Well, you may call them coupling capacitors in the range over which they are intended to transmit the signal without degradation just as you say, but they are blocking caps at lower frequencies.
Is the cap between a LISN power conductor and the EMI port a coupling or decoupling (blocking) cap? Depends on what frequency range you are talking about. Ken Javor Phone: (256) 650-5261 > From: John Woodgate <[email protected]> > Date: Wed, 16 Apr 2008 19:31:53 +0100 > To: <[email protected]> > Subject: Re: Bypass and decoupling capacitor definitions. > > In message <c42bac49.17e26%[email protected]>, dated Wed, 16 > Apr 2008, Ken Javor <[email protected]> writes: > >> Caps used to be used in series in audio amps to block dc from being >> amplified. Caps are used in series in ac-coupled o'scopes. In that >> sense, a cap can be a high impedance decoupler. > > No, those were, and are, called, for obvious reasons, 'coupling > capacitors'. Besides, the coupling only works as intended (unless > differentiation is intended) if the value of the capacitor is low enough > that its charge does not change appreciably during one cycle of the > lowest frequency of interest. If not, loss of gain and waveform > distortion (other than of a sine wave) result. So the capacitor is LOW > impedance compared with the source and load impedances in series. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > Murphy's Law has now been officially re-named The Certainty Principle > 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 - 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
