JPH1022739A - Muffler for voice amplifier - Google Patents
Muffler for voice amplifierInfo
- Publication number
- JPH1022739A JPH1022739A JP8169178A JP16917896A JPH1022739A JP H1022739 A JPH1022739 A JP H1022739A JP 8169178 A JP8169178 A JP 8169178A JP 16917896 A JP16917896 A JP 16917896A JP H1022739 A JPH1022739 A JP H1022739A
- Authority
- JP
- Japan
- Prior art keywords
- operational amplifier
- power supply
- amplifier
- output
- power source
- 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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、演算増幅器を使用
した音声増幅器の機器の起動、停止及び入力信号の切り
替え等の際に発生する過渡的な異音の出力を防止する消
音装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer for preventing output of transient abnormal noise generated when starting and stopping an audio amplifier device using an operational amplifier and switching input signals. is there.
【０００２】[0002]
【従来の技術】近年、安価で性能のよい汎用の演算増幅
器の入手が容易になり、音響製品にも音声増幅器として
多く使われるようになった。また、このような機器に使
われる電源も、ＡＣアダプタ−や電池動作への対応で片
電源の場合が多くある。2. Description of the Related Art In recent years, it has become easy to obtain a general-purpose operational amplifier which is inexpensive and has high performance, and has been widely used as an audio amplifier in audio products. Also, the power supply used for such devices is often a single power supply in response to AC adapters and battery operation.
【０００３】以下に従来の音声増幅器の消音装置につい
て説明する。図３は従来の音声増幅器の消音装置の回路
構成を示すものである。図３において、１は演算増幅器
である。２はリレ−スイッチで４の消音信号発生回路で
生成される信号（Ｖｍ）によって開閉される。３は外部
機器への出力端子である。[0003] Hereinafter, a conventional silencer for an audio amplifier will be described. FIG. 3 shows a circuit configuration of a conventional sound amplifier silencer. In FIG. 3, reference numeral 1 denotes an operational amplifier. Reference numeral 2 denotes a relay switch, which is opened and closed by a signal (Vm) generated by the mute signal generation circuit 4. Reference numeral 3 denotes an output terminal to an external device.
【０００４】以上のように構成された音声増幅器の消音
装置について、以下その動作について説明する。[0004] The operation of the muffler for an audio amplifier configured as described above will be described below.
【０００５】まず、演算増幅器１に電源（ＶＣＣ）が供
給されると演算増幅器１はその反転入力端子に入力され
た音声信号の増幅を開始するが、一般的に演算増幅器を
片電源で使用する場合、電源電圧（ＶＣＣ）と出力バイ
アス電圧を決定する非反転入力の電圧（Ｖｂ）を接地電
位から同時に立ち上げると、この演算増幅器の出力電圧
（Ｖｏ）の急激な変化が異音となって出力される。First, when power (VCC) is supplied to the operational amplifier 1, the operational amplifier 1 starts to amplify the audio signal input to its inverting input terminal. Generally, the operational amplifier is used with a single power supply. In this case, when the power supply voltage (VCC) and the non-inverting input voltage (Vb) for determining the output bias voltage are simultaneously raised from the ground potential, the sudden change in the output voltage (Vo) of the operational amplifier causes abnormal noise. Is output.
【０００６】また、機器のシステム全体の機動、停止時
には音声回路にも雑音が発生することが多いので、出力
回路にリレ−スイッチ２を挿入して機器の安定動作時の
みこのリレ−スイッチ２を消音信号発生回路４で生成し
た消音信号（Ｖｍ）によってＯＮすることで出力端子３
にこれらの異音、雑音を出力しないようにしていた。In addition, since noise often occurs in the audio circuit when the entire system of the device is activated or deactivated, the relay switch 2 is inserted into the output circuit, and the relay switch 2 is operated only during stable operation of the device. The output terminal 3 is turned on by the mute signal (Vm) generated by the mute signal generation circuit 4.
These abnormal sounds and noise were not output.
【０００７】図４に従来の音声増幅器の消音装置の電
源、入出力及び消音信号のタイミングを示す。FIG. 4 shows the power supply, input / output, and timing of a muffling signal of a conventional muffling device for an audio amplifier.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら上記の従
来の構成では、リレ−スイッチという高価で大型の部品
を使わなければならないという問題点を有していた。However, the above-mentioned conventional configuration has a problem that an expensive and large-sized component called a relay switch must be used.
【０００９】本発明は上記従来の問題点を解決するもの
で、安価で、小型の音声増幅器の消音装置を提供するこ
とを目的とする。An object of the present invention is to solve the above-mentioned conventional problems and to provide an inexpensive and small-sized sound muffler for an audio amplifier.
【００１０】[0010]
【課題を解決するための手段】この目的を達成するため
に本発明の音声増幅器の消音装置は、音声信号を増幅す
る演算増幅器と、該演算増幅器に入力される出力段のバ
イアスレベルを決定する電源の立上り速度を制御する手
段と、該演算増幅器に供給する電源回路を開閉する手段
と、消音時に該電源回路を開閉する信号を生成する手段
と、該演算増幅器に電源が供給されるまでの間に該演算
増幅器の電源端子と出力バイアス電圧を同レベルに保持
する手段とで構成されている。SUMMARY OF THE INVENTION To achieve this object, a muffling apparatus for an audio amplifier according to the present invention determines an operational amplifier for amplifying an audio signal and a bias level of an output stage input to the operational amplifier. Means for controlling the rising speed of the power supply, means for opening and closing the power supply circuit for supplying the operational amplifier, means for generating a signal for opening and closing the power supply circuit when the sound is muted, and means for controlling the power supply to the operational amplifier. A power supply terminal of the operational amplifier and a means for maintaining the output bias voltage at the same level are provided between them.
【００１１】この構成によって、該演算増幅器は、電源
と出力バイアス電圧の立上がり時間が制御されること
で、機器の安定動作時のみ音声信号を出力させることが
でき、また、該演算増幅器の出力電圧を緩やかに立上げ
ることによって異音を出力させないようにすることがで
きる。With this configuration, the operational amplifier can output an audio signal only during stable operation of the device by controlling the rise time of the power supply and the output bias voltage. By gently starting up, it is possible to prevent abnormal noise from being output.
【００１２】[0012]
【発明の実施の形態】以下本発明の一実施例について、
図面を参照しながら説明する。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described.
This will be described with reference to the drawings.
【００１３】図１において、１は演算増幅器、３は出力
端子、４は消音信号生成回路、５はＮＰＮトランジス
タ、６はコンデンサ、７はダイオ−ド、８はＰＮＰトラ
ンジスタ、９、１０、１１は抵抗器である。In FIG. 1, 1 is an operational amplifier, 3 is an output terminal, 4 is a muffling signal generation circuit, 5 is an NPN transistor, 6 is a capacitor, 7 is a diode, 8 is a PNP transistor, 9, 10 and 11 are It is a resistor.
【００１４】以上のように構成された音声増幅器の消音
装置について、図２を用いてその動作を説明する。The operation of the muffler for an audio amplifier configured as described above will be described with reference to FIG.
【００１５】まず、機器の電源（ＶＣＣ）が立ち上がる
とＮＰＮトランジスタ５がＯＮして演算増幅器１の非反
転入力にバイアス（Ｖｂ）が供給される。同時に、抵抗
器９によって出力端子（Ｖｏ）もＶｂまで上がる。この
Ｖｂはコンデンサ６が充電される時間内で徐々に立上が
る。このときダイオ−ド７を通じて演算増幅器１の電源
（ＶＣＭ）もほぼＶｂと同電位まで立上がる。コンデン
サ６がないとＶｂが急速に立上がって演算増幅器の出力
（Ｖｏ）も急激に変化するため、この電圧変動が出力端
子３に異音となって出力される。First, when the power supply (VCC) of the device rises, the NPN transistor 5 is turned on and the bias (Vb) is supplied to the non-inverting input of the operational amplifier 1. At the same time, the output terminal (Vo) is also increased to Vb by the resistor 9. This Vb gradually rises during the time when the capacitor 6 is charged. At this time, the power supply (VCM) of the operational amplifier 1 also rises to approximately the same potential as Vb through the diode 7. Without the capacitor 6, Vb rises rapidly and the output (Vo) of the operational amplifier also changes rapidly, so that this voltage fluctuation is output as abnormal noise to the output terminal 3.
【００１６】この時点で演算増幅器１は電源電圧（ＶＣ
Ｍ）が出力電圧（Ｖｏ）と同電位に固定されるので能動
にならず、また、反転入力に雑音が入っても抵抗器11の
値が抵抗器９＋10の値に比べて十分小さければＶｂに終
端されて出力されない。At this point, the operational amplifier 1 operates at the power supply voltage (VC
M) is fixed at the same potential as the output voltage (Vo), so that it does not become active. Even if noise enters the inverting input, if the value of the resistor 11 is sufficiently smaller than the value of the resistor 9 + 10, the voltage becomes Vb. It is terminated and not output.
【００１７】その後、消音信号生成回路４から出力され
る消音信号（Ｖｍ）によってＰＮＰトランジスタ８をＯ
Ｎさせることで演算増幅器１の電源（ＶＣＭ）がＶＣＣ
まで上がって通常の音声増幅器となる。能動状態の演算
増幅器の出力インピ−ダンスはほぼ０なので、抵抗器11
の値は出力レベルには無関係になる。Thereafter, the PNP transistor 8 is turned on by the silence signal (Vm) output from the silence signal generation circuit 4.
N, the power supply (VCM) of the operational amplifier 1 becomes VCC.
Up to a normal audio amplifier. Since the output impedance of the active operational amplifier is almost zero, the resistor 11
Becomes independent of the output level.
【００１８】また、機器の電源が立下がるときにも、ま
ず消音信号（Ｖｍ）によってＰＮＰトランジスタ８をＯ
ＦＦさせることで立上がり時と同様の消音が可能にな
る。When the power supply of the device falls, first, the PNP transistor 8 is turned off by the silence signal (Vm).
By performing FF, the same silencing as at the time of startup can be performed.
【００１９】図２に本実施例の音声増幅器の消音装置の
電源、入出力及び消音信号のタイミングを示す。FIG. 2 shows the power supply, input / output, and timing of the muffling signal of the muffling device of the audio amplifier of this embodiment.
【００２０】以上のように本実施例によれば、音声信号
を増幅する演算増幅器と、該演算増幅器に入力される出
力段のバイアスレベルを決定する電源の立上り速度を制
御する手段と、該演算増幅器に供給する電源回路を開閉
する手段と、消音時に該電源回路を開閉する信号を生成
する手段と、該演算増幅器に電源が供給されるまでの間
に該演算増幅器の電源端子と出力バイアス電圧を同レベ
ルに保持する手段とを備え、演算増幅器の電源端子と出
力バイアス電圧を制御することにより、安価で小型の音
声増幅器の消音装置を実現することができる。As described above, according to this embodiment, the operational amplifier for amplifying the audio signal, the means for controlling the rising speed of the power supply for determining the bias level of the output stage input to the operational amplifier, Means for opening and closing a power supply circuit supplied to the amplifier, means for generating a signal for opening and closing the power supply circuit when sound is muted, and a power supply terminal of the operational amplifier and an output bias voltage until power is supplied to the operational amplifier. And a means for maintaining the same level and controlling the power supply terminal and the output bias voltage of the operational amplifier, thereby realizing an inexpensive and compact sound amplifier for a sound amplifier.
【００２１】なお、本実施例において演算増幅器に入力
される出力段のバイアスレベルを決定する電源を供給す
る手段はＮＰＮトランジスタ５としたが、ＮＰＮトラン
ジスタ５は演算増幅器をリップル成分の除去を兼ねた電
流増幅器として用いてもよい。In this embodiment, the means for supplying power for determining the bias level of the output stage input to the operational amplifier is the NPN transistor 5, but the NPN transistor 5 also serves to remove the ripple component from the operational amplifier. It may be used as a current amplifier.
【００２２】[0022]
【発明の効果】以上のように本発明は、音声信号を増幅
する演算増幅器と、該演算増幅器に入力される出力段の
バイアスレベルを決定する電源の立ち上り速度を制御す
る手段と該演算増幅器に供給する電源回路を開閉する手
段と、該電源回路を開閉する信号を生成する手段と、該
演算増幅器に電源が供給されるまでの間に該演算増幅器
の電源端子と出力端子の電圧を同レベルに保持する手段
とを設けることにより、・安価で小型の音声増幅器の消
音回路を実現するものである。As described above, the present invention provides an operational amplifier for amplifying an audio signal, a means for controlling a rising speed of a power supply for determining a bias level of an output stage inputted to the operational amplifier, and an operational amplifier. Means for opening and closing a power supply circuit to be supplied, means for generating a signal for opening and closing the power supply circuit, and the same voltage applied to the power supply terminal and output terminal of the operational amplifier until power is supplied to the operational amplifier. By providing the holding means, a low-cost and small-sized sound amplifier for a sound amplifier can be realized.
【図１】本実施例の音声増幅器の消音装置の回路構成図FIG. 1 is a circuit configuration diagram of a sound attenuating device for an audio amplifier according to an embodiment.
【図２】本実施例の音声増幅器の消音装置の動作説明の
ための電源、入出力及び消音信号のタイミング図FIG. 2 is a timing diagram of a power supply, input / output, and a muffling signal for explaining the operation of the muffling device of the audio amplifier according to the embodiment.
【図３】従来の音声増幅器の消音装置の回路構成図FIG. 3 is a circuit configuration diagram of a conventional audio amplifier silencer.
【図４】従来の音声増幅器の消音装置の動作説明のため
の電源、入出力及び消音信号のタイミング図FIG. 4 is a timing diagram of a power supply, input / output, and a muffling signal for explaining the operation of the muffling device of the conventional audio amplifier.
１ 演算増幅器 ２ リレ−スイッチ ３ 出力端子 ４ 消音信号生成回路 ５ ＮＰＮトランジスタ ６ コンデンサ ７ ダイオ−ド ８ ＰＮＰトランジスタ ９、１０、１１ 抵抗器 DESCRIPTION OF SYMBOLS 1 Operational amplifier 2 Relay switch 3 Output terminal 4 Silence signal generation circuit 5 NPN transistor 6 Capacitor 7 Diode 8 PNP transistor 9, 10, 11 Resistor
Claims (2)
増幅器に入力される出力段のバイアスレベルを決定する
電源の立上り速度を制御する手段と該演算増幅器に供給
する電源回路を開閉する手段と、消音時に該電源回路を
開閉する信号を生成する手段と、該演算増幅器に電源が
供給されるまでの間に該演算増幅器の電源端子と出力バ
イアス電圧を同レベルに保持する手段とを備えた音声増
幅器の消音装置。An operational amplifier for amplifying an audio signal, means for controlling a rising speed of a power supply for determining a bias level of an output stage inputted to the operational amplifier, and means for opening and closing a power supply circuit for supplying the operational amplifier Means for generating a signal for opening and closing the power supply circuit when the sound is muted; and means for holding a power supply terminal of the operational amplifier and an output bias voltage at the same level until power is supplied to the operational amplifier. Sound amplifier silencer.
る請求項１に記載の音声増幅器の消音装置2. The muffling device for an audio amplifier according to claim 1, wherein the power supplied to the operational amplifier is a single power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16917896A JP3785682B2 (en) | 1996-06-28 | 1996-06-28 | Sound amplifier silencer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16917896A JP3785682B2 (en) | 1996-06-28 | 1996-06-28 | Sound amplifier silencer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1022739A true JPH1022739A (en) | 1998-01-23 |
| JP3785682B2 JP3785682B2 (en) | 2006-06-14 |
Family
ID=15881699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16917896A Expired - Fee Related JP3785682B2 (en) | 1996-06-28 | 1996-06-28 | Sound amplifier silencer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3785682B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013110726A (en) * | 2011-10-24 | 2013-06-06 | Rohm Co Ltd | Audio signal processing circuit and electronic apparatus using the same |
-
1996
- 1996-06-28 JP JP16917896A patent/JP3785682B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013110726A (en) * | 2011-10-24 | 2013-06-06 | Rohm Co Ltd | Audio signal processing circuit and electronic apparatus using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3785682B2 (en) | 2006-06-14 |
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