Abstract: A fan power supply control system includes a power supply module, a power control circuit, a signal control circuit, a PWM generator. The power supply is adapted to input a power signal to a fan. The power control circuit is between the power supply module and the fan and adapted to connect or disconnect the power supply module to the fan. The signal control circuit is connected the power supply module to the power control circuit and adapted to switch on or off the power control circuit. The PWM generator is adapted to generate a predetermined cycle square signal according to the power signal, to intermittently switch on or off the signal control circuit, and a switch on/off state of the power control circuit is synchronous with the signal control circuit.

Abstract: A fan control system includes an infrastructure management module (IMM), a heat element, a fan module, and a fan board for controlling the fan module. The heat element includes a heat detecting unit. The IMM is connected to the heat detecting units. A fan module includes a plurality of fans. The IMM is configured to calculate a fan input control signal according to a temperature value. The fan board is configured to input an input speed information to the fan module, receive an output speed information of the fan module, and determine whether the fan works as predefined by the fan board according to the output speed information and the input speed information.