Patent GB-538603-A (GB)
Title: Improvements in or relating to electric systems for the transmission of statistical data
Filed: 1940-02-05
Abstract: 538,603. Electric telegraphy; thermionic distributers. BRITISH TABULATING MACHINE CO., Ltd. Feb. 5, 1940, No. 2219. Convention date, Feb. 3, 1939. [Classes 40 (iii) and 40 (v)] [Also in Group XIX] Electric signalling or control for the transmission of statistical data is effected by generating from a single source of synchronizing A.C. a number of signalling or control currents of different phases and a number of biasing currents of correspondingly different phases, the biasing currents being applied to respective signal receivers (thermionic valves) which respond only if the phase of the signalling or control current coincides with the phase of the biasing current. The different phases are used to differentiate between different columns of statistics and for control operations, anc different intervals ir which the signals may occur during a cycle of the statistical machine represent different values within the columns. As described, the invention is applied to the transmission of data from the card-reading mechanism of a Hollerith tabulating machine to the counting, printing and read-out mechanisms which may or may not be located at a distant point. Assuming switches S1, 2, 4 at the transmitter, Fig. 7, and S3, 5 at the receiver, Fig. 7a, are closed, carrier current from generator 95 is applied to the wireless transmitter 100 and synchronizing current from generator 96 is applied to the wireless transmitter, to the machine driving motor TM and to a phase transformer feeding a thermionic valve distributer 111-128, filters to separate the two currents being provided where necessary. The outputs of the secondary windings of the phase transformer comprise 16 regularly phase displaced voltages which are subjected to full wave rectification in the diode portions of double-diode-triodes 111- 128, the resultant wave forms, one of which is shown in Fig. 9a, being applied to the triode portions which are back biased so that the outputs are of phase displaced impulsive form as shown in Fig. 10. Phases 1 to 12 are used to differentiate between columns at the lower reading brushes of a Hollerith machine, the position of the holes being determined by the times of occurrence of the signals in the machine cycle. Phases 13-16 are used for receiver control. At the receiver, Fig. 7a, the synchronizing current drives motor Tmr and is also applied to a similar phase transformer and valve distributer, the outputs of which are applied to a series of triodes such as 159a which also receive the variably phased signals from transformer 146 and valve 185. Any particular triode operates only if the phase of the incoming signal is in phase with the biasing current from the distributer. When a card datum column is read at the lower brushes, one of the phases 5-12 from valves 115-122 is connected to transmitter 100 and causes the response at the receiver of one of the triodes subject to the corresponding biasing phase whereby the adding and printing magnets 581, 37 are operated and function in the usual manner. Controls.-Phase 14 (valve 126) is used for starting, phase 15 (valve 127) for re-setting, and phase 16 (valve 128) for total-printing, and operate corresponding relays 153-155 at the receiver.