A variable speed control module used by the Casablanca
fan company from 1980 until 1984. Utilized a "heat sinc" module and a variable speed potentiometer. The circuit board would increase and lessen the voltage traveling to the motor
via the potentiometer in order to speed up and slow down the
fan's rotation. Very nice
fan control, but also very prone to malfunctioning and in extreme cases even catching on fire.