ALEX -Original Message- From: Jim Eichner [mailto:jim.eich...@xantrex.com] Sent: 18 September 2002 21:36 To: 'Ken Javor'; Jim Eichner; 'EMC-PSTC - forum' Subject: RE: Current from Car 12V cigarette lighter socket Thanks. The solution you propose is in the works. The SAE is working on a completely different style connector for power connections to 12Vdc, and 2 other styles for 42Vdc and 120Vac connectors. This effort is just getting off the ground however. Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. e-mail: jim.eich...@xantrex.com web: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. No really. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, September 18, 2002 1:14 PM To: Jim Eichner; 'EMC-PSTC - forum' Subject: Re: Current from Car 12V cigarette lighter socket An excellent post. Seems like a solution here would be for the newer electrical outlet to be designed differently and not mate with the older male cigarette lighter insert, and then provide an adapter that would take the cigarette lighter insert to the new electrical outlet. Then the 8 Amp limit could be relaxed for appliances with the new plug, and any old devices would still be taken care of. -- From: Jim Eichner jim.eich...@xantrex.com To: 'EMC-PSTC - forum' emc-p...@majordomo.ieee.org Subject: RE: Current from Car 12V cigarette lighter socket Date: Wed, Sep 18, 2002, 1:47 PM UL2089 covers appliance using the socket. There is no UL or CSA standard covering the socket itself, but there is SAE J563, which provided dimensions and limits the continuous current drawn through lighter sockets by appliances to 8Adc. The intent is to protect the wiring in behind the lighter socket, because that wiring is based on an intermittent 10-15A load (how often do you light a cigarette?) and is therefore undersized for its overcurrent protection. In a sample of 7 or 8 cigarette lighter sockets and wiring harnesses that I pulled out of different makes of car in the mid 90's, I found wire sizes ranging from No. 16AWG to 22AWG, being protected by fuses ranging from 15 to 30A! In the world of continuous 12Vdc loads - aftermarket accessories like chargers for cell phones and laptops, in-your-car coffee makers and vacuum cleaners, etc - we need to know what continuous load the lighter socket and its harness can sustain. The SAE pegs this at 8A and UL and CSA are enforcing that limit, both in what they will allow a 12Vdc appliance to draw, and in requiring a max. 8A fuse in the lighter plug. Recognizing the limitations on lighter sockets, the automotive industry has come up with the power point: a cylindrical connector based on the cigarette lighter socket but designed, fused, wired, and rated for continuous loads and lacking the bimetal fingers that release the lighter plug when it's hot. These are usually rated for 15-20Adc continuous, allowing designers to be free of the 8A limit. In theory. However, since the male plugs on 12Vdc automotive appliances will fit both the true lighter socket and these newer power points, UL and CSA will not back down (nor should they) from the 8A limit for a 12Vdc appliance equipped with a male plug that fits a lighter socket. They also will not accept a marking such as Use only with power points, not with lighter sockets because too many cars only have lighter sockets. Not sure you're trying to do anything with that kind of power level, but you should be aware of the limitations. Regards, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. e-mail: jim.eich...@xantrex.com web: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. No really. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
Re: subcontracted parts - compliance with EN's
I read in !emc-pstc that Alexandru Guidea gui...@cae.com wrote (in 1c89780c4179d3118c580090277193580fc11...@caemsx01.cae.ca) about 'subcontracted parts - compliance with EN's' on Wed, 25 Sep 2002: Dear colleagues, This questions might have been asked before. Still looking for answers... Our company purchases power distribution equipment designed per our specs. This equipment is not put on the market, but integrated in our products, and does safety/EMC functions(EMI filtering, protection, emergency stop) among other things, in accordance to the EC Directives applicable to our product. We believe there is no point to have it CE marked but only compliant with the standards we need. Correct. The text of the EMC Directive reads the manufacturer may subcontract certain operations, e.g., apparatus design or production, provided that he retains overall control and responsibility for the apparatus as a whole. By the same token, he may use ready-made items or components, CE marked or not, to produce the apparatus without losing his status as a manufacturer. We follow the Technical Construction File route for CE marking. What's the documentation required from our sub-contractors that proves compliance with the EN standards we indicate? Do we need complete copies of test reports, technical description, analysis, or just a statement of compliance would do the job? You need all the data you list, to go the TCF route. What's the legal value of such a paper in North-America? As we don't control their production (parts, quality, etc,) what's the documentation we shall request to ensure all production units are compliant? What's the industry/your practice in this case? Alexandru Guidea CAE Inc. Montreal, CANADA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: EN61000-3-2
I read in !emc-pstc that Jim Eichner jim.eich...@xantrex.com wrote (in 67C475A5ECE7D4118AEC0002B325CAB603510EAB@BCMAIL1) about 'EN61000-3-2' on Wed, 25 Sep 2002: This harmonics thing is still, after all these years, annoyingly slippery. I have a very basic question, that until yesterday and today I thought I knew the answer to: What harmonic current limits standard should I tell designers to design to today? I thought the answer was EN61000-3-2:2000, on the understanding that it was the same as, but clearer than, the A14 version, and that it was the final foreseeable version. Now I hear that no, there are actually differences that make the 2000 version tougher to meet, and I hear that the 2000 edition will be superceded (yet again) by an updated IEC version that has so far not been voted on and could therefore incorporate further changes. No, it has been voted on, but a problem arose after the voting, which will need a controversial amendment to settle. How is a manufacturer supposed to design products, with 3-10 year expected lifetimes and long development cycle times, in the face of constantly changing requirements and effectivity dates? The transition periods between editions are long enough to prevent any serious difficulties - except that of keeping up with the developments. But national standards bodies run automatic updating services which solve that one - at a cost. At present, it seems the only thing I can do is to tell designers to work to A14, even though it will be superceded, since the 2000 edition is also going to be superceded. Comments? You can at present work to either. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: EN61000-3-2
I read in !emc-pstc that plaw...@west.net wrote (in chh4puck35u0eb2jm11 rnu9n7p67ai7...@4ax.com) about 'EN61000-3-2' on Wed, 25 Sep 2002: What type of products are affected? Only lighting, AFAIK. I have both the IEC 1995 with which amendments? and the EN 2001 editions. Can you reference the clauses? Clause on the limits for lighting. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Safety Symbol
Probably will get a deluge of replies, but in case not, I think you are looking for symbol 5041 in IEC 60417. (Three wiggly lines [S-shaped] suspended above a horizontal line, all surrounded be the usual warning triangle.) (Also referenced in IEC 61010-1.) best regards, glyn -- TUV Rheinland of North America, Inc. Product Safety Quality Industrial Machinery Division (Chicago Office) Glyn R. Garside Senior Engineer 1945 Techny Rd, Unit 4 NORTHBROOK, IL 60062-5357, USA Tel (847)562-9888 ext 25 Cell (847)612-1574 Fax (847)562-0688 email ggars...@us.tuv.com http://www.us.tuv.com Cereceres, David dcerece...@pelco.comTo: 'emc-p...@majordomo.ieee.org' emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordom Subject: Safety Symbol o.ieee.org 09/25/2002 18:13 Please respond to Cereceres, David Hello Group, Does anyone know if there is a specific symbol for hot surfaces? I looked in IEC 417, but have been unable to locate anything specific. Thanks, David Cereceres Pelco --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: EN61000-3-2
What type of products are affected? I have both the IEC 1995 and the EN 2001 editions. Can you reference the clauses? Patrick Lawler plaw...@west.net On Wed, 25 Sep 2002 12:03:16 +0100, John Woodgate j...@jmwa.demon.co.uk wrote: I read in !emc-pstc that Joe P Martin marti...@appliedbiosystems.com wrote (in of0f009cfb.c7f0c310-on88256c3e.00798...@pe-c.com) about 'EN61000-3-2' on Tue, 24 Sep 2002: To make it less confusing, use the 2nd edition. EN 61000-3-2 Ed. 2:2000. The 2nd edition supersedes EN 61000-3-2: 1995 + A1: 1998 + A2: 1998 + A14:2000. Ah! Be careful! There are subtle differences between the fully-amended 1995 edition and the 2000 edition, which does not YET mandatorily supersede the amended 1995 edition, whose dow is 2004-01-01. For some products, the amended 1995 edition is easier to satisfy than the later edition. In due course, all this will be sorted out. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Difference between Receivers and Spectrum Analyzers
Muriel: The biggest difference is the first stage of the spectrum analyzer. The typical SA presents the signal (possibly through a bandpass filter and attenuators) to the first stage mixer. A receiver typically has a tuned RF section, which improves selectivity. A SA thus has a higher noise figure, and it is more vulnerable to overload and mixer burn-out. Now, if your SA has a tunable pre-selector, it starts to look a lot like a receiver. And, if your receiver can be swept in frequency, it begins to look like a SA. Modern SA's and receivers are not all that different in performance. More importance is being given to processing beyond the RF/IF signal chain, and BOTH now look more like computers than anything else. Regards, Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis -Original Message- From: Muriel Bittencourt de Liz [mailto:mur...@eel.ufsc.br] Sent: Wednesday, September 25, 2002 11:51 AM To: Lista de EMC da IEEE Subject: Difference between Receivers and Spectrum Analyzers Hello Group, For EMC measurements (conducted and radiated emissions), electromagnetic fields measurements (via antennas), what is the difference between using a EMI Receiver or a Spectrum Analyzer?? Some guesses that I've been thinking are: - The Receiver is more accurate than the Spectrum Analyzer, so it is more suitable for EMC measurements that aim to respect the EMC standards. - For measuring electromagnetic fields (eg electric field) for safety (human safety standards for man-made electromagnetic fields, like ICNIRP) the Receiver is suitable because it can give an accurate value to a particular frequency that is being studied. - The spectrum analyzer is qualitative, i.e. it gives an idea of how the spectra measured is distributed in the frequency range. The receiver is quantitative, i.e. it gives accurate amplitude for each frequency swept. Well, I think this subject is very controversial, and it will generate a lot of discussions, that will be good for us all. Best Regards, Muriel B. de Liz --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Safety Symbol
Hello Group, Does anyone know if there is a specific symbol for hot surfaces? I looked in IEC 417, but have been unable to locate anything specific. Thanks, David Cereceres Pelco --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Difference between Receivers and Spectrum Analyzers
The lines between spectrum analyzers and receivers have grown very fuzzy, but in the old days the biggest difference was that a receiver had a narrow band tuned front end and an S.A. had a broadband one. This makes the S.A. more susceptible to out of band interference. I certainly wouldn't say that an S.A. is only a qualitative device. Regards, Brent DeWitt --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: EN 61000-3-3 + A1
I read in !emc-pstc that jim.hulb...@pb.com wrote (in OFB53635ED.69BF8D 46-on85256c3f.004ee...@pb.com) about 'EN 61000-3-3 + A1' on Wed, 25 Sep 2002: When measuring dmax voltage changes caused by manual switching per Annex B, what is the best way of making sure that any dmax mitigation devices have had time to cool to the ambient temperature before the next measuring interval is started? Do you have to connect thermocouples to those devices or is there a simpler way? Just wait; you must have some idea how long the devices take to cool down sufficiently. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
