| 摘要 |
PURPOSE:To detect a disconnection and a short circuit at the side of a knocking controller, irrespective of a number of revolution of an engine by containing a resistor in a recessed part of a substrate fixed side of a connector unit. CONSTITUTION:A resistor 37 is contained in a recessed part 36 formed on the lower face of a substrate part 34 of a connector unit 31. One lead wire 38 of the resistor 37, and the other lead wire 39 are spot-welded to a lead part 33 of a terminal 32, and one face of a substrate 23, respectively. Also, one electrode of a piezoelectric ceramic 30, and the other electrode conduct to the substrate 23 and the terminal 32, respectively, and an electric signal corresponding to a vibration is outputted. Moreover, a DC power source 54 and a resistor 55 (the resistance value is the same as that of the resistor 37) are connected in series between an input end of a knocking controller 53 and an earth. Therefore, by monitoring a check voltage VC generated across the resistor 55 of the controller 53 side, a disconnection, a short circuit, etc. of a knock sensor 52 and a connector harness can be checked in a state installed to an engine block, etc. |
