triggering bt136 triac using moc3021

pdsherathia said:

i have tried switching a load using bt136. the gate of bt136 is supplied necessary triggering voltage by moc3021 opto isolator.
the problem is, moc3021 is triggered but the bt136 is not responding
schematic is attached.

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mujid said:

1. you have to make sure the connection of the triac. MT1 and MT2 should not reverse.
2. try to move the load to upper side of the triac, MT2 and Line.
3. good luck

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Boncuk said:

MT1 and MT2 are connected properly!

I agree with ericgibbs if he supposes a NAND-gate is used to control the cathode of the IR-LED within the optocoupler. It will not be able to sink 20mA.

Better use an NPN-transistor (BC547) as an inverter if the MCU control output is positive.

Boncuk

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