Abstract: A digital control device for an internal combustion engine ignition system includes a shaft angle digital encoder, a shaft speed digital encoder, a matrix memory addressed by the speed digital encoder and programmed to produce a digital output representing the required ignition angle for each speed value, a comparator connected to the angle encoder and the matrix to produce an output pulse when the digital signals therefrom coincide and means controlled by the angle encoder, the matrix memory device and the comparator for determining the shaft angles at which current flow through the ignition coil is initiated and terminated.

Abstract: An electronic ignition control device for an internal combustion engine includes a power amplifier which controls current through an ignition coil and a triggering circuit for the power amplifier. To protect the power amplifier against damage resulting from being connected to a higher voltage source during starting there is a protection circuit which switches off the power amplifier when an over voltage is detected but allows it to switch on for a very short period when a spark is required. The protection circuit uses conventional logic elements, sensing the output of the triggering means, the output of a delay circuit driven by the triggering means, and the output of an over voltage sensing circuit.