GB998837A - Improvements in or relating to control of the transmission of electrical signals through networks - Google Patents

Improvements in or relating to control of the transmission of electrical signals through networks

Info

Publication number
GB998837A
GB998837A GB506762A GB506762A GB998837A GB 998837 A GB998837 A GB 998837A GB 506762 A GB506762 A GB 506762A GB 506762 A GB506762 A GB 506762A GB 998837 A GB998837 A GB 998837A
Authority
GB
United Kingdom
Prior art keywords
feed
conducting
transistors
amplifier
feb
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
GB506762A
Inventor
Hugh Spence Leman
George John Preston Barnes
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 GB506762A priority Critical patent/GB998837A/en
Publication of GB998837A publication Critical patent/GB998837A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/04—Control of transmission; Equalising
    • H04B3/10—Control of transmission; Equalising by pilot signal
    • H04B3/12—Control of transmission; Equalising by pilot signal in negative-feedback path of line amplifier

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Control Of Amplification And Gain Control (AREA)

Abstract

998,837. Transistor amplifier circuits; automatic gain control. STANDARD TELEPHONES & CABLES Ltd. Feb. 8, 1963 [Feb. 9, 1962], No.5067/62. Headings H3T and H4R. An amplifier has a gain controlling negative feedback network which includes at least two resistive elements and two switching devices controlled by a unidirectional voltage so that operation of the switching devices varies the impedance of the feed-back network and hence the gain of the amplifier by two or more fixed amounts. Fig. 2 shows the preferred embodiment in which the amplifier transistors TR 3 and TR 4 have negative feed-back from output to the emitter circuit of transistor TR 3 via the feedback network R" R 2 and R 3 . Variation of the feed-back is accomplished by switching symmetrical transistors TR 1 and TR 2 . With TR 1 conducting the feed-back is zero, TR 1 non- conducting and TR 2 conducting the feed-back is at an intermediate value and with both TR 1 and TR 2 non-conducting the feed-back is a maximum. Capacitors Ca and Cb are D.C. blocking capacitors and resistor R 5 or R 5 <SP>1</SP> or R 5 <SP>11</SP> is inserted to prevent any D.C. surge on operation of transistors TR 1 or TR 2 . Transistors TR 1 and TR 2 . may be replaced by diodes.
GB506762A 1962-02-09 1962-02-09 Improvements in or relating to control of the transmission of electrical signals through networks Expired GB998837A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB506762A GB998837A (en) 1962-02-09 1962-02-09 Improvements in or relating to control of the transmission of electrical signals through networks

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB506762A GB998837A (en) 1962-02-09 1962-02-09 Improvements in or relating to control of the transmission of electrical signals through networks

Publications (1)

Publication Number Publication Date
GB998837A true GB998837A (en) 1965-07-21

Family

ID=9789129

Family Applications (1)

Application Number Title Priority Date Filing Date
GB506762A Expired GB998837A (en) 1962-02-09 1962-02-09 Improvements in or relating to control of the transmission of electrical signals through networks

Country Status (1)

Country Link
GB (1) GB998837A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2347833A1 (en) * 1976-04-06 1977-11-04 Int Standard Electric Corp REMOTE CONTROL SYSTEM OF THE REPEATER GAIN OF A SUBMARINE CABLE

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2347833A1 (en) * 1976-04-06 1977-11-04 Int Standard Electric Corp REMOTE CONTROL SYSTEM OF THE REPEATER GAIN OF A SUBMARINE CABLE

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