Please clarify: Have you built it and it doesn't work? Or are you asking for design hints?
Any triac probably will work to some extent in all 4 quadrants, but most that I've seen are significantly more sensitive in some quadrants than others. In either case, the triac part number would help you receive an answer that doesn't have to include the words 'probably' and 'most'....
There's a little known issue with triacs that has probably burned out many a microprocessor. When they are conducting, a significant amount of current is available on the gate pin, in phase with the load current. When the load current is negative, this current is negative, and if you connect directly to the processor I/O it might not like it.
Hi for both of you thanks for the response.I'm using TIC206 Triac.
I'm driving the gate pin via a 470R resistor from the uC pin.
The uC detects ZX.On every 10mS time (50Hz) it will detect ZX.
When it detects rising edge on ext interrupt pin I turn on a timer for the desired angle.After timer value expires I'll apply positive trigger signal to the triac.
Same applies to the negative side.When it detects falling edge on ext interrupt pin I turn on a timer for the desired angle After expires the timer I'll apply positive trigger signal to the triac.
Now you see in both side wave forms I'm applying positive signal.
Is this the correct way?I still cannot understand what gate trigger voltage positive or negative to provide in all four quadrants?