Variable low voltage AC supply

[drakke]

There are a lot of DC lab powers supply design circuits (AC to DC conversion) but how do you experiment with them when you don't have any safe AC supply?

I have been looking for a variable AC supply but there are very few compared to DC supplies. I suppose I don't need 120v but possible 0-24v at 50-60Hz.

I want to be very safe. What are the options?

Thanks.

[AG6QR]

A Variac (common brand name for a variable autotransformer) is a way of providing an adjustable AC voltage from mains.  Usually, they go from near-zero to about 120% of the supply voltage, or thereabouts.  Normally, you plug it straight into the mains, but if you plugged one into a step-down transformer with a 24VAC output, the output of your Variac would be capable of about 0 to 26 VAC, or thereabouts.  A Variac has a current limit, which must not be exceeded, neither on the input side nor on the output side, so beware of this.

Or you could use a function generator, perhaps followed by a buffer amplifier.  That would give you flexibility in frequency as well as voltage.

[edpalmer42]

Model train transformers have an isolated AC output of up to 20V or so.  Power rating can be as high as 50 - 100 watts.

Ed

[3roomlab]

a 50/60Hz signal generator + a small audio power amplifier (maybe car amplifier?) or even just a DIY BJT/MOSFET module?

[drakke]

Is this another possibility?

Class 2 Plug-in Transformer 120VAC - 24VAC

http://www.mroelectronics.com/mro/product.php?id_product=4793

... then wire the output terminals of the transformer to the binding posts on my breadboard.

[Zero999]

Is this another possibility?

Class 2 Plug-in Transformer 120VAC - 24VAC

http://www.mroelectronics.com/mro/product.php?id_product=4793

... then wire the output terminals of the transformer to the binding posts on my breadboard.

That's a transformer which outputs a fixed voltage. The original poster wanted a variable transformer.