摘要 |
A control circuit for controlling rotational speed of a fan for an electronic device includes a temperature detecting unit for detecting an ambient temperature of the electronic device, and outputting a corresponding detection result; a control unit receiving the detection result from the temperature detecting unit, and outputting a corresponding control signal; and an operational unit receiving one or both of the control signal from the control unit and a pulse-width modulation (PWM) signal, and outputting a backup control signal for controlling the rotational speed of the fan, so that the fan can continue operating when needed, even if the PWM signal disappears.
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