acresistorsswitchestriac
I have used BTA41-600 with MOC3083. I Keep frying my MT1/2 connected 330E and 360E resistors. Resistors were used as per datasheet recommendation. I was using 330E and 360E but, both kept frying. 240V ac load of 100W (incandescent bulb) was connected exactly as per datasheet recommendation. Circuit is shown below.
Capacitor is MPC Triac fires "OK"(thanks to ANDY aka), but as soon as it fires it blows the resistors as told. Help needed.
This is exactly how it is done. Your circuit should work fine. There isn't much worry about the off time, since the parts will be off near the zero crossing, the current involved will be small. However, the zero-cross circuit may make the turn-on time longer than necessary, I don't know.
Also consider that most loads will have some inductance. The effect of this is that the voltage the triacs see will not be sinusoidal, but will go from zero to some non-zero value instantly at turn-off. This works in your favor for a faster turn-on.
Again, all of this switching occurs at zero current, so it won't be noticable to the load.
You could try building an ZCD circuit using Transistor. CE configuration. You need to size your AC input voltage to something reasonable using Voltage Divider.
Choose the voltage divider resistors and keep in mind the power dissipation too. Mostly 1/4W resistors will be sufficient.
Triggering Quadrant of Triac
Best Answer
As soon as the opto-triac turns on it should trigger the power triac and the dissipation in the resistors should drop to about nothing. 1/4-W is fine.
If the resistors are 'frying' it's a good indication that your power triac is connected incorrectly, missing entirely or faulty.