Fan control system

摘要

A fan control system includes a fan and a fan control circuit. The fan control circuit includes a connector, a control unit, a switch unit, and a delay unit. The control unit is connected to the connector to receive a rotation speed control signal, and connected to the fan. The switch unit is connected to the connector to receive a voltage signal, and connected to the control unit. The delay unit is connected to the connector to receive the rotation speed control signal, and connected to the switch unit. When the delay unit receives the rotation speed control signal, the delay unit outputs a control signal to turn on the switch unit after a time delay, the voltage is transmitted to the control unit through the switch unit, the fan operates, the control unit controls rotation speed of the fan according to the rotation speed control signal.

主权项

1. A fan control system, comprising:
a fan; and a fan control circuit comprising:
a connector comprising a control pin to output a rotation speed control signal, and a power pin to output a voltage signal;a control unit connected to the control pin of the connector to receive the rotation speed control signal, and connected to the fan;a switch unit connected to the power pin of the connector to receive the voltage signal, and connected to the control unit; anda delay unit connected to the control pin of the connector to receive the rotation speed control signal, and connected to the switch unit; wherein the delay unit outputs a first control signal to turn off the switch unit in response to the delay unit not receiving the rotation speed control signal, the voltage cannot be transmitted to the control unit through the switch unit, the fan does not operate; and wherein the delay unit outputs a second control signal to turn on the switch unit after a delay time in response to the delay unit receiving the rotation speed control signal, the voltage is transmitted to the control unit through the switch unit, the fan operates, the control unit controls rotation speed of the fan according to the rotation speed control signal.