Re: strange variac

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

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Andrew,

If all else fails, you can take it apart and trace out the connections.  I
took a used powerstat 1256 apart to clean everything up and found the
connections very easy to figure out.  Anyway, I didn't like the physical
placement of the terminals since it would be easy for the output to get
shorted and repositioned them and also made it more intuitive to hook up.
These things aren't rocket science.

Gerry R.

 > Original poster: "Andrew Genseal" <aggniu-at-hotmail-dot-com>
 >
 > Hello all,
 >
 > This is my first time attempting to post anything, so please bare with
 > me.  At any rate, I am in the process of building my first coil and at a
 > recent Ham-fest, I picked up a variac that looked as though it was in
 > excellent shape (good brush, easy rotation, no burnt windings).  Anyways,
I
 > have come to find out that I cannot find any litterature anywhere about
the
 > terminal assignments for this thing(except for the brush on T-3).  It is a
 > Staco Adjust-a-Volt with the following characteristics:
 > Type: 500 BU
 > Rated Current:  7.5A
 > Input V: 120V 50/60Hz
 > Output V: 0-140V
 > Additionally, it has 7 terminals to choose from(That is the real source
for
 > my confusion).
 >
 > The first time I hooked it up with the common on T-4 and hot on T-5, I got
 > 140V at max scale between common and brush.
 > The second time, I used T-4 for common and T-6 for hot and tripped the
 > circuit breaker.
 > Then, I changed it back to T-4 and T-5 and was checking the current into
it
 > with my meter in series.  It was not drawing much current in a steady
state
 > senario, but once I hit the terminal and backed of and hit it again and a
 > nice spark roasted my fine point of my meter into a flat.  Is this the
 > effect of "inrush current?" (BTW, it was still operating at the prescribed
 > 140V out at max on the scale.)
 > Also, if anybody knows anything about this crazy variac.  How do I hook it
 > up to get 120V max output for my NST?
 > I cannot find anything from Staco's site that says that this thing ever
 > existed, so any help will be greatly appreciated.
 >
 > Thanks,
 > Andy
 >
 >