RE: New Inductance Formula

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

Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Hi Jan,

>I got a new, provocative version... hehe... ;)

>     (N*R)^2 * 10^-6 * kg * m
> L = --------------------------
>     [(350*R)+(390*H)] * coul^2
> (R and H in _metres_, N is unitless)

Here is a formula that approximates the inductance of the coil and the
inputs are in meters.  It works good for solenoid secondaries with 3 to 1
H/D ratio.  But it differs noticeably from Wheeler's formula when the H/D
ratio is .5/1 or lower.

         (N*R)^2 * 4 * 10^-6 * kg * m
 henry = ----------------------------
                (R + H) coul^2

R and H in meters, N is unit less.

Dave