Patent GB-600312-A (GB)
Title: Improvements in or relating to communication systems and apparatus
IPC: G11C11/28
Filed: 1944-05-19
Abstract: 600,312. Type-printing telegraphy. NATIONAL CASH REGISTER CO. May 19, 1944, No. 9755. Convention date, Oct. 15, 1943. [Class 40 (iii)] [Also in Group XL (c)] In a telegraph receiver responsive to signals comprising bursts of impulses representing symbols, a translating means is operated in response to each burst to set up a direct representation of the symbol, a number of electronic storage devices being rendered operable in succession to store the symbols produced by the repeated operation of the translating means. The apparatus shown is arranged to receive five bursts of impulses, representing five digits or symbols. During each burst of impulses, the symbol to be represented is set up on translating means, comprising a number of gas-filled tubes, Fig. 2, operated in succession, and in the intervals between bursts control signals are generated, Fig. 1, which operate symbol storing devices, Fig. 3, one by one to store the symbols represented by the translating means and also operate selecting means, Fig. 4, so that the succeeding symbol is set up on the succeeding symbol storing device. The control impulse also resets the translating means ready for the reception of the next burst of impulses. Control impulse generator. Negative impulses are impressed on the grid of normally conducting tube 102, Fig. 1, rendering it non- conducting, and producing positive impulses at the anode, which are applied from terminals 128, over terminal 129 to the grids of the gasfilled tubes, Fig. 2. The positive impulses are also applied to the grid of tube 106 of a triggerconnected pair 105, 106 and to the grid of tube 107, tubes 106 and 107 normally being non- conducting. The impulse on the grid of tube 106 will cause it to conduct, cutting off tube 105, so that the negative bias is removed from the grid of tube 108 allowing it to conduct, the positive impulse applied to tube 107 causing it to conduct. Tube 107 stops conducting when the impulse ceases, but its anode potential does not rise immediately due to condenser 194 and resistor 195, so that the next impulse is applied to tube 107 before its anode potential has risen sufficiently to remove the negative bias from the grid of tube 105, to allow it to conduct again. Thus, during the burst of impulses, tube 105 will remain non-conducting, but during the space between bursts the anode voltage of tube 107 will rise sufficiently to remove the bias on the grid of tube 105, causing it to conduct. The drop of anode potential of tube 105 is applied to the grid of pulse-sharpening tube 108 rendering it non-conductive and producing a positive control impulse at its anode which is applied to the shielding electrodes of the symbol storing tubes, Fig. 3, through terminal 350, to the grids of the control tubes, Fig. 4, controlling the symbol storing tubes through terminal 395 and to the " reset " tube, Fig. 2, through terminal 259. Translating means. The bursts of impulses are applied to the grids of the gas-filled tubes, Fig. 2, through conductor 103. Before the first burst of impulses is applied the " prime " tube is fired by opening switch 239 and removing the negative bias on its grid, thus priming tube " O." The rise in cathode voltage as one tube fires is applied to the grid of the next tube to prime it, so that the tubes fire in succession on receipt of the impulses, the drop of anode potential as one tube fires being applied to all the other anodes to extinguish any other conducting tube. At the end of the burst, the tube corresponding to the symbol transmitted is left conducting. The control impulse generated at the end of the burst fires the ' reset ' tube, causing any conducting tube to be extinguished, subsequently causing the "prime" tube to fire, thus priming tube " O " for receipt of the next burst of impulses and extinguishing the " reset " tube. Symbol-storing device. The five symbol storing tubes, Fig. 3, of the type described in Specification 600,311, [Group XL (a)], are controlled by five gas-filled control tubes, Fig. 4, the cathode of each control tube being connected through terminals such as 343, 344 to the shielding electrode 323 of the corresponding tube, Fig. 3, so that if control tube 341 is conducting it primes symbol storing tube 320. Each of the control grids 324 in the discharge paths 0 ... 9 of the symbol storing tubes is connected to the cathode of the corresponding tube 0 ... 9, Fig. 2, through terminals 336, 337 so that the translating tubes control in which path conduction will take place when the primed symbol storing tube is fired by the control impulse. Tube 341 is fired prior to the first burst of impulses, by opening switch 396, so as to prime tube 320. Tube 320 will fire when the first control impulse is applied to shielding electrode 323 from terminal 350, conduction only taking place in the discharge path containing a control electrode 324 connected to the translating tube which is conducting at the end of the first burst of impulses. Thus, the symbol represented by the first burst of impulses is transferred from the translating tubes to the symbol storing tubes and stored there. The control impulse also fires tube II, Fig. 4, extinguishing tube 341 and priming tube II, Fig. 3, so that the next symbol is stored in the second tube and so on. The state of the symbol storing tubes may be sensed by a switch having a wiper passing over contacts 365 connected over resistances to the appropriate control electrode of each tube, the control electrode of the conducting section assuming a higher potential than those in the non-conducting sections. Specification 592,797 also is referred to.