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Re: I need a bigger variac. (fwd)





---------- Forwarded message ----------
Date: Wed, 17 Dec 1997 12:23:23 EST
From: Esondrmn <Esondrmn-at-aol-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: I need a bigger variac. (fwd)

In a message dated 97-12-16 12:38:59 EST, you write:

<< I have a 1kVA variac (powerstat 116 120VAC/7.5A is the exact nameplate 
 rating) and it vibrates when I crank it all the way up powering my two 
 9kV 60mA transformers.  Is there any place I can get a 2-3kVA variac for 
 $100 or less?  Soon?  
 
 I know that these can be purchased at hamfests, but there aren't any in 
 Boston in winter as far as I know, and I need the variac like, yesterday. 
  This is the only thing that keeps me from firing up to full power today. 
  Surplus catalogs that I've got have these for about $300+, but I know 
 that when I was last at the Rochester Hamfest these were selling for 
 around $20-$30.  Huge difference.  
 
 Thanks,
 
 -Adam
  >>

Adam,

Your transformers should draw about 5 amps each for a total of 10 amps.  Your
present variac should be able to handle that without getting too hot.  This is
providing you are using power factor correction caps across the primary of the
transformers.  Without pfc caps, the total input current may be 15 amps or
more, which is too much for your variac.

Ed Sonderman