1. Attached is the circuit for capacitive supply making +5Vdc from 220Vac. Earlier I was using old zero cross ckt as marked in schemtaic , but now I have changed it to new zero cross ckt.

2. Is this new zero cross circuit ok? Old zero cross ckt was reference I took from internet source.

3. Problem is when I turned on this circuit suddenly triac burst.
I have placed Q1 in the circuit as I have +5V powered micrcontroller whereas zener had 9.1V across it. So placed a bc547 which acts as gate.

4. One issue I found that pin of R8 & microcontroller were not soldered i.e R8 was floating. Bt how does it can cause triac to burst? Or is there any other reason?
Load is always 700ohm resistive one.

 

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