Abstract: A depression sensor for an electronic ignition advance device for an internal combustion engine especially intended for use in a motor vehicle, the sensor being of the kind having a membrane which in use is deformable in response to the value of said depression, wherein the sensor comprises resistive means having an ohmic value which varies in accordance with the force applied to said means, and an electronic control circuit controlled by said resistive means so that variations in the value of said depression applied to the membrane will vary the force applied to the resistive means and consequently will vary an output voltage of said electronic control circuit.

Abstract: An electronic ignition circuit utilizing a magnetic pick-up winding has both ends of the pick-up winding connected by biasing resistor networks to the output terminal of the input stage of the circuit at which a positive going pulse appears when a negative going signal is induced in the pick-up winding. One end of the winding is connected by a diode to the base of a first transistor which controls a second transistor through a capacitor/resistor chain/diode series combination connected between the collector of the first transistor and said one end of the winding. The arrangement ensures that a spark can be produced even at low speed when a small signal is induced in the winding at the instant when ignition is required.

Abstract: An ignition distributor for use in an internal combustion engine, the distributor having in known manner a fixed contact and a movable contact wherein there is provided a support for the fixed contact having a housing which contains a nut threadably engaged with an adjustment screw whereby angular divergence is permitted between the screw and said support for the fixed contact when the screw is rotated.

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.

Abstract: An ignition system and a method of ignition for an internal combustion engine in which an element is rotated in association with a position detector to provide a reference signal varying in duration with engine speed. Impulses of constant frequency are produced by a generator and the impulses appearing during the duration of the reference signal are counted and coded. A further generator produces pulses as a function of induction depression and these are also counted and coded, and this coded value is corrected as a function of engine speed. The first coded value and the corrected coded value are compared and, when these coincide, an ignition spark is produced.