i have one of these gear motors. 6VDC 3RPM Gearhead Motor-The Electronic Goldmine What i am wanting to do is to run it on it's slowest speed. I have a 12v. and i need to bring it down to 3v. Can i use resistors to drop the voltage? or a rheostat to trim it down to 3v? i'd rather not speed the money on a pwm if i don't have to.