Re: Equivalent lumped inductance and toroidal coils

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

Original poster: "Antonio Carlos M. de Queiroz" <acmdq-at-uol-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: Paul Nicholson <paul-at-abelian.demon.co.uk>
 >...
 > The only sure answer, I suppose, is to code up the familiar
 > Neumann integral for the whole coil, say on a turn-by-turn
 > basis, with each turn weighted by the current distribution.
 > We've done this for all sorts of other coil shapes, but not
 > I think toroidal coils.
 >
 > Does Antonio have this case covered?

No, I don't. I was about to start coding toroidal coils, but this will
have to wait some time. The calculation of the low-frequency inductance
is no great problem with the decomposition of the coil in rings,
specially considering the many symmetries. The consideration of the
distributed capacitance looks complicated, because the charge
distribution would be not uniform along a turn.
I was thinking about a program that could at least calculate the
low-frequency inductances and mutual inductances, but considering
sets of coils with the shape of a "curved conical coil", that with
adequate parameters could be a solenoid, a flat coil, a conical
coil, a partial or total toroid, a straight wire, etc.

Antonio Carlos M. de Queiroz