초록 ▼

A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes a first amplifier, a second amplifier, and a thermistor. The control circuit includes a first terminal, a second terminal, and a third terminal. The detecting circuit det

A fan control system includes a temperature detecting circuit and a rotation rate control circuit. The detecting circuit includes a first amplifier, a second amplifier, and a thermistor. The control circuit includes a first terminal, a second terminal, and a third terminal. The detecting circuit detects temperature and outputs a voltage signal. The control circuit receives the voltage signal and controls the rotation rate of the fan according to the voltage signal.

대표청구항 ▼

1. A fan control system for controlling a rotation rate of a fan, 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 connected to a first power supply, ground term

1. A fan control system for controlling a rotation rate of a fan, 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 connected to a first power supply, ground terminals of the first amplifier and the second amplifier are grounded, a non-inverting input of the first amplifier is connected to a second power supply via a first resistor, an inverting input of the first amplifier is grounded via a second resistor, an output of the first amplifier is connected to the non-inverting input of the first amplifier via a third resistor, the output of the first amplifier is also connected to a non-inverting input of the second amplifier via the thermistor, an inverting input of the second amplifier is grounded, an output of the second amplifier is connected to the non-inverting input of the second amplifier via a fourth resistor, the output of the second amplifier outputs a voltage signal; anda 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. 2. The fan control system of claim 1, wherein the control circuit comprises a third amplifier, and a metal oxide semiconductor field effect transistor (MOSFET), a drain of the MOSFET functions as the first terminal of the control circuit, a source of the MOSFET functions as the third terminal of the control circuit, the source of the MOSFET is grounded via a fifth resistor and a sixth resistor in series, a non-inverting input of the third amplifier functions as the second terminal of the control circuit, an inverting input of the third amplifier is connected to a node between the fifth resistor and the sixth resistor, an output of the third amplifier is connected to a gate of the MOSFET, a power terminal of the third amplifier is connected to the first power supply, a ground terminal of the third amplifier is grounded.