In message <f50a4280b6033741b1dd2b4e902258b1024de...@orsmsx411.amr.corp.intel.com>, dated Fri, 6 Oct 2006, "Pettit, Ghery" <ghery.pet...@intel.com> writes >It turned out that the manufacturer had designed the primary on the >power transformer so that if an overload occurred the excess current >would heat the undersized wires and melt the insulation (thin) between >them, thus shorting the mains wires and ensuring that the fuse in the >product would blow. Of course, this necessitated replacing the >transformer, as well as fixing the original cause of the problem. I DO >NOT recommend this design.
Nearly that technique is used in many wall-wart mains transformers. The primary wire has a special coating which causes the winding to go quietly open-circuit if it gets too hot. There is no separate thermal fuse. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Swine wave - a waveform whose spectrum is exceptionally difficult to calculate. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com 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 ______________________________________________________________________
