GB524930A - Improvements relating to the power supply to repeater stations in a transmission system - Google Patents

Abstract

524,930. Repeaters. STANDARD TELEPHONES & CABLES, Ltd., and JACOBSEN, B. B. Feb. 1, 1939, No. 3336. [Class 40 (iv)]. The. " go " and " return " lines of a carrier transmission system are grouped to provide two or more circuits for feeding power to the repeater valves. For example alternating current for the heaters and other purposes may be fed over the central or outer conductors in series and direct current for the anodes may be fed over a circuit involving the two central conductors in parallel and the two outer conductors in parallel. The alternating current feed may be arranged for a constant current or a constant voltage supply. Alternatively direct current may be supplied over the central or outer conductors in series and alternating current over these conductors in parallel and the outer conductors in parallel. The source using the conductors in series may be symmetrically or asymmetrically arranged with respect to that using them in parallel. In the case of the symmetrical arrangement, the utilizing arrangement may involve an adjustable tapping or a choke or network to compensate for line inequalities. As a further alternative, direct current may be fed over the central conductors in series and alternating current over the outer conductors in series or vice versa. Preferably the repeaters are fed from both ends simultaneously or alternatively. As shown, stations B, C are fed from station A and station C<SP>1</SP> is fed from a distant station (not shown). The alternating current feeds are effectively separated by chokes K1, K2 but the direct current feed circuit is continuous so that if the distant direct current source fails station C<SP>1</SP> is fed from A. Means may be provided to short-circuit the chokes when the alternating current source fails at either end. If the two alternating current sources are held in suitable phase relationship the chokes may be omitted. Preferably the systems are provided with protective arrangements of the kind described in Specification 524,627, [Group XXXV].