Abstract: A function signal having a desired characteristic curve is generated through the logical operation on a vehicle speed signal indicative of the speed of a vehicle, a ratio signal indicative of the air-to-fuel of the mixture supplied to the engine mounted on the vehicle, and a pressure signal indicative of the pressure in the intake manifold of the engine. The position of an electromagnetic valve for adjusting the amount of fuel supplied to the engine is controlled in response to the function signal, thereby controlling the air-to-fuel of mixtures in accordance with the various driving conditions of the vehicle including the vehicle speed.

Abstract: A desired function signal is provided by a logical circuit which selects one of a signal corresponding to the speed of a vehicle carrying an internal combustion engine, a signal corresponding to the intake pressure, a signal corresponding to the air-to-fuel ratio of the mixture supplied to the engine, and a signal corresponding to the opening of a throttle valve in accordance with the driving conditions of the vehicle. The amount of additional intake air flowing through an additional intake system provided in the engine is controlled in accordance with the desired function signal, thus providing an air-fuel mixture ratio which suits the driving conditions of the vehicle, the running speed of the vehicle in particular.

Abstract: A fuel injection timing control system is provided wherein a fluid actuator having a fluid chamber containing therein a movable wall member and the amount of pressure medium in the fluid chamber are controlled by electromagnetically operated control valve means to cause the actuator to operate an element for controlling the fuel injection timing of a fuel injection pump.

Abstract: There is provided a vehicle engine-driven alternator wherein an internal combustion engine is coarsely adjusted to a preset speed by an engine governor, the turning driving force of the engine is transmitted to an alternator through a magnetic slip coupling, and the excitation current to the magnetic slip coupling is controlled by an excitation control circuit which compares the number of revolutions of the alternator with a preset value to generate an output depending on the result of the comparison, thereby providing a source of alternating current having an extremely accurate preset frequency.