Patent GB-1159630-A (GB)
Title: Test apparatus for telephone equipments
IPC: H04M3/26
Filed: 1968-02-22
Abstract: 1,159,630. Telephone exchange apparatus. INTERNATIONAL STANDARD ELECTRIC CORP. 22 Feb., 1968 [28 Feb., 1967], No. 8739/68. Heading H4K. One set of test relays is used automatically to run through a sequence of elementary tests applied to circuits of one type one after the other and is similarly employed in testing circuits of different type. The tests are applied to the various kinds of junction and feeder circuits in a telephone exchange, these circuits being made available for test from eight-pin jack connections to one or more equipment racks 1. The test wires comprised of all the jack leads 5 are selectively connected by a set of relays C and a distribution field provided by a set of plug-in edge connectors 8 to the test wires 7 of the test routiner shown in the chain line box 2. The test routiner 2 is controlled from a test desk 3 having keys TRC each of which, by operating one of a set of relays TR, determines the type of circuit to be tested by the routiner. Operation of a type relay TR prepares a set of test sequence relays 22, so as to connect the test relay set 21 to the test wires 7 of the routiner in a manner appropriate to the circuit type, and so as to provide an appropriate order of operation of the sequence relays 22 from a stepping circuit 24 which cycles the routiner through its test sequence for each circuit connected over the test wires 7. The stepping circuit 24 is shown as a stepping switch but may be a relay chain. Testing of a group of circuits chosen by a type key TRC is begun in response to a start key DPC on the test desk, a control relay group 26 in the routiner 2 starting the stepping circuit 24 which step-by-step controls the sequence relays 22 to connect the test relay set 21 in a manner appropriate to each test. The correct response of test relay set 21 to each test advances the stepping circuit 24 to the next test. If a correct response is not achieved the stepping circuit 24 fails to advance and a timing circuit in the control relay group 26, constituted by a capacitor discharged through a relay to give a dead-line for each test, signals the test desk 3 to set off an alarm AL and light lamps to identify the circuit being tested and the test involved. If a circuit tests correctly to the whole test sequence the end-of-sequence position of stepping circuit 24 is detected by control relay set 26 which advances stepping circuit 25 to connect the next circuit for test and sets stepping circuit 24 at the start of the test sequence. The stepping circuit 25, shown as a stepping switch but which may be a relay chain, controls the relays C to select the wires appropriate to the circuit to be tested among the jack cables 5. The pattern of connect tions between stepping circuit 25 and relays C may be selectively established by a card connector 13. When all the circuits of the selected type have been subjected to the test sequence the stepping circuit 25 advances but energizes no C relay, the first attempted test by the routiner in this circumstance produces a fault time but in the control relay set 26 which is interpreted at the test desk as a test-cyclecomplete signal. A detailed circuit of the routiner 2 and its function in applying a test sequence to a particular junction circuit are described with reference to Fig. 2, not shown.