Re: Solid State Tesla Coil Book Available

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Loudner, Godfrey by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU>
> 
> Hello Antonio
> 
> The ideally exact formula for an isolated toroid is located at
> http://www.eece.ksu.edu/~gjohnson . Since the formula is an infinite series
> of Legendre functions of two types, numerical computation is a problem. I
> don't know yet the rate of convergence of the series. An error term will
> have to be derived. If particular values of the parameters required the
> addition of 100 terms of the series to obtain three place accuracy, then a
> software package like Mathematica or Maple would be necessary. The formula
> has an appealing analytical look, but is a computational nightmare. A toroid
> used as a top load of a tesla coil is not isolated, but the formula could
> have theoretical value.
> 
> BTW math. people use the word torus for the word toroid.
> 
> Godfrey Loudner

	The analytical expression for Nagaoka's constant, used in inductance
calculation, involves the difference between two elliptic integrals,
which converge slowly.  A few years ago some fellow worked out an
approximation good to a couple of parts/million.  Uses a few simple
terms and computes very rapidly.  Maybe some ambitious person  could do
the same thing for the isolated torus problem.

Ed