Patent GB-729743-A (GB)
Title: Improvements in or relating to electrical storage devices for coded electrical signals
Inventor: BAKER GEORGE THOMAS
IPC: H04L17/30
Filed: 1951-12-31
Abstract: 729,743. Printing-telegraphy. BRITISH TELECOMMUNICATIONS RESEARCH, Ltd. Dec. 19, 1952 [Dec. 31, 1951], No. 30489/51. Class 40 (3). An electrical storage arrangement for registering information in the form of binary digits, comprises a plurality of sets of cold cathode gas discharge tubes, the first set being selectively operated in accordance with the incoming signals whilst the tubes of each of the subsequent sets are primed from the corresponding tubes of the preceding set and supplied with striking potential when transfer is to take place. To effect operation of the set of cold cathode tubes in accordance with the sequence of binary digits, a set of cold cathode discharge tubes is operated in succession in response to a series of pulses locally generated at the digit recurrence interval and effectively priming the corresponding tubes of the first-mentioned set to all the tubes of which striking potential is applied selectively in accordance with the incoming signals and simultaneously so that solely a tube which is primed can be operated or fired by the incoming signal. General operation. The initial or starting signal applies a priming voltage to the first tube V of the timing set and after a delay of approximately half a signal period, produced by a circuit DE, fires tube S of a trigger S, Z to allow a multivibrator MV to run and to effect the striking of tube V1 which primes the tube V2 and also the first storage tube VA2 for the first signal of the combination to be set up on the series VA2 ... VA6. When the next multivibrator impulse occurs, if there is a signal element on the line INC, it passes through gate G to cause the primed tube VA2 to strike. The multivibrator impulse also fires tube V2 which cuts off V1, primes V3 and fires VA1. The tube V2 also primes VA3 so that if an impulse is on the line INC when the next vibrator impulse occurs, the tube VA3 is struck to record the signal element. The purpose of the chain V1 ... V5 is to prime the tubes VA2 ... VA6 for successive element periods so that the tubes are selectively fired in accordance with the positive signals on the line INC. The firing of the tube V7 of the timing chain fires tube VB1 which had been primed by the tube VA1 so that the tubes VB2 ... VB6 are simultaneously and selectively fired by the operated tubes of the series VA2 ... VA6. Tube V7 fires the tube Z of the trigger SZ so that the tube S is extinguished. The tube VB1 also fires the circuit V2 producing a pulse which restores the tubes VA1 ... VA6 to normal. The firing of VB1 primes tube VC1 of the final storage chain and if the signal is to be transmitted by the transmitter T, the latter provides an impulse firing the tube VC1 effecting the simultaneous firing of those tubes VC2 ... VC6 primed by the fired tubes of the set VB2 ... VB6. At the same time, the firing of tube VC1 operates circuit V3A to erase the selection set up on the tubes VB2 ... VB6 and to extinguish VB1. At the end of a signal combination, an impulse from the transmitter T operates the circuit V3B to reset the set VC1 ... VC6. The circuit represented by EX extinguishes the members S, Z of the trigger on the occurrence of breaks in transmission or of abnormal conditions. Detailed circuit operation. The received signals are applied via terminal T2 and resistors R6, R7 and capacitors C1, C9 to the control electrode of the tube S. The capacitor C1 and a resistance network (not shown) provide a delay of approximately 10 ms. before the tube strikes and the rise of its cathode potential removes the clamp provided by the diode V so that the multivibrator V1A, V1B starts running with V1B conducting. After 15 ms. VIA conducts and the positive impulse generated by V1B passes over lead 5 to the control electrodes oftubes V2 ... V7 of the timing circuit. The striking of the tube S passes an impulse over lead 4 to the tube V1 already primed by the incoming control impulse. On the first impulse from the multivibrator 30 ms. after the beginning of the signals, V2 is struck and the gate G comprising rectifiers MR4, MR5 in opened if the line signal is positive so that this impulse can fire tube VA2. When the tube V7 strikes, a positive impulse over lead 7 causes tube Z, already primed, to strike, thereby extinguishing the tube S and stopping the multivibrator. The cathode of tube V7 is connected to the control electrode of VB1, Fig. 4, which strikes and fires those tubes of the set VB2 ... VB6 already primed by the fired tubes of the set VA2 ... VA6. The striking of VB1 applies a positive impulse over lead 2 to the grid of valve V2B which conducts and over lead 8 reduces the voltage of the tubes VA1 ... VA6 which become extinguished. For the transfer of the signals to the third group VC2 ... VC6 and their transmission, a transmitter (not shown) applies an impulse to the terminal, T5, Fig. 4, and the tube VC1 to strike since it has been. primed by the firing of the tube VB1. The tubes VC2 ... VC6 selectively primed by the fired tubes of the set VB2 ... VB6 are fired simultaneously and the striking of the tube VC1 applies a positive pulse to the grid of the tube V3A of the double triode V3A, V3B and current flow over the lead 9 reduces the anode voltage of the tubes VB1 ... VB6 which are extinguished. When the stored impulses have been utilized, a positive impulse over terminal T4 causes V3B to conduct, cutting off V3A, and current flow over the lead 10 decreases the anode potential of the tubes VC1 ... VC6 which are extinguished. If there is any undesirable pause in the reception of information to be stored and transmitted, the tube Z, which in its normal condition is fired, changes a capacitor C5 over rectifier MR3, and after a predetermined time, say 2 secs., C5 is charged to fire a tube ZE and the heavy surge of current drawn by the capacitors C6, C7, C8 is effective to extinguish the tube Z. Subsequently, the current through the resistor R8 falls off and the tube ZE is extinguished. The tube SE performs a similar function for the tube S if through any abnormal working condition the tube S remains struck for a long period.