The more I look into this subject the worse it seems to become. I first stumbled across it debugging a system failing ESD testing and subsequently wrote a paper on that case in the Institute of Physics representing Oxford University in 2015. Here is the paper:
* An Unusual Source of Multiple ESD Events in Electronic Equipment<https://emcesd.com/pdf/An_Unusual_Source_of_Multiple_ESD_Events_in_Electronic_Equipment_final.pdf> * (2015 Institute of Physics Electrostatics Symposium paper) Since then I realized only high quality supplies have the effect which can increase the stress of an EFT or ESD current flowing in the system causing 10x the stress (amplitude and di/dt) on the system while really cheap supplies (think Amazon) which do not meet EMC specs and are illegal to sell in most places do not have this problem because they do not have EMC line filters. Friends have been sending me power supplies and I have a table full of them, some of them I have looked into the innards of the supplies and I have been testing fixes. It turns out a cheap (couple of US cents) component that has been available since before printed circuit boards were invented fixes the problem, think NE-2. I used to make relaxation oscillators with these when I was 15, a long time ago and they are still available! Anyone interested in this topic? If so, we can start a discussion group. I have lots of pictures and plots so we may need to discuss elsewhere so I can send the data. This effect applies to all systems with EMC line filters, which are just a bunch of Ls and Cs with self resonances in parallel and series modes. Doug [https://lh4.googleusercontent.com/_HuR3Ky2TF_XhFHyxnYRmiq7nHQldnMsPNYFaLG6kb5T4y8MeCe-BDC_BscJtSFgszSSjssihHS-pjM3-jwNP8S0CwE-gN8fsRsPkojiAlmpBwb20vIVizS-siCUywW_jqrefbVr] - ---------------------------------------------------------------- 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: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://pses.ieee.org/wp-content/uploads/2024/12/EM-PSTC-List-Rules.pdf For help, send mail to the list administrators: Mike Sherman at: [email protected] Rick Linford at: [email protected] For policy questions, send mail to: Jim Bacher: <[email protected]> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
