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GB1404331A - Selectively switchable compressor/expanders - Google Patents

Selectively switchable compressor/expanders

Info

Publication number
GB1404331A
GB1404331A GB3362472A GB3362472A GB1404331A GB 1404331 A GB1404331 A GB 1404331A GB 3362472 A GB3362472 A GB 3362472A GB 3362472 A GB3362472 A GB 3362472A GB 1404331 A GB1404331 A GB 1404331A
Authority
GB
United Kingdom
Prior art keywords
expander
configuration
path
compressor
switch
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
GB3362472A
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.)
DOLBY LABORATORIES Inc
Original Assignee
DOLBY LABORATORIES Inc
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 DOLBY LABORATORIES Inc filed Critical DOLBY LABORATORIES Inc
Publication of GB1404331A publication Critical patent/GB1404331A/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
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/62—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
    • H04B1/64—Volume compression or expansion arrangements

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Television Signal Processing For Recording (AREA)

Abstract

1404331 Companders DOLBY LABORATORIES Inc 18 July 1972 [2 Aug 1971] 33624/72 Heading H4R A selectively switchable compressor and expander comprises two adding circuits 51A, 51B, in series in a main path between an input and an output and a further path 26 with its input connected to a point in the main path between the two adding circuits and its output connected to one adder circuit to provide a compressor configuration, and to the other adder circuit to provide an expander configuration. A switch 24 is provided to disable one connection between the further path and one of the adders and the further path includes a limiting circuit, to limit the signal level passing therethrough so that compression or expansion is only effective at low signal levels. In Fig. 5, the compressor operates in a feed forward configuration, with the path to the adder 51A disabled at either switch 24 or 24<SP>1</SP>, and the expander operates in feedback configuration with a signal inverter 52 in the feedback path. In the expander configuration the output is taken from terminal 25 and a recompressed signal is provided at terminal 35 for connection to a recorder &c. In Fig. 6, the compressor operates in a feedback configuration via an isolating buffer stage 54 and the expander in feed forward configuration via the inverter 52. Switch 55 is provided to enable the compressor and expander to be rendered inoperative. The further path may have a filter with adjustable cut off as disclosed in Specification 1,279,634.
GB3362472A 1971-08-02 1972-07-18 Selectively switchable compressor/expanders Expired GB1404331A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US16806971A 1971-08-02 1971-08-02

Publications (1)

Publication Number Publication Date
GB1404331A true GB1404331A (en) 1975-08-28

Family

ID=22609984

Family Applications (4)

Application Number Title Priority Date Filing Date
GB3364572A Expired GB1404333A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander
GB3362472A Expired GB1404331A (en) 1971-08-02 1972-07-18 Selectively switchable compressor/expanders
GB3364672A Expired GB1404334A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander
GB3364472A Expired GB1404332A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB3364572A Expired GB1404333A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander

Family Applications After (2)

Application Number Title Priority Date Filing Date
GB3364672A Expired GB1404334A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander
GB3364472A Expired GB1404332A (en) 1971-08-02 1972-07-18 Selectively switchable signal compressor/expander

Country Status (4)

Country Link
US (1) US3729693A (en)
JP (4) JPS5737134B2 (en)
DE (4) DE2237540C2 (en)
GB (4) GB1404333A (en)

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3903485A (en) * 1968-01-10 1975-09-02 Ray Milton Dolby Compressors, expanders and noise reduction systems
US3972010A (en) * 1968-01-10 1976-07-27 Ray Milton Dolby Compressors, expanders and noise reduction systems
GB1432763A (en) * 1972-05-02 1976-04-22 Dolby Laboratories Inc Compressors expanders and noise reduction systems
JPS572970B2 (en) * 1973-09-10 1982-01-19
US4045731A (en) * 1974-11-21 1977-08-30 Takeda Riken Kogyo Kabushikikaisha Filter having an automatically controlled variable cut-off frequency
JPS51118718U (en) * 1975-03-19 1976-09-27
US4155041A (en) 1976-05-13 1979-05-15 Burns Richard C System for reducing noise transients
GB1579138A (en) * 1976-07-06 1980-11-12 Sony Corp Noise and cross-talk elimination in recording and reproducing video signals
JPS5313860A (en) * 1976-07-23 1978-02-07 Pioneer Electronic Corp Tone control device
US4068139A (en) * 1976-08-09 1978-01-10 Fairchild Camera And Instrument Corporation IC compatible variable shunt impedance for Dolby B system
JPS5329007A (en) * 1976-08-30 1978-03-17 Victor Co Of Japan Ltd Signal transmitter
JPS5373020A (en) * 1976-12-13 1978-06-29 Victor Co Of Japan Ltd Signal transmission device
JPS53121506A (en) * 1977-03-31 1978-10-24 Pioneer Electronic Corp Signal compressing and expanding device
JPS5439516A (en) * 1977-09-02 1979-03-27 Sanyo Electric Co Ltd Noise reduction unit
US4328465A (en) * 1978-09-26 1982-05-04 Pioneer Electronic Corporation Tone control circuit utilizing variable gain amplifier
JPS55121698U (en) * 1979-02-21 1980-08-29
JPS55156431A (en) * 1979-05-24 1980-12-05 Sony Corp Noise reduction system
JPS55158715A (en) * 1979-05-29 1980-12-10 Sony Corp Gain control circuit
DE3102945A1 (en) * 1980-05-19 1981-12-24 Hitachi, Ltd., Tokyo SWITCHABLE SIGNAL COMPRESSOR / SIGNAL EXTENDER
US4457014A (en) * 1980-10-03 1984-06-26 Metme Communications Signal transfer and system utilizing transmission lines
JPS57142013A (en) * 1981-02-27 1982-09-02 Sony Corp Active equalizer
AU7585581A (en) * 1981-08-26 1983-03-08 Bloy, Graham Philip System for maximum efficiency transfer of modulated signals utilizing line systems
JPS57117111A (en) * 1981-11-20 1982-07-21 Matsushita Electric Ind Co Ltd Tape recorder
DE3249333T (en) * 1982-01-26 1984-01-12 Coghill, Marvin, Bangkok System for maximum effective transmission of modulated energy
JPS58209234A (en) * 1982-05-29 1983-12-06 Sony Corp Noise reduction circuit
JPS5933113U (en) * 1982-08-23 1984-03-01 株式会社東芝 Tape recorder switching device
JPS5995414U (en) * 1982-12-17 1984-06-28 株式会社日立製作所 Tape recorder with noise reduction circuit
JPS6062639U (en) * 1983-10-05 1985-05-01 カヤバ工業株式会社 Hydraulic shock absorber mounting device
US4747141A (en) * 1983-10-24 1988-05-24 Kahn Leonard R AM stereo signal decoder
JPH0725854B2 (en) * 1984-05-18 1995-03-22 帝国化学産業株式会社 Water-solubilization method of polyamide resin
DE3543907A1 (en) * 1985-12-12 1987-06-25 Stefan Knauer Device for noise suppression in the transmission of audio-frequency signals
JPH0244113Y2 (en) * 1987-03-26 1990-11-22
JPS6421833U (en) * 1987-07-29 1989-02-03
AU4207089A (en) * 1988-08-23 1990-03-23 B.W.N. Wavepur Rights Company Frequency-compensated linear sliding-band network

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH447890A (en) * 1965-07-09 1967-11-30 Dowty Electrics Ltd Electrically controlled indicator
GB1120541A (en) * 1965-08-11 1968-07-17 Dolby Ray Milton Improvements in noise reduction systems
GB1253031A (en) * 1968-01-10 1971-11-10
US3631365A (en) * 1968-11-01 1971-12-28 Dolby Laboratories Inc Signal compressors and expanders

Also Published As

Publication number Publication date
JPS53888B2 (en) 1978-01-12
US3729693A (en) 1973-04-24
JPS4825425A (en) 1973-04-03
GB1404332A (en) 1975-08-28
JPS5625824B2 (en) 1981-06-15
JPS4825427A (en) 1973-04-03
DE2237542C2 (en) 1982-04-29
DE2237543B2 (en) 1977-12-08
JPS4825426A (en) 1973-04-03
GB1404333A (en) 1975-08-28
DE2237543A1 (en) 1973-02-22
DE2237541A1 (en) 1973-02-22
DE2237540A1 (en) 1973-02-22
DE2237540C2 (en) 1982-07-15
GB1404334A (en) 1975-08-28
JPS4825424A (en) 1973-04-03
JPS5737134B2 (en) 1982-08-07
DE2237541C2 (en) 1982-08-05
DE2237542A1 (en) 1973-02-22
JPS5737135B2 (en) 1982-08-07

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PE20 Patent expired after termination of 20 years