> Subject:       Re: zero crossing detector for mains ?

> >Consider using an Opto Isolator.  You could put series resistors on both
> >sides of the LED, and then the Sensor side goes to your logic isolating
> >the logic from the mains.  Also putting a zener and diode circuit in
> >parallel with your LED could bring the "on" time closer to the zero line
> >without frying the LED.
> >
>
> Only drawback, 240V @ 10mA = 2.4W dissipated in the resistors (assuming the
> opto-isolator requires 10mA).
How about the X-10 PL513/23 interface modules? They have a TTL level
zero crossing output.