GB1319263A - Circuit testing apparatus - Google Patents

Abstract

1319263 Cable continuity testing RIST'S WIRES & CABLES Ltd 26 Sept 1970 45958/70 Heading G1U Cables 25, 26, 27, Fig.2, particularly in a car wiring harness, are tested for continuity by connecting each between corresponding contacts US1 US2 of a uniselector arranged to step automatically until a non-continuous cable is located. In order that different cable harnesses may be tested, circuit boards 20 are employed each carrying appropriate couplings 21, 22 for the particular harness to be tested and being connectible by plugs and sockets to the test apparatus. The board 20 shown is designed for a harness in which the third cable 27 has an internal branch connection to a cable 28. Also in order to be able to test a large number of cables, a second uniselector having banks BS2, BS3, is provided so that pairs of banks US1, US2; US3; US4; &c., of the main uniselector are brought into operation sequentially. As described uniselector BS2, BS3 moves to its first position in which banks US1, US2 of the main uniselector are selected. Testing then proceeds, each continuous cable under test causing the stepping coil US of the main uniselector to be energized and advance the uniselector to its next position. When a non- continuous cable is encountered stepping of the uniselector stops and lamps on a further bank then indicate the location of the faulty cable. Testing may be restarted by depression of a key S3. When the main uniselector has made one revolution, a pulse from a bank not shown advances the second uniselector so that the next pair of banks US3, US4 becomes operative. After the whole harness has been tested, this being detected by the presence of a voltage on the wiper of a switch S4 which was initially set in the appropriate position, the system automatically resets itself. (For Figure see next page)