Re: pole pig ballast

["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 1/16/02 7:16:21 AM Pacific Standard Time, tesla-at-pupman-dot-com
writes: 


>
> Hey guys, 
>
> I intend to use an arc welder to limit current to my pole pig. However, 
> I would like to use a little resistance to "smooth" the power supply   
> and make the system more easy to handle. Any advice on what sort of 
> numbers I need here? This is especially important as I may series 2 
> 11kV pigs and will have heaps of core to energize when the gap fires. 
>
> Cheers, 
>
> Greg Peters 



Greg, 

I use some large resistors that I bought from a surplus company.  From memory,
they are 1.5 ohm  1,000 watt.  They are about 3.0" in diameter and about 16"
long.  I bought three of them, to use in various combinations, but normally
only use one.  When running with a primary current of 30 amps, this resistor is
trying to dissipate 1,350 watts.  It gets very hot.  I have it mounted in a
steel frame and usually keep a large fan blowing on it.  Prior to buying these
resistors, I used several electric stove oven elements in parallel.  These were
difficult to mount into a frame and take up a large amount of space.  I think
their resistance varies from about 15 ohms to 22 ohms so it takes quite a few
to build a one or two ohm resistor. 

Ed Sonderman