Dunno, have never seen from ESD, but have for the EFT tests - suppose that some people employed by SMPS manufactures have seen this at least once or twice, or have had their design shoved back in their face by the resident compliance person. Can also result from a weird end-use installation of the p/s.
Brian -----Original Message----- From: Doug Smith [mailto:[email protected]] Sent: Tuesday, November 04, 2014 1:14 AM To: [email protected] Subject: [PSES] New electrical phenomenon reproduced tonight! Hi All, I was able to measure in my lab late tonight, a very important extension of an effect I discovered earlier. That discovery describes how some power supplies can take in a single ESD pulse and generate from it many ESD pulses of both polarities with both human metal model and cable discharge current waveforms embedded in corona discharges from the single original ESD pulse. Tonight, I was able to create the same effect using EFT (electrical fast transient) pulses. Some power supplies can take a single EFT pulse and a microsecond to several microseconds later generate one or more EFT pulses, some larger that the stimulus one, embedded in corona discharges! This is very bad as EFT occurs much more than ESD and is not visible to equipment operators. The EFT can be amplified and made worse by some power supplies! This could easily the the cause of equipment failure either at compliance testing or in the field. This appears to be a new phenomena that I have not seen published. I have been able to reproduce the ESD version at a NASA Ames laboratory, my own laboratory, and at an ESD test site on the US East Coast using different ESD simulators and equipment. If you are interested in this, contact me privately at [email protected] or call me. Doug - ---------------------------------------------------------------- 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]>
