Abstract: Spark advance apparatus for an internal combustion engine utilizes an electronic counter circuit to count pulses generated at a rate proportional to engine speed and also utilizes a device energized by the counter circuit to control the charging time of the ignition coil. The counter circuit includes a first counter that is active until a first count is reached. Thereafter, a second counter of the counter circuit counts a predetermined number of pulses occurring at a frequency relates to a particular engine parameter. The device to control charging of the coil is activated at the end of the count by the second counter.BACKGROUND OF THE INVENTIONThis invention relates to a spark advance apparatus in internal combustion engines comprising an electronic counter circuit for counting frequency pulses proportional to the speed of rotation of the engine and a device for controlling the charge time of the ignition coil as a function of the count.

Abstract: A solid state ignition system for an internal combustion engine is controlled by a spark advance means in relation to one or more parameters affecting spark quality. Supply battery voltage is monitored by the spark advance means whereby the latter generates control signals that regulate primary ignition current so that the latter attains a predetermined level before primary ignition current is interrupted.

Abstract: A device for automatically varying the ignition spark advance angle in an electronically controlled ignition system for an internal combustion engine, in which there is a first sensor for producing a train of pulses the pulse repetition frequency of which represents the engine speed and a second sensor for producing a single pulse once each revolution of the engine when the crankshaft is at the top dead center position.