Re: Q about E-tesla-6

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

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

Hi Peter,

At 04:49 PM 9/10/2001 -0700, you wrote:
>Terry,
>      I've started using E-Tesla-6, and have read your short overview about
>it but I have some questions about its design.
>
>I think I understand how the electric field is computed at any point (the sum
>of the electric fields from the charge at many individual points for all the
>TC "parts"), but how is the distribution of charge on a toroid computed - do
>you assume it is evenly distributed over the entire surface of the toroid plus
>the center plate, or is there an iterative method to determine the charge 
>distribution, or is there a known formula?

E-Tesla places a virtual sphere around the entire coil.  The coil is
assumed to be symmetrical about the center axis.  A 2 dimensional grid is
computer from the center axis out to the wall and that grid is "spun"
around the coil.  Through calculus, The total field through the surface is
summed up to compute the interior charge.  The file "original.txt" explains
the basic physics.  "Gausses law" is key to the whole thing.

"The total flux passing outward through any closed surface equals (1/eo) times 
the total electric charge inside the closed surface."

Q = Sum E x eo

C = Q / V

The shape of the internal object is not important.  Buy knowing the total
flux through the sphere that encloses the coil, you can find the total
effective capacitance.  That with the inductance of the coil gives the Fo
frequency.  Maybe see:

http://hot-streamer-dot-com/andrewb/

>
>I am wondering both to understand E-Tesla-6, and because I would be interested
>in knowing how an "exact" formula for the free-space capacitace of a toroid
>could be determined, I've seen the derivation in physics books for a sphere,
>but never anything more complicated.

The "exact formula" does not take into account the room and coil proximity
effects and E-Tesla is iterative so it can never be "exact".  Maybe just
"like real close" :o)

The source code is in the file E-Tesla611.C

Hope that helps.

Cheers,

	Terry


>
>thanks,
>Peter Lawrence.
>