Mains transformer only outputting 2V instead of 22V

Sep 22, 2006 24 Replies

For well regulated DC you wouldn't.

-- _____ _ _ |_ _| | | | | | | __ _ _ __ ___ | |__| | ___ _ __ ___ ___ _ __ | | / _` | '_ ` _ \ | __ |/ _ \| '_ ` _ \ / _ \ '__| _| |_ | (_| | | | | | | | | | | (_) | | | | | | __/ | |_____| \__,_|_| |_| |_| |_| |_|\___/|_| |_| |_|\___|_| __ ____ / _| | _ \ ___ | |_ | |_) | ___ _ __ __ _ / _ \| _| | _ < / _ \| '__/ _` | | (_) | | | |_) | (_) | | | (_| |_ \___/|_| |____/ \___/|_| \__, (_) __/ | |___/

...

...

Art Deco spake thus:

It sounds like your mixing up a *transformer* with a *power supply*. A transformer *always* outputs AC. A power supply (which may include a transformer) rectifies, filters, and sometimes regulates this into DC. So you'd always use an AC range to measure a transformer's voltage, but you'd use a DC range to measure a DC power supply's voltage. (There are AC power supplies too.)

Save the Planet Kill Yourself - motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

OK, I meant the output from the power supply. Apologies for any confusion.

BTW as I understand it, some power supply output is only half-rectified. Is this correct?

Art Deco spake thus:

Yes, but I think all wall warts use bridge rectifiers (meaning full-wave output), since the parts are, like, about a dime each.

Save the Planet Kill Yourself - motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

I had a Shure wireless mike receiver power supply last week that was supposed to output 18V that was outputting 2 V dc. It turned out the secondary windings of the transformer shorted out. Chuck

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required