zero crossing detector?

raschemmel:
330k on each leg of the line.
220V x 1.414= 312V
312v/0.001A=312000=>330k

I would recomnend 1 Meg for each leg to be safe.

230V ac mains
half wave or full wave rectified.
trying to get zero crossing, so there is no capacitors in this circuit.

1.414 ?

general question ;
what is your rule of thumb about a single resistor in a high voltage application ? at what point to you address flashover ? before you start using either a resistor designed for the voltage or start to use resistors in series ?

A simple 1/4 watt carbon 1meg resistor has a voltage limit of about 150v.