Device for detecting fan type and controlling fan e.g. 4-wire pulse width modulation fan, in computer, has tachometer connected with direct current generator and receiving tachometer signal to detect change in speed of fan

摘要

The device (300) has a pulse width modulation (PWM) generator (306) connected with input evaluation components (302) to maintain an input evaluation signal (SJ) e.g. large signal. The generator transmits a PWM control signal to a fan to control the fan when the evaluation signal indicates that the fan is a 4-wire PWM fan with an internal pull-up resistor. A tachometer (308) is connected with the generator and a direct current generator (304). The tachometer is configured such that the tachometer receives a tachometer signal to detect a change in speed of the fan. Independent claims are also included for the following: (1) a circuit for detecting a fan type and controlling a fan (2) a method for detecting a fan type.