Scott: Regulatory requirements aside, I have a personal rule of design learned >from many years of high volume production. 'Never use an undocumented feature of a component.' This one of Mr. Murphy's favorite I got yas. Engineers succumbing to this sin are often bitten in the rear when the manufacturer changes the product or your own purchasing decides to save a few mills and buy from another vendor. Resistors stated as 'fusible' cost a bit more but will save you a production stoppage down the road.
Just this man's opinion. Fred Townsend From: [email protected] [mailto:[email protected]] On Behalf Of Scott Xe Sent: Wednesday, July 18, 2007 7:49 AM To: [email protected] Subject: Carbon film resister acts as fuse to avoid temp rise I recently evaluated an audio product. During fault condition test, I short-circuited an electrolytic capacitor in power supply unit and found two small-value carbon resistors in series with a group of output windings of the isolating transformer and rectifier circuitry burned out in a couple of seconds. I repeated it several times and it worked reliably. I am wondering if this method is deem to be acceptable as a reliable means to prevent overheating. Any different comments about such means of protection? Thanks and regards, Scott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
