I'd like to have a constant PWM signals, much like this:
Wherein the blue trace have centered it's
hi at the 0 of the fully rectified AC & the red have centered it's
lo on the
0 of the fully rectified AC, as well.
Note, also, that the blue & red traces aren't complementing waveforms that are
0 sum, as they have noticeable gaps. Being able to do this dichotomously is required, rather than inverting at a last step.
For robustness, I allow for distortions in the original AC (slight shifts in phase, say), so PWMs that started on the initially correct trigger won't be enough, as it won't follow the rectified AC properly.
What I'm looking for is a cheap, yet robust mechanism, where the PWM generator keeps re-aligning itself to the
0 point; one that keeps falling into it.
So I've been looking at crystals, oscillators, resonators, but I'm quite ill-informed with using them.