Patent GB-224865-A (GB)
Title: Improvements in or relating to telephone systems
IPC: H04Q3/42
Filed: 1924-08-26
Abstract: 224,865. Siemens & Halske Akt.-Ges. Nov. 17, 1923, [Convention date]. Automatic, semi-automatic, and manual exchange systems.-A multi-digit impulse-recorder comprises an impulse relay A2, Fig. 2, which controls a pair of relays W, V2, which controls a similar pair X, Y. These pairs are operated cyclically, requiring respectively two and four impulses to complete their cycles, and, jointly with relay A2, control digit-recording groups such as ZR1 - - ZR5 with which they are associated in succession by relays Ta, Hu, Ze. Different numbers of impulses cause the energization of relays ZR1 - - ZR5 in different combinations. The recorder can be used in the control of talking-connection switches, but is described with reference to a call-indicator system in which each operator's position has three call indicators which control each other so that only one can display at a time. Selection of an idle call-indicator. When the cord shown, Fig. 1, is seized, relay C1 energizes over a contact 6 (which is opened when the operator leaves the position), locks up, and energizes winding I of relay D1, which completes a circuit for relays AR1 - - AR3 in series with the relays C2 in their respective indicators. Assuming that shown in Fig. 2 to be idle, relay AR1 locks up and relay C2 cuts in its high resistance winding II. Relay D1 and the relays AR2, AR3 (if energized) fall back. Relays A2, B2, Fig. 2, are now respectively under control of relays A1, B1, Fig. 1. Relay A1 responds to dialled impulses, and relay B1 remains energized during each digit. Control of thousands register. At the beginning of the first impulse, relay A2 energizes relay V2 over 47, 45, 25, 35 and digit relays ZR1, ZR4 over 52, 54, 55, and their windings I in parallel. Relay ZR1 locks over its winding II and relay ZR4 cuts in an opposing winding II but does not fall back. At the end of the impulse, relay W pulls up over its winding II which has hitherto been short-circuited and energizes relay X. The next operation of relay A2 releases relay V2 and sends a reverse current from 67 to the windings 1 of the relays ZR1, ZR4. The former remains locked up, but the latter, owing to the opposing winding, falls back. The relapse of relay A2 releases relay W so that relay Y is allowed to energize over its winding I. The third impulse re-energizes relay V2 and, owing to the operation of relay Y, energizes relays ZR2, ZR5 which complete circuits for their windings II in the same way as relays ZR1, ZR4. The relapse of relay A2 re-energizes relay W so that relay X falls back and the fourth impulse releases relay V2 and relay ZR5 in the same way as the second released relay ZR4, and at the end of the impulse relay W falls back and releases relav Y. In response to the remaining impulses, relays W, V2, and X, Y are similarly controlled, i.e. during odd impulses relay V2 is energized and during even impulses relay W, during the fifth neither of relays X or Y is energized, during the sixth relay X is but Y is not, during the seventh both are. and during the eighth relay Y is but X is not. The cycle of the group X, Y then begins again. The fifth impulse energizes relays ZR4, ZR3 and the sixth releases relay ZR4. The seventh energizes relay ZR5 and releases relay ZR1 bv energizing its reverse winding III. The eighth releases relay ZR5. The ninth energizes relay ZR4 and releases ZR2 over its winding III and the tenth releases ZR4. Control of remaining registers. The relapse of relay B2 at the end of the digit allows relay S to energize over its winding I. Relay R which operated when relay B2 first pulled up remains energized. Relay S energizes relav Ta which connects a hundreds register (not shown) to the controlling relays. During the hundreds digit, the energization of relay B2 releases relay R, but relay S holds up until the end of the digit and then falls back and energizes relay Hu to associate a tens register. The cycle of operations of relays R, S is repeated during the tens and units digits and results in the successive energization of relays Ze, E the latter of which prepares the display circuit. Mutual control of indicators. Each of the indicators has a pair of relays, e.g. F, F1 with different times of release. The quick relay F shortcircuits the relays of one of the other two indicators and the slow relav F1 those of the other. When, therefore, relay E operates, the relays F, F1 cannot operate if either of the other indicators is in the display position. The different times of release arrange for the display of the indicators in succession. If, for example, the relays E of the indicators SP1, SP3 are both operated when the F relays of register SP2 fall back, onlv the indicator SP1 operates, the short-circuit being maintained on the relays F of the indicator SP3 by the relay F<1>1 for a short time and then by the. energization of relav F. Relay F1 completes the selected lamp circuits, and relay F energizes relay VI in series with a lamp AL individual to the cord. Supply of ringing current and release of indicator. When the operator takes the cord to plug in, springs 7. 142, 155 change over, but the indicator is held by relay V1. Relay Bl pulls up to open contact 5 to mark the cord busy. When the plug is inserted the following circuit is made : 60 volt battery, P1(II), H1, 136, P1(I), 138, T1. Only relays H1, T1 energize in this circuit, as the two windings of relay P1 are in opposition. Relay HI unlocks relay AR1 to release the indicator and cause the sluggish relapse of relay V1. Relay V1 on falling back de-energizes relay H1 and the winding II of relav PI and connects 20 volt battery over 145 to its winding 1 so that the relay now pulls up. Relay D1 which was originally energized over its winding II by relay H1 now holds up over its winding III in series with relay L and a slow interrupter LU. Relay L pulls up and connects ringing current to the line. During the spacing period of the interrupter LU, relay D1 falls back sluggedly and puts relay L under control of the rapid (10 seconds) interrupter RS. The reply of the called party energizes relays A3, B3, and relay P1 being now short-circuited falls back and energizes relay Q which cuts off the ringing relay L. Release. When the called party hangs up, the relapse of relay A3 allows relay PI to re-energize but relay Q remains looked up. The relapse of relay C1 when the calling party clears, lights the lamp SL. The change over of contacts 142, 155 releases relays B1, Q, P1, T1. Busy test. If the plug is inserted in a busy jack, relay H1 energizes as before but is followed immediately by relay P1 the windings of which now assist each other. Winding I is energized in a circuit 20-volt battery. 166, 163, 138, and winding II over H1, 160, 161. Relay P1 locks up relay VI over its winding II and energizes relay R1. Ringing or other disturbance is prevented since relays HI, V1 remain energized and keep the cord circuit open and the ringing relay disconnected.