Hi Bill and the group, But the noise emitted by some simulators has nothing to do with reality and designing for that does not produce any benefit. Also, the noise from simulators is not included in their specifications and can change overnight, so one cannot say a simulator is (worst case) because there is no characterization.
It boils down to a poorly written standards and the lack of understanding of metrology for fast di/dt waveforms at high voltage. Even if acknowledged, standards bodies are more likely to keep a poorly written standard around than to correct it in my experience. What would help is to populate the committees with a broader set of engineering experience. Also, my opinion is that many of the simulator manufacturers clearly do not understand what they are building! Having been on various IEC and other ESD committee over the last 40 years, it is abundantly clear than some of the members do not understand what they are writing. The IEC 61000-4-4 capacitive (and just as inductive, almost perfect transformer) clamp that sends more energy to the auxiliary equipment than to the EUT is a perfect example. If the clamp is terminated in 50 Ohms on the Aux end, it would fix the problem, not sure if that has happened. But that clamp is very directional due to its strong magnetic field coupling acting with the e field coupling. The committee that designed it had no idea! But the effect can be duplicated in the lab in about 10 minutes. Similarly shielded cables are also nearly perfect transformers with the shield often being the primary and the center conductor the secondary. If they did not act this way, there would be no shielding! Doug [SYMBOL] From: Bill Owsley <[email protected]> Sent: Monday, October 14, 2019 18:06 To: [email protected]; doug emcesd.com <[email protected]> Subject: Re: [PSES] Any Different Results in ESD Testing when Changing Brands of ESD Simulator (IEC 61000-4-2) My experience, is that all brands, commercial and custom private built, will all make for different results. The ESD generators can all make the required waveforms as poorly defined and tested. Yet each different brand or model will give different results. Why ? Incomplete performance definition and verification procedures. So we test to extremes and build to pass, then no matter what equipment is used to test, the product complies, so far ! On Monday, October 14, 2019, 03:42:00 PM EDT, doug emcesd.com <[email protected]<mailto:[email protected]>> wrote: Hi Montara, There are more stories than I can type here. The standard as written is not very good. We addressed this in the early to mid-1990s and determined what was necessary. We also did a lot of round robin testing. Probably most of what you want has been published in the 1990s. Look at the ESD Association papers from the era. Look for authors like myself (we were all involved with revising 61000-4-2), Jon Barth, Ken Hall, Hugh Hyatt. Everything you need was done back then and rejected by the EU members for various reasons that I do not consider valid. Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: [email protected]<mailto:[email protected]> Website: http://dsmith.org ________________________________ From: Monrad Monsen <[email protected]<mailto:[email protected]>> Sent: Monday, October 14, 2019 9:43:54 AM To: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Subject: [PSES] Any Different Results in ESD Testing when Changing Brands of ESD Simulator (IEC 61000-4-2) Hi! Does anyone have any stories that can be shared of a product getting a different ESD test result when changing the brand/model of ESD simulator? I am a member of the US Technical Advisory Group (TAG) for CISPR/I international standards committee (Electromagnetic compatibility of information technology equipment, multimedia equipment and receivers). There is a proposal that SC77B begin work on changes to IEC 61000-4-2 (ESD) to improve the ESD waveform verification (some call this “calibration”) because under today’s rules different simulators create different levels of high frequency signal content which some believe is the primary reason for different test results. Some believe that the IEC 61000-4-2 waveform requirement fails to include any evaluation of the slope (dV/dt or dI/dt) of the impulse, and that uncontrolled parameter directly affects spectral content. I would like to know if anyone has experienced any actual ESD test result consistency when using different Brand/model ESD simulators even though they are all calibrated simulators under today’s rules. I admit that our company uses the same brand & model ESD simulator as local labs, so I have never observed this issue myself. My initial preference is to not add cost to testing and avoid forcing labs to buy new ESD simulators, but perhaps this cost is warranted if there are actual wide variations in ESD test results depending on the brand of ESD simulator. Thanks. Monrad Monsen | Hardware Compliance Strategist Phone: +1.303.272.9612 Oracle Market Access & Hardware Compliance Strategy 500 Eldorado Blvd | Broomfield, CO 80021 - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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To post a message to the list, send your e-mail to <[email protected]<mailto:[email protected]>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
