GB348543A - An improved distributor for use in telegraphy or the like - Google Patents

Abstract

348,543. Multiplex telegraphy. STANDARD TELEPHONES & CABLES, Ltd. and SANDEMAN, E. K., Columbia House, Aldwych, London. Feb. 12, 1930, No. 4737. Addition to 344,444. [Classes 40 (iii) and 40 (v).] Tn the parent Specification the paralysing waves alpha1 alpha2 of the lowest frequency were applied to the smallest group of valves, and those of the highest frequency #1, #2 to the group having the largest number of valves. To obviate errors due to the practical difficulty of generating square waves of the form shown, the paralysing waves of the lowest and highest frequencies, alpha1, alpha2, #1, #2 are supplied to the groups of valves having the largest and smallest numbers of valves respectively. In consequence, the paths from the valves D1 .. D16 to the apex valve L are not opened in numerical sequence, but the relay tongues T1 .. T16 are connected to the valves, so that the impulses from the relays R1 .. R16, when operated, will be transmitted in numerical sequence. In a modification, Fig. 2, the square paralysing waves alpha1, alpha2, #1, #2 of the lowest frequencies are replaced by sine waves alphaa .. alphad, #a .. #d, the a, b curves being opposite in phase to the c, d curves and being displaced in phase, relative to each other by a quarter of a period. In a further modification, Fig. 3 (not shown), the square waves alpha1, alpha1, #1, #2 are replaced by sine waves as described in connection with Fig. 2, but the paralysing waves of the highest frequency are, as in the parent Specification, applied to the row of valves having the greatest number of valves. Each single valve of the rows to which the displaced sine waves are supplied, is replaced by a number of valves corresponding to the number of waves utilized to simulate a single square wave.