why capacitors are used in ceiling fans

Capacitors are commonly used in ceiling fans for motor starting and speed control.

1. Motor Starting: Most ceiling fans use single-phase induction motors. These motors need an initial push or phase shift to start rotating. Capacitors provide the necessary phase shift for the motor to start. When the fan is turned on, the capacitor briefly shifts the phase of the current flowing through the motor winding, creating a rotating magnetic field that initiates the motor's motion.

2. Speed Control: Capacitors in ceiling fans are also used for speed control. By changing the capacitance value or using multiple capacitors, the fan can be set to different speed settings. The capacitor's role in this context is to alter the phase relationship between the current and voltage, which, in turn, affects the motor's speed. More capacitance generally results in slower fan speeds, while less capacitance results in higher speeds.

3. Efficiency: Ceiling fans with capacitors for speed control are more energy-efficient than fixed-speed fans. Users can select the appropriate speed setting to achieve the desired airflow while consuming less electricity compared to running the fan at maximum speed all the time.