GB557013A - Improvements in or relating to telephone systems - Google Patents

Improvements in or relating to telephone systems

Info

Publication number
GB557013A
GB557013A GB5664/42A GB566442A GB557013A GB 557013 A GB557013 A GB 557013A GB 5664/42 A GB5664/42 A GB 5664/42A GB 566442 A GB566442 A GB 566442A GB 557013 A GB557013 A GB 557013A
Authority
GB
United Kingdom
Prior art keywords
filter
signalling
line
frequencies
relay
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
GB5664/42A
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.)
Automatic Telephone and Electric Co Ltd
Original Assignee
Automatic Telephone and Electric Co Ltd
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 BE466455D priority Critical patent/BE466455A/xx
Application filed by Automatic Telephone and Electric Co Ltd filed Critical Automatic Telephone and Electric Co Ltd
Priority to GB5664/42A priority patent/GB557013A/en
Priority to US474905A priority patent/US2364685A/en
Publication of GB557013A publication Critical patent/GB557013A/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)
  • Interface Circuits In Exchanges (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

557,013. Exchange systems. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd., and BAKER, G. T. April 28, 1942, No. 5664. [Class 40 (iv)] In a system employing voice frequency signals for the setting up and supervision of a connection, the transmission line is normally, blocked to the signalling frequency at some point and the blocking means is neutralized by the arrival at that point of non-signalling frequencies, thus allowing speech to pass without interference. In Fig. 1, a filter rejecting the signalling frequency is cut out by the operation of a relay K which is connected to the line through a similar filter. For one-way operation the relay K may be connected to the output of the line filter. In Fig. 2, the filters F1, F2 are similar to those in Fig. 1, and the output of F2 controls a, variable attenuator SSD (made up of rectifiers for example) shunting the filter F1. In Fig. 3, the line includes a bead TSD of material such as uranium oxide or silver sulphide which when heated by the passage of non-signalling frequencies through its heater winding and a filter F3 changes its resistance rapidly from a high to a low value. In Fig. 4, the line is normally barred to all frequencies and is rendered operative by an echo suppressor ES which is controlled through a filter F4 passing only non-signalling frequencies.
GB5664/42A 1942-04-28 1942-04-28 Improvements in or relating to telephone systems Expired GB557013A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE466455D BE466455A (en) 1942-04-28
GB5664/42A GB557013A (en) 1942-04-28 1942-04-28 Improvements in or relating to telephone systems
US474905A US2364685A (en) 1942-04-28 1943-02-06 Telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5664/42A GB557013A (en) 1942-04-28 1942-04-28 Improvements in or relating to telephone systems

Publications (1)

Publication Number Publication Date
GB557013A true GB557013A (en) 1943-11-01

Family

ID=9800312

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5664/42A Expired GB557013A (en) 1942-04-28 1942-04-28 Improvements in or relating to telephone systems

Country Status (3)

Country Link
US (1) US2364685A (en)
BE (1) BE466455A (en)
GB (1) GB557013A (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3060275A (en) * 1958-11-07 1962-10-23 Bell Telephone Labor Inc Telephone system signaling
NL252835A (en) * 1959-06-23
US3103558A (en) * 1959-09-24 1963-09-10 Int Standard Electric Corp ligotky
US3201524A (en) * 1961-03-27 1965-08-17 Itt Multi-frequency tone signaling system
US3436487A (en) * 1965-09-14 1969-04-01 Bell Telephone Labor Inc Telephone signaling arrangement
DE1280280B (en) * 1966-06-29 1968-10-17 Siemens Ag Method and circuit arrangement for the mutual transmission of pulse-coded messages between subscriber stations via a voice channel
US4726095A (en) * 1986-07-17 1988-02-23 Bissell Jr Norman L Bucket fish scaler

Also Published As

Publication number Publication date
BE466455A (en)
US2364685A (en) 1944-12-12

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