728,651. Automatic exchange systems. POSTMASTER GENERAL. Jan. 16, 1951 [Jan. 27, 1950], No. 2242/50. Class 40 (4). [Also in Group XIX] An electronic translator common to a number of registers sequentially offers code translations to all registers simultaneously, the individual registers being conditioned to receive and store only the translations required by them. The invention is illustrated schematically in Fig. 2. Operation of impulse accepting and release control circuit 1 causes distributer 2 to open gates 10-16 in turn so that incoming digits are entered in counters 3-9. At an appropriate time the distributer 2 opens a gate 29 in a translator common to all the registers to start up a code ring 58 consisting of a ring of valves or cold cathode tubes, each element corresponding to a complete code for which the translator supplies translations and the elements conducting in turn. Each element in the ring 58 is connected to two sets of electronic switching elements 36- 38 and 39-41. A common pulse generator 30 supplies shaped pulses P1-16 through the operated gate 29 and a distributer 59 to open gates 31-35 in turn. Gate 32 emits P1 pulses, Fig. 1, to reset a counting device 23 in each of the registers. Switching elements 36-38, when marked over wire 65 by the corresponding element in code ring 58, are stimulated by P2-P4 pulses respectively from gates 33-35. Signals from elements 36-38 then appear in sequence on wires 66-68, which are joined respectively to one wire in different sets of 11 wires, each set terminating on one of the register code counters 3-5. If these signals are applied to marked elements in the code counters, resultant pulses pass over leads 70-72 to the coincidence recorder 23. The end of pulse P4 causes gate 35 to open gate 42 so that pulse P5 passes through gate 43 and over wire a to the electronic outgoing control switch 22 in the register. Any register requiring the first translation train of the ABC code offered signals over wire 75 to the coincidence recorder, which if it has already received signals over leads 70-72 emits a pulse over wire 73 to shut gate 42. Coincidence recorder 23 signals over lead 74 to open gates 24, 92, 93 and pulse P16 passes through sequence gate and translation gate 51 already prepared by gate 43, through switching element 39 stimulated by the condition on lead 65, over wire 80 to one of ten digital terminals, and so to equipment 17. The next pulse P1 is of opposite polarity to reset coincidence recorder 23 and close gates 24, 92, 93. The next set of P2-4 pulses operate elements 36-38 as before and, as no signal has been sent to change the code ring 58, the same code signals are applied to wires 66-68. At the end of pulse P4, gate 35 operates gates 42 and 44 so that pulse P5 pulses wire b. If then a register requires the second translation train, the transmission is effected over gates 52, 40 and wire 81. If the second train is not required, pulse P6 operates gate 45 to pulse wire c in respect of the third train and so on for pulses P7-10 and wires d-g. If there is no demand following pulse P10, P11 operates gate 69 to step on code ring 58 which then marks another wire 65. Equipment 17 responds as described above to pulse P16 to register the translation digits in turn. Equipment 17 then receives pulses from source 18, reverting step-by-step to normal condition and counting out the digit to device 20, after which 17 cuts off 18 and signals equipment 21 to measure off an inter-digital pause during which gate 84 is kept shut. Restoration of 17 also signals outgoing control switch 22 which energizes the element associated with the next wire b-g for transmission of the next digit. If the number of translation digits is less than seven, the translator signals after the last digit over a path such as 41, 91, 93, 22 to operate gate 25, whereupon the first numerical register 6 transfers its stored digit to equipment 17. At the next inter-digital pause, 22 transfers the signal to gate 26 and so on for the other numerical digits. When the last digit has been sent out, the control switch 22 signals over lead 89 to the impulse accepting and release circuit 1 which then restores the register. Special codes. For trunks, tolls, telegrams, operator and other codes without numerical digits, the operation is as above until the last translation digit is sent, but if the number of code digits is less than three, coincidence between the normally energized elements in counters 37, 38 and 4, 5 causes signalling over lead 89 to circuit 1. If the dialled code is not recognised by the translator, so that equipment 58 signals to the register for a second time over wire 87 after offering that register every available translation, the device 22 signals circuit 1 to release the register. In the drawings illustrating the following description a downward arrow over an anode indicates that the related valve is normally in conducting condition. Impulse accepting and release control circuit, Fig. 3. When an A digit selector encounters battery on wire P, relay H pulls up and after a short delay reverses incoming impulse detector valve A2, while removal of earth from wire PU restores A2, which controls the seize and clear detector valve A6 and the impulse train detector A8. When earth is removed from wire PU for more than 150 millisecs., A6 restores to give a clear-down signal. Operation of A6 energizes A10 and so All, A12, raising grid and cathode potential to +100 volts, so energizing A13 and relay BA, which disconnects the P-wire earth condition from valve A2. Impulse break detector A8 reverses at the first operation of A2 and restores only at the occurrence of a break exceeding 120msecs., producing a +ve pulse on its right anode to indicate the end of the impulse train. Incoming distributer, Fig. 4. Cold cathode tubes VC1-7 are fed by +100 volt pulses over lead 131 from tubes All, A12, Fig. 3, the first train firing VC1 over lead 128. At the end of the train, the restoration of impulse train detector A8 applies a +ve pulse over lead 108 to extinguish VC1 and fire VC2 and so on for each of the tubes VC1-7. Tubes VC9-11 record the receipt of thousands, hundreds and tens trains and with VC7 remain energized until the register is released. Code storage counters, Fig. 5. Tube D1 acts as a gate for the counter and is operated by pulses over lead 124, so that +ve pulses over lead 128 enter the digit to extinguish D2 and fire D3-D12 one by one. During code offering, one of wires 181-190 or 191-200 from the translator is energized by a +ve pulse and if the corresponding tube D3-D12 is conducting the related rectifier 5W1-5W10 conducts and a signal appears across the common load resistor 8R1, Fig. 8, to signal coincidence. Numerical counters. The numerical counters are substantially as shown in Fig. 5 but make no comparison with data from the translator and use reversed rectifiers which respond to +ve pulses to transfer the digit stored to a sender counter, Fig. 6, over one of wires 141- 150. This counter is of known type and can also receive digits from the translator over wires 171-180. Any tube K2-K11 striking extinguishes K1 which reverses sequence step pulse generator B16 to cause the sequence counter, Fig. 7, to operate the next tube in the sequence and permit W pulses from the translator to bias B17 so that the right-hand anode conducts. While B16 is reversed, W and Y pulses from the translator repeatedly reverse B17 over wires 208, 210, so that +ve pulses are transmitted to the impulse line common to the sender tubes. Thus the chain of counter tubes is run down step by step until K1 conducts again. At the same time relay PU, Fig. 9, is operated by the potential on the righthand grid of valve B17 and relay PU responds to Y impulses to send out line impulses. At the same time as K1 re-energizes a pulse on wire 126 is applied to inter-digital pause tubes N8, N9, Fig. 9, which mark wire 121 to inhibit operation of the send impulse generator for 700 msecs. Normally transmission of the translated digits is followed by reversal of potentials on the wires incoming to the register resulting in the operation of tube A15 and relay OD, Fig. 6, which energizes relay D. For calls to exchanges fitted with Coder Call equipment, however, the numerical digits have to be translated into potential code and in this case the potentials are not reversed so that relay D does not operate at this time. Sequence counter circuit, Fig. 7. At register seizure, a priming pulse on wires 122 fires tube L1. The cathodes of all tubes L1-7 are connected by rectifiers WL1-7 to wire 120 which prepares a gate to pass signals to the coincidence recorder. After offering a code, the translator offers pulses on each of seven wires 201-207 to ask the register which component is required, and the rectifier such as WL10 relating to an energized tube L1-7 conducts and a coincidence signal is sent to resistor 8R1, Fig. 8. The receipt of a digit by the sender counter, Fig. 6, causes generator B16 to pulse lead 109 to advance the sequence counter L1-7 one step. When the sender counter is at normal, transfer pulse generator B13 can gate W pulses over wire 127 to energize one of tubes M2-5 (M3- M5 not shown) which control the thousands, hundreds, tens and units gates M8-11 to permit a T pulse to transfer the related digit to the sender counter, the gates M8-11 being dependent also on the energization of tubes VC9-11 and VC7 respectively. The last pulse from generator B16 strikes tube M6, which permits N6, Fig. 9, to fire in response to a Y pulse. For translations not involving the maximum number, the translator follows the last train by signalling over lead 169 (Figs. 18 and 7) to operate tube OD which through tube A15 and relay OD, Fig. 6, offers the D relay to the outgoing loop. No translation available. Tubes L2, M1 M12 record when the translator has offered all codes without the register achieving c