OK, I gotta be curious... is the whole purpose of this *just* to start a generator?
Do you really need to detect zero crossing and all that?

How about just stepping down the voltage (little transformer), rectifying and putting a small filter cap on the output. Feed it to a PIC pin. If the pin is high... got power. If the pin is low... no power. Poll the pin about once a second should be fine for starting a generator, eh?
Seriously. How quickly do you need to get a generator running? How quickly will it even start? It seems a few seconds delay without power is inevitable if you gotta start an engine.

Of course maybe you have other ideas for this that need the zero crossing anyway?
Just curious...

Heck, I still gotta go out in the rain and put a hand crank on mine to start it.


steve