[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

JPS57173213A - Muting circuit - Google Patents

Muting circuit

Info

Publication number
JPS57173213A
JPS57173213A JP56058272A JP5827281A JPS57173213A JP S57173213 A JPS57173213 A JP S57173213A JP 56058272 A JP56058272 A JP 56058272A JP 5827281 A JP5827281 A JP 5827281A JP S57173213 A JPS57173213 A JP S57173213A
Authority
JP
Japan
Prior art keywords
muting
current
trs
signal
terminal
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
JP56058272A
Other languages
Japanese (ja)
Inventor
Hiroto Shibuya
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP56058272A priority Critical patent/JPS57173213A/en
Publication of JPS57173213A publication Critical patent/JPS57173213A/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)
  • Amplifiers (AREA)

Abstract

PURPOSE:To eliminate a shock sound and to obtain the substantially-necessary amount of muting by constituting the variable impedance part of a muting circuit by using the 1st and 2nd circuit parts composed of transistor (TR) of complementary polarities whose emitters are connected directly. CONSTITUTION:An input signal ei from a signal source 24 is transferred as an output signal e0 to an output terminal through a coupling capacitor 23 and a resistance 22. A muting signal is inputted from a terminal 25 to generate a muting control current IM by TRs 12 and 14 and a resistance 16, and thus while a current IM flows through TRs 11 and 18 constituting a current mirror circuit, the current IM flows TRs 19 and 20 forming a current mirror circuit. At this time, a voltage at a terminal 26 is biased from an earth point by the voltage value 1/2VCC of a constant voltage source 31, and then is raised by a VBE through a TR13; and it is lowered by the VBE through the TR19 to be held a half as high as the VCC, so that muting operation generates no switching noise.
JP56058272A 1981-04-16 1981-04-16 Muting circuit Pending JPS57173213A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56058272A JPS57173213A (en) 1981-04-16 1981-04-16 Muting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56058272A JPS57173213A (en) 1981-04-16 1981-04-16 Muting circuit

Publications (1)

Publication Number Publication Date
JPS57173213A true JPS57173213A (en) 1982-10-25

Family

ID=13079540

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56058272A Pending JPS57173213A (en) 1981-04-16 1981-04-16 Muting circuit

Country Status (1)

Country Link
JP (1) JPS57173213A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6451812A (en) * 1987-08-24 1989-02-28 Matsushita Electric Ind Co Ltd Agc circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5428543A (en) * 1977-08-05 1979-03-03 Toshiba Corp Variable impedance circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5428543A (en) * 1977-08-05 1979-03-03 Toshiba Corp Variable impedance circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6451812A (en) * 1987-08-24 1989-02-28 Matsushita Electric Ind Co Ltd Agc circuit

Similar Documents

Publication Publication Date Title
JPS57173220A (en) Comparator circuit
JPS5515512A (en) Constant voltage output circuit
JPS57173213A (en) Muting circuit
JPS57173212A (en) Muting circuit
JPS56119517A (en) Amplitude limiting circuit
JPS5745715A (en) Schmitt trigger circuit
JPS5744312A (en) Automatic level control circuit
JPS55120205A (en) Loudness circuit device
JPS5755605A (en) Differential amplifier
JPS5772408A (en) Variable gain equalizer circuit
JPS56100531A (en) Frequency converting circuit
JPS55123233A (en) Switch unit
JPS5472943A (en) Bias stabilizing circuit of differential amplifier
JPS57171811A (en) Variable attenuating circuit
JPS57181215A (en) Variable gain circuit
JPS57162843A (en) Muting circuit
JPS54103662A (en) Hysteresis circuit
JPS57162812A (en) Noise reduction device
JPS57127312A (en) Signal amplifying circuit
JPS5546601A (en) Variable bias circuit
JPS5797227A (en) Electronic switching amplifying circuit
JPS56168407A (en) Amplifier
JPS6439818A (en) Switching circuit
JPS5765912A (en) Differential amplifying circuit
JPS55121734A (en) Variable impedance circuit