Re: AWG vs. Diameter

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

But welding cable is uninsulated strands, so from a skin effect standpoint,
it's the same as a solid bar....  True it's nice and flexible.. Even 4/0 is
reasonably flexible..
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, March 17, 2002 4:03 PM
Subject: Re: AWG vs. Diameter


> Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
>
> Hi Jim -
>
> How about welding cable? It's noted to be good for moving rf to ground
> considering the hgih
> quantity of thin strands. Might also be good in the primary (granted, it's
> physically large, but
> there might be smaller similar bundles).
>
> Bart
>
> Tesla list wrote:
>
> > Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jimlux-at-earthlink-dot-net>
> >
> > It occurs to me that a primary wound with several parallel smaller wires
> > might actually work better than a "skin effect" equivalent
crosssectional
> > area tube or single wire.  Consider that you were to stack (vertically)
a
> > half dozen AWG 10-14 wires, separated by, say 0.1 inches, and wind the
> > primary using the "ribbon".  Since the wires are physically separated,
the
> > self inductance (which relates to skin effect) would be reduced (much as
> > "bundling" does for HV transmission lines).  One could even work out
some
> > sort of "braiding" so that each conductor spends the same amount of time
on
> > the "surface" (essentially what's going on with Litz wire), or stagger
the
> > various spiral layers.
> >
> > One might also be able to figure out a winding configuration that
reduces
> > the amount of loss on the inner turns: Say the cross section of the
whole
> > primary were thick in the middle and thin at the edges... like a spiral
> > galaxy viewed edge on.  In the multiconductor scheme outlined above, the
> > vertical spacing between windings would be greater in the inner turns
than
> > in the outer.
> >
> > .
> > >
> > > Then, as the recent discursion about the inner turns getting hot
showed,
> > we
> > > have to consider proximity and eddy current effects.  Unfortunately, I
> > don't
> > > have an answer there.  I would think the thinner wire would be better,
but
> > I
> > > don't really know.
> > >
> > > In general, people tend to find that the thicker tubing does better
than
> > > thinner wire.  We always attributed that to the differences in skin
depth
> > but
> > > these new proximity and eddy current factors may matter a lot too.
> > Primary
> > > losses can really eat up a coil's performance so this is pretty
critical
> > stuff.
> > >
>
>
>