Re: Breakdown voltages of toroids

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:

 > Original poster: Paul Nicholson <paul-at-abelian.demon.co.uk>

 > You asked about this in your last post in the 'Charge distribution
 > on a Toroid' thread we had going.  Sorry I haven't had time to
 > continue that most interesting discussion - I will pick it up
 > later on, but for now I'll just confirm that I too obtain the same
 > non-physical distortion of the charge distribution at the
 > 'poles' of the objects.   I try to mitigate this by using the
 > centroid of each ring for both the location of its charge, and
 > for collocation,  although that doesn't (in my case) completely
 > solve the problem.  I think it comes back to having a good enough
 > self potential formula for those rings which are actually small
 > discs.

I was experimenting in varying the self-potential calculation
along the curve, but this seems complicated. For a sphere, I get
some improvement if I leave small openings at the poles.

This effect is causing an error in the calculation of the
maximum electric field between two spheres too (the calculation
only converges to the ideal value with less than 0.1% of error with
many rings). The use of openings improves the accuracy in this
case too.

But I don't like this solution. I will see what happens in a toroid,
after coding the exact expressions for potential and electric field,
if I manage to extricate them from the papers.

 > I hope to get back onto this topic at some point soon, and also
 > the 'Magnifer vs. Tesla Coil' thread.

I will eventually code a simulator like yours, since I have how to
calculate inductances and capacitances from coils.

 > PS, perhaps 26kV/cm would be better than 30kV/cm for the high
 > frequency breakdown field strength?

I will leave this as a field to be filled. I don't like those formulas
where the breakdown voltage depends on the gap distance. This doesn't
look physical.

Antonio Carlos M. de Queiroz