When it comes to Ceiling Fans there are two different types of motors available on the market. One is an AC motor (alternating current) and the other is a DC motor (direct current). AC motored ceiling fans need to be connected directly to your home (AC) power supply. This power source is what creates the force required to rotate the motor. With DC fans, the direct power source (AC) is connected to a transformer in the fan, which converts the power to DC. This will decrease the amount of power by using a direct current (DC) instead of the alternating current (AC).