I will add a little to Gremmen's input. The source of the common mode signal is typically the rising and falling edge of the switched waveform. That will give you the time domain potential. But since the requirement is in the frequency domain, you would have to perform an FFT to figure out what your driving potential is relative to the CE limit. Ken Javor
Phone: (256) 650-5261 > From: <[email protected]> > Date: Fri, 12 Dec 2008 23:47:16 -0800 > To: 'Ken Javor' <[email protected]>, 'Untitled' <[email protected]> > Subject: RE: Common-mode emissions from SMPS > > > > > The question I have is: > > What is the Thevenin equivalent circuit > looking back up the ground wire with > respect to the line and neutral conductors? > > Is the source driving the current a current > source or a voltage source or something in > between? If in between, what is the source > impedance (approximately)? And, what is the > approximate value of the open-circuit voltage? > > > Rich > > > - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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]>
