摘要:
An ignition secondary sensor is provided which is disposed in a high voltage path between an ignition coil and a spark plug for use with a detecting circuit for detecting ignition current and ion current flowing through a spark plug. The sensor comprises an ignition path connected in series with the high voltage path and having a pair of reverse current preventing diodes and a detection path connected to a spark plug side end portion of the ignition path and having a pair of current detecting diodes. A path portion of the detection path on the side of the current detecting diodes opposite to the ignition path and a path portion of the ignition path connecting between the reverse current preventing diodes are capacitively coupled. The detecting circuit is connected to the sensor for detecting the ignition current (ignition timing) on the basis of current flowing into the sensor therefrom and the ion current (combustion timing) on the basis of current flowing from the sensor thereinto.
摘要:
In a second voltage waveform detecting device for internal combustion engine, an electrical conductor is provided in an ignition circuit in proximity of a lead wire of a secondary circuit which supplies high voltage to a spark plug in an internal combustion engine by way of the lead wire. The lead wire is provided through an insulator. A condensor is connected between the electrical conductor and the ground. A secondary voltage detector circuit which devides a secondary voltage in accordance with a static capacity of the condensor and a static capacity between the electrical conductor and the lead wire.