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New Pig Power Supply

 * Original msg to: Esondrmn-at-aol-dot-com


Ed,

I have just been reading through your posts again, and was
looking for any other suggestions or ideas that I might have to
help you get that new pig under control and firing. 

Putting a pig on line throws a couple of new variables at you at
the same time. You have no doubt observed that pole pigs just
want to pump through current, they don't want to limit down, and
the spark gaps don't (or won't) passively quench with all of this
current thrown at them.

Then there is the inductive delay through an inductive ballast,
(arc welder in this case), the heavy variacs, and the pole pig
core, before any power will develop on the HV bushings. In real
time this delay is pretty much over a full second. When you are
messing with these power levels, a one second delay is difficult
to become comfortable with: when nothing happens you dial in a
little more voltage with the variac, nothing still happens so you
dial in a little more, the gaps fire and you think things are
cool, then about one second later you realize the Hoover Dam is
pouring into your tank circuit. As you now know, it is not at all
the feeling of turning on and off a light switch, or even using a
dimmer circuit.

A pointer here might come from your lack of discussion about the 
settings you are using on the arc welder secondary circuit. If
too much current is pouring into the tank circuit and shorting
out your spark gap, then choke the current down some. By changing
the output setting on the welder secondary, you change the input
current into the pole pig. It sounds like you are starting out
with the current limiter opened up too much. An arc welder will
choke down any pig to the point it can be controled.

And lastly about the spark gaps. Try engineering a heavy-duty
single gap similar to my airblast gap plans. This will allow for
better control of the gap breakdown voltage, and you can quench
this transformer at these power levels with the ducted output of
a high speed vacuum motor/blower unit. I happen to have an extra
Hoover vacuum motor/blower that has a ducted output. It should be
perfect for the job. $5.00 and it is yours if you pay the
shipping costs. 

Just some thoughts to help out. 

Richard Quick

... If all else fails... Throw another megavolt across it!
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