Abstract: A switch drive circuit for a fan processor is applied to a fan processor. The switch drive circuit includes multiple upper arm switch components, multiple lower arm switch components correspondingly electrically connected with the upper arm switch components, a first drive switch unit and a second drive switch unit. The upper arm switch components are driven by a first pulse width modulation signal and a second pulse width modulation signal. The first and second drive switch units serve to receive a third pulse width modulation signal and a high-frequency puke width modulation signal. The third pulse width modulation signal is switched between a voltage high-level state and a voltage low-level state to trigger and turn on the lower arm switch components.

Abstract: A multi-fan speed single-wire output system and a method thereof are disclosed. The system includes at least one first fan and one second fan, which have a first and a second rotation speed, respectively. The first fan transmits the first rotation speed to the second fan, and the second fan performs a logical operation on the first and the second rotation speed to generate an output rotation speed.

Abstract: A multi-fan speed single-wire output system and a method thereof are disclosed. The system includes at least one first fan and one second fan, which have a first and a second rotation speed, respectively. The first fan transmits the first rotation speed to the second fan, and the second fan performs a logical operation on the first and the second rotation speed to generate an output rotation speed.

Abstract: A method for preventing a fan from burning down includes steps of: using a central processing unit (CPU) to detect rotational speed of forward operation of a fan and defining as a highest backward rotational speed value; using the CPU to detect operation direction and rotational speed of backward operation of the fan; and using the CPU to activate the fan to operate forward or activate a rotation stop control signal to stop the fan when the fan impeller rotates forward or backward by return air, if the rotational speed of the rotation stop control signal is smaller or larger than the highest backward rotational speed value, the CPU activating the fan to operate forward or making the fan to generate a warning signal and keeping providing the rotation stop control signal. The method can prevent the fan from burning down and enhance the stability.

Abstract: A switch drive circuit capable of saving timers of fan processor is applied to a processor. The switch drive circuit includes multiple upper arm switch components, multiple lower arm switch components correspondingly electrically connected with the upper arm switch components, a first drive control unit and a second drive control unit. The upper arm switch components are driven by a first pulse width modulation signal and a second pulse width modulation signal. The first and second drive control units serve to receive a third pulse width modulation signal and a high-frequency pulse width modulation signal. The third pulse width modulation signal is switched between a high-level state and a low-level state to trigger and turn on the lower arm switch components.

Abstract: A method for preventing a fan from burning down includes steps of: using a central processing unit (CPU) to detect rotational speed of forward operation of a fan and defining as a highest backward rotational speed value; using the CPU to detect operation direction and rotational speed of backward operation of the fan; and using the CPU to activate the fan to operate forward or activate a rotation stop control signal to stop the fan when the fan impeller rotates forward or backward by return air, if the rotational speed of the rotation stop control signal is smaller or larger than the highest backward rotational speed value, the CPU activating the fan to operate forward or making the fan to generate a warning signal and keeping providing the rotation stop control signal. The method can prevent the fan from burning down and enhance the stability.

Abstract: A synchronizing method of fan rotational speed includes steps of: using a first Hall sensor to detect pulse period width generated by the rotational speed of the first fan and converting the pulse period width into a first pulse signal and transmitting the first pulse signal to a microprocessor; using a second Hall sensor to detect pulse period width generated by the rotational speed of the second fan and converting the pulse period width into a second pulse signal and transmitting the second pulse signal to the microprocessor; using the microprocessor to compare the first and second pulse signals corresponding to the pulse period widths of the rotational speeds of the first and second fans; and the microprocessor generating a pulse modulation signal to the second fan so as to control the rotational speed of the second fan to be equal to the rotational speed of the first fan.

Abstract: A detection system for detecting fan's connection and disconnection states includes a detection module connected to a fan and a host. The fan has four external connection terminals for connecting to the detection module. Two of the four external connection terminals are a rotation speed control terminal, via which a detection signal and a rotation speed control signal are transmitted from the detection module to the fan, and a rotation speed feedback terminal, via which a fed back detection signal and a fan rotation speed signal are transmitted from the fan to the detection module. The host determines whether the fan is connected to or disconnected from the detection module according to whether or not a fed back detection signal is received by the detection module from the fan.