PWM amp from 'Power Physics'?

[IanS]

Can anyone comment on the new PWM amplifier from 'Power Physics' ?

To quote MIX online (http://mixonline.com/mag/audio_nht_xd_series/):

"Examining the drawbacks of existing PWM (Pulse Width Modulation) digital switching amplifier designs, Power Physics developed a new nonlinear control method (U.S. patent #6084450). This One-Cycle Sound™ approach monitors the switched variable on a cycle-by-cycle basis, so in each cycle, the average value of the output (power to the speaker) equals the control reference (audio input signal). This rejects power supply disturbances, non-ideal switching edges, component variation with temperature and other distortion-creating problems in typical PWM amps."

How might this compare to UcD?

[classd4sure]

Hi,

Glad you posted about this, it's been mentioned before and I've been looking for it for weeks ever since I lost everything.

I just did some searching and I wasn't able to find the thread it was brought up in, Bruno had some comments on it, anyone have a link?

Just had a glance at their white paper as well. They claim "soft switching" hmmm... It's the error that hits zero each cycle, not the inductor voltage or current, I may have missed or missunderstood something, I realize they didn't claim ZVS, but how can they claim soft switching, I was under the impression class d audio= hard switched?

Seems funny they got a patent there's nothing new in single pulse control is there?

Thanks

[AGGEMAM]

Absolutely agree. It seems like every old idea can be patented nowadays. Don't the US Patent office bother to check up old research or what?