From: Paul
Date: Thu, 16 May 2002 18:30:51 +0100
Subject: Re: [TSSP] Topload breakout potentials
John, Bart,
Thanks for the details on the primary winding, that's very helpful.
I'll work through those this evening.
John wrote:
> I seem to see about 220kHz which doesn't seem correct.
For the larger toroid, that sounds a bit high. I've had to
guess a few things...can you measure the secondary inductance?
> you mention a base height of 20 something
> inches. What does this base height refer to?
Height of the secondary base above the ground plane. In you case
it's hard to decide what to call the ground, so I'm happy to
tweak the base height, wall distances, etc in order to get a
match with measured resonances.
Bart's secondary Fres was about 5% higher than predicted, which is
a big discrepancy. I had the walls at 60" and the roof at 120".
I took these away altogether and got
Measured Modeled Error
ba0: 69.8 kHz 69.9 kHz +0.1%
which is more like it. I guess that even though there is a wall
and a ceiling present, they are not terminating much of the E-field.
Bart's coil present an even bigger mystery now, because as well as
the good match on the secondary we also have for the primary
Measured Modeled Error
ba0: 61.3 kHz 61.5 kHz +0.3%
so the -12% tuning is genuine and we ought to be getting less than
17kV/cm on the toroid.
Is there any possibility that some resonant effect in the charging
circuit is giving a larger than expected bang? Bart, can you confirm
the toroid dimensions 30"x9", sorry if I've asked before but so
much stuff crosses my desk at the moment I'm losing track!
--
Paul Nicholson,
--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.