Patent GB-213227-A (GB)
Abstract: 213,227. Siemens & Halske Akt.-Ges. March 19, 1923, [Convention date]. Automatic exchange systems; metering.-In a zone metering system in which the charge is repeated for each unit of time and metering takes place upon release, a warning signal is sent to the calling subscriber on the expiry of each unit of time, and the connection is severed unless he performs a definite operation, e.g. dialling 0. The call cannot be prolonged after the total charge has reached a predetermined amount. A call is extended over preliminary selectors IVW, IIVW, group selector IGW, and thence over a trunk 74, 84, with which is associated a repeater Ue. The second train of impulses which determines the zone of the wanted subscriber is repeated by a relay A2 to a switch MS. A time switch ZeS which is driven by low and high speed interrupters 99, 97 controls the warning signal and automatic disconnection, the latter being avoided if the call is prolonged by the operation of a relay S2, which prevents the energization of a relay TR to break the connection. The switch ZeS also controls a time switch ES, and an assessing switch AbS operates under control of the switches MS, ES. to transmit impulses through relays ZR2, ZR1 to the meter Z. When the total charge has reached the maximum allowed, the relay TR becomes energized over terminals of the switches ES, AbS. In the following description, the operative windings of relays are indicated in brackets where necessary. Preliminary selectors IVW, IIVW. The line relay R1 connects up the driving magnet D1 of the primary switch IVW to select an idle secondary switch IIVW. When this is found, the test relay II and relay R2 energize in series, stopping the rotation of the switch IVW and connecting up the driving magnet D2 of the secondarv switch IIVW to select an idle group selector IGW, whereupon the test relay T2 energizes and stops the rotation. Group selector, IGW. The line relays A1, B1 energize, and relay C1(I) energizes over the test wire 25, closing a locking circuit over relays VI(I)CI (II). The first train of impulses is repeated to the vertical magnet H1 at contact 43, relay V2 being operated by the removal of a short-circuit at contact 40, and falling back to connect up the rotary magnet D3. The test relay P1 energizes when an idle trunk is found and stops the rotation. Cam springs 62 are closed when the selector is raised to a level corresponding to another zone. Repeater Ue. Relay C2 operates over the test wire 53 and at contact 63 energizes relay V3(I), which at contact 66 connects the impulse relay A2 to wire 84 and at contact 67 places the magnet D4 of the switch MS under control of the impulse relay. The second train of impulses is repeated over wire 84 by relay A1 at contact 81 to the succeeding selector and to switch MS through relav A2, relay V2 being operated and energizing relay S2(I) over wire 74 to connect battery to wire 80 to energize a controlling relay at the succeeding selector. Relay V3(II) is held over the impulse circuit and then releases. The connection is completed, and upon reply of the called subscriber, contact 88 is closed, energizing relay B2(I), which at contact 202 short-circuits relay ZR2(III) and at contact 91 closes a starting circuit for the time switch ZeS over high-speed interrupter 97, relay U being energized. The switch ZeS moves one step and is then controlled by low-speed interrupter 99. Warning signal and automatic disconnection. The switch ZeS performs a revolution in a unit of time, e.g. 3 minutes. A buzzer Su is connected up over wiper 101, terminal 102 and re- Jays A2(III), B2(III), which transmit the warning signal to the calling and called subscribers. When the buzzer is disconnected, wiper 93 stands on terminal 104<1>, and magnet D5 is connected to interrupter 99 over relay TR(I). advancing the switch ZeS and energizing relay TR, which locks and opens the connection. When wiper 93 reaches terminal 111, relay HR (I) is energized in the driving circuit, and the calling subscriber cannot now re-establish the connection, since relay S2 is disconnected from wire 74. Metering and release. Relay HR(II) locks over wire 74 in series with relay Sl, which locks independently and short-circuits relay C1(II), which at contact 32 disconnects relay V1(I), at contact 36 connects relay V1(II) in place of impulse contact 81 to wire 84, and at contact 37 connects up metering relay ZR1 instead of relay S1. Relay V1(II) energizes in series with relays A2(I), HR (III), which close a circuit for magnet D7 of the assessing switch AbS in series with relay V3(II) over contacts 119, 68. The terminals of switch MS are connected to different wipers of switch ES, the terminals of which are connected to the terminals of switch AbS, so that a terminal of the latter is marked according to the zone and the duration of the call. Relay V3 unlocks relay TR which at contact 213 disconnects relay HR(II) from wire 74, while relay A2 at contact 124 connects metering relay ZR2(I) to wire 74, so that relays ZR1, ZR2(I) are now in series and both energize, the former shunting resistance 28 to operate meter Z over the test wire 25, and the latter shunting relay A2(I), which releases. Relays A2(I), ZR2(I) thus interact to step the assessing switch AbS and transmit metering impulses until wiper 127 reaches the marked terminal, whereupon relay S2(II) energizes over contact 63, releasing relay B2(I) at contact 77, and at contact 85 connecting battery over relay A2(II) to wire 84 instead of earth over relay HR(III). Relav V1(II) therefore releases, disconnecting earth from the test wire 53, so that relays C2, U are released, and the repeater switches are restored to normal. Magnet D5 is connected up over contact 130 and relay ZR2(II), which connects busy potential to the test wire 53 at contact 54. and at contact 134 energizes relays C(T), ZR2(III), so that magnet D5 and relay U interact to restore switch ZeS. Magnet D4 is then substituted at contact 134', to restore switch MS, and switches AbS, ES (if necessary) are restored similarly. Relay ZR2 is then released. At the group selector IGW, the release magnet M1 is connected up when the calling subscriber hangs up, and the test wire 25 is opened, so that the primary switch IVW rotates to normal. Prolonging a call by dialling O. Ten impulses are sent, and relays V2, S2(I) are energized as above, and at contact 151 high-speed interrupter 97 is substituted for low-speed interrupter 99. Relay TR cannot now lock since contact 105 is open, and the momentary energization of relay HR(I) is without effect. When wiper 101 stands on contact 153, magnet D6 energizes and moves switch ES one step, and switch ZeS then begins a second rotation, and the action is repeated. Metering and release by calling subscriber. Relays A1, B1 fall back, and relay C1(II) is shortcircuited, connecting metering relay ZR1 to wire 74 and relay V1(II) to wire 84 to initiate metering as before. Relays VI, P1 are then released and the switches are restored to normal. Release, when maximum charge is reached. Relay TR(II) is connected to the last terminal 171 of switch AbS, and when this is marked and wiper 93 stands on terminal 104<1>, relay TR energizes and locks, so that it cannot be released by the operation of relay S2. Relay HR(I) energizes over terminal 111, and a holding circuit is closed over relays HR(II), S1 to effect metering and release.