Electronic speed control for a variable speed fan drive

摘要

An electronic speed control system for controlling the drive speed of a cooling fan for a motor vehicle. The system includes a temperature sensor to monitor the temperature of the motor coolant to be cooled by the fan. The sensor develops a signal which is proportional to the temperature of the coolant which signal is amplified and modified by an electronic control unit to provide a speed control signal. A rotatable drive unit is coupled to the vehicle drive motor and rotates at a speed which is proportional to the vehicle drive motor's speed. A variable coupler is connected between the drive unit and the cooling fan and is controlled by the speed control signal in order to regulate the speed of the fan and thereby control the temperature of the coolant. The electronic control unit includes means for monitoring the speed of the fan and for limiting the maximum speed of the fan.