Ignition device for an internal combustion engine

An ignition arrangement for an internal combustion engine having an electrical power source, comprising:

• an ignition transformer having first and second primary coils and a secondary coil;
• a spark plug coupled to said secondary coil for igniting said engine in response to a voltage induced in said secondary coil by a current flowing in either of said primary coils;
• a first switching element, a first diode and a first current sensing resistor connected in series with said first switching element forming a first circuit for (a) coupling power from said power source to said first primary coil when the first switching element is closed and (b) preventing a flow of power from the power source to said first primary coil when the first switching element is open;
• a second switching element, a second diode and a second current sensing resistor connected in series with said second switching element forming a second circuit for (c) coupling power from said power source to said second primary coil when the second switching element is closed and (d) preventing a flow of power from the power source to said second primary coil when the second switching element is open;
• means for generating a signal synchronized with the rotation of said engine;
• and
• a control circuit having inputs coupled to said generating means and to said current sensing resistors for controlling the switching of said first and second switching elements by providing an OFF-ON repetitive signal to one of said switching elements and an ON-OFF repetitive signal to the other of said switching elements so as to operate said switching elements in push-pull, the ON and OFF intervals of the repetitive signals being controlled as a function of the current flowing in said first and second circuits and the signal provided by the generating means so that current flow in one of the circuits is shut-off when the magnitude of current flow in that circuit reaches a predetermined value and simultaneously the other circuit is switched so that current will flow therein, the alternating current flows through the first and second circuits and their respective primary coils inducing a voltage in the secondary coil.