Good points about the complex relationship of the components making up a transformer. I especially liked the reminder about the bia used on recording heads... I had completely forgot about that.
73, Mark W1EOF > BTW audio analog tape recorders minimized this problem with the head > by using a high frequency bias, say 22 kcs, to keep the flux > constantly changing and allowing good LF response while making the > recording. The HF signal is filtered out on playback either by the > playback head or immediately before the first preamp. > > Larry W3LW > > Some folks on here surely can amplify this and correct my fuzzy > memory if needed. > > > The problem is the energy transfer medium - THE IRON. > > > > At 01:02 PM 3/13/2006, John E. Coleman (ARS WA5BXO) wrote: > > Perhaps I should clarify one point that we may all be forgetting > >here. A XFMR will only transfer energy during the movement of > the magnetic > >field (EXPANDING OR CONTRATING). If the magnetic field becomes > stationary > >then no energy will be transferred to the secondary regardless > of the amount > >of iron. But if the magnetic movement is fast enough then transfer > >efficiency can be high. As the frequency is lowered the > magnetic movement > >is slowed down then the efficiency drops off. I'm not sure if > this is the > >proper term mathematically but it is as if the coefficiency of > coupling is > >not as good when the frequency becomes too low. > > > > I hope I'm not boring folks with this and some may say > I am making a > >mountain of a mole hill. I just find it fascinating. I guess > it is just my > >type of thing. > > > >John, WA5BXO > >----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED] On Behalf Of John E. > Coleman (ARS > >WA5BXO) > >Sent: Monday, March 13, 2006 11:36 AM > >To: 'Discussion of AM Radio' > >Subject: RE: [AMRadio] Class AB and B audio XFMRS > > > >The Band pass and energy Xfer of a transformer with no load is > one thing but > >it all changes depending on the load and the DC involved. In class A > >balanced PP circuits the XFMR will still saturate at some > frequency and load > >even if it is perfect balance on the PP circuit. XFMR > saturation distortion > >in class A single ended service has a trapezoidal shape if the quiescent > >current is too high but in PP class A the shape is weird because the XFMR > >remains balance as for as DC is concerned but yet the XFMR will > not produce > >the sign wave on the output if the frequency is too low. It > resembles cross > >over distortion even though there is no cross over in class A push-pull. > > > > > > > > > >______________________________________________________________ > >AMRadio mailing list > >Home: http://mailman.qth.net/mailman/listinfo/amradio > >Help: http://mailman.qth.net/mmfaq.html > >Post: mailto:[email protected] > >AMfone Website: http://www.amfone.net > >AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 268.2.1/279 - Release Date: 3/10/06 > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 268.2.1/279 - Release Date: 3/10/06
