Patent ID: 6889677

Claim:
A capacitor discharge ignition device for an internal combustion engine comprises: a magneto generator having an exciter coil that generates one-and-a-half cycle of an AC voltage constituted by a positive half cycle of an output voltage and first and second negative half cycles of output voltages generated before and after said positive half cycle of the output voltage, respectively, at least once during one rotation of a crankshaft; an ignition coil; an ignition capacitor that is charged with one polarity with the positive half cycle of the output voltage of said exciter coil; a thyristor that is turned on when a trigger signal is provided to discharge charges stored in said ignition capacitor through a primary coil of said ignition coil; a thyristor trigger circuit that provides a trigger signal to said thyristor at an ignition position in said internal combustion engine using the negative half cycle of the output voltage of said exciter coil as a power supply voltage; and a trigger inhibiting circuit that inhibits said thyristor from being triggered when a current flowing from said exciter coil through said thyristor is detected and when a charging current of said ignition capacitor is detected.