Re: AutoTransformer vs. Variac

To: tesla-at-pupman-dot-com
Subject: Re: AutoTransformer vs. Variac
From: TeslaTec-at-webtv-dot-net (Tony R Greer) (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Sat, 10 Apr 1999 17:07:34 -0600
Approved: twf-at-verinet-dot-com

Hi Tom,
'Variac' is just the brand name for a (variable) auto-transformer
"Powerstat' is another brand name for the same thing.There is no
differance, that is, all Variacs are auto-transformers, but not all
auto-transformers are'Variacs'....................... I would think with
your present NSTs, you should look for a rating (assuming 120 volts) of
about 1 kVA, or in the 8.7 to 10 amp range, mininum. Variacs can
tolerate being overloaded intermittantly without harm, if they don't
overheat..................A PFC cap would be placed across the NST
primary, and could increase the power factor from about 55 to about 90,
and should reduce the input current. I don't recall the proper cap value
for a 12/60 NST, but I'm sure someone does, or you can search the TCML
archives........................    Don't know if you could add another
NST, maybe if all were PFC corrected, and run times were kept short.
Also, have a few extra 15 Amp fuses handy ;-)  Happy Sparkin'
Tony Greer