JPH0427207A - Audio signal processing circuit - Google Patents
Audio signal processing circuitInfo
- Publication number
- JPH0427207A JPH0427207A JP2133522A JP13352290A JPH0427207A JP H0427207 A JPH0427207 A JP H0427207A JP 2133522 A JP2133522 A JP 2133522A JP 13352290 A JP13352290 A JP 13352290A JP H0427207 A JPH0427207 A JP H0427207A
- Authority
- JP
- Japan
- Prior art keywords
- input
- level
- circuit
- signal
- audio signal
- 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
Links
- 230000005236 sound signal Effects 0.000 title claims abstract description 27
- 238000001514 detection method Methods 0.000 claims description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Landscapes
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Control Of Amplification And Gain Control (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、オーディオ信号のゲインを自動調整するオー
ディオ信号処理回路に関するもので、例えばテープレコ
ーダのＡＬＣ（ＡＧＣ）回路等に適用される。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an audio signal processing circuit that automatically adjusts the gain of an audio signal, and is applied to, for example, an ALC (AGC) circuit of a tape recorder.
〈発明の概要〉
本発明はテープレコーダのオーディオ信号のＡＬＣ（Ａ
ｕｔｏｍａｔｉｃ Ｌｅｖｅｌ Ｃｏｎｔｒｏｌ
）処理を行なうオーディオ信号処理回路において入力オ
ーディオ信号の周波数に応じてＡＬＣ処理をする周波数
を可変し処理を施すようにしたものである。<Summary of the Invention> The present invention provides ALC (ALC) for audio signals of tape recorders.
Automatic Level Control
) The processing is performed by varying the frequency at which the ALC processing is performed in accordance with the frequency of the input audio signal in the audio signal processing circuit that performs the processing.
〈従来の技術〉
以下、従来のテープレコーダのオーディオ信号処理回路
について説明する。第２図は従来のオーディオ信号処理
回路の構成を示すブロック図である。このブロック図に
おいて、オーディオ信号処理回路の入力端子１１にオー
ディオ信号が入力されると、ピークレベル検出回路１２
がレベル検出をし、過大入力を検出すれば、整流回路１
８により直流信号に変換され、その信号の大小により制
御回路１４がアッテネータ１５を可変させ、入力端子１
１の信号を過大入力のときは減衰させるＡＬＣ処理をす
るようになっている。１６は出力端子である。<Prior Art> A conventional audio signal processing circuit for a tape recorder will be described below. FIG. 2 is a block diagram showing the configuration of a conventional audio signal processing circuit. In this block diagram, when an audio signal is input to the input terminal 11 of the audio signal processing circuit, the peak level detection circuit 12
detects the level, and if excessive input is detected, the rectifier circuit 1
8 converts it into a DC signal, and the control circuit 14 changes the attenuator 15 depending on the magnitude of the signal, and the input terminal 1
When the signal of 1 is excessively input, ALC processing is performed to attenuate it. 16 is an output terminal.
〈発明が解決しようとする課題〉
オーディオ信号処理回路において、レベルの高い信号が
入力されるとＡＬＣがかかり、その信号のゲインをＡＴ
Ｔにより減衰させるが、これだと可聴範囲外の大信号（
例えばバイアス発振）が入カされてもＡＬＣがかかって
しまう。<Problem to be solved by the invention> In an audio signal processing circuit, when a high level signal is input, ALC is applied and the gain of that signal is changed to AT.
It is attenuated by T, but with this, large signals outside the audible range (
For example, even if bias oscillation is input, ALC is applied.
く課題を解決するための手段〉
本発明に係るオーディオ信号処理回路は、上述の問題点
を解決するため、入力信号のレベルを検出するレベル検
出回路と、その出力を直流信号に整流する整流回路と、
信号のレベル調整を行なうアッテネータと、その周波数
を決定する共振回路を備えて成ることを特徴とするオー
ディオ信号処理回路。Means for Solving the Problems> In order to solve the above problems, an audio signal processing circuit according to the present invention includes a level detection circuit that detects the level of an input signal, and a rectifier circuit that rectifies the output into a DC signal. and,
An audio signal processing circuit comprising an attenuator that adjusts the level of a signal and a resonant circuit that determines its frequency.
く作 用〉
本発明に係るオーディオ信号処理回路は、入力オーディ
オ信号のレベル検出をし、過大入力に対しそのレベルを
アッテネータにより自動調整をし、なおかつレベル調整
を行なう周波数成分を入力信号より検出し、過大入力周
波数成分のみレベル調整を行なう。Function> The audio signal processing circuit according to the present invention detects the level of an input audio signal, automatically adjusts the level using an attenuator in case of excessive input, and detects the frequency component for level adjustment from the input signal. , the level is adjusted only for excessive input frequency components.
〈実施例〉
以下、本発明に係るオーディオ信号処理回路の実施例に
ついて図面に従い詳細に説明する。<Embodiments> Hereinafter, embodiments of the audio signal processing circuit according to the present invention will be described in detail with reference to the drawings.
第１図に示す実施例は、本発明をテープレコーダの信号
処理系に適用したものである。この実施例においてオー
ディオ信号は入力端子２１からアンプ２２に入力される
。入力信号の一部はピークレベル検出回路２８へ入力し
、信号レベルを検出する。その出力信号は整流回路２４
へ入力され直流信号へと変換される。その出力はアッテ
ネータ制御回路２５へと入力されアッテネータ２６を制
御する。The embodiment shown in FIG. 1 is an application of the present invention to a signal processing system of a tape recorder. In this embodiment, an audio signal is input to an amplifier 22 from an input terminal 21. A portion of the input signal is input to a peak level detection circuit 28 to detect the signal level. The output signal is the rectifier circuit 24
is input into the DC signal and converted into a DC signal. The output is input to an attenuator control circuit 25 to control an attenuator 26.
又、入力信号の一部はピーク周波数検出回路２７へと入
力され周波数を検出し、共振回路制御回路２８へと入力
され共振回路２９を制御する。Further, a part of the input signal is input to the peak frequency detection circuit 27 to detect the frequency, and is input to the resonance circuit control circuit 28 to control the resonance circuit 29.
上記構成により入力オーディオ信号はアッテネータによ
り、レベルコントロー／Ｉ／（ＡＬＣ）処理をされるか
共振回路で周波数選択をすることによりＡＩ、Ｃ処理を
する帯域過大入力のみに限定する。With the above configuration, input audio signals are subjected to level control/I/(ALC) processing using an attenuator, or frequency selection is performed using a resonant circuit to limit input audio signals to only excessive band inputs that are subjected to AI and C processing.
２０は出力端子である。20 is an output terminal.
〈発明の効果〉
本発明に係るオーディオ信号処理回路は、入力オーディ
オ信号のレベル検出をし、過大入力に対しそのレベルを
アッテネータにより自動調整をし、なおかつレベル調整
を行なう周波数成分を入力信号より検出し、過大入力周
波数成分のみレベル調整を行なうので、過大入力に対し
周波数全域のゲインを下げるのではなく、過大入力周波
数成分のみをゲインを下げることができる。<Effects of the Invention> The audio signal processing circuit according to the present invention detects the level of an input audio signal, automatically adjusts the level using an attenuator in case of excessive input, and detects a frequency component for level adjustment from the input signal. However, since the level is adjusted only for the excessively input frequency component, it is possible to reduce the gain only for the excessively input frequency component, instead of reducing the gain for the entire frequency range for the excessively input frequency component.
第１図は本発明に係るオーディオ信号処理回路の実施例
を示すブロック図である。第２図は従来例のオーディオ
信号処理回路のブロック図である。
２３゛°ピ一クレベル検出回路、 ２４・・・整流回路
、 ２５・・・アッテネータ制御回路、 ２６・・・
アッテネータ、 ２７・・・ピーク周波数検出回路、２
８・・・共振回路制御回路、 ２９・・・共振回路。FIG. 1 is a block diagram showing an embodiment of an audio signal processing circuit according to the present invention. FIG. 2 is a block diagram of a conventional audio signal processing circuit. 23° peak level detection circuit, 24... Rectifier circuit, 25... Attenuator control circuit, 26...
Attenuator, 27...Peak frequency detection circuit, 2
8... Resonant circuit control circuit, 29... Resonant circuit.
Claims (1)
の出力を直流信号に整流する整流回路と、信号のレベル
調整を行なうアッテネーターと、その周波数を決定する
共振回路を備えてなることを特徴とするオーディオ信号
処理回路。1. It is characterized by being equipped with a level detection circuit that detects the level of an input signal, a rectifier circuit that rectifies the output into a DC signal, an attenuator that adjusts the level of the signal, and a resonant circuit that determines its frequency. audio signal processing circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2133522A JPH0427207A (en) | 1990-05-22 | 1990-05-22 | Audio signal processing circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2133522A JPH0427207A (en) | 1990-05-22 | 1990-05-22 | Audio signal processing circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0427207A true JPH0427207A (en) | 1992-01-30 |
Family
ID=15106758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2133522A Pending JPH0427207A (en) | 1990-05-22 | 1990-05-22 | Audio signal processing circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0427207A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102195581A (en) * | 2010-03-18 | 2011-09-21 | 承景科技股份有限公司 | Method for adjusting volume of digital audio signal |
-
1990
- 1990-05-22 JP JP2133522A patent/JPH0427207A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102195581A (en) * | 2010-03-18 | 2011-09-21 | 承景科技股份有限公司 | Method for adjusting volume of digital audio signal |
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