Re: Sphere/Toroid Comparison Chart

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

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

Hi John,

Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net>
>
> Kurt -
>
> I agree the equations shown on my web site do not represent the table shown
> below. However, for toroids above 20" large diameter there is a close
> agreement. The graph I show in my books is based on my web site equations.
> The graph covers toroids with large diameters from 10" to 80" and spheres
> 10" to 60". There are straight line curves for 3"-6"-12" and 20" small
> diameter toroids. None of the curves overlap.

I also graphed my data. The linearity is definate. This is good news.

> The equations were shown in the Tesla Coil Builders Association Newsletter
> Vol 6, #2. The graph was made several years ago using the Quattro Pro
> program. The graph shows isotropic capacitances which have to be reduced a
> certain percentage when the toroid is placed on the secondary coil. I
> estimated the percentage reduction should be about 20% but this may be too
> high.

I understand how you came to a percent based on your graph. This is good.
However, 20% may not be too high. I
think it will depend on many variables.

I propose that both JHCTES and JavaTC should change Fr and leave Ctop alone
(Fr is the affected parameter as
you know - regardless of C or L changes - Fr is what counts). Why not make
Fr the changed value. In all
probable systems, it will be less than 20%. You could easily adjust your
graphs accordingly to represent Fr (Fr
"did" change to this value regardless of C or L unknowns).

The programs can be more appropriately representative to real world coils.
Later when C and L are better
defined, the programs can more accurately represent these values and Fr
should then be even better. Just food
for thought - something to chew on. I'm sure you've been down this road before.

> Terry's E-Tesla6 program will certainly give a more accurate
> capacitance because it takes more of the surrounding variables into
> consideration.

I totally agree!

Take care,
Bart A.