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Help me trigger the TRIAC using MOC3021(optocoupler)

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rameshdanas

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i am involved in doing a soft switch using triac i can not switch triac(BTA12) using MOC3021 but i can do this with SCRpair can any one guide me to over come the problem. i use 5V at the input of MOC3021.
thanks
ramesh
 

A.Anand Srinivasan

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triac as switch

PLEASE restate your question.... MOC3021 is a triac based optocoupler and contains a triac in itself and i dont understand what you mean when you say that you want to trigger BTA12 using MOC3021... please post your circuit....
 

rameshdanas

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moc3021 triac

Here i have attached the circuit i am trying

thanks
ramesh
 

A.Anand Srinivasan

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triac as a switch

when you trigger the MOC3021 it gets latched and hence the voltage across it would be very low.... also this would pull down the supply voltage.... so please check the voltage across the BTA12 and post the voltage value... if possible post the SCR pair circuit and the output waveform......
 

rameshdanas

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triac switch circuit

I need to turn on a lamp load 230V using TRIAC so i want to trigger the TRIAC using MOC3021(optocoupler) with 5V input
 

A.Anand Srinivasan

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triac switch using moc3021

then you should have a isolated supply for the triac of the optocoupler too..... because the optocoupler triac triggers first and makes the voltage across the triac to be triggered to become very low....
 

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