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GB479485A - Improvements in degenerative feed-back circuits for audio frequency amplifiers - Google Patents

Improvements in degenerative feed-back circuits for audio frequency amplifiers

Info

Publication number
GB479485A
GB479485A GB213/38A GB21338A GB479485A GB 479485 A GB479485 A GB 479485A GB 213/38 A GB213/38 A GB 213/38A GB 21338 A GB21338 A GB 21338A GB 479485 A GB479485 A GB 479485A
Authority
GB
United Kingdom
Prior art keywords
volume
feedback
lamp
amplifier
expansion
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
GB213/38A
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.)
Philco Radio and Television Corp
Original Assignee
Philco Radio and Television Corp
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 Philco Radio and Television Corp filed Critical Philco Radio and Television Corp
Publication of GB479485A publication Critical patent/GB479485A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D1/00—Demodulation of amplitude-modulated oscillations
    • H03D1/02—Details
    • H03D1/06—Modifications of demodulators to reduce distortion, e.g. by negative feedback
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
    • H03F1/36—Negative-feedback-circuit arrangements with or without positive feedback in discharge-tube amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)
  • Control Of Amplification And Gain Control (AREA)
  • Selective Calling Equipment (AREA)

Abstract

479,485. Automatic volume control. JOHNSON, G. W. (Philco Radio & Television Corporation) Aug. 4, 1936, No. 213/38. Divided out of 479,440, [Group XL]. [Class 40 (iv)1 [Also in Group XL] In an audio-frequency amplifier with degenerative feedback from the output to the input, the feedback path includes impedances, one of which is variable slowly with time in dependance on current flow. The Figure shows an amplifier V2 with the tungsten filament of an incandescent lamp R3 in series with resistances Rl, R2 so that volume expansion is obtained. Since feedback is taken from resistances R1, R2 volume expansion is obtained. If the lamp is used in place of R] volume contraction is obtained, or if a lamp with a negative temperature coefficient is used in place of R1 volume expansion is obtained. Alternatively, both types of lamp may be used, one for R1 and the other for R3 to give expansion or contraction of volume. The amplifier may be frequency selective by including impedances varying with frequency, e.g. condenser C1 in the feedback path, and be associated with a detector to which feedback is applied as described in Specification 479,440.
GB213/38A 1936-08-04 1936-08-04 Improvements in degenerative feed-back circuits for audio frequency amplifiers Expired GB479485A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB21487/36A GB479440A (en) 1936-08-04 1936-08-04 Improvements in or relating to valve amplifying and detecting circuits

Publications (1)

Publication Number Publication Date
GB479485A true GB479485A (en) 1938-02-04

Family

ID=10163765

Family Applications (2)

Application Number Title Priority Date Filing Date
GB213/38A Expired GB479485A (en) 1936-08-04 1936-08-04 Improvements in degenerative feed-back circuits for audio frequency amplifiers
GB21487/36A Expired GB479440A (en) 1936-08-04 1936-08-04 Improvements in or relating to valve amplifying and detecting circuits

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB21487/36A Expired GB479440A (en) 1936-08-04 1936-08-04 Improvements in or relating to valve amplifying and detecting circuits

Country Status (2)

Country Link
US (2) US2374071A (en)
GB (2) GB479485A (en)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428039A (en) * 1942-06-20 1947-09-30 Standard Telephones Cables Ltd Feedback amplifier
US2432033A (en) * 1944-10-04 1947-12-02 Colonial Radio Corp Compensation for battery voltage changes in radio receivers
US2546156A (en) * 1944-11-30 1951-03-27 Sperry Corp Computer apparatus
US2533803A (en) * 1945-08-13 1950-12-12 Cornell Dubilier Electric Audio controlled limiter
US2506365A (en) * 1945-08-27 1950-05-02 Zenith Radio Corp Tone control circuit
US2710721A (en) * 1945-11-27 1955-06-14 Amasa S Bishop Electronic dividing circuit
US2576145A (en) * 1945-12-06 1951-11-27 Int Standard Electric Corp Volume expansion system for audio and like amplifiers
BE476372A (en) * 1946-04-30
US2548901A (en) * 1947-07-23 1951-04-17 Time Inc Cathode compensated electronic tube circuit
US2591915A (en) * 1948-08-07 1952-04-08 Hartford Nat Bank & Trust Co Feedback amplifier circuit
GB682140A (en) * 1950-09-27 1952-11-05 Amalgamated Wireless Australas Improvements in volume control arrangements for radio receivers
US2871304A (en) * 1956-02-03 1959-01-27 Philco Corp Remote control for a signal transfer channel employing feedback means
US2876299A (en) * 1956-08-29 1959-03-03 Zenith Radio Corp Signal-translating apparatus
US3064203A (en) * 1961-01-23 1962-11-13 Irvin M Wilbur Ripple balancing system

Also Published As

Publication number Publication date
US2151829A (en) 1939-03-28
GB479440A (en) 1938-02-04
US2374071A (en) 1945-04-17

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