"Sam Goldwasser" wrote in message
...
"James Sweet" writes:

"Sam Goldwasser" wrote in message
...
"Michael A. Covington" writes:

It is either a circuit very similar to a light dimmer, or possibly
just
a
rectifier.

A rectifier would cut the power in half compared to 230 VAC for a
constant
resistive load. This is not what you want.

I thought the high powered ones were nothing but diodes? They're only
good
for resistive loads, mostly they're made for irons and hair dryers.

A diode would produce half wave rectified 230 V. This would cut
the power in half compared to using raw 230 VAC but would still
be twice the power expected by a 115 VAC resistive load.

For example: 115 VAC 1.5 kW space heater.

On 230 VAC: 6 kW.
On half wave rectified 230 VAC: 3 kW.

Either would result in failure very quickly.

Or, did you have something else in mind?

I was thinking they had a chain of diodes and made use of the voltage drop,
guess I could be wrong though.