"Ground" is a commonly misunderstood term by many analogue, digital, safety and EMC specialists. "Return" or "Common" are likely far more useful terms. I like "local reference" too.
Ralph McDiarmid, AScT Xantrex Technology Inc. From: emc-p...@ieee.org on behalf of John Woodgate Sent: Mon 12/22/2008 5:10 AM To: emc-p...@ieee.org Subject: Re: Thevenin equivalent circuit for SMPS emission sources - issues In message <FCA549BE3ECF9D4CB8CB8576837EA489053430@ZEUS.cetest.local>, dated Mon, 22 Dec 2008, Gert Gremmen <g.grem...@cetest.nl> writes: >All designers (but the RF specialists) overlook the third connection to >any circuit , the real earth ! (sometimes represented by a conductive >enclosure) There is no such thing as 'real earth'. There are only purely local 'zero reference potentials'. I gave a talk on this recently to the UKRI section, and I'm trying to get time to write it up for the section web site. At 3 GHz, 'local' usually means 'REALLY local' (millimetres, even). At mains frequency, significant voltage differences can occur between points not many metres apart. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk All these closing-downs have been caused by dozing clowns John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 <emc-p...@ieee.org> 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 <emcp...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - 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 <emc-p...@ieee.org> 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 <emcp...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
