Patent GB-735501-A (GB)
Title: Improvements in or relating to register translators for telecommunication switching systems
Inventor: HARTLEY GEORGE CLIFFORD
IPC: H04Q3/42
Filed: 1949-02-14
Abstract: 735,501. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd. Feb. 10, 1950 [Feb. 14, 1949], No. 3972/49. Class 40 (4). In a system in which a common translator may be associated temporarily with a number of registers the code digits and their translations are passed to and from the translator as coded combinations of a sequence of pulses selected from a 'regularly recurring cycle of such pulses. The pulses are also used for identifying a register calling for a translator each register being associated with a particular one of these pulses. The sequence of pulses is also used to time and control the various operations of the register after the manner of a sequence switch. The translator may preselect a calling register while the translator is passing a translation to another register. As described, 50 positive pulses PI ... P50 are used of which P1 ... P48 may be used for register identification. These may be generated as described in Specification 735,508. Seizure of register and registration of digits. The register is seized in known manner whereupon impulsing relay AE operates and fires tube T2 which operates BE and extinguishes the normally conducting tube T1. Tube T3 is extinguished during each impulse and C1 then charges slowly but discharges quickly each time T3 refires so that T1 does not fire and BE remains operated. In an alternative circuit BE is held in the anode circuit of valve V1 which is biased to conduction by condenser C4 which charges rapidly over rectifier D1 but discharges slowly over resistance R4. Tube T4 is also fired by P14 or P24 when AE operates but C4 discharges over rectifier D4 at the beginning of the first impulse and cannot recharge during impulsing so that T4 is extinguished during the reception of each digit. Relay BE connects up dial tone and also H.T. to tubes in the register among which T5 is caused to fire the resulting pulse firing T109, T7 and T33 thus establishing correct initial operating conditions for their circuits. T5 also fires T120, T123 in the timing circuit, Fig. 5, which then proceeds to count off 7 impulses after which T121, T123 are cut off so permitting the transmission of the first digit of the translation as described subsequently. Pulse P24 is passed by T4 and T6 to zeroize the receiving binary counting chain T10 ... T17. The counting chain then registers the first received digit. Tubes T7 ... T9, T18 are arranged so as to absorb an initial digit of value " 1." The first impulse of the digit ignites T8 and extinguishes T7 which blocks T6 to prevent the subsequent transmission of pulse P24. If the digit is " 1 " when T4 conducts at the end of the digit it passes pulse P14 via T19, T20 to refire T7 and extinguish T8. Since T9 is not fired T21 of the " in sequence counting chain does not fire. Tube T4 then passes pulse P24 via T6 to reset the counting chain T10 ... T17. If the digit is " 2 " or more T9 also fires to enable P14 to fire T21 at the end of the digit. Tube T18 fires in parallel with T9 to bring up relay DT which disconnects dial tone and starts the impulse generator. When T21 fires it produces a pulse which is applied to the triggers of tubes T28 ... T31 ... of the storage set SA, and those tubes receiving enabling bias from such of tubes T10, T12, T14, T16 as are non-conducting fire to store the digit. Pulse P24 then passes through T4 and T6 to reset the counting chain and subsequent digits are received in a similar manner and transferred to storage groups SB, SC and S1 ... S4 under control of the distributing chain T21 ... T27 which advances one step at each pulse P14, passed by T20. Connection of translator and translation of office code. At the end of the third digit T23 fires T32 and T33 is extinguished. Tube T34 is thereby permitted to pass the pulse PA characteristic of the register to the connector circuit, Fig. 16, to cut off valve V2, the resulting anode pulse being passed via R3, V4 and gated by pulse PA through one of the networks R27 ... C12. These networks prevent permanent seizure of the connector circuit by the continuous emission of pulses from a faulty register since after a short period C11 charges up and prevents the passage of further pulses. Normally a single pulse is passed and after reshaping by V5, V6 passes via V7 and lead L to all the registers and also to T35 which fires to block V2 to pulses from other registers. The pulse is gated by pulse PA to fire T36 in the appropriate register. T36 then passes pulse P48 to fire T33, T37 and T32 is extinguished. T33 prevents T34 from passing further pulses PA to the connector circuit. T37 back-biases rectifiers D22, D23 (which otherwise shunt the signal paths to the grids of V10, V11) and enable the office code and its translation to pass to and from the translator. Valve B12 conducts between pulses P49, P1 to extinguish T35 in the connector circuit and T36 in the register. Pulses P1 ... P4 are applied to storage tubes T28 ... T31 and such of these as are fired pass the pulses via V10, V12 and V13 to the translator which gates them in by pulses P1 ... P4 to fire a combination of T39, T41 ... T45 similar to that of T28 ... T31. Such of T39, T41 ... T45 as fire extinguish their normally conducting mates T38 ... T44. The stored number is then decoded into the decimal system by the arrangement of rectifiers D38 ... D41 which allows the biasing of only one of the ten leads leading to the triggers of tubes T51 to T60. The second and third digits are fed to similar storage devices (not shown) under control of pulses P5 ... P8 and P9 ... P12 which in turn translate the digits into decimal form and bias the triggers of a tube in each of the sets T61 ... T70 and T71 .... T80. Immediately prior to the sending of the digits the register sends a pulse P50 which fires T46 and extinguishes T47 to allow pulse P17 to fire T48 and extinguish T49. The drop in anode voltage of T47 causes the anode voltage of V17 to rise and this rise is passed via V18 and V19 to fire the three valves of T51 ... T80 whose triggers are biased. Thus if the office code was 326 tubes T53, T62 and T76 are fired. For each translation to be made there is provided a tube such as T81 arranged so as to fire only when biased from the cathodes of all three of its associated tubes. The anode of T81 is pulsed by a combination of pulses selected from P18 ... P42 representing the binary codes of 6 routing digits. These pulses are repeated by V14, V15 and V16 to the register where they are admitted by V11 to set storage sets SR1 ... SR6 under control of pulses P18 ... P41. At the end of the translation pulse P43 is transmitted over V16 to the register and also to T49 which extinguishes T48. Valve V17 is thereby caused to conduct, its fall in anode volts passing via V18, V19 to extinguish T51 ... T80, and so disable the translator tubes such as T81. The storage sets T38 ... T41 are reset by pulse P18. In the connector circuit the cross-connected pair B14, B15 changes over for the period between pulses P45, P47 to reduce the output of V9 thereby extinguishing T37 in the register. The connector is now conditioned for connecting the translator to a second register which may have been preselected by its pulse PA during the transmission of the routing digits from the translator to the first register. Arrangements are described where more than 48 registers are used in which the circuit of Fig. 16 is switched at a rate of 20 c.p.s. between two circuits of the type shown in Fig. 6. Outward transmission by the register. The " end of translation " pulse P43 received from the translator is gated in by rectifier D52 and fires T101 and T86 of the out-sequence chain T86 ... T96. The latter biases rectifier D57 to permit such of pulses P32, P34 ... P38 as are connected to fired tubes in the set T82 ... T85 to pass via tube T104 to tube T105. Pulse P25 zeroizes the counting chain T112 ... T119 and fires T 107 (which was originally extinguished when P13 fired T108) thereby biasing T105 to permit it to pass the digit pulses P32, P34 ... P38 to the counting chain, which is thus set to a number complementary with respect to 15 to that stored on T82 ... T85.. T110, fired by the train of code pulses, extinguishes T109 and prevents T111 and T107 from being fired by further pulses P25 until the first routing digit has been sent. Meanwhile P12 from T106 has fired T87 in the out-sequence chain but P13 fires T108 to prevent T105 passing the next routing digit from SR2 and to prevent T106 passing further pulses P12 to the out-sequence chain. 10 i.p.s. pulses connected by dt1 pass via tube T126 (enabled by the present state of the counting chain, Fig. 5) to the counting chain T112 ... T119 and also to tube T127 which operates relay AG to repeat the pulses to the first code selector. The setting of the counting chain to " 15 " causes a pulse, developed over R88, to fire T109 to disable T126 so stopping the out-impulsing. The pulse over R88 is also applied to start the counting circuit T120 ... T125 which disables tube T126 while it counts off seven pulses to provide the inter-digital pause. T126 may also be disabled by the operation of the polarized relay DD over the outgoing line to delay the sending of further impulses until the distant switching equipment is ready to receive them. Meanwhile T109 extinguishes T110 to enable T111 to pass P25 to reset the counting chain. Pulse P25 also fires T107 which extinguishes T108 to enable T105 to transmit the next digit from SR2 to the counting chain and so on. If the translation consists of less than 6 digits, when the last of these has been transmitted T110 is not fired from the " empty " storage units so that T126 does not fire and transmit any more digits and successive pulses P12 are gated by T106 to step the out-sequence chain until T92 thereof is fired and T102 in parallel with it. This prevents further " skipping " of unregistered digits in case the subscriber has bee