Method for achieving an elevated charge of an ignition capacitor in a capacitive type ignition system
AssigneeSaab-Scania Aktiebolag
InventorsHans Johansson, Jan Nytomt
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AssigneeSaab-Scania Aktiebolag
InventorsHans Johansson, Jan Nytomt
Estimating the term…
The invention relates to a method for achieving elevated charging of an ignition capacitor in a capacitive type ignition system for internal combustion engines. When starting a cold engine or when starting the engine under other conditions in which the battery capacity is low, activation of the engine starting motor will result in a drop in voltage in the electric system serving both the starting motor and the ignition system. The voltage drop in the electrical system will vary sinusoidally synchronously with the crankshaft rotation, owing to the fact that the starting motor will momentarily subject the electrical system to higher loads when the pistons are located adjacent their top-dead-center position L in the compression stroke. The method solves this problem, by delaying the re-charging of the capacitor until a position is reached in which the voltage drop in the electrical system has its lowest value.
A method for achieving elevated charging of an ignition capacitor of a capacitive ignition system for internal combustion engines when starting the engine with the starting motor activated, in which the starting motor and ignition system are served by a common electrical system, characterized in that charging of the ignition capacitor is not commenced until a state in the engine working cycle is reached in which the starting motor has its substantially lowest requirement of power from the electrical system of the engine, this state falling between two compression strokes in the engine working cycle where the instantaneous torque resistance of the engine is substantially at its lowest value.
Dependencies are inferred from the claim text.