Hi Ed and Ken, An ESD event can be produced without any direct addition of charge. It only takes an E field and two conductors near each other as in: http://emcesd.com/tt2001/tt060101.htm http://emcesd.com/tt2001/tt050101.htm Unobserved discharge not needed and generally is not involved with these type of events. Just a static E field will induce a spark. Doug On Sun, 7 Jan 2018 00:17:35 +0000, Edward Price wrote: Ken: My guess would be that there was an unobserved discharge from the fabric to the dangling earphone cord, which then discharged into your body capacitance in your ear canals (which were extra conductive due to trapped moisture filling the ear canals and the earbud orifices). I wonder if a vapor of perspiration and earwax will fluoresce? Ed Price WB6WSN Chula Vista, CA USA From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, January 05, 2018 6:21 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] ESD question Just curiosity. Spent a week in the cold frozen north. Single Fahrenheit digits (above and below zero) outside, snow on the ground, 70 degrees inside – dry air. Was able to generate some pretty decent lightning simulations walking around and especially stripping a bed that had some sort of fuzzy (no doubt synthetic material) blanket. While stripping the bed, I was listening to a podcast on an iPhone, through wired earbuds. I could hear the discharges through the earbuds. That was some sort of interference, but not the question of interest here. What was interesting is that the bigger sparks not only zapped where I made contact (typically hands) but also from the earbuds to my inner ear (ouch)! That’s not what I said, but close enough. The iPhone was in a leather pouch suspended from by belt. The hook around the belt was metal, the belt was leather, and there were (denim cotton) pants between the hook on the inside of the belt and my skin. To my understanding, the iPhone and earbuds should have been at near or the same potential I was, and even if not, it was certainly no sort of ground – completely isolated from anything except me. So the question is why was there such a potential difference between iPhone and earbuds and me that my ears were zapped? Ken Javor Phone: (256) 650-5261 - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com> - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
