| 摘要 |
PROBLEM TO BE SOLVED: To actually detect combustion in a cylinder, and optimize a spark discharging time by providing means for extending the spark discharging time of an ignition coil and means for judging the ignition of mixture, and stopping the means for extending the spark discharging time after ignition of the mixture is judged. SOLUTION: The time for extending spark discharging of a boost-up circuit 3 is set longer with the premise that the time is stopped by a signal from a detecting circuit 8. Required voltage is applied on an ion gap 5 disposed in a cylinder and an exhaust passage, and is made electrically conductive when flame and combustion gas exist between electric poles of the ion gap 5, and ion current is made flow from an ion power supply 6 through a resistor 7 and the ion gap 5. Voltage change of both ends of the resistor 7 are monitored by the detecting circuit 8 to detect combustiop in the cylinder, and the means for extending the spark discharging time is stopped by the detecting signal. It is thus possible to optimally hold the spark discharging time. |
