Arrangement for detecting internal combustion engine combustion state has discharge current limiter between ignition current path formed by ion discharge at ignition plug, bias device

摘要

The arrangement has an ignition coil arrangement (2), a bias voltage arrangement (13,12) for charging a bias voltage required for detecting ions generated as a result of discharges in the ignition plug (4a) when a high ignition voltage is applied, a limiter (10,11) for the discharge current, an ion current detector (30) and an ECU (20) for detecting a combustion state in the ignition plug depending on the detected ion current. The limiter is arranged between an ignition current path formed by the ion discharge at the ignition plug and the bias arrangement