Abstract: A fuel supply system for an internal combustion engine includes a pump having a control member movable by an actuator. The actuator is powered by an amplifier which receives a control signal from an operational amplifier. One input of the opertional amplifier is connected to a summing junction to which signals representing speed demand, actual speed and control rod position are supplied by three transducers. The signal from the transducer which indicates the control rod position passes by way a circuit means which ensures that a derivative of the signal is applied to the summing junction.

Abstract: An electronic governor, particularly for a diesel engine has a summing amplifier receiving signals representing the output of the pumps supplying fuel to the engine, engine speed, and engine demand. The summing amplifier serves to produce an output for operating the pump in accordance with predetermined engine current characteristics. A second summing amplifier may be used to override the first summing amplifier to limit maximum fuel. Alternatively, the first summing amplifier may compare demanded fuel supply with actual fuel supply, in which case the second amplifier sets the maximum speed.

Abstract: A frequency to voltage converter includes an operational amplifier having its non inverting input terminal connected to a supply line which has a voltage intermediate a pair of supply terminals for the amplifier, a resistor connected in series with first and second diodes between the inverting input terminal and the line a first capacitor through which the input of the converter is connected to a point intermediate the diode and a second capacitor connected between the junction of the first diode and the resistor and one of the supply lines, a feed back resistor connected between the output terminal of the amplifier and the junction of the first diode and the resistor and a third capacitor connected between the output and inverting input terminals of the amplifier.

Abstract: A control system for a vehicle having an engine and a gear box includes an electronic fuel control system for controlling the fuel supplied to the engine by means of a pump. The selection of a particular ratio of the gear box is effected by a control circuit which senses the speed of the vehicle by means of a sensor. When a change in gear ratio is effected, the control system for the gear box provides a signal to the electronic fuel control system which produces a reduction in the amount of fuel supplied to the engine during the gear changing process.