Patent ID: 8324854
Filing Date: 2012-12-04
Classification: F04D,Y02B

Abstract:
1. A fan control system, comprising: a temperature detecting circuit comprising a first amplifier, a second amplifier, and a thermistor, wherein power terminals of the first amplifier and the second amplifier are to be connected to a first power supply, ground terminals of the first amplifier and the second amplifier are to be grounded, a non-inverting input of the first amplifier is to be connected to a second power supply through the thermistor, an inverting input of the first amplifier is to be grounded through a first resistor, an output of the first amplifier is connected to the non-inverting input of the first amplifier through a second resistor, the output of the first amplifier is also connected to a non-inverting input of the second amplifier through a third resistor, an inverting input of the second amplifier is to be grounded, an output of the second amplifier is connected to the non-inverting input of the second amplifier through a fourth resistor, the output of the second amplifier outputs a voltage signal; and a rotation rate control circuit comprising a first terminal connected to the first power supply, a second terminal connected to the output of the second amplifier to receive the voltage signal, and a third terminal connected to the fan, to control the rotation rate of the fan according to the voltage signal.