Single stage PWM amplifiers.

Anybody tried to make a single stage PWM amplifier.

I'm working on an amp that uses the so called 4-generation inverter technology, used in UPS's. It looks pretty neat, one switching power transformer only, regardless of AC or DC operation.
For off-line AC operation, I probably will put in a power factor correction stage to.

The trick is to rectify the signal, feed it to the PWM, then use a MOSFET bridge to restore the waveform.

This way, one can make an pwm amplifier using two inductive power elements only, one power transformer and one filter inductor.

Rhesus
 
i think you can see something like it done at http://listen.to/audioexperiment. I don't see how what you describe can be called single stage though. The rectifier (integrator) would be the first stage, and it also receives the feedback signal. The second stage is the comparator, which produces the PWM signal, and the last stage is the output stage, the half-bridge.