Device for generating a trigger signal from ignition pulses in an ignition system

A device connected to an ignition system for generating a trigger signal from ignition pulses of the ignition system, wherein the ignition system includes at least one ignition coil having a primary winding and at least one secondary winding, wherein a first terminal of the primary winding is connected with a first terminal of a voltage source and a second terminal of the primary winding is connected by a controllable switch with a second terminal of the voltage source, the device comprising:

• a first detection means coupled to the second terminal of the primary winding for detecting ignition pulses and providing corresponding output signals,
• a controllable short-circuiting means, connected in parallel with the primary winding, for short-circuiting the primary winding, said controllable short-circuiting means including a second detection means for detecting ignition pulses occurring if ignition processes are suppressed, the second detection means including a current sensor for sensing short-circuit current of the primary winding and a comparator connected to the current sensor for providing output signals when the sensed short-circuit current exceeds a predetermined value, and
• a combining means for combining the output signals of the first and the second detection means in order to produce the trigger signal as an output.