RE: capacitance equation for toroids

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

Original poster: "John H. Couture by way of Terry Fritz <teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Dr Resonance -

There is a graph in one of my books that shows the capacitance of toroids
using the equations below. One of the advantages of the graph is that it
does not require calcs. It can also be reversed engineered. For example if
you know only the capacitance it is a simple matter with the graph to find
several toroids that will work. This is much easier than trying to find the
different toroids using the equations when you only know the capacitance.

I will put the graph on my web site if there is enough interest.

John Couture

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-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, June 05, 2003 8:37 PM
To: tesla-at-pupman-dot-com
Subject: capacitance equation for toroids


Original poster: "Dr. Resonance by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<resonance-at-jvlnet-dot-com>


Someone on the list recently inquired regarding the equation for a torus:

let D = major dia. measured to outer edge of toroid

let d = minor dia. measured across "inner tube"

then, for conditions in which the ratio of d/D is greater than 0.25,

Cpf = (0.94 *d) + (0.584 * d)

and for conditions in which the ratio of d/D is less than 0.25,

Cpf = 4.57 * (D-d) / ln (8 * (D-d) / d))


Another simple equation, although not as accurate (but close for most
sizes) is:

Cpf = D + d / 2.56


For a sphere the equation is Cpf = 1.4 * dia.


Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913