Re: 8 kHz Tesla Coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 09:28 PM 10/1/2005, you wrote:
> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
> Hi Jim,
>
> I went thru all my text books and did find a section on skin depth 
> for round conductors.  Funny that you mentioned it, it does involve 
> Bessel functions. I will study up on it and report what I can learn 
> from it.  I'm hoping that we can find an easy way to come close to 
> finding the Rac without proximitry effects first then we can tackle 
> those effects later.  Another approach might be to have a RDRE table 
> for each wire guage that would give the Rac/Rdc vs frequency.  This 
> should be easy to incorporate into a program and easy to interpolate 
> between frequency points.

That would work..
BUT, I think there are enough other factors (proximity effect) that a 
"better" overall solution would be useful.

One might be able to build up some sort of useful table with wire 
diameter, frequency, and spacing as the independent variables.  Or, 
use the long form equations or a FEM program to calculate the 
numbers, then find a simple interpolating function that works nicely.

Or, just grind out the explicit equations for the whole thing.  Once 
it's coded, everyone can use it.

Probably the real question is to settle on what level of precision 
you think you might need.  In general, I'd think that trying to get 
better than 1% is not worth it, and at that level, a simple 
approximation might work just fine.

> Gerry R.