Re: Vf,Zo,R,G,L,C.....

To: tesla-at-pupman-dot-com
Subject: Re: Vf,Zo,R,G,L,C.....
From: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Wed, 30 Dec 1998 14:23:56 -0700
Approved: twf-at-verinet-dot-com

Tesla List wrote:

> A single lossy line model.  The corums like the balanced pair but that does
> not seem realistic to me...  But perhaps they have a good reason to use the
> two lines that I don't understand...??

The model is always the same for a TEM line. Only the parameters change.

> BTW - the lumped models give pretty much the same waveforms and results
> just like I always said :-))  However, with the transmision lines you can
> see the impulse effects of the coil's 3/2, 5/2, 7/2... wavelengths
> reflecting back which is sorta neat...  but for most uses, the lumped
> parameters ar vastly easier to deal with and give perfectly good results.

Some time ago I posted something about some measurements that I made to
find these higher-order resonances. They were all there, with the
expected
voltage distributions along the length of a coil, but all at the -wrong-
frequencies (significantly lower than what the TEM line predicts).
I attributed the difference to the fact that a vertical coil is not a
TEM line, because there is significant magnetic field in the 
vertical direction. A model of this behavior can be obtained by
including coupling between successive LRC sections of the usual TEM
model, but I didn't try to derive one.

Antonio Carlos M. de Queiroz