GB951058A - Improvements in or relating to amplifiers - Google Patents

Improvements in or relating to amplifiers

Info

Publication number
GB951058A
GB951058A GB1383860A GB1383860A GB951058A GB 951058 A GB951058 A GB 951058A GB 1383860 A GB1383860 A GB 1383860A GB 1383860 A GB1383860 A GB 1383860A GB 951058 A GB951058 A GB 951058A
Authority
GB
United Kingdom
Prior art keywords
voltage
filter
frequency
low
impedance
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
GB1383860A
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.)
Philips Electrical Industries Ltd
Original Assignee
Philips Electrical Industries 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
Application filed by Philips Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB951058A publication Critical patent/GB951058A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G9/00—Combinations of two or more types of control, e.g. gain control and tone control
    • H03G9/02—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers
    • H03G9/025—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers frequency-dependent volume compression or expansion, e.g. multiple-band systems
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/16—Automatic control
    • H03G5/18—Automatic control in untuned amplifiers

Landscapes

  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

951,058. Automatic volume control. PHILIPS ELECTRICAL INDUSTRIES Ltd. April 20, 1960 [April 23, 1959], No. 13838/60. Heading H4R. In an audio amplifier embodying automatic volume control, control voltages corresponding to at least two frequency bands are derived from the output signal and are then separately used to control the amplification of the frequency bands. A signal from the output of amplifier 3 is fed into a high-pass filter 5 so that when the voltage amplitude of a high-frequency signal exceeds the bias voltage 7, the anode current of valve 15 is reduced with a consequent decrease of emission from incandescent lamp 17 and hence increased impedance of photoresistor 20. Consequently low frequency signals are passed by low-pass filter 21, 20 with a decreased attenuation relative to that of the high frequency signals. A high voltage low frequency signal passed through low-pass filter 9 similarly increases the impedance of photoresistor 19 with a consequent increase of the low frequency impedance of the filter-capacitor 25, resistor 19. Amplifiers 2, 3 may also be gain controlled over an intermediate frequency band or over all frequencies by a voltage derived from the output signal by diode 22 and filter 23; the tappings on the resistors in filter 23 are for varying the bias voltages 7, 8 with respect to the output voltage.
GB1383860A 1959-04-23 1960-04-20 Improvements in or relating to amplifiers Expired GB951058A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEN16612A DE1085919B (en) 1959-04-23 1959-04-23 Playback device with automatic gain control

Publications (1)

Publication Number Publication Date
GB951058A true GB951058A (en) 1964-03-04

Family

ID=7340244

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1383860A Expired GB951058A (en) 1959-04-23 1960-04-20 Improvements in or relating to amplifiers

Country Status (2)

Country Link
DE (1) DE1085919B (en)
GB (1) GB951058A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3518566A (en) * 1968-11-21 1970-06-30 Us Navy Audio system with modified output
US3569852A (en) * 1969-01-23 1971-03-09 American Optical Corp Frequency selective variable gain amplifier
US3676792A (en) * 1970-06-09 1972-07-11 Us Navy Frequency multiplexing agc amplifier
US3781703A (en) * 1972-10-06 1973-12-25 Jerrold Electronics Corp Electronic amplifier with dual automatic slope control
FR2283586A1 (en) * 1974-08-27 1976-03-26 Northern Electric Co ALTERNATIVE SIGNAL PROCESSING CIRCUITS FOR COMPRESSORS-EXPANDERS
US4307348A (en) * 1979-01-17 1981-12-22 Racal-Dana Instruments Limited Automatic gain control circuit
WO2008093954A1 (en) 2007-02-01 2008-08-07 Samsung Electronics Co, . Ltd. Audio reproduction method and apparatus with auto volume control function

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4327250A (en) * 1979-05-03 1982-04-27 Electro Audio Dynamics Inc. Dynamic speaker equalizer
JPS57200909A (en) * 1981-06-01 1982-12-09 Victor Co Of Japan Ltd Reproducing device for information recording medium

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3518566A (en) * 1968-11-21 1970-06-30 Us Navy Audio system with modified output
US3569852A (en) * 1969-01-23 1971-03-09 American Optical Corp Frequency selective variable gain amplifier
US3676792A (en) * 1970-06-09 1972-07-11 Us Navy Frequency multiplexing agc amplifier
US3781703A (en) * 1972-10-06 1973-12-25 Jerrold Electronics Corp Electronic amplifier with dual automatic slope control
FR2283586A1 (en) * 1974-08-27 1976-03-26 Northern Electric Co ALTERNATIVE SIGNAL PROCESSING CIRCUITS FOR COMPRESSORS-EXPANDERS
US4307348A (en) * 1979-01-17 1981-12-22 Racal-Dana Instruments Limited Automatic gain control circuit
WO2008093954A1 (en) 2007-02-01 2008-08-07 Samsung Electronics Co, . Ltd. Audio reproduction method and apparatus with auto volume control function
EP2127074A1 (en) * 2007-02-01 2009-12-02 Samsung Electronics Co., Ltd. Audio reproduction method and apparatus with auto volume control function
EP2127074A4 (en) * 2007-02-01 2010-01-20 Samsung Electronics Co Ltd Audio reproduction method and apparatus with auto volume control function
US9635459B2 (en) 2007-02-01 2017-04-25 Samsung Electronics Co., Ltd. Audio reproduction method and apparatus with auto volume control function

Also Published As

Publication number Publication date
DE1085919B (en) 1960-07-28

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