Abstract: An ignition system of the type incorporating, instead of the usual distributor, high-voltage rectifier diodes connected between the secondary winding of an ignition coil and respective spark plugs. In response to voltages developed in the secondary winding in its opposite directions the diodes function to cause discharges at the spark plugs in the firing order of the engine. Each diode is composed of a multiplicity of laminated silicon rectifier diode chips each having a reverse breakdown voltage in the range of 400-850 volts. The reverse breakdown voltage of each diode is 1.1 to 1.8 times the maximum discharge voltage of the spark plugs. Thus constructed, the diodes can well withstand overvoltages that may develop in the secondary circuit of the ignition system.

Abstract: A contactless ignition system for internal combustion engines of the type including an ignition coil with two primary windings whose primary currents are alternately switched on and off by two power transistors, further includes two Zener diodes each having a breakdown voltage of 300 to 400 volts and connected in series with one of the power transistors and one of the ignition coil primary windings to function as a reverse current blocking diode. By virtue of two series circuits each including the Zener diode, a diode connected in inverse parallel with one of the power transistors and the primary winding, each of the Zener diodes serves both the reverse current blocking function and the overvoltage protection function. The Zener diodes may be replaced with diodes of the avalance type.

Abstract: A control signal the value of which gradually changes in response to the turning on of a switching element connected in series to the primary winding circuit of an ignition coil is generated. By use of this control signal, the voltage across the primary winding is caused to rise slowly when the switching element is on, thus preventing an unnecessary high voltage from being generated across the secondary winding of the ignition coil.

Abstract: An electric governor for an internal combustion engine comprises an engine speed sensor, a phase shifter, a twin-T type filter and a multiplier for multiplying outputs of the phase shifter and the twin-T type filter. The twin-T type filter is arranged to vary its gain and phase in response to the difference between the peculiar frequency thereof and the frequency of the speed signal, whereby the multiplied outputs varies its amplitude and polarity in response to the frequency difference. A servo motor which is adapted to control the engine speed control mechanism is connected to the multiplier, so that the engine can be controlled to run at a predetermined speed which corresponds to the peculiar frequency of the twin-T type filter.

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.