Re: Spheres vs Toroids

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Antonio,

Fantc (level 3 detail):  = 40.47pF
Javatc  (level 2 detail [by default]): = 40.41pF

I also ran Fantc at a level 10 (off my pc as I can set the code for higher 
details).
Anyway, it showed 40.55. I would say your 40.5648 is doing quite well

Certainly, all these variances are insignificant.

Take care,
Bart



Tesla list wrote:

>Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
>Hi:
>
>I have just finished a routine that calculates exact capacitances
>of toroids in free space. The routine uses that series with
>Legendre functions, that is not after all so difficult to evaluate
>with precision. The values that I am obtaining, however, are a bit
>different from the ones that I see in the document prepared by
>Gary L. Johnson (that I don't remember from where I obtained).
>The formula is the same, but I am evaluating the functions in a
>different way, using elliptic integrals, that should be almost
>exact.
>
>Example:
>Major diameter: 90 cm
>Minor diameter: 30 cm
>I get: Exact capacitance: 40.5648 pF (all the digits correct)
>The document lists:       40.46   pF
>
>(Of course, the difference is insignificant for practical
>purposes, but I want the calculations correct.)
>
>There is also a table in the documentation of the program Mandk,
>but that table appears to use an approximate formula, the same
>listed in Gary's paper.
>
>Antonio Carlos M. de Queiroz
>
>
>
>