In message <[email protected]>, dated Tue, 18 Apr 2006, [email protected] writes >To follow on from Stuart's question, the circuit you describe, relies >on the grounding for EMC being provided by another device (usually the >PC). How effective is the suppression of the Y cap when it has the >inductance on the USB cable etc. in series with it?
Ipso facto, it's 'effective enough to get through the test'. If it wasn't, it wouldn't be there. I suspect it had indeed most of its effect at the lower harmonics of the switching frequency. But it's a bit of a mystery how it works, anyway. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immensely. 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 [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
