Abstract: Two closed circuits respectively are each comprised of a primary coil of a transformer for plug ignition, a transistor, a diode, a resistor and a common power source. When one of the transistors is conductive during the ignition period, the current in the related closed circuit increases. When the increased current appearing across the associated resistor exceeds a reference value, the associated comparator renders the conducting transistor nonconductive while it renders the other nonconductive transistor conductive, whereby the transistors continues a push-pull operation at given periods. Each diode is inserted either between the associated primary coil and the associated transistor or between the associated primary coil and the common power source.

Abstract: An ignition system for a spark-ignition engine includes an ignition coil for applying a high voltage to each spark plug, a switch device connected in series with the secondary of the ignition coil for preventing in response to its conduction the supply of the high voltage to the spark plug, and a control circuit for turning on the switch device at a predetermined time after the generation of the high voltage, whereby the discharging at the spark plug is prevented under the combustion condition.

Abstract: Spark ignition plugs are used in place of the glow plugs in a Diesel engine. As long as engine preheating contacts remain closed, pulses of a fixed frequency are applied to two transistors arranged in a push-pull configuration and connected to the primary coil of a transformer so that an engine plug connected to the secondary coil of the transformer repeatedly discharges continuously.

Abstract: An engine ignition system includes a throttle sensor for detecting the position of a throttle valve. A control circuit is responsive to the detected throttle signal as well as the signals from other negative pressure and engine rpm sensors to generate a spark plug discharge start signal and a discharge stop signal. A high voltage generator supplies a high voltage to the respective spark plugs during the time interval between the time that the discharge start signal is generated and the time that the discharge stop signal is generated.

Abstract: When the contact breaker of a distributor is in the off position, pulses with constant frequency which are generated from an oscillating circuit are supplied to a transistor push-pull coupling which is connected to the primary coil of a transformer. In accordance with the transistor's constant frequency switching a discharge through the spark plugs connected to the secondary coil of the transformer is repeated.

Abstract: An ignition system for rotary piston engines includes a glow plug in addition to the normal leading spark plug and trailing spark plug. The glow plug is mounted in the housing of the engine on the leading side with respect to the trochoidal minor axis in the direction of the rotor rotation and performs continuous ignition of the mixture during low speed and load operation of the engine. Thus, during the low speed and load operation the glow plug performs ignition in place of the leading spark plug whereas during other engine operating conditions the leading spark plug and the trailing spark plug perform the ignition of the mixture.

Abstract: The temperature of a glow plug mounted on an epitorocoidal engine housing on a leading side of the torocoid minor axis of a rotary piston engine in the direction of the rotor rotation is sensed. When the sensed temperature exceeds a predetermined temperature within a temperature range which allows the ignition of air-fuel mixture, power to the glow plug is stopped whereby the life of the glow plug is extended and the power consumption is saved.

Abstract: An ignition system for rotary piston engine wherein a glow plug mounted in the epitrochoidal housing of the engine is supplied with electric power to maintain the surface temperature of the glow plug within a range from 900.degree. to 1100.degree. C. A control unit for controlling the supply of electric power to the glow plug produces an output pulse signal the pulse width thereof being varied depending on engine operating conditions such as the amount of fuel supply and engine rotational speeds. A power circuit receives the pulse signal from the control unit and on-off controls the supply of electric power to the plug from a battery.

Abstract: An electronically controlled fuel injection system in which terminating fuel injection is improved is disclosed. A reference position detector is adapted to generate a synchronizing signal at the predetermined angular position of an engine. A first computing circuit is connected to compute the required fuel injection interval in response to the synchronizing signal and a second computing circuit is connected to compute the rotation interval between two synchronizing signals successively generated. A further computing circuit is connected to compute the time interval which is equal to the difference between the rotation interval and the injection interval. The fuel injection is started when the time interval computed by the further computing circuit has passed after the generation of the synchronizing signal and is attained during the computed injection interval, whereby the fuel injection is terminated at the same position as the predetermined angular position.

Abstract: A logarithmic function generating system which generates an output signal bearing a logarithmic functional relation to the input signal. The time constant RC of a resistance-capacitance circuit is increased for every unit time elapsed in proportion to the unit time to produce a broken line approximating the logarithmic function. With its simple circuit construction employing no elements whose characteristics vary with ambient temperature changes or which tend to involve variations in characteristics among the elements of the same type, the system is capable of generating the desired logarithmic function output with a high degree of accuracy.