Patent ID: 7355359

Claim:
An apparatus applying to a computer system for driving a first fan or a second fan, rotation speed of the first fan being controlled by a speed control signal, rotation speed of the second fan being controlled by a power signal, the apparatus comprising: a receptacle for connecting one of the first fan and the second fan, comprising a power pin, a speed detection pin and a speed control pin, wherein the power pin is for transmitting a drive voltage to the first fan or the second fan and for controlling rotation speed of the second fan, the speed detection pin providing a speed signal of the first fan or the second fan, the speed control pin transmitting the speed control signal to control rotation speed of the first fan; a power switch connecting to the power pin, controlling the drive voltage to continuously/intermittently transmit to the power pin according to the power signal; a integrator in circuit connection with the speed detection pin of the receptacle, integrating the speed signal to obtain a integrated-speed voltage; and a comparator in circuit connection with the integrator, comparing the integrated-speed voltage with a comparative voltage for outputting a comparative signal; wherein the computer system identifies whether the first fan or the second fan is configured to the receptacle according to the comparative signal.