Jacobs ladder ballast (fwd)

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Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 15 May 2005 09:51:47 -0400
From: David Speck <dave@xxxxxxxxxxxxxxxx>
To: jaholmes@xxxxxxxxxxxxxxxxxx, hvlist@xxxxxxxxxx
Subject: Jacobs ladder ballast

Aaron,
Only problem with using heater elements is that they are dissipative 
ballasts -- they convert a good portion of your power to useless heat.

Using inductive ballasts converts significantly less of the input power 
to heat, allowing more power for the display.

I'd suggest using a bank of 9 to 15 microwave oven transformers with 
their outputs shorted.  If you run multiple parallel chains of three 
transformers, then none will ever see more than 220/3 volts, and they 
will run reasonable cool.  Use you relays to  switch in more or fewer 
chains to get more current to your pig.  These would not have to be  in oil.

Are you familiar with the huge continuous arc display that was shown at 
the 1939 NY World's fair by GE?  They used three seriesed three phase  
HV transformers to get a three point 1.5 megavolt continuous flaming 
discharge.  The transformers were specially designed for the system, and 
used high leakage inductance to limit the arc current, just like a neon 
sign transformer. 

I have a neat book by T. Blalock describing the production of HV 
transformers by GE at Pittsfield MA, and I've corresponded with him 
about the display.  His mentor at GE designed the NYWF display  system, 
can't remember his name  at the moment, but he's gone now.  I'd love to 
see a movie of the whole show.  I understand that parts of the show were 
used in the intro to a "GE Theater" series in TV in the 50's, and sort 
of dimly remember seeing it, but I'd sure like to see the whole thing 
some day.  Man, wouldn't that be a display do see again!  Unfortunately, 
the transformers were parted out, and only one of them remains intact, 
but unused now.

Dave Speck