Re: I need a bigger variac. (fwd)

---------- Forwarded message ----------
Date: Wed, 17 Dec 97 17:39:11 -0500
From: Adam <absmith-at-tiac-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: I need a bigger variac. (fwd)

>> 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.  

>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

If the PFC caps will help extend the small variac's range, it's certainly 
worth a try!  Mostly I was looking for a new variac so that I can add 
another transformer to the project stack for a total of 9kV -at- 180mA, and 
I can use the small variac for my spark gap fan speed control.  I was 
using no PFC caps with the two transformers, and the variac was growling 
and blowing the 10A fuse when I cranked it up to 140V.   I'll buy some 

In the time elapsed since I sent that post, a lengthy search through the 
ham radio usenet groups has scored me an 18amp powerstat for $35.  I 
almost overlooked those groups entirely.

So this subject is now resolved, thanks.


Adam Smith
Epoch, Inc. Digital Music Project

www.tiac-dot-net/users/absmith/                 MP3 Demo Tracks Now Available!