triggering bt136 triac using moc3021

[pdsherathia]

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.

 

[Boncuk]

Hi,

the circuit looks OK to me. What value did you use for Rin?

At 5V (VCC) the value should be 150Ω.

Boncuk

 

[ericgibbs]

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.

hi,
Which type of NAND gate are you using, if any.??

 

[mujid]

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

 

[mrdauz]

just use the typical application circuit in MOC3020 data sheet. i hve been success to do that

 

[Boncuk]

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

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

 

[pdsherathia]

its fine,
i changed mt1 and mt2 by mistake
now its working
no snubber is required if normal inductive load is used
thanx

 

[pdsherathia]

yeh, u identified my problem
i was doing the same mistake(reversing mt2 and mt1)
thanx

 

[mujid]

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

ofcourse the MT1 and MT2 connected properly at the drawing, but what I mean is at the board sir . ha ha ha...
Congratulation pdsherathia....