GB716633A - Improvements in or relating to electric signalling systems - Google Patents

Improvements in or relating to electric signalling systems

Info

Publication number
GB716633A
GB716633A GB94752A GB94752A GB716633A GB 716633 A GB716633 A GB 716633A GB 94752 A GB94752 A GB 94752A GB 94752 A GB94752 A GB 94752A GB 716633 A GB716633 A GB 716633A
Authority
GB
United Kingdom
Prior art keywords
valve
cathode circuit
feb
apparent
amplifiers
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
GB94752A
Inventor
Knut Styren
Aeke Sandin
Harold Jefferson
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.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
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 Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to GB94752A priority Critical patent/GB716633A/en
Publication of GB716633A publication Critical patent/GB716633A/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)
  • Amplifiers (AREA)

Abstract

716,633. Voice-frequency receivers. TELEFONAKTIEBOLAGET L.M. ERICSSON. May 19, 1953 [Feb. 19, 1952; Feb 19, 1952], Nos. 947/52 and 948/52. Class 40 (4) In a four-wire telecommunication system employing voicefrequency signalling, the voice frequency receiver is included in the cathode circuit of an amplifier valve or in the cathode circuit of the last valve if a multi-stage amplifier is used and the valves used are of high impedance so that outgoing signals from the two-wire line do not actuate the signal receiver. The incoming signal on-line 1 is applied over transformer 3 and potentiometer 7 to the grid of valve 8 wherein it is amplified and passed to the two wire line 25, via output transformer 18 and hybrid network 23. Signal receiver 14 is in the cathode circuit and negative feedback to increase the apparent' anode impedance is provided by resistor 12 and network 13. The application of the invention to systems employing multistage amplifiers is described with reference to the drawings accompanying the second Provisional Specification, and in such amplifiers the apparent anode impedance of the last valve is increased by both current and voltage feedback provided around one or more stages.
GB94752A 1952-02-19 1952-02-19 Improvements in or relating to electric signalling systems Expired GB716633A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB94752A GB716633A (en) 1952-02-19 1952-02-19 Improvements in or relating to electric signalling systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB94752A GB716633A (en) 1952-02-19 1952-02-19 Improvements in or relating to electric signalling systems

Publications (1)

Publication Number Publication Date
GB716633A true GB716633A (en) 1954-10-13

Family

ID=9713323

Family Applications (1)

Application Number Title Priority Date Filing Date
GB94752A Expired GB716633A (en) 1952-02-19 1952-02-19 Improvements in or relating to electric signalling systems

Country Status (1)

Country Link
GB (1) GB716633A (en)

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