IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine for detecting the signal output for detecting a spark discharge time and the combustion state of the internal combustion engine by detecting the ion current. SOLUTION: The ignition device for the internal combustion engine comprises a primary coil in which the primary current is subjected to the ON-OFF control by a primary current breaking device, a secondary coil which is electromagnetically coupled with the primary coil to supply the high voltage to an ignition plug 2, and an ion current detection circuit which is provided with a power supply circuit 6 for detecting the ion current and an ion current amplification circuit 7 on the secondary coil low-voltage side. The ignition device has the ion current detection function of detecting the current of the ignition coil, in other words, the spark discharge current during the discharge time in the plug gap, outputting it as the spark discharge time signal, and outputting the ion current detected by an ion current detection circuit as the voltage waveform in the combustion time of the internal combustion engine after completing the output of the secondary coil current. COPYRIGHT: (C)2009,JPO&INPIT