GB1189454A - Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges - Google Patents

Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges

Info

Publication number
GB1189454A
GB1189454A GB3691567A GB3691567A GB1189454A GB 1189454 A GB1189454 A GB 1189454A GB 3691567 A GB3691567 A GB 3691567A GB 3691567 A GB3691567 A GB 3691567A GB 1189454 A GB1189454 A GB 1189454A
Authority
GB
United Kingdom
Prior art keywords
exchange
telephone
relays
provision
circuit arrangement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB3691567A
Inventor
Winfried Schuberth
Roland Kaiser
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Priority to GB3691567A priority Critical patent/GB1189454A/en
Publication of GB1189454A publication Critical patent/GB1189454A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/18—Electrical details
    • H04Q1/30—Signalling arrangements; Manipulation of signalling currents
    • H04Q1/38—Signalling arrangements; Manipulation of signalling currents using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

1,189,454. Exchange systems. INTERNATIONAL STANDARD ELECTRIC CORP. 11 Aug., 1967, No. 36915/67. Heading H4K. Equipment at a telephone or telegraph exchange for responding to key-sent digital signals consisting of a ground connection to either or both line wires through a resistor, R 1 , R 2 with or without a rectifier D1-D4, is powered by a stabilized voltage source separate from the normal exchange battery and of greater voltage. Such source may be a converter fed from the exchange battery. As shown, selection is made in two stages by two pairs of relays A, B and C, D, the former operated by a capacitor CA charged by the separate voltage source Uabfr, the latter (C, D) operated directly thereby. Provision is made for sending and receiving an end-of-selection signal with the aid of relay WE. The provision of a very high testing voltage allows current limiting resistors R1, R2 to be retained in the sub-set without any ambiguous operation of the relays A-B due to induced voltages in the line. In a PBX, retention of the resistors is of importance because operation of special function keys, e.g. ST 1 , ET is easily distinguished by the digit receiver due to the increased current level in one or both line wires.
GB3691567A 1967-08-11 1967-08-11 Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges Expired GB1189454A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3691567A GB1189454A (en) 1967-08-11 1967-08-11 Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3691567A GB1189454A (en) 1967-08-11 1967-08-11 Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges

Publications (1)

Publication Number Publication Date
GB1189454A true GB1189454A (en) 1970-04-29

Family

ID=10392205

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3691567A Expired GB1189454A (en) 1967-08-11 1967-08-11 Circuit Arrangement for Receiving Key-Controlled Selecting Information in Telephone or Telegraph Exchanges

Country Status (1)

Country Link
GB (1) GB1189454A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees