GB651457A - Improvements in or relating to electric signalling systems - Google Patents

Improvements in or relating to electric signalling systems

Info

Publication number
GB651457A
GB651457A GB371247A GB371247A GB651457A GB 651457 A GB651457 A GB 651457A GB 371247 A GB371247 A GB 371247A GB 371247 A GB371247 A GB 371247A GB 651457 A GB651457 A GB 651457A
Authority
GB
United Kingdom
Prior art keywords
signal receiver
incoming
high impedance
output terminals
effect
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
GB371247A
Inventor
Thomas Frederick St Hargreaves
William Frederick Gould
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
Priority to BE481448D priority Critical patent/BE481448A/xx
Priority to FR960660D priority patent/FR960660A/fr
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB371247A priority patent/GB651457A/en
Priority to GB1160547A priority patent/GB651461A/en
Priority to CH272712D priority patent/CH272712A/en
Priority to US23438A priority patent/US2577755A/en
Priority to CH274626D priority patent/CH274626A/en
Priority to FR65204D priority patent/FR65204E/en
Publication of GB651457A publication Critical patent/GB651457A/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
    • H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
    • H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
    • H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
    • H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

651,457. Voice frequency signalling. STANDARD TELEPHONES & CABLES, Ltd. Feb. 7, 1947, No. 3712. [Class 40 (iv)] In a system incorporating a signal receiver SC, GC in the incoming pair of a four-wire circuit and subject to unwanted signals from the near end 2-4 wire termination (i.e. coming in over the OUTPUT terminals), the effect of these unwanted signals is minimized by the use of a high impedance valve V1 fed by the wanted incoming signals and whose output is fed jointly to the signal receiver and to the incoming side of the 2-4 wire termination which comprise conjugate arms of a hybrid transformer T2. The Specification shows mathematically how the use of the high impedance valve V1 inserts a large loss between the OUTPUT terminals and the signal receiver and this effect is further enhanced by the use of the hybrid transformer T2. Specification 501,028 is referred to.
GB371247A 1947-02-07 1947-02-07 Improvements in or relating to electric signalling systems Expired GB651457A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE481448D BE481448A (en) 1947-02-07
FR960660D FR960660A (en) 1947-02-07
GB371247A GB651457A (en) 1947-02-07 1947-02-07 Improvements in or relating to electric signalling systems
GB1160547A GB651461A (en) 1947-02-07 1947-04-30 Improvements in or relating to alternating current signalling systems
CH272712D CH272712A (en) 1947-02-07 1948-02-07 Arrangement for audio-frequency signaling in four-wire systems.
US23438A US2577755A (en) 1947-02-07 1948-04-27 Alternating-current signaling system
CH274626D CH274626A (en) 1947-02-07 1948-04-27 AC pulse signal receiver.
FR65204D FR65204E (en) 1947-02-07 1948-04-30 Electrical signaling systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB371247A GB651457A (en) 1947-02-07 1947-02-07 Improvements in or relating to electric signalling systems

Publications (1)

Publication Number Publication Date
GB651457A true GB651457A (en) 1951-04-04

Family

ID=27799323

Family Applications (2)

Application Number Title Priority Date Filing Date
GB371247A Expired GB651457A (en) 1947-02-07 1947-02-07 Improvements in or relating to electric signalling systems
GB1160547A Expired GB651461A (en) 1947-02-07 1947-04-30 Improvements in or relating to alternating current signalling systems

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB1160547A Expired GB651461A (en) 1947-02-07 1947-04-30 Improvements in or relating to alternating current signalling systems

Country Status (1)

Country Link
GB (2) GB651457A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3319011A (en) * 1964-05-11 1967-05-09 Bell Telephone Labor Inc Multifrequency signal receiver circuit

Also Published As

Publication number Publication date
GB651461A (en) 1951-04-04

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