JPS57129005A - Muting circuit - Google Patents
Muting circuitInfo
- 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
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
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)
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)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5746508A (en) * | 1980-09-03 | 1982-03-17 | Matsushita Electric Ind Co Ltd | Muting amplifier |
-
1981
- 1981-02-04 JP JP56014304A patent/JPS57129005A/en active Granted
Patent Citations (1)
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)
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 |
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