Re: Effective Resistance

["Bert Hickman" <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
> 
> I won't pretend to fully understand the factors in determining Q and
> effective resistance but the discussion of operating vs. non-operating(?) Q
> has me wondering about the proximity effect.  As far as I understand this, I
> visualize it something like the drain-source channel of an FET, becoming
> constricted as the surrounding E-field increases.  But this model produces a
> resistor which is voltage-dependant for the FET, or current-dependant for
> the coil.  If this is so, I can see where the operating Q would be less than
> a low-power run.
> 
> So, is the proximity effect current-dependant?
> 
> Gary Lau
> Waltham, MA USA
> 

Gary, Malcolm, and all,

This is a GREAT question! Although it's not at all intuitive, proximity
effect, as with skin effect, is apparently not a function of the amount
of current flow, but only the geometry, frequency, and conductivity of
the conducting material. One would intuitively think that, as the
current increased, the magnetic "forces" would increase, impacting the
degree of the effect. 

Sort of a poser, isn't it!  :^)

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-com
Web Site: http://www.teslamania-dot-com