Patent attributes
A fan system circuit module including a stable voltage input terminal for receiving a stable voltage, an operation unit electrically connected to the stable voltage input terminal and a drive chip. The operation unit includes a first resistor, a second resistor, a first capacitor and a third resistor. After powered on at the stable voltage, the operation unit generates an operation signal for the drive chip to decrease drive current value of the fan. In case that a lock of the fan takes place, the drive chip can effectively decrease the block current. The circuit module has soft-start function and provides block current protection effect so as to avoid malfunctioning of the fan system due to too great start current of the fan and avoid burnout of the fan due to high rise of temperature.