Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx> Hi Adriano,It is a complex problem. It depends on the coil dimensions and even some on the size of the room the coil is in. But there is a program here that does it to within about 3%:
http://hot-streamer.com/TeslaCoils/Programs/E-Tesla6.zip It finds the capacitance be working out all the electrostatic fields and such: http://hot-streamer.com/andrewb/This is the original DOS based program, but it still runs fine under Windows too. there are text files in the zip that tell how it works.
There is also an on-line JAVA program here that can do it: http://www.classictesla.com/fantc/fantc.html http://www.classictesla.com/java/javatc.htmlI have a coil a tune by raising or lowering the top terminal and it works very well. But you do have to get it set up right to begin with to be sure it will tune in the range you need. The above program will help a lot there.
Cheers,
Terry
At 12:46 AM 2/5/2006, you wrote:
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