PURPOSE: To ensure the accurate detection of an ignition signal and to make it possible to control an engine effectively by a computer and the like, by making the ignition signal a pulse shaped signal, and counting the number of the pulses.
CONSTITUTION: The signal from an electromagnetic pickup 11, which is provided in an ignition plug, is rectified by a diode 12 and compared with a reference voltage Vs in a comparator circuit 13. The output signal from the circuit 13 is counted by a counter circuit 16. Meanwhile, a clearing signal is sent to the counter circuit 16 from an Ig signal processing circuit 19. The counting is performed only during a section corresponding to the ignition signal Ig. When the counted value equals to a preset value or more, the signal is judged to be the ignition signal, and the signal is outputted from an output terminal 20. When the counted value is less than the preset value, the signal is judged to be a noise signal and not outputted. Therefore, the ignition signal is detected positively and accurately.
| JP3311814 | MISFIRE DETECTOR FOR ENGINE |
AKIYAMA SUSUMU
SATOU YOSHIHISA
