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Re: Many dry caps in series?



Tesla List wrote:
> 
> Original Poster: David Huffman <huffman-at-fnal.gov>
> 
> Something I have wondered is if there will still be corona on the caps that
> are at the top of the voltage string. That is even though the individual
> voltages on the sections will be under 1KV, the voltage on some sections
> will be several KVs WRT ground or the surrounding air. Does someone know for
> sure ?
> Dave Huffman

You could reduce this effect by putting in "grading rings", i.e.
electrodes that establish the overall efield. Imagine a stack of toroids
at successively higher voltages. Anything between a pair of toroids will
only see a E field determined essentially by the voltage difference
between the toroids, with almost no concern for the outside world.


However, for the low voltages one sees in TC primary service, I wouldn't
think this is necessary. The breakdowns in dry caps occur within the
cap, determined entirely by the voltage on that cap. You won't get much
corona or flashover from the cap to ground.


-- 
Jim Lux                               Jet Propulsion Laboratory
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