Ignition apparatus for internal combustion engine

Claim 1

In an ignition apparatus for an internal combustion engine comprising a direct current potential source, an ignition coil having a primary winding, an energizing circuit including a switching transistor for controlling an energizing current through said primary winding, an ignition signal generator for producing an alternating current ignition signal in timed relationship with the rotation of an engine, and an energization time duration signal generator means for generating an energization time during signal in means for generating an energization time during signal in synchronism with said alternating current ignition signal, and wherein said energizing circuit for operating said switching transistor feeds said energizing current to said primary winding at the beginning of said energization time duration signal and breaks said energizing current at the end of said energization time duration signal; the improvement comprising means for producing a reference time duration signal in synchronism with said energization time duration signal, a time duration difference detector means for producing a duration difference signal proportional to the difference in length of time duration between said reference time duration signal and said energization time duration signal, a feed back means to negatively feed back said time duration difference signal to said energization time duration signal generator means thereby minimizing the difference in length of time duration between said energization signal and said reference time signal.