Re: the finger of God

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 5/19/01 11:46:05 PM Central Daylight Time, 
tesla-at-pupman-dot-com writes: 


>
> >Hi Christopher 
> > 
> >Now you see why I like x-ray transformers so much. But there is something I 
> >feel you should know about them. Pole pigs are designed to dissipate enough 
> >heat so that they can be operated continuously. Some x-ray transformers 
> >will 
> >consume over 100,000 watts in their x-ray application, and in less than a 
> >second the primaries becomes blazing hot. Their primaries are not designed 
> >to dissipate such heat on a continuous basis. For continuous operation and 
> >to save the primary from destruction, the primary should be ballasted to 
> >consume between 5000 and 10,000 watts. I keep my x-ray transformers at the 
> >5000 watt level. 
> > 
> >Godfery Loudner 
>
>
> I'm just running it for about .5 seconds at a time, with minutes in between 
> runs, so I'm sure it will live. Thanks for the info though....I'll have to 
> forget that idea of a giant JL :) 
>
>
> Duck (Geek-1) 



Hi Chris, Godfrey, 

No, Chris, you won't have to forget the giant Jacob's Ladder :-) 
Like Godfrey said, just properly ballast the input to the x-ray 
transformer and you can run a 10 kVA Jacob's Ladder till your 
heart's content :-) What Godfrey was saying is that if you have 
an x-ray transformer rated at say 100 kV -at- 500 mA, you can't 
run it continuously at 50 kVA! They're designed for their name- 
plate rating at a very short duty cycle. I have a 140 kV -at- 500 
mA transformer that I just picked up from Steve Flowers that 
weighs in at 980 lbs and I ballast it with another fairly large x- 
ray transformer that's pulled out of its oil-bath tank, with its sec- 
ondary shorted. I can get away with running this monster at 15 
to 20 kVA in a JL configauration and boy is it HOT! And I get 
this level of power output with the variac turned only about 1/3 
of the way up and the JL rails minimum gap at 3"! But my 280 
volt, 30 amp variac won't handle this kind of abuse for more than 
about 30 secs. at a time w/ several minutes of cool-down. Yep, 
I need a bigger variac or to gang some more togehter ;-) But boy 
is this thing fun! Godfrey's correct, x-ray trnasformer's rule! 

Sparkin' in Memphis, 
David Rieben