wrote:

"using an iron transformer to produce 120V AC output. "

What other kind is there ?


** The most common is a full bridge, mosfet output stage producing a "modified square wave" output.

More expensive units use a similar stage running is a class D to produce a good sine wave.

In both cases, the 12VDC input is stepped up to 170V ( or 340V ) DC to power the output stage.


..... Phil