Re: Inductance of a conical coil

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Original poster: "Godfrey Loudner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <ggreen-at-gwtc-dot-net>

Hello Antonio

I haven't yet worked directly with integrating Neumann's integral.
In my initial approach, the secondary and primary are modeled by
a collection of filament circles. In a vague description, I integrate
across a "sheet" of elliptic integrals to obtain an approximate M.
I'm trying to optimize this circle approach. In the next level of
approximation, I'll try and remodel the primary as a collection
of circular rings to account for thick primary conductors. The
optimized M from the circle approach will play a role in the
ring approach. At least with circles and rings, I can move the
mathematics along. My goal is a good approximation formula
that you can carry in your pocket. I think tonight I'll set up
the Neumann's integral for Bart's old 12.75" coil, using a
parametric representation of the spiral. Of course I'll use
filaments for the conductors. I want to see if the powerful
Mathematica software will numerically integrate the Neumann
integral.

Godfrey Loudner

 > It seems that we are integrating the same equation.

 > Antonio Carlos M. de Queiroz