JPS57129005A - Muting circuit - Google Patents

Muting circuit

Info

Publication number
JPS57129005A
JPS57129005A JP56014304A JP1430481A JPS57129005A JP S57129005 A JPS57129005 A JP S57129005A JP 56014304 A JP56014304 A JP 56014304A JP 1430481 A JP1430481 A JP 1430481A JP S57129005 A JPS57129005 A JP S57129005A
Authority
JP
Japan
Prior art keywords
trs
constant
switching
turned
amplifiers
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.)
Granted
Application number
JP56014304A
Other languages
Japanese (ja)
Other versions
JPH0219648B2 (en
Inventor
Tetsuo Sato
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 JP56014304A priority Critical patent/JPS57129005A/en
Publication of JPS57129005A publication Critical patent/JPS57129005A/en
Publication of JPH0219648B2 publication Critical patent/JPH0219648B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Control Of Amplification And Gain Control (AREA)
  • Amplifiers (AREA)

Abstract

PURPOSE: To reduce a pop sound in case of switching, by providing a controlling circuit for selectively switching an operation of the first and second amplifiers, and setting the gain of both the amplifiers to the same gain of 1 or above.
CONSTITUTION: A constant-current circuit constituted of transistors (TR) Q5, Q6 and emitter resistances R1, R2 is provided on the respective emitters of differential TRs Q1, Q2 and Q3, Q4. The TRS Q5, Q6 are selectively operated by a constant-current switching and controlling circuit constituted of PNP TRs Q18, Q19. Also, when switching to a control signal Vc < reference voltage VB2, the TR Q19 is turned off, the TR Q18 is turned on, and a constant-currentI0 is made to flow to a TR Q20, therefore, the same constant-current flows to the collector of the TR Q6. Accordingly, the TRs Q1, Q2 are turned off and the TRs Q3, Q4 are operated, therefore, only the DC bias voltage is applied to an output OUT.
COPYRIGHT: (C)1982,JPO&Japio
JP56014304A 1981-02-04 1981-02-04 Muting circuit Granted JPS57129005A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56014304A JPS57129005A (en) 1981-02-04 1981-02-04 Muting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56014304A JPS57129005A (en) 1981-02-04 1981-02-04 Muting circuit

Publications (2)

Publication Number Publication Date
JPS57129005A true JPS57129005A (en) 1982-08-10
JPH0219648B2 JPH0219648B2 (en) 1990-05-02

Family

ID=11857355

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56014304A Granted JPS57129005A (en) 1981-02-04 1981-02-04 Muting circuit

Country Status (1)

Country Link
JP (1) JPS57129005A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59188205A (en) * 1983-04-08 1984-10-25 Sanyo Electric Co Ltd Muting circuit
JPH0254609A (en) * 1988-08-18 1990-02-23 Nec Ic Microcomput Syst Ltd Attenuation circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5746508A (en) * 1980-09-03 1982-03-17 Matsushita Electric Ind Co Ltd Muting amplifier

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5746508A (en) * 1980-09-03 1982-03-17 Matsushita Electric Ind Co Ltd Muting amplifier

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59188205A (en) * 1983-04-08 1984-10-25 Sanyo Electric Co Ltd Muting circuit
JPH0328843B2 (en) * 1983-04-08 1991-04-22 Sanyo Electric Co
JPH0254609A (en) * 1988-08-18 1990-02-23 Nec Ic Microcomput Syst Ltd Attenuation circuit

Also Published As

Publication number Publication date
JPH0219648B2 (en) 1990-05-02

Similar Documents

Publication Publication Date Title
EP0346011A3 (en) Amplifiers
JPS5644208A (en) Amplifier
GB1472899A (en) Transistor control circuits
GB2037111A (en) Signal change-over amplifier
JPS5545264A (en) Switch circuit
JPS57129005A (en) Muting circuit
JPS5760710A (en) Adjusting circuit for input bias of amplifier
EP0354513A3 (en) Gain controlled amplifier circuit
JPS5643808A (en) Signal converting circuit
JPS5552605A (en) Detector circuit
JPS5746508A (en) Muting amplifier
JPS57121305A (en) Muting circuit
JPS5797210A (en) Amplifier
JPS5689108A (en) Bias setting circuit of push-pull amplifier
JPS5748809A (en) Muting circuit
JPS56141622A (en) Switching circuit
JPS5746511A (en) Muting amplifier
JPS5769908A (en) Muting circuit
JPS5783912A (en) Current amplifying circuit
EP0180337A3 (en) Buffer circuit
JPS57164618A (en) Comparator circuit
JPS55127773A (en) Switching unit
JPS56140800A (en) Control circuit of sound volume balance
JPS5336450A (en) Gain control circuit
JPS57181215A (en) Variable gain circuit