Patent ID: 8513908

Claim:
A fan speed control circuit, comprising: a first fan adapted to dissipate heat for a first component; a second fan adapted to dissipate heat for a second component; a first temperature sensor adapted to sense a temperature of the first component to generate a first temperature signal; a second temperature sensor adapted to sense a temperature of the second component to generate a second temperature signal; a PWM regulator connected to the first temperature sensor and the second temperature sensor, the PWM regulator adapted to generate a first PWM signal according to the first temperature signal and adapted to generate a second PWM signal according to the second temperature signal; and a driving module connected to the PWM regulator, the driving module adapted to generate a first driving voltage to the first fan according to the first PWM signal, and to generate a second driving voltage to the second fan according to the second PWM signal; a time sharing sampling module, wherein the PWM regulator is connected to the first temperature sensor and the second temperature sensor via the time sharing sampling module, and the time sharing sampling module is adapted to periodically sample the first temperature signal and the second temperature signal at different time periods during a cycle.