Checking Out a Small Variac

RE: Checking Out a Small Variac

volly — Tue, 16 Aug 2016 18:49:41 GMT

[mention:f80b53cee57c44bc9d7c577d07d7c791:e9ed411860ed4f2ba0265705b8793d05]. What else do you have in your "arsenal of goodies"....I really enjoy you posts...very informative and useful.....

Thanks John....

Yunus.

RE: Checking Out a Small Variac

DAB — Wed, 29 Jun 2016 18:05:11 GMT

Hi John,

Once again you provided me with many memories of the old days of electronics.

I have an old variac I found when we cleaned out my father in law's basement.

I have not fired it up but he used in in his electronics repair business in the 1920's.

I do agree with Michael, be very careful with these devices. They can provide a lot of current, so treat them with the respect they deserve.

DAB

RE: Checking Out a Small Variac

michaelkellett — Wed, 29 Jun 2016 14:47:35 GMT

You can still buy new ones quite easily - I have one but I very rarely use it. In the 1970s I used them all the time to start up mains powered audio power amplifiers. We didn't have any DC supplies able to put out +/- 50V at 5A or more so we just used the amp's main supply. The only way to start it gently was to wind up the mains via the variac and watch the current.

BTW - Variac is a Hoover - ie the historically dominant manufacturer's name has become the part name.

There are lots of Chinese ones on Ebay - many with built in meters (and rather lethal looking 4mm terminals)