Abstract: 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.

Abstract: A xenon flash lamp mounted on a target flashes at a rate which is determined by the frequency of an oscillator also mounted on the target. A detector assembly which is mounted on a gun receives flashes of light from the lamp only when the gun is aligned with the target. The detector assembly includes a photodetector which produces an electrical signal pulse for each flash of light received. A local oscillator mounted near the gun and tuned to the frequency of the oscillator at the target produces voltage pulses at the same frequency as the frequency of the light flashes from the target. A counter connected to the photodetector counts the number of pulses of light received over a given period of time. Another counter connected to the local oscillator counts the number of voltage pulses received over the same period of time. The readings of the counters are processed by an electronic divider circuit to produce a signal which is proportional to the percent of time that the gun is aligned with the target.

Abstract: An electronic governor for controlling the speed of one of two coupled prime movers wherein signals corresponding to wheel speeds of each of the two prime movers are compared to produce an error signal for controlling an actuator on one prime mover. The speed of the controlled prime mover may be abruptly reduced where the error signal exceeds a pre-determined threshold value. Monitoring means generally comprise digital circuitry, while control of the actuator is primarily analog acting through a servo loop containing a throttle position sensing device on the master prime mover, the error signal generating device and a throttle control device for the controlled prime mover.