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Re: Pole Pigs



Tesla List wrote: Original Poster: Nteslamoot-at-aol-dot-com I
Have 2 pigs and

I have yet to use them because I dont know how to limit
to  current with a welder or
better yet(cost) a homemade reactance of some sort. Any
ideas that could help me?? > thanks

Since I haven't limited my pig via a welder, I'll let
those who have reply on that. But I have limited my pig
with a modified variac. You can use either a good variac
or a bad variac. Size is a factor. You'll want at least
a 30A variac or preferably a 40A.

-------------------------------
>From DR. RESONANCE:
Try to scrounge the surplus yards or old theater groups
to find a burned out variac --the 30 amp variety has a
good cross sectional area which is the key ingredient. 
Remove all the old windings.  Clamp the variac solidly
so it doesn't go "sprong" and carefully saw through with
a fine hacksaw. In the gap epoxy a piece of plastic
approx 0.100 inches thick (100 mils). Next hand wind the
variac with 160 turns of #8 AWG insulated wire.  Tap at
150, 140, and 130 turns.  You now have a cheap and very
good pole pig current limiter -- save the welder for
welding.  Use a 1/2 Ohm, 10 KW resistor (about 12 feet
of heater nichrome) in series with this limiter and your
coil will run even smoother --- eliminates the 100 kw
peak surges.
--------------------------------

I used a good variac, so I had no need to rewind it. It
is rated at 30A. I cut the core to prevent saturation
since I knew I could easily overwelm the 30A variac
easily. I did this in a machine shop at work with a
gravity bandsaw (took quite a while to get through the
core). It has worked great. I am not using a resistive
ballast with the variac, but it is definately a good
idea and something I plan to add soon, as mentioned in
DC's post above.

Hope this bit of info helps, 
Bart