PIC + Triac motor rpm controller

[Vack]

hi,can i use a PIC to speed control an AC motor(220v)
if theres a method can you tell me what are main steps to be followed?

thank you all!!

 

[(*steve*)]

What sort of motor is it?

The easiest way is phase control via a triac, but it doesn't work on all motors.

You also need to determine how you're going to isolate your circuit from the mains because it can be very dangerous otherwise (perhaps I should say it can be even more dangerous otherwise)

 

[Vack]

I am going to use a brushed motor found from some drilling machine.is it possible?
can i use a optocoupler to do isolation?
tnx

 

[duke37]

Electric drills usually have AC/DC universal motors, these are good to be controlled by a triac. The easy way is to use a lamp dimmer.
DC permanent magnet brushed motors are not suitable without extra circuitry.

You have not said what the purpose of the PIC is, what will the input to the pic be?
The pic will need a regulated DC power supply and an optocoupler.

 

[Vack]

tnx for the reply duke37.my purpose is to bulid an automatic computer controlled drilling machine.(for eg PCB driller ).PIC is to communicate with computer , change motor position and send speed control pulses to triac. all i need to finish is the motor driving part.
can you give me a link or just tell me the steps to control the motor?
thnk u

 

[duke37]

I have never used a PIC or any of its relatives so cannot help with suggestions.

I wonder why you need to control the motor speed, the drills bits will be of more or less the same diameter so the speed could be preset and the motor just turned on or off. This will make the programming easier.