Re: OLTC update

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 9/22/02 7:54:53 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:


>
> > I am interested if anyone has any tips on how to wind a 34mH air core
> > inductor with #20 wire using the least amount of wire (least resistance).
> > I figure a very short large diameter coil?
>
> The highest inductance per length of wire is scored with highest 
> coupling between all turns. Therefore, a multi-layer coil with the 
> number of layers = number of turns per layer is the way to go.


Hi All,
It can be shown that the highest achievable inductance for a given length of
wire for a helical coil occurs when Height= 0.9 x Radius. There is a similar
maximum for a flat coil at 8R=11B. I can send you a paper showing the
derivations, if you desire.
Matt D.