| 摘要 |
PURPOSE:To ensure the display for the core wire number or the disconnection and false connection of the core wires, by coding through an encoder the number of the core wire with which the core wire is connected with earth by an earth connection switch and then comparing the encoded number with the output of a counter which is counted up with detection of the earth. CONSTITUTION:The core wires at one end of a multi-core cable 1 to be tested are connected successively in the order of the younger numbers to earth receiving terminals LN0-LNn of an encoder 8. An earth connection switch 19 is operated to connect the earth to the core wire of the number which is displayed at a test core number display circuit 5. When the connected core wire is normal, a coincidence is obtained through a comparator 7 between the binary code of the output of an encoder 6 and the contents of a counter 4. Then an OK signal is delivered. In case a disconnection arises, the counter 4 is not counted up and the display 5 works continuously. In the case of a false connection, no coincidence is obtained through the comparator 7 and a contact remote number display circuit 11 displays the output of the encoder 6. And a test of a laid long-size and multi-core cable is possible by separating and extending the circuit 5 from a tester. |
