RE: Coil Design

            RE: Coil Design
            Mon, 14 Apr 1997 08:20:37 +1200
            "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
            Wellington Polytechnic, NZ

Hi Barry,

>   From: 
>         Benson_Barry%PAX5-at-mr.nawcad.navy.mil
>     To: 
>         tesla-at-pupman-dot-com
> Hi Malcolm, All,
> Interesting article.  I don't understand the sentence:
> "This {mutual inductance} can be reduced or eliminated
> by proper geometry where the loops overlap each other
> such that the net mutual inductance is zero".

A similar thing is done for induction-balance metal detectors. It 
simply means the coils are positioned in such a way that coupling 
between them is reduced to near zero (there's one for the critical 
coupling enthusiasts :)  There was a short article in Electronics 
Australia a year or two back which showed the method invented to 
eliminate coupling between air-cored coils in early radio sets where 
the coils were mounted in a line but at around 40 degrees or so lean 
from vertical, all leaning in the same direction.