| 摘要 |
PURPOSE:To prevent the noise which gives receiving interference car-mounted audio devices such as a radio and a communicator, by providing the earth line, which becomes the reflux line of I/O signal lines, and the earth line of the low-pass filter independently of each other. CONSTITUTION:Sensor groups or actuator grups 71-79 having earth point G in engine block 70 are connected to the metalic case where the car-mounted digital device is stored, and low-pass filter group 90 is inserted for the purpose of preventing clock pulses, which are used by the car-mounted digital device, from leaking to I/O signal lines 41-49 to give interference to the car-mounted radio. Earth line 81 of low-pass filter group 90 is provided independently of earth line 80 of I/O signal lines 41-49, and line 81 is grounded through the metallic case of filter at fixed point M on the vehicle body, thereby obtaining the by-pass effect of the high- frequency noise current of filters sufficiently. |
