Controlling LED lamps with Triac.

Thread Starter

shein

Joined Sep 11, 2012
6
Hi All,

I'm building a little project that controls my lamps. I have 220V LED lamps installed everywhere.
In order to fit everything into a wall switch I had to use as compact components as I can.
So, I decided to use a Triac as a load switch. To isolate mains I use optocoupler.
I used a circuit from the datasheet:

Triac: BT134-600E (from aliexpress)
Optocoupler: MOC3021 (from aliexpress)

Problem:
When I start using the whole device at first everything works as expected. LED lamps are controlled fine. After some time (from minutes to hours) the triacs start to fail. One triac failed completely. Others just start leek some current in off state (so LED lamps start to flicker)

Question:
I'm I doing something wrong?
Can 220V LED lamps be the cause of triac destruction? (the triacs stay cold).

Thanks!
 

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Thread Starter

shein

Joined Sep 11, 2012
6
Thanks @Dodgydave for the reply!

Yes, my load is in the Neutral side.

As far as I understand the zero-crossing prevents big inrush currents when load is turned on at peaks of sinusoidal AC signal.
Can It be that big to destroy an output triac?

I also have a question about the snubbing circuit that is recommended to use to drive an inductive load with a Triac.
I'm not sure if my load is inductive enough to require such a circuit? Suppose I have some kind of SMPS inside my LEDS.
Do I need a snubbing circuit to drive a switch mode power supply?
circuit.PNG

Thanks!
 
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