KNOCKING SIGNAL PROCESSING CIRCUIT

摘要

PURPOSE:To realize high precise detection and to properly perform the control of the ignition time of an internal combustion engine, by performing the detection of knocking on the basis of the signals of a knocking generating region and a region containing a reference signal. CONSTITUTION:The output of the vibration detector 42 attached to the main body 41 of an internal combustion engine supplied to BPF44 and HPF53 through an amplifier 43. The output of PBF44 is sampled by a switching circuit 45 and inputted to a comparator 47 through a rectifier circuit 46 as voltage to be subjected to knocking detection while the output signal of HPF53 is sampled by a switching circuit 54 to be inputted to the comparator 47 as reference voltage through a rectifier circuit 55, a smoothing circuit 56 and a reset circuit 57. A line signal changed in a pulse number and amplitude corresponding to a time wherein voltage to be detected exceeds the reference voltage is outputted by the comparator 47 to be inputted to an integrator 48. The voltage accumulated in the integrator 48 for a predetermined time is sent out as knocking detecting voltage through an amplifier 50.