Interested in slowing a motor. I have a roller pump run by a 12 volt motor power by 120 AC to 12V-500 mAmp power supply. It pumps too fast and I want to slow it down by half to two thirds. If I place a Potentiometer in the line to vary the line power output or use a 6Volt 500mAmp power supply my understanding is this will eventually damage the motor. I think I would like to pulse it on and off at full power to control the pump output, like 2 seconds on followed by 3 seconds off, or something similar. However, the pump is turned on by a controller so the power supply will not always be on. Radio Shack does not seem to have any PWM controllers that will do this. Suggestions please.
Tom
Tom