Don't have a variac? how about a SCARYIAC!

yep it's dangerous! but works! https://www.youtube.com/watch?v=P9UjxG8sN1c

For what it is going to cost you to make that you might as well buy a real variac. Even if you have most everything already on hand it still would be more trouble to build than its worth. Not to mention possibly lethal..

Way too dangerous. Kids, don't ever try this.

EEEEEEP!!!!!!!

I just purchased this unit from radiodaze;

http://www.radiodaze.com/category/407.aspx

I have one of these and wouldn't trade it for anything. Its a very good piece to use. If you get a chance to get one I recomend it.
http://www.ebay.com/itm/Sencore-PR57-AC-Powerite-Isolation-Transformer-And-Safety-Analyzer-/300909497124?pt=LH_DefaultDomain_0&hash=item460f9a8b24

As far as a scaryac I would say its more of a deadlyac. I do rust removal using water and electricity but that is not something I would build even to say I have. That thin plastic box looks to dangerous.

MEZLAW wrote:I just purchased this unit from radiodaze;

http://www.radiodaze.com/category/407.aspx

That is pretty much like mine. It's lasted 11 years so far.

I've got two variacs. They both have needed some servicing, including on my latest one when it fell, and, on-off switch broke. That made a nice spark.
I was using it at the time..............
Bent the case, too, and, I had to stratighten that. Iw was causing it to scrape.
This variac I've had for three years. My oldest one for about five years. They are both ten amp variacs.
Neither one has a meter.Both have outlet, and, a fuse.

And, let me tell you. I've seen the gambit of what happens when a variac fails.
Worn brush, they smoke, spit, and, sputter. By the way, in most variacs, that brush is adjustable.
When over loaded, and, winding shorts, they go in GLORY, like the fourth of July. Sparks fly everywhere!
And, trip the hose circuit breaker.
Pow!

I'm lucky. I have an Eico 1078. It has an amp meter that switches between 2.5 and 7.5 amps. The voltage goes up to 140 and it has both a power and meter fuse.

On the right is a B & K isolation transformer and on top 0-30VDC power supply

I have yet to own a variac. When i get one it will probably be like the one Mezlaw showed. My dim bulb tester does the trick for me right now.. I'd never consider a scaryac nor would i ever recommend it for anyone to build. Not only is the water and electricity dangerous, but lye is also dangerous.

Scary allright, but I kind of like it. Reminds me of the water and baking soda 120VAC rectifier I made once. LOL

Rob

This thread finally got me to do something for my variac. I found a decent ac ammeter and voltmeter to set up to put in the circuit to the unit under test. I have always liked an ammeter to monitor during power tests.

Along with a Variac, or any variable transformer, there should also be an isolation transformer. Mine has two non-isolated outlets at the top, handy for quickly plugging in a radio or test instrument.

In addition to the two isolated outlets and power switch there is a voltage select grid -
110 125 140
100 115 130
90 105 120
One switch chooses the rows and one switch controls the columns. Mine is set at 115. Of course I have my variable transformer plugged into one of the isolated outlets.

I keep my feelers out for what's available on ebay. One day I might get one of those RCA or VIZ type isolation xfmrs. My finances are the deciding factor on when to take the plunge. Right now it's the variac and the one hand rule.