Re: [Fwd: California Instruments AC Power Supplies in Stock]

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

Hi Stork,

I believe these AC power supplies use a rectifier to
convert the line voltage to DC, then an inverter to
turn it back to AC at the frequency and voltage of
your choice. They should replace a variac no problem.
I think the variable frequency would be fun too, since
you can use 400Hz transformers, and change the
breakrate of a sync rotary gapped system. If you can
get one that generates three phase current off a
single phase input, even more fun :-)

But bear in mind that they might well be bulkier and
heavier than an equally rated variac. I know a guy who
has a <1kVA unit at his work and he says it's a real
chunky piece of kit with a big iron-cored inductor or
transformer inside.

Some of the low powered units might use a Class-B
linear amplifier as the output, rather than a Class-D
PWM, which would make them even heavier and
inefficient. But I'm not sure about that.

Steve Conner
http://www.scopeboy.com/