12F683 Light Dimmer Problem (SOLVED)

[Jerson]

Try this way.

1. The zero crossing is where the triac turns off.

2. You need the period between 2 zero crossings to decide the time after the zero crossing you need to turn ON the triac

3. Depending on the amount of power you need to output, you need to turn on the triac that much earlier than the zero crossing.

The period is 10mS for a half period of 50Hz,
if you need 50% power, you need to turn on your triac 5mS after the zero crossing.
if you need 25% power, you will turn on the triac 10-2.5ms = 7.5mS after the zero crossing.
for 10% power, you will turn on the triac 10-1mS = 9mS after the zero crossing.

I hope I was able to communicate clearly without using a diagram.

Cheers

[DavyJones]

Chris, I believe I understand your explanation I picture the diagram perfectly in my head no need for it and it makes perfect sense now. Let me give that a go. I am running at 60hz so my half cycle time period would be 8.33mS
So for half power I would turn on 4.16mS after zero crossing, 25% 6.25mS after zero crossing and 10% would be 7.49mS after zero crossing. Sound about right?
Regards
David