RE: Mutual Inductance & K Factor

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Original poster: "Loudner, Godfrey by way of Terry Fritz <twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU>

Hello Paul

When you set up the Neumann integeral, did you view the conductors of the
primary and secondary as filaments through the centers of their cross
sections, or did you take into account the thickness of one or both the
conductors. Is the mutual inductance of two conductors of circular cross
section equal to that their central filaments? I feel that this is not true
in general. Have you seen a mathematical demonstration that Wheeler's
formula approximates the ellipitic integrals? What is the formula of Lundin?

To evaluate Neumann integral, I assume that you have employed a numerical
approximation method for which there exist a proof that the computation
converges to the desired result for the indicated situation.

Godfrey Loudner

  

> -----Original Message-----
> From:	Tesla list [SMTP:tesla-at-pupman-dot-com]
> Sent:	Sunday, March 17, 2002 6:05 PM
> To:	tesla-at-pupman-dot-com
> Subject:	Re: Mutual Inductance & K Factor
> 
> Original poster: "Paul Nicholson by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>
> 
> ACMI and MandK both work by directly computing the inductance 
> using the Neumann integral.  This involves integrating an
> elliptic integral over the coil - in MandK by direct computation
> of the elliptic integral, and in acmi by table lookup.
> The computation converges to an exact solution for wires which are
> small compared to the turn radius.
> 
> The familiar Wheeler and Lundin equations are derived as
> approximations to the elliptic integrals.
> 
>