Potentiometer controlling AC Motor

Thread Starter


Joined Nov 2, 2004
I have a potentiometer that I want to control an AC motor with. The pot has 3 pins, one in, one out, and one for the wiper. Can this be connected between a 110V AC plug(white, black, and green ground) and AC motor so that the motor can be controlled? If so how is it connected?




Joined Oct 30, 2004
No, deffinately not.

A potentiometer usually can only handle a few milli amps of current and a motor may take several amps of current (Thousands of times higher)

The result would be you would burn out the the potentiometer and it could even go on fire.

What you need to do is make a circuit designed for properly controlling the motor speed. This would usually consist of a phase control circuit a bit like that used in a dimmer switch for lighting in a home but suitable for an inductive load.

I have no such circuits at hand to give you, but essentially they would contain a triac and maybe a diac a couple of capacitors and resistors and your pot.

Have a search on google or similar search engine for motor control circuits or maybe try phase control circuits, you also need to find out what current your motor draws or the wattage and take that into consideration when selecting a circuit.



Joined Jan 22, 2004

maybe you just want to simplifiy the control of your ac motor by using a pot. what you need is a rheostat but you have to tailor that according to the need of your motor like wattage, current draw etc.

the suggestion of maxx to go the distance in controlling your motor is most advisable, have not seen the recommended circuit but triacs are one of the best way to control ac motor. :)