Re: Primary Heating

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>



Tesla list wrote:
> 
> Original poster: "Peter Lawrence by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <Peter.Lawrence-at-Sun-dot-com>
> 
> Are you suggesting that the current flow in a thick primary conductor is not
> uniform across the cross section of the conductor, 

This is a well known phenomenon, and manifests itself as "skin effect"

and that this non-uniformity
> would be different for inner turns verses outer turns?

Presumably..


 Wouldn't this have to be
> something other than skin effect since inner and outer are both operating at
> the same frequency?

Radius of curvature, etc. are different for inner and outer turns, so the
effect of the magnetic field from the current in adjacent windings and from
adjacent parts of the same winding would be different.  

Consider an extreme case.. 1cm diameter conductor, 1 turn at 1 meter radius
and 1turn with 1 cm radius.  Now consider a tiny radial slice... Consider
the field from the slice directly opposite it.  In the 1 meter case, that
field will be quite small (being from 2 meters away), and probably has
little or no effect on the skin depth.  In the 1cm radius case, though, the
field from the other side is fairly significant, being only 2 diameters
away.  Since it is opposite in sign, it will tend to increase the skin
depth (because it "neutralizes" the self field which causes skin effect in
the first place).

The same argument can be applied to fields from adjacent conductors, and
from pieces of the conductor other than 180 degrees away.


 Are