Patent ID: 8569989

Claim:
A pulse width modulation (PWM) fan controller for an electronic device, the electronic device comprising a plurality of fans, the PWM fan controller comprising: a plurality of PWM signal generators configured for generating a plurality of PWM signals; a control unit comprising a plurality of outputs; and a plurality of PWM signal output elements, an input of each PWM signal generator electrically connected to a corresponding output of the control unit, an input of each PWM signal output element electrically connected to an output of a corresponding PWM signal generator, an output of each PWM signal output element configured to be electrically connected to a corresponding fan, wherein during the boot process of the electronic device, the control unit controls the PWM signal generators to sequentially generate a PWM signal to drive a corresponding one of the fans to rotate in a preset time, such that the fans are driven to rotate in turn, asynchronously.