GB963358A - Improvements in or relating to automatic telephone systems - Google Patents

Abstract

963,358. Automatic exchange systems. GENERAL ELECTRIC CO. Ltd. May 2, 1962 [May 11, 1961], No. 17230/61. Heading H4K. In an arrangement for identifying a calling line, a relay ND in the line circuit energizes in response to potential applied to the private wire at a junction relay set and marks wires 51 ... 60 in accordance with the digits of the line number, these markings being effective in succession by a control over wires 62 ... 64. As shown, the markings are transferred in a 2-out-of-5 code to a tape perforator which is associated with the junction relay set and records also the called number and metering information. Each digit repeated over the junction steps switch 1C which at the end of the digit connects up the appropriate magnets of the tape perforator. After the reply of the called party, relay D then being operated, switch 1C is stepped by metering impulses received by relay M. Sequence switch PD advances at this time, and an allotter associates the identifying circuit with the junction relay set, whereupon relay 1D operates and applies potential to the private wire to energize relay ND in the subscriber's line circuit. In this and subsequent positions of PD, the markings applied by relay ND to wires 51.. 60, which indicate the digits of the calling number, are effective through a coder to operate the relevant magnets of the tape perforator. At each tenth metering impulse switch 1C transfers a record to the tape perforator, and a further record of impulses less than ten is made at the end of the call. Magnetic drum registers may be employed in place of a tape perforator, and use of a 2-out-of-5 code is not essential. The marking wires may control lamps to indicate the calling number visually. According to the Provisional Specification a separate group of marking wires may be provided for each digit, and the tape perforator may be common to the junction relay sets.