Light Dimmer Control using a Triac

I mentioned using the PWM output to control a LARGE load with a Triac and someone asked what other parts you need so here is the circuit needed.


I have an electrical box with 3 of these circuits inside. That way I can keep it separated from the low voltage PIC. With proper heat-sinking and part selection 1200W Halogen lights are not a problem. It is optically isolated from the PIC but remember if your using PWM you may generate a lot of noise with a long cable run to the control head.


I got a nice heat sink electrical box combo from P&T Surplus for $10. If you’re ever in Kingston NY its a must see shop. Old dead PC power supply cases also make nice enclosures and can usually be had for free from your neighborhood trash bins or techie.

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