Engine knock control apparatus.

摘要

There is disposed a knock sensor for detecting a knock signal of an engine. The output of the knock sensor is applied to a bandpass filter for bandpassing only the knock signal. The output of the bandpass filter is applied to an automatic gain control circuit for variably controlling the gain of the knock signal. The output of the automatic gain control circuit is applied to an averaging circuit via a maximum clamp circuit. A comparator produces an output to an integration circuit of the next stage when the output of the bandpass filter becomes greater than that of the averaging circuit. An ignition control device for controlling the spark timing of an ignition coil ignites the ignition coil by the output from a pick-up coil and that of the integration circuit and delivers a feedback signal to the integration circuit.