GB1232167A - - Google Patents

Abstract

1,232,167. Locating faulty repeaters. SIEMENS A.G. 16 July, 1969 [17 July, 1968], No. 35825/69. Heading H4R. In an arrangement for feeding power to repeaters over the line and in which the " go " and " return " amplifiers at each repeater are connected in parallel, in respect of the power supply, to reduce the voltage required to be supplied, a relay is provided with its coil R connected in the power return path and its contacts arranged to connect the go and return paths together in the event of a break in the transmission path beyond the repeater. The break contact r is connected between the tapping points of a series arrangement of diodes D1 and D2 or D3 and D4 connected respectively across the parallel connected amplifier power circuits, and the relay coil R. The arrangement allows the amplifier power supply to be derived alternately from the supply and return conductors for successive repeaters along the line, while retaining the unambiguous fault position indication of the relay operation, which is lost if the relay contacts are not connected via diodes D1to D4, as shown. The system allows identical circuits to be used at all repeaters irrespective of the direction of power flow provided the current flow direction in the loop is maintained. In an alternative arrangement, Fig. 3 (not shown), the resistor RQ is removed and replaced by two resistors of equal value to RQ placed one in series with each of diodes D3 and D4, an arrangement which provides a greater voltage drop across the parallel branch including diodes D3 and D4 to operate relay R, which in the embodiment of Fig. 2 has to be operated by the threshold voltage of diodes D3 and D4.