GB1353282A - Circuit for detecting signals transmitted onto a two wire line - Google Patents

Circuit for detecting signals transmitted onto a two wire line

Info

Publication number
GB1353282A
GB1353282A GB3401472A GB3401472A GB1353282A GB 1353282 A GB1353282 A GB 1353282A GB 3401472 A GB3401472 A GB 3401472A GB 3401472 A GB3401472 A GB 3401472A GB 1353282 A GB1353282 A GB 1353282A
Authority
GB
United Kingdom
Prior art keywords
line
subscribers
circuit
line wires
july
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
GB3401472A
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
Publication of GB1353282A publication Critical patent/GB1353282A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/22—Arrangements for supervision, monitoring or testing
    • H04M3/2272—Subscriber line supervision circuits, e.g. call detection circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)

Abstract

1353282 Automatic exchange systems INTERNATIONAL STANDARD ELECTRIC CORP 20 July 1972 [27 July 1971] 34014/72 Heading H4K A relayless subscribers' line circuit incorporates a first resistor potential divider R4, R5 connected across the battery terminals, a second divider R2, R3 connected across the line wires, a pair of battery feed resistors R6, R7 and a comparator, e.g. differential amplifier AM, connected between the tapping points on the two dividers. The arrangement detects earthing of either or both line wires by means of a subscribers' key switch, e.g. contacts I2, I3, and is uninfluenced by length of line or battery voltage. Earth leakage of the line wires is compensated by inserting a variable resistor in series with R5 thereby permitting a threshold level to be obtained for the circuit. The resistors R2 to R5 have the same value which is considerably higher than that of R6, R7. The subscribers' key is provided for recalling an operator or initiating a call back condition.
GB3401472A 1971-07-27 1972-07-20 Circuit for detecting signals transmitted onto a two wire line Expired GB1353282A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7127393A FR2147408A5 (en) 1971-07-27 1971-07-27

Publications (1)

Publication Number Publication Date
GB1353282A true GB1353282A (en) 1974-05-15

Family

ID=9080962

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3401472A Expired GB1353282A (en) 1971-07-27 1972-07-20 Circuit for detecting signals transmitted onto a two wire line

Country Status (4)

Country Link
BE (1) BE786796R (en)
DE (1) DE2236266B2 (en)
FR (1) FR2147408A5 (en)
GB (1) GB1353282A (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7904429A (en) * 1979-06-06 1980-12-09 Philips Nv FLOW DETECTION DEVICE FOR AN AUTOMATIC TELEPHONE CONTROL PANEL.
DE3108264C2 (en) * 1981-03-05 1984-05-30 Deutsche Fernsprecher Gesellschaft Mbh Marburg, 3550 Marburg Circuit arrangement for detecting the switching state of an earth button on a telephone set
US4423292A (en) * 1981-09-30 1983-12-27 Bell Telephone Laboratories, Incorporated Detector circuit for communication lines
DE3433330A1 (en) * 1984-09-11 1986-03-20 Siemens AG, 1000 Berlin und 8000 München Circuit arrangement to indicate the earthing of a wire of a subscriber line when the earth key is pressed

Also Published As

Publication number Publication date
FR2147408A5 (en) 1973-03-09
DE2236266A1 (en) 1973-02-08
BE786796R (en) 1973-01-29
DE2236266B2 (en) 1978-03-23

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Legal Events

Date Code Title Description
PS Patent sealed
746 Register noted 'licences of right' (sect. 46/1977)
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee