Abstract: A glow plug heating control device for a diesel engine includes a detector for detecting the heat variable resistance of the glow plug, and a device effecting insertion of a resistor in series with the glow plug and the power source at a given point so as to vary the manner of current application to and the heating of the plug in an advantageous non-linear manner.

Abstract: Disclosed herein is a plant that supplies a diesel oil-gas fuel mixture to diesel cycle engines and comprises: a device for interrupting the travel of the lever that controls the injection pump and is connected to the accelerator; and a mixer group placed along the manifold for the induction of air to the cylinders, comprising two separate parallel pipes, the first of which provided with a first throttle valve movable between two extreme positions, namely a position for opening the air passage when the engine is running on diesel oil and a position for closing the air passage when the engine is running on a mixture of diesel oil and gas, and the second of which provided with a Venturi tube and with a second throttle valve for blocking the air passage, movable continuously and connected to the accelerator, the said Venturi tube being connected to a pipe for the supply of the gas at low pressure; the said pipes being jointly provided with an air passage area at least identical to that required for maximum engin

Abstract: The volumetric efficiency of an internal combustion engine is calculated from the detected flow rate of the intake air and from the detected rotational speed. The changing rate of the calculated volumetric efficiency is restricted to a limit rate. Then, the amount of fuel to be injected into the engine is calculated, depending upon the restricted volumetric efficiency.

Abstract: Ignition timing is changed within a predetermined range at a slow frequency and the fluctuations in vibrations of the engine block at that slow frequency are detected. By monitoring the phase of the vibrations with the phase of the slow frequency, whether the timing is on the advanced side or delayed side with respect to the optimum ignition timing can be determined. Ignition timing is controlled based on the result of the determination so that the ignition timing can approach the optimum ignition timing. As a result, shifts from the optimum ignition timing can be reliably corrected, so that the engine always operates at the best condition.

Abstract: Disclosed is an air/fuel control system for an internal combustion engine which selectively carries out open loop control and feedback control in which the air/fuel ratio is controlled based on the sensed concentration of an exhaust gas component. The system has a means for generating a variable reference signal corresponding to an exhaust gas sensor output and a means for measuring a period after the air-fuel mixture becomes rich and for generating a signal for switching control operation from feedback control to open loop control. The latter means clears the measured period responsive to interrupting feedback control after the expiration of a given period. This effectively prevents control operation from switching too frequently between feedback control and open loop control.

Abstract: The Hall generator integrated circuit in the transistor-controlled ignition system of an internal combustion engine and an integrated circuit board which carries the circuit elements for overvoltage protection, amplification, and the power output stage are mounted together in one building block. Preferably, the conductive element and the permanent magnet of the Hall generator are also integrated into the building block as is a pressure sensor. The output of the pressure sensor is directly applied to the circuits in the printed circuit board. The unit occupies little space and eliminates the need for external leads interconnecting the ignition coil and the output circuit.

Abstract: A novel electronic control circuit which may be used in different types of electronic engine control systems is disclosed. Illustrative usage in various types of electronic spark timing control systems contemplates 4, 6, and 8 cylinder engine configurations as well as single or multiple pick-ups. The circuit is intended for fabrication as an integrated circuit device to provide a low-cost unit which is advantageous in mass production usage.