Patent ID: 8701638

Claim:
A method for igniting a fuel-air mixture in a cyclically operating internal combustion engine comprising one or more combustion chambers, which are delimited by grounded walls, wherein an electric transformer is used to excite an electric oscillating circuit, which is connected to a secondary winding of the transformer and in which a capacitor is formed by an ignition electrode, which extends in an electrically insulated manner through one of the walls delimiting the combustion chamber, together with the grounded walls of the combustion chamber, and wherein the excitation of the oscillating circuit being controlled to generate a corona discharge that ignites the fuel-air mixture in the combustion chamber at the ignition electrode, wherein before each ignition time of the internal combustion engine, the electric voltage applied to a primary winding of the transformer—hereinafter referred to as the primary voltage—is incrementally increased, and the intensity of the electric current flowing in the primary winding as a result of the primary voltage—hereinafter referred to as the primary current—is measured repeatedly at the same primary voltage, the variation of the measured values of the related primary current is determined, and the incremental increase in the primary voltage is aborted at a value of the primary voltage at which the related variation of the primary current intensity reaches or exceeds a predetermined limit.