Re: Rotary missfiring.....

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 11/5/01 3:42:55 PM Pacific Standard Time, tesla-at-pupman-dot-com
writes: 


>
> Original poster: "david baehr by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <dfb25-at-hotmail-dot-com> 
>
> Howdy, As I was doing a search on the tesla page, i ran across a mailing from
>
> Ed Sonderman about having problems with his rotary gap missfiring,not running
>
> smoothly,etc. This was the exact problem with my old system. I had only a 
> rotary and the electrode gap was set to just miss.....when first bringing up 
> the variac, the gap would fire, but erraticly.I would let it run like that
> for 
> a while, then it would smooth out, then I could turn up the power the rest of
>
> the way. I had a welder current limit with no resistance, tried using some in
>
> series but that did not help,Had to keep gaps as tight as possible. Now that 
> I'm building a new coil, I got the feeling this condition may come up again. 
> Was there a solution to this problem????, If it was posted I could not find
> it 
> .No way I could use series gaps with the rotary....don't understand how other
>
> coiler's do it, H E L P  thankyou!!!!! 
>


David, 

Yes, I remember it well.  It was being caused by a resonant charging condition
between the pole pig and the welder that I was using for primary ballast.  It
caused a popping sort of noise, like small explosions in the async rotary gap. 
I placed a safety gap across the rotary, set at 5/8", and it was firing with
the variac set only to one half to three quarters power.  I killed one
Condenser Products capacitor with this set up and am lucky that is all.  The
voltage in the primary must have been going to 30 or 40 kv. I swapped the
welder for a 40 amp variac for ballast and the problem went away.  I now use a
synchronous rotary and of course, things run nice and smooth.  I do still use
some small amount of resistance in series with the ballast variac - and I still
have a safety gap across the rotary, set to about .40", and it does not fire. 

Ed Sonderman