Re: Measuring self-capacitance directly (Re: flat secondary)

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

Original poster: "Peter Lawrence by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>

Paul,
     what was the ID of this flat coil, and what would happen for a center
feed coil if ID/OD where about 0.2 to 0.3 (rather than ~0.01 for an all-the-
way-to-the-center flat coil). I ask because that would be the "upside down"
TC, one of the configurations I've wondered about.

the curious engineer...
-Peter Lawrence.



>Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
<paul-at-abelian.demon.co.uk>
>

>
>The utilisation factor of this inductance, by which I mean the ratio
>Les/Ldc, is 113/134 = 0.84, which is typical of this middling h/d. 
>This ratio gets bigger with smaller h/d, and with short coils, the
>ratio can exceed unity, sometimes by 10 or 20%.  Interestingly, the
>flat spiral coils are coming out with a very high Les/Ldc, eg 140%,
>but only if they are driven from the rim, ie center hot.  See some
>modeled data for Marc's 20" flat coil,
>http://www.abelian.demon.co.uk/tssp/mm250202/
>which compares rim feed with center feed.  
>

>Paul Nicholson
>--