potentiometers help? varying the speed of a moter.

[olly12345]

i need to regulate the speed of a motor running of a 12v battery i want to use a potentiometer but i don't know what type for a twelve volt power supply 22k,47k,100k,470k etc which one?

please help many thanks.

 

[chuckey]

Motors normaly take between .03 to 50 amps. These potentiometers are far too high in value. What current does your motor take?
Frank

 

[BradtheRad]

A potentiometer can control a transistor, which varies the speed of the motor.

Screenshot of simulation:

The transistor is NPN type. It shows a motor which takes 2A at 12V. As long as your transistor is rated for the power, it should be able to provide almost full voltage to the load.

If you need to connect the motor ground to 0V, then you can use a PNP transistor, by rearranging some components.