using moc3023 triac opto coupler to fire a triac

Thread Starter

denison

Joined Oct 13, 2018
58
This is a further note on the Fairchild schematic for using moc3023. The .05uf capacitor obviously has to be able to withstand 240vac as can be seen from the schematic. It is being charged through a 470 ohm resistor and the load even when the moc 3023 is turned off.
The .05 capacitor is not optional but is vital for the operation of the moc3023. In my circuit the capacitor fires at 29 volt providing 80ma of current to the gate of the main triac.
The 360 ohm resistor shows 2.7w of instant power and the 470 ohm 3.6 watts. However the average power is very low being less than 0.25 watts.
I initially used a 560 ohm 3 watt resistor without the capacitor and it burnt out.
Use a 3 watt resistor for the 360 and 470 ohm resistors to be on the safe side.
I hope this will assist other uses of the moc3023.
 

Thread Starter

denison

Joined Oct 13, 2018
58
hi,
I have posted a clip from the MOC3023 d/s so that others can refer to a circuit diagram, using your text
E
View attachment 174820
Hi Eric Gibbs, I tried to upload the schematic but it was apparently in the wrong format to be accepted on the forum website. Thanks for adding the circuit for people to view. Unfortunately Fairchild did a poor job of explaining the circuit.
I usually switch the neutral in my triac trigger circuits as it is safer than having the hot wire switched.
 
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