| 摘要 |
<p>PURPOSE:To detect break of signal wires instantaneously, by connecting a Zener diode to each of switches provided on devices to be controlled and each element in parallel, and providing No.1 and No.2 modes for selecting signals: No.1 for detecting switches, and No.2 for detecting break of the signal wires. CONSTITUTION:Selecting signal output terminals 7 and selecting signal input terminals 8 are provided. The selecting signal output terminals 7 output a selecting signal for selecting one of switches SW1-SW6 provided on devices to be controlled and each element, and the selecting signal input terminals 8 receive the signals described above. The terminals 7 and 8 are connected each other in series by a signal wires 11 via the switches SW1-SW6 to which Zener diodes 12 are connected in parallel. The signals described above have No.1 mode for detecting the switches SW, and No.2 mode for detecting break of the signal wires 11. In No.1 mode, the signals are supplied in the reverse direction against the diodes 12. The switches SW are selected to withstand a voltage lower than the break-down voltage of the diodes 12, and the signal wires 11 are selected to withstand a voltage higher than the break-down voltage described above. Therefore, break of the signal wires can be detected instantaneously.</p> |
