GB272596A - Improvements in telegraph circuits - Google Patents

Improvements in telegraph circuits

Info

Publication number
GB272596A
GB272596A GB718426A GB718426A GB272596A GB 272596 A GB272596 A GB 272596A GB 718426 A GB718426 A GB 718426A GB 718426 A GB718426 A GB 718426A GB 272596 A GB272596 A GB 272596A
Authority
GB
United Kingdom
Prior art keywords
line
windings
currents
signalling
earth
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
GB718426A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB718426A priority Critical patent/GB272596A/en
Publication of GB272596A publication Critical patent/GB272596A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

272,596. Standard Telephones & Cables, Ltd., and Thompson, A. E. March 15, 1926. Eliminating effects of disturbing currents; duplex telegraphs.-In a two-line circuit one line with an earth return is used for the signalling currents, and the other line is so connected conductively to the signalling apparatus as to protect the signalling circuit against interference and to afford protection to neighbouring tedegraph or telephone circuits. The transmitting apparatus is connected to one line through the primary of an induction coil, of which the secondary is connected to the other line in such a manner that surge currents are transmitted over the two lines in opposite directions. The figure shows a differential duplex arrangement in which the lines 1, 2 are balanced in known manner by the networks 8, 12. Each station is provided with a polarized receiving relay 3 of which two windings 4, 5 are in series between the line 1 and one side of the adjacent network, and two other windings 6, 7 are in series between the line 1 and the other side of the network. The windings 4, 5, 6, and 7 have equal electrical characteristics. The local transmitter 10 is connected to the junction of the windings 4, 5 through one winding of a transformer 9, and the junction of the windings 6, 7 is connected to earth through the other winding of the transformer. Earth currents and currents due to interference from neighbouring circuits neutralize each other in the relay windings 5, 7 at each station.
GB718426A 1926-03-15 1926-03-15 Improvements in telegraph circuits Expired GB272596A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB718426A GB272596A (en) 1926-03-15 1926-03-15 Improvements in telegraph circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB718426A GB272596A (en) 1926-03-15 1926-03-15 Improvements in telegraph circuits

Publications (1)

Publication Number Publication Date
GB272596A true GB272596A (en) 1927-06-15

Family

ID=9828213

Family Applications (1)

Application Number Title Priority Date Filing Date
GB718426A Expired GB272596A (en) 1926-03-15 1926-03-15 Improvements in telegraph circuits

Country Status (1)

Country Link
GB (1) GB272596A (en)

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