Ignition system for internal combustion engine

Claim 1

An ignition system for an internal combustion engine comprising: a first energy source having a high energy density and a very short decay time; a second energy source having an energy density and a decay time which are respectively lower and longer than the energy density and decay time of said first energy source; means, connected between said first and second energy sources, for preventing the flow oF current from said first energy source to said second energy source while permitting the flow of current from said second energy source; an ignition coil, coupled to said first and second energy sources, to be energized by the energy therein; and means, coupled to said ignition coil, for controlling the supply of energy to said ignition coil from said first and second energy sources in synchronism with the rotation of the engine, by effecting the application of the energy in said first energy source to said ignition coil at each point in time when said engine is to be ignited and then successively applying the energy in said second energy source to said ignition coil at the instant when the energy in said first energy source becomes less than the energy in said second energy source, wherein said first energy source comprises a capacitor, said current flow preventing means comprises a first diode and said controlling means comprises a transistor circuit connected between the primary winding provided in said ignition coil and said second energy source, said ignition coil further including first and second secondary windings, the first of which is connected to the discharge gap in said engine, and the second secondary winding of which is connected through a second diode to said capacitor.