Ignition system for internal combustion engines

Abstract

An ignition system for an internal combustion engine. The ignition system comprises a pulser for generating positive and negative output pulses responsive to the rotation of the engine, a DC power source and an ignition coil having a primary coil connected across the DC power source via a controllable current switching element. The system further comprises a control circuit for controlling the switching element which includes triangular wave generators for generating different triangular wave signals in response to the positive and negative output pulses of the pulser, respectively, a first comparator for comparing a first output signal of one triangular wave generator with a signal which is formed by multiplying a second output signal of the other triangular wave generator by a constant and adding it with a fixed voltage, and a second comparator for comparing the second output signal with a signal which is formed by multiplying the first output signal by a constant and adding it with a fixed voltage. Output terminals of the first and second comparators are connected to the controllable switching element for the ignition primary coil, whereby the output of one comparator controls the conduction start position of primary coil current of the ignition coil and the output of the other comparator controls the ignition position.