Am not aware of increasing number of general power supply fires - would be very interested in, and appreciative of, any recent data on this subject.
The 'charger' fires seen so far seem to be related to counterfeit goods, where plastics have no flame rating, there inadequate internal spacings, and units cannot meet di-electric withstand levels even for BI. There have been fires where an over-loaded unit was under a pile of blankets - but susceptibility to this fault mode is from poor electrical design and poor test methods by the conformity assessment body(s). Brian -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Tuesday, November 04, 2014 11:57 PM To: [email protected] Subject: Re: [PSES] New electrical phenomenon reproduced tonight! In message <[email protected]>, dated Tue, 4 Nov 2014, Doug Smith <[email protected]> writes: >Don't have a good explanation yet as I am hesitant to take apart one of >the supplies that is the worst offender as it is the supply for a >D-Link router I have. I am beginning to formulate possible mechanisms. >But from the point of view of equipment, supplies that do this should >not be used. I have been using a simple test setup (on a normal lab >bench, not a standards based setup) that would suffice for prescreening >supplies. > >There is some sort of discharge happening and the delay could be the >time it takes for a discharge to form. I have been able to repeat the >results with ESD as the stimulus in three different labs using >different equipment. Understood. I wonder if this effect may be involved in the power supply/charger fires that seem to be increasing in number. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? 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 <[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]>
