i am trying to build a circuit to control a rumble motor. but i forget how to build a basic motor control circuit. can anybody help?
If you want to move the motor in each direction and with varying speeds I would use a h-bridge. It's easy to build, cheap and works fine:
Another approach is to use a PWM signal to the base of a MOSFET transistor. It will only go one way but is simpler than an H-bridge.
Be sure to put a resistor between the gate pin and ground to prevent short circuits and use a diode across the motor leads to dissipate back emf.
Or use a L293 for an H-bridge.