Hi,

I just built a zero cross detect circuit that was published in Elektor
Electronics (July/Aug 1998?) involving two TIL117 optos for isolation and 6
resistors (originally, there were two but I didnt like the thought of a
catastrophic failure of the single input resistor so I used a chain, instead).

It gives a 100Hz output (every half cycle for triac control) and the output edge
rise time is around 150uS.....I feed it into a 68HC11 micro for a Uni assignment
I have for a oven controller.

If you want, I can post it here or mail it to you? Whichever is easier.

Dan