Abstract: An ignition device for an internal combustion engine includes an ignition coil which is feedable on its primary side by a voltage supply unit, a secondary current measuring device for measuring the course of the secondary side current, a control device for at least temporary controlling of the primary side voltage or the primary side current in dependence on the measured course of the secondary side current. Subsequent to an interruption of the primary side voltage or current supply of the ignition coil during an ignition process or subsequent to the drop of the primary side voltage or the primary side current in the ignition coil below a predeterminable threshold during the ignition process, the control device energizes or regulates the primary side voltage or current supply of the ignition coil above the predeterminable threshold only when the secondary side current induced thereby acts in the direction of the predetermined course of the secondary side current.

Abstract: Method for determining the timing of an indirect injection internal combustion engine, in which the following steps are performed: use is made of a first sensor (2) including a target (6) connected to the crankshaft and having a plurality of marks (8), use is made of a second sensor (12) including a target (16) connected to the camshaft and having: a plurality of teeth (D1, D2, D3), a plurality of gaps (C1, C2, C3), and a plurality of fronts (F1, F2, F3, F4, F5, F6) separating the teeth (D1, D2, D3) and the gaps (C1, C2, C3), the engine is turned over from a starting position, the marks (8) on the target (6) of the first sensor (2)are counted, the fronts (F1, F2, F3, F4, F5, F6) on the target of the second sensor are detected, this is used to deduce the engine timing.

Abstract: A mechanically timed ignition system for an internal combustion engine has a variable reluctance transducer mechanically operated by the engine to produce an output waveform having zero crossings coinciding with the desired instants of sparks. A comparator means at the input of an integrated ignition control circuit is connected to a winding of the transducer. The i.c. output point, which controls a semiconductor switch connecting an ignition coil across a supply, is connected by a C-R feedback path to the input of the comparator means, to provide transient positive feedback, which is effective at cranking speed to provide improved rejection of low level audio frequency interference signals.

Abstract: A switching transistor (7, 9) is serially connected with the primary (5) of an ignition coil; current flow therethrough is controlled from an a-c signal generator (16) with respect to an ON threshold level (Ue) to store electromagnetic energy, and an OFF threshold level (Ua) to generate a spark; a variable conductivity circuit (26) controlled from a sensing resistor (8) modifies the response level of the threshold switch (13) with respect to the null or cross-over level of the applied signal. To prevent excessive current flow under idle-speed conditions, in accordance with the invention, the ON threshold level, at least, of the switch is shifted by introducing an auxiliary bias voltage derived from an auxiliary capacitor (36) and connected (37, 38) by the signal source through a diode (38) which prevents application of an auxiliary bias voltage to the threshold switch (13) under extremely low, e.g.

Abstract: An electronic ignition device for use with an internal combustion engine is coupled between an ignition coil switch and a magnetic pick-up. The pick-up produces a cyclical signal A which is integrated and applied to a first comparator, the other input of which receives a threshold. The comparator output actuates the ignition coil switch. A logic circuit combines the output Z of a zero detector receiving the cyclical signal A with the output of the first comparator. The logic circuit output is integrated to provide a signal R indicative of actual ignition displacement, and which is compared with a signal RS representing the required ignition displacement. In a first embodiment this comparison takes place in a second comparator the output of which is fed back to constitute the threshold input of the first comparator. In a second embodiment the threshold for the first comparator is defined by RS, the signals R and I being combined before application to the first comparator.