Abstract: In order to mount the control circuit for the ignition system at a location remote from the spark plug and ignition coil, i.e. at a location not subject to electromagnetic or electrical interference, photoconductors are used to interconnect the control circuit with the final output stage. Photoconductors are also used to interconnect the basic synchronization unit, that is the unit which furnishes a pulse for each rotation of a shaft of the engine, to the input of the control circuit. A theft prevention device is also incorporated. Specifically, the control circuit compares a sequence stored in a microprocessor to the on/off pattern of a received light pulse sequence. The latter is applied from a light emitter through a convex lens and a photoconductor to a second input of the control unit. Only if the stored pattern corresponds to the received light pattern can control signals initiating a spark be generated.

Abstract: In an electronic ignition control apparatus having RAM to initially store first and second signals indicative of the starting and terminating points for calculation of a time necessary for rotation of a predetermined angle defined by integer times as large as a predetermined angular interval of an output shaft of an engine, a rotation time of the output shaft is calculated during rotation of an angle of the output shaft defined by the first and second signals from RAM to calculate an optimum spark advance angle in relation to the operating condition of the engine such that an angular position defined by integer times as large as the predetermined angular interval at the advance angle side of the calculated advance angle is determined to be stored in RAM as a third signal.

Abstract: This invention relates to a contactless ignition circuit for internal combustion engines characterized in that a primary short-circuiting current flowing through the primary winding of an ignition coil is made to flow through a power transistor controlled to be conducted and interrupted by a photoswitching means, the formation is small and simple, the contact is not worn and the life is long.

Abstract: An optoelectronic ignition device for an internal combustion engine requiring a single wire connection.A light-emitting diode, a photo-detector 2 and a first resistor 9 are energized in series, and a second resistor 3 is connected in parallel with the photodetector 2. The spark producing means 10, 11, 12, 13 is controlled by the signal which is taken from the terminals of the resistor 9.

Abstract: An ignition system for a multi-cylinder engine having a distributor shaft for timing the ignition, a plurality of spark plugs and a means of producing a high voltage signal for firing the spark plugs, including: a discharge device interconnected between the means for producing a high voltage signal and each spark plug and incapable of conducting in response only to a high voltage signal; and means, operated by the distributor shaft, for selectively, sequentially energizing each discharge device to enable it to conduct and deliver the high voltage signal to the associated spark plug in time with engine operation.

Abstract: In an ignition system of an internal combustion engine the provision of a device for fast switching the primary circuit, this device including an infra-red radiation source and an infra-red radiation sensitive element, the radiation path being interrupted in timed relation to the engine revolutions whereby switching current is provided which is amplified for fast switching transistorized elements and applied to the primary winding of the ignition coil. Advance or retard of the ignition system can be achieved in relation to speed and/or load conditions on the engine by altering the line of sight between the radiation source and the radiation sensitive element in relation to a device which interrupts the radiation in timed relation to the engine revolutions.

Abstract: An engine control wherein a shaft driven by the engine causes a first signal to be generated and then a second signal after the shaft has rotated through a predetermined degree. The first signal starts a timer into operation, the timer producing a timer pulse of predetermined duration. Time coincidence of the timer signal and second signal indicates that a critical engine speed has been reached and such time coincidence is used to effect a control function. If the shaft rotates in the opposite direction the sequence of generation of the first and second signals in such direction is detected and used to generate a reverse-direction signal which is used to effect a control function. An automatic impedance-changing circuit enables the control to be used with a wide range of batteries.