ESD in Britain! I think of wet when I think of Britain......Now the American Southwest desert, where I live, is the ESD capital of the world, even more than cold places as it is drier here and the dryness lasts most of the year, except August when the dew point gets up into the 50s and once in a while to 60 F. I run miles and miles mid-day at 110 degrees F all the time here in the summer and I am not hot because the dew point is often 0-10 degrees F. My skin is cool. Once in a water fight (popular in the desert) at 95 degrees F, I was actually shivering because the dew point was near zero F! My mouse pad is cut from an ESD dissipative mat and is grounded. When I put the key in the office door in the morning I often get a 10-15 kV discharge! If your product works here, in Boulder City, NV, it will work anywhere! We have the world's largest ESD testing lab, the whole city.
Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: [email protected] Website: http://dsmith.org On Sat, Jan 6, 2018 at 10:38, John Allen <[email protected]> wrote: This is a close parallel to the scenario where some gets a “shock” from the very small amount of residual stored energy in an appliance filter which has no bleeder resistors and is fitted on the supply side of the Mains ON/OFF switch. It “wakes them up” but does little actual harm – unless, of course, they fall over/drop something on a foot, cut a finger with a knife and so on J Then, of course, there may be attempted legal action – which, is, I guess, a minefield against which to defend if you are the manufacturer /supplier! John E Allen W.London, UK. From: Douglas Smith [mailto:[email protected]] Sent: 06 January 2018 18:28 To: [email protected] Subject: Re: [PSES] ESD question I have had this happen to me using a conventional telephone handset as I rose from sitting on a bed. The charge available then was from the full capacitance of my body as opposed to the capacitance between the iPhone and the body. This has been going on for as many years as there have been telephones and headsets, I have been involved in a number of studies and lawsuits, some while at AR&T Bell Labs and some on my own since then. In general, I believe lay people think that have been harmed when that is very unlikely, there just isn't enough energy. But what energy there is, finds itself applied to a sensitive part of the body. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: [email protected] [[email protected]] Website: http://dsmith.org [http://dsmith.org] On Sat, Jan 6, 2018 at 10:15, Adam Dixon < [email protected] [[email protected]] > wrote: Doug, How significant are differences between the telephone/radar operators cases and Ken's experience? Equipment capacitances (higher pF for telephone/radar operators), discharge location and voltage (Ken's in-ear ear buds vs. "on/over ear" for operators), wire lengths and floating vs. earthed configurations? Both deal with energy transfer to/from cells that are likely more sensitive (electrically/neurally/perceptually) than the human hand. Sounds (pun intended) like an interesting neuroscience topic! Maybe this could be an occasional benefit to not having a 3.5mm audio jack on a hand set. And this probably isn't a good idea for a new experiment at your workshops. ;-) Cheers, Adam in Atlanta On Sat, Jan 6, 2018 at 2:48 AM, Douglas Smith < [email protected] [[email protected]] > wrote: Thus is a common occurrence. The iPhone was not actually connected to you so the large E field induced a different charge on you than on the phone and hence the discharge through your ear (the lowest breakdown between the iPhond and you. Such discharges have led to claims of injury that ended up in court. Telephone operators and radar operators (such as in air traffic control) experience this effect. The first case I was involved with was 20 years ago and since have provided expertise to lawyers on legal cases involving this effect. The discharge is not dangerous, but people have been convinced they were nearly electrocuted and have been hauled off to the hospital on a stretcher! Doug Smith Sent from my iPhone IPhone: 408-858-4528 [tel:(408)%20858-4528] Office: 702-570-6108 [tel:(702)%20570-6108] Email: [email protected] [[email protected]] Website: http://dsmith.org [http://dsmith.org] On Fri, Jan 5, 2018 at 18:21, Ken Javor < [email protected] [[email protected]] > wrote: 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 [tel:(256)%20650-5261] - ---------------------------------------------------------------- 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 < [email protected] [[email protected]] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [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/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [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 [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < [email protected] [[email protected]] > Mike Cantwell < [email protected] [[email protected]] > For policy questions, send mail to: Jim Bacher < [email protected] [[email protected]] > David Heald < [email protected] [[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] [[email protected]] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [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/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [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 [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < [email protected] [[email protected]] > Mike Cantwell < [email protected] [[email protected]] > For policy questions, send mail to: Jim Bacher < [email protected] [[email protected]] > David Heald < [email protected] [[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] [[email protected]] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [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/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [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 [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < [email protected] [[email protected]] > Mike Cantwell < [email protected] [[email protected]] > For policy questions, send mail to: Jim Bacher < [email protected] [[email protected]] > David Heald < [email protected] [[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] [[email protected]] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [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/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [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 [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < [email protected] [[email protected]] > Mike Cantwell < [email protected] [[email protected]] > For policy questions, send mail to: Jim Bacher < [email protected] [[email protected]] > David Heald < [email protected] [[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] [[email protected]] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [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/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [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 [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < [email protected] [[email protected]] > Mike Cantwell < [email protected] [[email protected]] > For policy questions, send mail to: Jim Bacher < [email protected] [[email protected]] > David Heald < [email protected] [[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]>
