Re: Toroid Modeling

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 8/29/01 10:13:36 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:

> Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest.
> net>" <tesla123-at-pacbell-dot-net>

Bart,

Your results are very interesting.  So I guess when the
toroid is small, the shielding of the secondary dominates, 
and as it gets larger, ground plane effects of the floor 
begin to dominate.  It would seem then that as a coil is made
larger, it should be made taller also, or at least higher off the floor,
to reduce ground plane effects.  I guess the primary itself may
act as a ground plane.  This may argue against the use
of large diameter primaries.  Of course a coil with a large toroid
is normally made taller anyway, otherwise the sparks
would strike the floor.  As it is, a 20" to 24" toroid is probably
larger than would be normally installed onto a 3" x 15" secondary.
Your results should scale linearly I would think.  For instance
if everything was doubled in size, for instance a 6" x 30" 
secondary, at twice the height, and twice the toroid size, etc,
should give the same graph characteristics.  It would be
interesting to do some graphs for various coil heights I would
think, and also some graphs for existing coils, to see where
they fall on the graph.

Thanks,
John