GB430297A - Improvements in or relating to telegraph repeater circuits - Google Patents

Abstract

430,297. Code telegraphy. STANDARD TELEPHONES & CABLES, Ltd., 63, Aldwych, London.-(Assignees of Herman, J. ; 837, Dorian Road, Westfield, Union, New Jersey, U.S.A.) Nov. 23, 1934, No. 33711. Convention date, July 5. [Class 40 (iii)] In a two-way repeater, telegraph signals in both directions of traffic are regenerated by the same apparatus 7 whose output contact 14<a> can be switched into circuit with either the E or the W line, while its input circuit 10 and the direction-control relay 4 are continuously accessible to both line-magnet armatures 1<a>, 2<a>. The neutral relays 1, 2 are differentially wound and have line balances N so that the relay on the outgoing side is unaffected by signals. A battery B applies marking potential to the incoming line in accordance with half-duplex double-current practice. The repeater as shown is ready for W-E transmission, the line W receiving marking (idle) polarity from battery B while the line E receives it from the regenerator contact 14<a>. Signals arriving at relay 1 do not affect relays 6 and 5, since winding 6 is connected from earth to positive and winding 5 is connected to positive at both ends, whatever the position of armature 1<a>. Signals from line W are applied to the input circuit 10 of the regenerative device 7, which is shown schematically only, and are passed on with a slight delay through contact 14<a> to line E. When, however, signals are to be sent in the E-W direction, line E is interrupted at the distant end, (not shown), and armature 2a moves to its spacing contact, applying negative potential to the polarized relay 6 via resistance 20. Armature 6<a> thereupon moves to its right-hand (spacing) contact and holds on, energizing relay 5 which reverses the connections of the lines with the central battery B and the regenerator armature 14<a>. The circuits are so dimensioned that when both lines send a break signal simultaneously the armature 6<a> remains in whichever position it happens to occupy. Polarized relay 6 may have separate operating and locking windings, or may be replaced by a neutral relay with a locking circuit, or relays 5 and 6 may be replaced by a simple relay with multiple contacts.