Patent GB-636667-A (GB)
Title: Improvements in or relating to electric signalling systems
IPC: G08C15/12
Filed: 1946-02-19
Abstract: 636,667. Electric indicating systems. STANDARD TELEPHONES & CABLES, Ltd., McWHIRTER, E. M. S., DUNN, R. H., and LENNOX, P. W. Feb. 19, 1946, No. 5152. [Class 40 (i)] [Also in Group XL (b)] An electric signalling system comprises a plurality of meters which actuate individual contacts to transmit characteristic codes which at the receiver actuate corresponding indicators which thus record the readings of the meters General description.-A system for signalling the position of contacts 1 ... 4, Fig. 1, comprises a distributer 13 ... 16 which sequentially frees each of code-transmitters 9 ... 12 to stop the distributer and generate an individual code if the related contact 1 ... 4 has been operated, and after transmission of the code, to cause resumption of the operation of the distributer. The distributer consists of four cold-cathode tubes 13 ... 16, Fig. 2, cyclically connected so that when one conducts it extinguishes the preceding tube and biasses the succeeding one to become conducting when a pulse arrives from generator 20 over line 21. Thus each code-transmitter is sequentially biassed at intervals determined by the pulses from generator 20. When the first tube in any code transmitter becomes conducting, the corresponding tube in the distributer is extinguished so that the succeeding valve receives no bias and is not ignited when the next pulse arrives over line 21 from generator 20. Each code transmitter comprises seven cold cathode tubes 31, 27, 40 ... 52, Fig. 2, whose anodes are appropriately connected to spacing and marking relays S.M., Fig. 1, of relay 17, which actuates contact 18 for transmitting impulses to line 19. The first tube 31 in each transmitter energizes the spacing winding S to constitute a start signal, and the last tube energizes marking winding M to constitute a stop signal, the five intermediate tubes energizing windings S, M in accordance with the individual code. When a contact, e.g. contact 4, is actuated, condenser 47, which is charged over normally conducting tube 46, is discharged through transformer 48 to make tube 49 conducting ; the anode potential of tube 48 is thereby reduced to render tube 48 non- conducting. The anode current of tube 49 biasses valve 31, and this bias is further increased when tube 16 of the distributer is made conducting by a pulse from generator 20, Fig. 1. Generator 20 also supplies pulses over line 22 to the code transmitters, these pulses being intercalated with those supplied over line 21 to the distributer 13 ... 16. Tube 31 becomes conducting only when the bias from conducting tube 49 and the bias from conducting tube 16 is further reinforced by a pulse over line 22. When tube 31 conducts, it renders tubes 16 and 49 non-conductive, energizes spacing winding S and biasses tube 27 so that when the next pulse arrives over line 22 tube 27 conducts to extinguish tube 31, energizes the appropriate winding S or M and prepares tube 40 &c. The code associated with contact 4 is thus transmitted, and the last tube 52 biasses tube 13 of the distributer over line 26 so that tube 13 conducts when the next pulse arrives over line 21. General.-The operation of meters 1, 2, 3, 4 at one Station 91, Fig. 5, may be signalled to indicators 87 ... 90 at a Station 92 and passed on together with the operations of meters 94, 95 to indicators 83 ... 99 at a central station 97. Specifications 566,156, [Group XL], 629,244, 629,245, [both in Group XXXVI], 629,246, [Group XIX], 636,668 and 636,700, [both in Group XL (c)], are referred to.