| 摘要 |
PURPOSE:To perform a reliable detection of knocking, by a method wherein a circuit time constant of an output of an average value of an oscillating sensor at a given crank angle range of an engine is made larger than a time constant outside the given crank angle range, and is compared with a peak value of an output. CONSTITUTION:An oscillating signal is applied to an input terminal 21, and an ignition timing signal connected to a contact point is inputted to an input terminal 37. A signal, at a given crank range in the proximity of an upper dead point, of the oscillating sensor signals passes an analogue switch (S) 23, and a peak value is outputted by a peak hold circuit 24. Further, it is integrated by a rectifying circuit 26. At a given crank angle range, an S27 is closed, an S28 is opened, and at a crank angle range other than the given crank angle range, the S28 is closed, and the S27 is opened. Thus, at the given crank angle range, a time constant is made large, and through comparision of outputs of circuits 24 and 25 by means of a comparator 34, a result is provided to an FF35. This permits to obtain a reliable knocking signal from a knocking detecting output terminal 36. |
