"Once a lack of immunity exists, there are limitless possibilities"
Indeed, that should be written on a wall in everbody's lab. Failures don't always go the way we expect; everything that the product does correctly has to be monitored for degradation, but beyond that, you have to be aware of the possibilities of the unexpected. How far you should continue down this dark tunnel of investigation depends on the cost and consequences of device failures, and the limit of your budget, paranoia and suspicion. Ed Price WB6WSN Chula Vista, CA USA -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Sunday, March 10, 2013 4:32 AM To: [email protected] Subject: Re: [PSES] Immunity and emissions below 150 kHz and lithium batteries In message < <mailto:[email protected]> [email protected]>, dated Sun, 10 Mar 2013, Ed Price < <mailto:[email protected]> [email protected]> writes: >The battery controllers themselves sometimes proved very vulnerable, >lacking radiated immunity, but they always failed by disabling the >battery; no dying controller ever forced the cells into a conflagration. But that is critically dependent on the detailed design of the controller. Once a lack of immunity exists, there are limitless possibilities (including simultaneous multiple disturbances) of something switching ON in error rather than switching OFF in error. In fact, switching ON is, in principle, more likely, as any sufficiently large high-frequency disturbance presented to a bipolar base circuit WILL turn on the device: turn-off requires a more complex scenario. -- OOO - Own Opinions Only. See <http://www.jmwa.demon.co.uk> www.jmwa.demon.co.uk SHOCK HORROR! Dinosaur-like DNA found in chicken and turkey meals John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- 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 < <mailto:[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://listserv.ieee.org/request/user-guide.html> http://listserv.ieee.org/request/user-guide.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 < <mailto:[email protected]> [email protected]> Mike Cantwell < <mailto:[email protected]> [email protected]> For policy questions, send mail to: Jim Bacher: < <mailto:[email protected]> [email protected]> David Heald: < <mailto:[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://listserv.ieee.org/request/user-guide.html 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]>
