JPS56128004A - Muting circuit - Google Patents

Muting circuit

Info

Publication number
JPS56128004A
JPS56128004A JP3040080A JP3040080A JPS56128004A JP S56128004 A JPS56128004 A JP S56128004A JP 3040080 A JP3040080 A JP 3040080A JP 3040080 A JP3040080 A JP 3040080A JP S56128004 A JPS56128004 A JP S56128004A
Authority
JP
Japan
Prior art keywords
circuit
field effect
effect transistor
feedback
providing
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.)
Pending
Application number
JP3040080A
Other languages
Japanese (ja)
Inventor
Masanori Ienaka
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP3040080A priority Critical patent/JPS56128004A/en
Publication of JPS56128004A publication Critical patent/JPS56128004A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/34—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems

Landscapes

  • Control Of Amplification And Gain Control (AREA)

Abstract

PURPOSE:To prevent a change for worsening of a distortion rate and obtain a large extent of attenuation, by providing a field effect transistor on the output of the amplifying circuit and the AC feedback input of the amplifying circuit, and providing an AC feedback circuit through said field effect transistor. CONSTITUTION:The amplifier circuit 1 obtains an output by providing in series a coupling capacitor C1 to the next stage circuit, and a field effect transistor Q1 which is controlled by a mute signal Vc. Also, an AC feedback circuit is placed by constituting it of resistors Rf, Ri and a capacitor C2, by which an output passing through said field effect transistor Q1 is made an input, so that a signal which has been generated in said AC feedback circuit can be applied to the negative feedback input of the amplifying circuit 1 through the field effect transistor Q2 controlled by the muting signal Vc.
JP3040080A 1980-03-12 1980-03-12 Muting circuit Pending JPS56128004A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3040080A JPS56128004A (en) 1980-03-12 1980-03-12 Muting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3040080A JPS56128004A (en) 1980-03-12 1980-03-12 Muting circuit

Publications (1)

Publication Number Publication Date
JPS56128004A true JPS56128004A (en) 1981-10-07

Family

ID=12302874

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3040080A Pending JPS56128004A (en) 1980-03-12 1980-03-12 Muting circuit

Country Status (1)

Country Link
JP (1) JPS56128004A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4506381A (en) * 1981-12-29 1985-03-19 Mitsubishi Denki Kabushiki Kaisha Aural transmitter device
US4805272A (en) * 1985-12-27 1989-02-21 Morito Co., Ltd. Fastener with tape

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4506381A (en) * 1981-12-29 1985-03-19 Mitsubishi Denki Kabushiki Kaisha Aural transmitter device
US4805272A (en) * 1985-12-27 1989-02-21 Morito Co., Ltd. Fastener with tape

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