| 摘要 |
PROBLEM TO BE SOLVED: To further improve the accuracy of knocking determination referring to an ion current signal.SOLUTION: In a circuit for detecting an ion current passing through an electrode of an ignition plug 12 during the combustion of fuel so as to detect knocking in a cylinder of an internal combustion engine mounted on a vehicle, a filter 17 for attenuating or intercepting components of the same frequency band as a signal generated due to knocking is provided on a primary side circuit in which a primary side coil of an ignition coil 14 exists. Therefore, periodic noise mixing into an ion current signal h due to the operation of an alternator can be removed. |
