Method and system for controlling the spark ignition of ignition elements in an internal combustion engine

A system for controlling the spark ignition in an ignition system for an Otto-cycle engine with at least two cylinders, pistons of which simultaneously assume a top dead center position, the system comprising:

• a respective ignition element in each cylinder;
• at least two ignition coils each with a primary winding and a secondary winding electrically connected to a respective ignition element;
• a respective discharging circuit for each ignition coil, comprising the primary winding of such ignition coil and a series-connected circuit breaker element;
• a charging circuit having a coil and a series-connected circuit breaker element and including means for connection to a source of direct current;
• an ignition capacitor having one end connected to each discharging circuit and another end connected to the charging circuit;
• and
• control means for detecting the voltage level of the direct current source and for sending, when the same crankshaft angle close to the top dead center position of the pistons is passed through, respective signals to the above-mentioned circuit breaker element which signals are separate in time and which depend on such voltage level.

A method of controlling, during engine starting, the spark ignition of ignition elements in at least two cylinders of a multi-cylinder four stroke internal combustion engine, pistons of which cylinders simultaneously assume a top dead center piston and the ignition elements of which cylinders are supplied with energy from a direct current source, comprising the steps of:

• determining whether the engine has started, and, if not, then triggering ignition of an ignition element associated with a first of the cylinders with energy from the capacitor;
• thereafter initiating recharging of the capacitor from the direct current source;
• sensing voltage of the source and continuing recharging of the capacitor for a period of time varying as a function of source voltage, with longer recharging time corresponding to lower battery voltage within predetermined limits of source voltage;
• and
• thereafter triggering ignition of an ignition element of a second of the cylinders with energy from the capacitor.