Re: Toroid Capacitance

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi Eric,

Matt's page has this and most other TC equations:

http://home.earthlink-dot-net/~electronxlc/formulas.html#toroid

If you are trying to determine the Tesla coil's frequency, just knowing the
toroid capacitance is not enough.  The secondary also has it's own
capacitance too:

http://home.earthlink-dot-net/~electronxlc/formulas.html#medhurst

However, you cannot simply add these two to get the total (unless you just
want a rough idea).  The electrostatic fields around the two (toroid and
secondary) combine in complex ways.  The actual total will be somewhat less
than the two separate capacitances.  The computer program E-Tesla5 will
take all the dimensions and such into account and give you a system
frequency with a few percent.  You will need to know the secondary
inductance but the formula for that is at the above site too (Helical Coil
Inductance).

http://users.better-dot-org/tfritz/site/programs/E-TESLA5.ZIP

This program will give you the total secondary capacitance.  Subtract the
Medhurst (secondary coil's) capacitance from this to get an "effective"
toroid capacitance that can be plugged into the many other Tesla coil
programs.  Then everything will work out well.

Cheers,

	Terry


At 09:42 AM 7/23/00 -0400, you wrote:
>hey everyone,
>
>Would anyone here be able to supply me with an equation to get a rough 
>estimate of how to determine a toroid's capacitance?
>
>If you are able to, I thank you greatly
>
>            ---eric gendron---
>