triac 24v

i'm trying to control a 24v motor. can i do it by a triac or i would have to use a tr. or a relay?
thanks

It's an AC motor I presume? You should onyl use a TRIAC with an AC motor.

TRIAC - switching speed control
relay - just on or off for continuous periods of time

Tr. = transformer? That's only needed if your source voltage is different from the motor voltage (and you would use it in addition to a switching device).

Regarding the switching speed control, it's not as simple like PWM with DC motors. I don't know much about variable speed AC drives so...Most AC motors are designed for constant speed operation.

You can control an AC motor with a triac but for a DC motor you need to use a transistor, bipolar or mosfet. A little more detail on what you want to do would help.

I'm assuming this is an AC supply, otherwise you want to use PWM and a MOSFET not a triac.

That depends on whether it's an squirrel cage or universal motor; the latter will work and the former won't.

yes dknguyen it's an ac motor. my question is :the triac works with 24v? (i know it works with220v)

Yes, a properly rated TRIAC should work just fine. I don't think there is a problem with using a TRIAC that can handle 220V in a 24V circuit as long as you can meet the switching requirements in the same way you can use a 800V FET in a 24V circuit.

24V AC is a bit strange though...

More importantly what sort of AC motor is it?

It will only work with universal motors.

if its a Universal AC-DC Motor, you can also use an SCR (like BT169 , if the current is small ),

but the input AC should be made into pulsating DC using a Full wave bridge rectifier

arun