Patent GB-657058-A (GB)
Title: Improvements in or relating to apparatus for reproducing information from stored information by correlating the stored information with received stimuli
Inventor: FLOWERS THOMAS HAROLD
IPC: G06F7/02
Filed: 1947-11-10
Abstract: 657,058. Automatic telephones. POSTMASTER GENERAL. Nov. 10, 1947, No. 29870. [Class 40 (iv)] [Also in Group XL (b)] Stored data is made available at the reception of electrical signals corresponding to a call to be made through an automatic exchange. A continuously-rotating perforated disc serves as a memory to translate the code digits into routing digits, the perforations activating photocells to apply pulses to a set of valves which conduct only when the dialled digits correspond with the set of perforations then being scanned, whereby the related routing digits are transmitted. Figs. 5-27 together form one circuit arranged as shown in Fig. 4, those figures in squared brackets not being shown. Valves are indicated by a number with the number of the figure in parentheses. Seizure of a register-translator. A subscriber initiating a call is connected to a first code selector which drives a uniselector H, Fig. 7, until it finds a free register translator, when relay K operates to reduce the potential of the P wire to mark the register translator busy and operates KR, which applies earth over lead PU into the register, supplies dial tone over lead FR to the subscriber and connects the register translator over contacts KR3, KR4 to the first code selector. Registration of dialled digits. Each pulse of a dialled digit operates contact L, Fig. 7, to switch a trigger unit comprising valves 1, 2 (9) on and off, to operate a pulse trigger 3, 4 (9), which restores before the next pulse. Each operation of trigger 3, 4 (9) switches off valve 5 (9), which restores only at the end of the train of pulses to operate pulse trigger 6, 7 (9). The positive dialling pulses from trigger 3, 4 (9) also operate valve 12 (10) to register the digit temporarily on a binary counter 1-8 (10). The control grids of valves 13-20 (12) are connected in different combinations to the anodes of three of the valves 1-6 (12) constituting a counter, so that a valve 13-20 (12) is prepared for conducting only when the valves in its particular combination are all off. The counter 1-6 (12) is driven by positive pulses from valve 7 (9) at each dialling of a digit, the end of the digital train causing valve 6 (9) to raise the potential on the suppressor grids of valves 13-20 (12) whereby that valve which has been prepared by the valves 1-6 (12) conducts momentarily to apply a negative pulse over the corresponding lead ID1-8 to switch off the valves such as 1-8 (11). As the pulse decays, the triggers made up of valves 1-8 (11) respond to the potentials on the anodes of valves 1-8 (10) over leads IC1-8 to register the digit. The first digit is registered on Store No. 1 (Fig. 11), the second and subsequent digits on Stores Nos. 2, 3 and so on (Figs. 13-17, not shown). The counter 1-8 (10) is released between digits by a negative pulse on lead Fl when trigger 6, 7 (9) releases. For a local call, the code is registered on the first three stores. For a trunk call, the subscriber dials TRU followed by the code and numerical digits and more than eight stores may be needed, in which case the early stores are used again after the digits stored there have been transmitted. Mechanical translating device. Fig. 3 shows part of a rotating disc serving as a translating device. The radial lines on the disc are perforated in tracks 2-4 with the translation digit ordinal, in tracks 5-16 with the code, in tracks 17-20 with the translation digit, all on a binary scale, and in the last line relating to a code, an end order in tracks T, L, S. Each line has a small hole in track 1. The disc rotates continuously, the holes in the various tracks activating photo-cells, the outputs of which are amplified (Figs. 5, 6, not shown) and fed to leads TA1-4, TB1-4, TC1-4, TD1-3, TD1-4, EX, EO, ECO, S, Figs. 18, 23. A translation digit is selected and transmitted only when there is agreement between the code digits dialled and those on the line being scanned and when the ordinal number of the digit is correct. Coincidence of code digits. The code registrations in Stores 1-3 apply potentials to leads A1-4, B1-4, C1-4 and Fig. 18 shows a circuit for detecting simultaneous coincidence between these potentials and those on leads TA1-4, TB1-4, TC1-1. When coincidence occurs, on all twelve pairs of leads, none of the valves 1-4 in the A, B or C circuits conducts. Coincidence of translation digit ordinal. Each time a digit is sent out, a counter 3-8 (22) is stepped on. The anodes of valves 3, 5, 7 (22) are connected to leads TD1-3, respectively, and when the potentials are coincident, valves 13, 15, 17 (22) are switched off in the same manner as valves 1-4 (18). Selection of translation digits. When, as just described, there is coincidence of code digits and of translation digit ordinal, and as described later, valve 2 (23) is off, the potential on lead F, Figs. 18, 23, rises and raises the potential on lead F, Figs. 18, 23, rises and raises the potential of the control grids of valves 3-9 (23) and when a short pulse in track 1 shuts down valve 1 (23) to raise the suppressor grid potential of these valves the valves 3-9 (23) are controlled by the presence or absence of holes in tracks 17-22 to apply pulses representing the translation digits to leads NT1-4 and control pulses to leads X, O, CO. Valve 2 (23), referred'to above, is off only at the end of each positive pulse from valve 1 (23) when, also, control leads F1, F2 are at near earth potential. Lead F1 is normally at near earth potential, but when valve 6 (9) is switched off for periods of 50 ms. during the storing of dialled digits, its potential rises to prevent accidental emission of digits. Lead F2 is held at near earth potential until the first translation digit is signalled over leads NT1-4 when the potential of lead F2 is raised to prevent further signalling. Transmission of digits.-General description. The first digit of the translation is sent out as a train of pulses by operating contacts PV, Fig. 27, after which a pulse trigger measures out an inter-train period, during which the counter 3-8 (22) is stepped one place. At the end of the inter-train period, lead F2 is reduced to near earth potential and the next time the radial strip corresponding to the dialled code and to the new combination of potentials on counter 3-8 (22) is scanned, the second translation digit is signalled by momentarily switching on the appropriate combination of valves 6-9 (23). The second and subsequent code translation digits are sent out in the same manner. For a local call, the last translation strip has a hole in track 22, which momentarily switches on valve 4 (23) to cause transmission of the numerical digits in Stores 4-7, after which the register releases from the first code selector. Trunk call. The digits TRU are translated in the same manner as for a local call, after which holes in tracks 22 and 21 momentarily switch on valves 4, 5 (23) to send the exchange and numerical digits, the register not disconnecting until all the latter, including any stored in Stores 1-3, have been sent, Service call. A service call is translated in the same manner as a local call except that the hole in track 22 is replaced by one in track 23 which switches on valve 3 (23) momentarily to disconnect the register. Sender. When counter triggers 1-8 (20) and triggers 1-8 (19) are in normal released condition, there is coincidence of distribution of potentials on their anodes, whereby a circuit (Fig. 21, not shown) adjusts the potential on lead OCC to maintain valve 10 (26) on. Momentary switching on of a combination of the valves 9-6 (23) at the translation of a code causes operation of a corresponding combination of the trigger 1-8 (19) over leads NT1-4, whereby the coincidence of potentials is destroyed and valve 10 (26) is shut off to cause a multivibrator circuit 1, 2, 3 (26) to operate and release relay PV to generate timed pulses in the + and - loop. Each time valve 3 (26) switches off to terminate a pulse over the loop, it operates counter driving valve 12 (20) to step on counter triggers 1-8 (20), until coincidence is restored between the triggers of Figs. 19 and 20, valve 10 (26) is switched on and sending stops. Switching on valve 10 (26) applies a negative pulse over lead OR to restore the triggers of Figs. 19, 20. It also operates pulse trigger 11, 12 (26) which remains operated for a predetermined time constituting the inter-train period. This trigger pulses valves 1 (22), 11 (22) to operate counter trigger 3, 4 (22) to enable the second translation digit to be signalled over leads NT1-4. When the first digit is signalled, valve 13 (26) is switched off and the potential on lead F2 is raised under the control of lead OCC. At the end of the first digit, the potential on lead OCC restores but pulse trigger 11, 12 (26) operates to maintain valve 13 (26) off and to maintain the potential on lead F2. The subsequent translation digits are signalled and sent in the same manner. Sending of numerical digits. When the last translation digit is signalled, the momentary switching on of valve 4 (23) operates trigger 8, 9 (26) and switches off valve 6 (26) whereby when trigger 11, 12 (26) releases at the end of the inter-train period, oscillator valves 7, 14 (26) function to apply rectangular voltages to lead RT, which applies successive positive and negative pulses to the suppressor grids of valves 10-17 (25), the positive pulses preparing the valves for conduction. These valves are interconnected to counter-triggers 1-6 (25) in the same manner as the circuit of Fig. 12. When valve 4 (23) is switched on by the last translation digit, to operate trigger 8, 9 (26) and switch off valves 5, 6 (26), and when valve 10 (26) switches off at the end of the inter-train period, valve 4 (26) switches off to set the counter triggers 1-6 (25) to fourth position, valve 13 (25) conducts momentarily to switch on any of valves in Store No. 4 corresponding to