| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that, when noises generated from an alternator are superposed on an ion current waveform, there may be the case of erroneously determining an alternator noise signal as a knock signal in determining knock before/after a peak value for the ion waveform, and the alternator noise signal causes erroneous determination that the combustion is continued even in determining misfire after a reduction of the ion waveform.SOLUTION: A second diode is arranged among an ignition plug, a connection part of a first diode, and a secondary coil, and a third diode is arranged among a first Zener diode, a connection part of a capacitor, and the secondary coil. The second diode has an anode terminal connected to the secondary coil, and the third diode has a cathode terminal connected to the secondary coil. The third diode has a capacity component of 10 pF or smaller. |
