Triac control AC motor, bulb

Thread Starter


Joined May 10, 2014
Hi all, I am playing with the AC control with triac and want to control AC motor and bulb using Triac,

I made the following schematic, the first part is a zero crossing detector,
and second is the actual triac control part,

Everything works fine and OK ---- the motor speed is controllable, and the bulb also dim OK, but the problem is that,

the motor gives jerks and the bulb gives fluctuations.when I make the speed very low

So pls help me to make a smooth speed controller and a smooth AC bulb dimmer ----- I think I have to change the snubber circuit but how to make a good snubber ----- i don't know, OR there is some other issue

pls reply soon and help me

thanks in advance



Joined Sep 17, 2013
Are you sure the Arduino isn't trying to exert a phase delay > 180°, which would cause the triac firing to skip some half cycles?