Knock detection system.

摘要

A knock detection system for an internal combustion engine comprises an input IN for receiving a signal from a vibration-sensing transducer, an amplifier S2,S3 to which the input is connected and a rectifying and integrating circuit S4,S5 connected to the output of the amplifier, the amplifier comprising a variable gain amplifier S2 and feedback means being provided for controlling the gain of the variable gain amplifier in dependence upon variations in the output level of the rectifying and integrating circuit. The gain control which is exercised tends to maintain the integrator output level within an optimum band so as to overcome problems due to input offset voltage errors.