Hi, Dave. John and I have discussed this very thing off the list this morning (morning for me, anyway). That flux analysis does seem intuitively correct. When I posted, I wasn't thinking of the complete magnetic system.
Still, if there's any question about the type of load effecting a waveform and contributing to hum (I've deleted the thread as it progressed, so I can't say who put that suggestion in my mind), establishing a magnitude equivalent load current of a different type will tell a tale. Regards, Peter L. Tarver, PE [email protected] > From: drcuthbert > Sent: Thursday, December 22, 2005 8:54 AM > > Peter, > > The primary current that is caused by the secondary load creates a > magnetic flux in the core. The secondary current creates a > magnetic flux > in the core. These magnetic fields are equal and opposite and > therefore > they cancel. Loading a transformer secondary does absolutely > nothing to > the magnetic core flux. The core flux is set by the > magnetizing current > and not the load current. Does this sound correct to the rest of the > group? This has come as a revelation to me, I must say. But, it is > intuitively obvious. The formulas support this but none of > the papers I > read pointed out why, or if they did, I missed it. > > Dave Cuthbert > Micron Technology, Inc. > _____________________________________________________________________________ Scanned by Sanmina-SCI eShield _______ _____________________________________________________________________ - 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
