Re: term understanding: voltage reversal.

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

Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net> 

Tesla list wrote:

>Original poster: Sean Taylor <sstaylor-at-uiuc.edu>
>
>>More robust 45 kV caps will survive in a similar environment: 
>>http://cgi.ebay-dot-com/ws/eBayISAPI.dll?ViewItem&item=2596506003
>>
>>Since the problem is associated with oscillatory discharge in the tank 
>>circuit, the method of charging the cap (AC or DC) is irrelevant.
>>
>>Best regards,
>>
>>-- Bert --
>
>This 45 kV cap that you have a link to is a 31xxx series cap, which I 
>believe are only rated for 1 PPS, that is if I remember correctly . . . 
>Anyone have more info on this cap?  It may work in a lower power coil 
>(it's about the right size for a 9/30, at LTR for a stationary gap), but I 
>would expect it to heat up a little more than one of the 37xxx caps.
>Like I said, that is if I remember the model numbers correctly.  Feel free 
>to comment if anyone knows for sure . . .
>Sean Taylor
>Urbana, IL
>
>.

Hi Sean,

You do remember correctly.

However, this particular capacitor happens to be one of the exceptions to 
the rule. Although most caps in the 31XXX series are indeed rated for 3 x 
10^4 or 1 x 10^5 pulses (i.e., low duty cycle), there are a few notable 
exceptions.

Model 31393 and 31981 are rated for 1 x 10^8 pulses, and the model 31583 
from the referenced eBay auction is actually rated for 90% survival after 4 
x 10^8 pulses and 20% voltage reversal. This specification is actually 
better than most of the caps in the 37XXX series... :^)

Best regards,

-- Bert --
-- 
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