FAN AND SPEED CONTROL CIRCUIT THEREOF

摘要

A fan includes a speed control circuit and a motor electrically connected with the speed control circuit. The speed control circuit includes an inputting circuit and a transforming circuit electrically connected with the inputting circuit. The inputting circuit supplies a constant current to the transforming circuit. The transforming circuit transforms the constant current to a fluctuating current and outputs the fluctuating current to the motor of the fan. The fluctuating current causes a rotation with a fluctuating speed to the motor of the fan.