Ignition system for a multicylinder internal combustion engine

Claim 1

An ignition system for a multicylinder internal combustion engine comprising first to n-th (n being an integer greater than unity) ignition coils respectively provided in conjunction with first to n-th cylinders of the engine, first to n-th capacitors respectively provided on the primary sides of said first to n-th ignition coils, at least one power source for charging said first to n-th capacitors, first to n-th semiconductor switches with a control terminal respectively provided on the primary sides of said first to n-th ignition coils and respectively adapted to be turned on for discharging said first to n-th capacitors through the first to n-th primary windings of said first to n-th ignition coils, a turn-on signal source for producing a turn-on signal for turning on said semiconductor switches at least n times per revolution of the output shaft of the engine at the rotational angles at which ignition is expected in any of the cylinders, first to n-th trigger signal sources for providing a trigger signal in sequence, each of said first to n-th trigger signal sources being adapted to generate a trigger signal at an angle in advance of the maximally advanced ignition angle of the associated one of said first to n-th cylinders, and first to n-th gate circuits, each being adapted to be opened upon receipt of the trigger signal from the associated one of said first to n-th trigger signal sources to enable the turn-on signal to be applied to the associated one of said semiconductor switches, characterized in that each of said first to n-th gate circuits comprises a flip-flop adapted to be set upon receipt of a trigger signal from the associated one of said trigger signal sources to produce an output signal for enabling the turn-on signal to be applied to the associated one of said semiconductor switches.