Poor mans variac

[tbryanh]

A pulsing DC will have an average voltage that will be more than zero and less than peak.

Correct.

the DC component would destroy your P.T.

Wrong. The RMS power in the primary of the transformer from the rectified half-cycle half of what it was before the signal was rectified.

“DC” can harm the transformer, “DC component” is a component. The composite signal (combination of the AC and DC components) is what heats the transformer.

[tbryanh]

... from the rectified half-cycle half of what it was ...

... from the rectified half-cycle is half of what it was ...