Fan-controlling system to control a plurality of fans with different pulse width modulation signals

摘要

A fan controlling system applicable in an electronic system having a plurality of fans is disclosed. The fan-controlling system includes a first signal generating module and a second signal generating module for generating a first and a second pulse width modulation (PWM) signals according to control instructions output by the electronic system. The fan-controlling system further includes a phase-inverting module and a delay module. Therefore, PWM signals, which are delayed with a time interval one another, can be generated by the fan controlling system, so as to respectively control a plurality of fans of the electronic system, thereby avoiding the peak value of the total power signals when the fans are run from increasing instantly, and power signal for supplying the electronic system from decreasing instantly, making the electronic system run abnormally, and its stability becomes worse.