Re: Capacitance of toroids

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Adriano,

If using the Javatc program and should you need any help, just ask me 
(offline as to not clog up the list). You can run only the toroid 
dimensions if you like. But, you need both the toroid and secondary 
installed to equate the distribution result. Even the primary helps 
if known (as it also affects the secondary frequency capacitively).

I am curious however why you decided you needed 29pF? Are you 
shooting for a specific frequency?

Take care,
Bart

Tesla list wrote:

> Original poster: "Adriano Mollica" <adriano.mollica@xxxxxxxxxxx>
>
> Hello to everyone,
>
> I almost finish the construction of my TC, but i have a little problem.
> I need a top load of 29pF, than i think is ok, and i'm going to make it by
> using a extensible aluminium pipe, that is pretty cheap and easy to put in a
> toroid shape.
>
> My question is, how can i calculate the capacitance of that toroid i'm gonna
> build?
>
> i found on internet two different way to calculate it, but  both use only
> two parametes witch are , in one case: internal diameter and external
> diameter, or in the other case: external diameter  and size of the pipe.
>  And of course, i obtained 2 quite different measurements. What i need, is a
> formula that use all three parameters toghether: inside diameter(d) ,
> external diameter(D), and size of the tube(x).
>
> do you know the answer?
>
> thanks, Adriano