JPS628673A - Detection circuit for sound multiplexing signal - Google Patents
Detection circuit for sound multiplexing signalInfo
- Publication number
- JPS628673A JPS628673A JP60148713A JP14871385A JPS628673A JP S628673 A JPS628673 A JP S628673A JP 60148713 A JP60148713 A JP 60148713A JP 14871385 A JP14871385 A JP 14871385A JP S628673 A JPS628673 A JP S628673A
- Authority
- JP
- Japan
- Prior art keywords
- output
- signal
- amplifier
- capacitor
- noise
- 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
- Television Receiver Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、米国の音声多重放送を受信可能なテレビ受信
機等において音声多重信号中の第２音声信号の有無を検
出する音声多重信号検出回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an audio multiplex signal detection circuit for detecting the presence or absence of a second audio signal in an audio multiplex signal in a television receiver or the like capable of receiving American audio multiplex broadcasts. It is something.
従来の技術
米国のテレビ音声多重放送ではステレオ放送時には、従
来の１ｓｋｌ−１ｚｉでの音音信号を（Ｌ−１−Ｒ）信
号とし、１５．７３４ ｋ Ｈｚにステレオ用パイロッ
ト信号を伝送し、３１．６ｋＨｚのキャリアを有する（
Ｌ−Ｒ）信号を用いてステレオ放送を行なう。Conventional technology In US television audio multiplex broadcasting, during stereo broadcasting, the conventional 1skl-1zi sound signal is converted into (L-1-R) signal, a stereo pilot signal is transmitted at 15.734 kHz, and 31 .6kHz carrier (
Stereo broadcasting is performed using L-R) signals.
更に、第２音声プログラム（ＳＡＰ ）が、６ｆＨをＦ
Ｍキャリアとする信号によシ伝送されている。Furthermore, the second audio program (SAP)
The signal is transmitted using the M carrier.
そこで、ＳＡＰ放送の有無は、ｔｓｆＨキャリアの有無
で判別する必要があシ、そのＳムＰキャリア（ｆ□＝７
８．６７ｋＨｚ）検出回路の従来列を第１図に示して説
明する。Therefore, it is necessary to determine the presence or absence of SAP broadcasting based on the presence or absence of the tsfH carrier.
A conventional array of 8.67 kHz) detection circuits is shown in FIG. 1 and will be described.
端子１の入力信号はｆｏ（＝５ｆｏ）’ｃキャリアとす
るＳＡＰ信号のＦＭ波で、バンドパスフィルター２で不
要信号を除去し、アンプ３で一定レベルまで増幅する。The input signal to the terminal 1 is an FM wave of the SAP signal as a fo (=5fo)'c carrier.The bandpass filter 2 removes unnecessary signals, and the amplifier 3 amplifies it to a certain level.
その信号はまず信号レベル検出回路４でピーク検波し、
電圧コンパレータ６で検波電圧が端子１１に加わる基準
電圧ｖ１ 以上であるか又は以下であるかを判定し、Ａ
ＮＤゲート６の一方の入力端へ印加する。他方、アンプ
３の出力はノイズ検出回路７へも加え、放送電波が微弱
になった時のノイズを検出する。その検出ノイズ電圧を
、コンパレータ８において端子９に加わる基準電圧ｖＯ
よシ高いか低いか判定し、その結果をＡＮＤゲート６の
他方の入力端へ入力する。The signal is first peak-detected by the signal level detection circuit 4,
The voltage comparator 6 determines whether the detected voltage is above or below the reference voltage v1 applied to the terminal 11, and
It is applied to one input terminal of the ND gate 6. On the other hand, the output of the amplifier 3 is also applied to a noise detection circuit 7 to detect noise when the broadcast radio waves become weak. The detected noise voltage is converted to the reference voltage vO applied to the terminal 9 by the comparator 8.
It is determined whether it is higher or lower, and the result is input to the other input terminal of the AND gate 6.
次に、この検出電圧と放送電波の電界強度の関係を第２
図に示し、説明する。Next, the relationship between this detected voltage and the electric field strength of the broadcast radio wave is calculated using a second method.
It is shown and explained in the figure.
強い電界強度では第２図のムの信号レベル検出電圧（キ
ャリア有り）とＢのキャリア無し時の信号レベル検出電
圧との差が明確で、雨検出電圧Ａ。At a strong electric field strength, there is a clear difference between the signal level detection voltage (with carrier) shown in Fig. 2 and the signal level detection voltage shown in Fig. 2 (without carrier), which is the rain detection voltage A.
Ｂの間に設定されたコンパレータ６の基準電圧ｖ１に対
する高低でＳＡＰキャリアの有無を明確に判別できる。The presence or absence of the SAP carrier can be clearly determined based on the level of the comparator 6 set between B and the reference voltage v1.
しかし第２図のレベルＥよシ左側は電界が弱くノイズが
大きくなると、ＳＡＰキャリアが無い時でも信号レベル
検出電圧Ｂが端子１１の基準電圧ｖ１よシも大きくなる
。これは検出誤りとなる。そこで、第１図のノイズ検出
回路７を働かせる。すなわち、ノイズレベルが高くなる
と（ノイズ検出電圧Ｃが基′１電圧ｖｏを越えると）、
コンパレータ８の出力をローレベルとして、ＡＮＤゲー
ト６の出力をローレベルにさせ、キャリア判別出力の誤
動作を防ぐ。However, if the electric field is weak on the left side of level E in FIG. 2 and the noise is large, the signal level detection voltage B becomes larger than the reference voltage v1 of the terminal 11 even when there is no SAP carrier. This results in a detection error. Therefore, the noise detection circuit 7 shown in FIG. 1 is activated. That is, when the noise level becomes high (when the noise detection voltage C exceeds the base voltage vo),
The output of the comparator 8 is set to a low level, and the output of the AND gate 6 is set to a low level to prevent malfunction of the carrier discrimination output.
ここで、コンパレーター５．８の基準電圧ｖ１及びｖｏ
を高くしてゆくとよシ弱い電界強度まで検出できるが
、キャリア信号レベル検出型圧入と基準電圧ｖ１との差
が小さくなり、放送局等でＳＡＰキャリアが小さくなる
と検出できず、キャリア縮小裕度がなくなる問題が発生
する。Here, the reference voltage v1 and vo of the comparator 5.8
By increasing the value, it is possible to detect even weaker electric field strengths, but the difference between the carrier signal level detection type press-in and the reference voltage v1 becomes smaller, and if the SAP carrier becomes smaller at a broadcasting station, etc., it cannot be detected, and the carrier reduction margin increases. A problem occurs where the data disappears.
発明が解決しようとする問題点
上記のごとく、従来はＳＡＰの検出がテレビ電波の弱電
界時のノイズにより誤動作しゃすい。それを補おうとす
ると小さいＳＡＰ信号が検出できなくなる。本発明は上
記を解決するものである。Problems to be Solved by the Invention As mentioned above, conventional SAP detection tends to malfunction due to noise in the weak electric field of television radio waves. If an attempt is made to compensate for this, small SAP signals cannot be detected. The present invention solves the above problems.
問題点を解決するための手段
上記問題点を解決するため、本発明の信号検出回路は、
ＳＡＰキャリア信号をアンプし、その出力から波形比較
器で正と負のレベルを検出し、正又は負の期間にコンデ
ンサーに充電又は放電を行なう回路と、その出力を基準
レベルと比較する比較回路と、その出力を積分する積分
回路とを設け、この積分器出力が規定レベルに達しだが
否かで信号検出を行なうものである。Means for Solving the Problems In order to solve the above problems, the signal detection circuit of the present invention includes:
A circuit that amplifies the SAP carrier signal, uses a waveform comparator to detect positive and negative levels from its output, and charges or discharges a capacitor during the positive or negative period, and a comparison circuit that compares the output with a reference level. , and an integrating circuit that integrates the output thereof, and detects a signal depending on whether the output of the integrator reaches a specified level.
作用
本発明によれば、ＳＡＰキャリア信号の有無をノイズの
影響を受けずに、かつキャリアレベルの大小にも左右さ
れにくく正確に検出できる。According to the present invention, the presence or absence of an SAP carrier signal can be accurately detected without being affected by noise and less influenced by the magnitude of the carrier level.
実施例
以下、本発明の一実施例について、図面に基づいて説明
する。EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings.
第１図は本発明の一実施例における信号検出回路図で、
信号入力端子１、バンドパスフィルタ２、アンプ３を経
てアンプ出力を差動アンプの一人力であるトランジスタ
１５のベースに加え、個入力抵抗２０を介してはバイア
ス人に接続する。差動アンプの一方の出力はカレントミ
ラー回路であるトランジスター１１．１２、そして１７
．１９で結合しコンデンサー２０に接続する。更に他方
の出力は又カレントミラー回路であるトランジスタ１３
及び１４で結合し、この回路もコンデンサー２０に接続
する。FIG. 1 is a signal detection circuit diagram in one embodiment of the present invention.
The amplifier output is connected through a signal input terminal 1, a bandpass filter 2, and an amplifier 3 to the base of a transistor 15, which is the single power of the differential amplifier, and is connected to a bias voltage via an input resistor 20. One output of the differential amplifier is a current mirror circuit, transistors 11, 12, and 17.
．． 19 and connected to a capacitor 20. Furthermore, the other output is a transistor 13 which is also a current mirror circuit.
and 14, and this circuit is also connected to the capacitor 20.
その結果、アンプ３の出力が負の時はコンデンサー２０
へ充電々流１（Ａ）が流れ端子電圧は上昇する（第２図
のａ、ｂ）。逆にアンプ出力が正の時はコンデンサー２
０は放電々流２ｉ（Ａ）が流れ、端子電圧は降下する。As a result, when the output of amplifier 3 is negative, capacitor 20
A charging current 1 (A) flows to the terminal, and the terminal voltage increases (a, b in Fig. 2). Conversely, when the amplifier output is positive, capacitor 2
0, a discharge current 2i (A) flows and the terminal voltage drops.
ここで、入力信号１が正常な時はアンプ３の出力はデュ
テー５０％である（第２図左Ｐ部）ため、コンデンサー
２３への充電は一定値を超えない。Here, when the input signal 1 is normal, the output of the amplifier 3 has a duty of 50% (part P on the left in FIG. 2), so the charge to the capacitor 23 does not exceed a certain value.
ところが、第２図右Ｑ部の如く信号にノイズが乗るとそ
のチューティーは６０チでなく、例えば正側３０％負側
８ｏ％の様な事がしばしば発生する。その結果、コンデ
ンサ２３への充電々流量が放電々量を超えるとその端子
電圧は上昇する。第２図すのＲ点、８点の電圧はノイズ
によってキャリア信号が乱れたために発生する。However, when noise is added to the signal as shown in the right part Q of FIG. 2, the tutee is not 60%, but often occurs, for example, 30% on the positive side and 80% on the negative side. As a result, when the amount of charge to the capacitor 23 exceeds the amount of discharge, its terminal voltage increases. The voltage at point R and point 8 in Figure 2 is generated because the carrier signal is disturbed by noise.
そこで、このノイズによるピーク電圧を比較電圧３１と
コンパレータ２５で取シ出し、更にその出力をコンデン
サー２７で積分すると、第２図Ｃの電圧が得られる。こ
れをコンパレータ８で波形整形すると第２図ｄの検出出
力が得られる。Therefore, by extracting the peak voltage due to this noise using the comparison voltage 31 and the comparator 25, and further integrating the output using the capacitor 27, the voltage shown in FIG. 2C is obtained. When this is waveform-shaped by the comparator 8, the detection output shown in FIG. 2d is obtained.
その結果、従来はノイズに対し信号検出が不安定であっ
たのに対し逆にノイズを検出する事で検出精度が向上す
るつ又アンプ３の増幅度を高くすれば小さい信号も検出
可能である。As a result, whereas in the past, signal detection was unstable due to noise, detection accuracy is improved by detecting noise, and small signals can also be detected by increasing the amplification degree of amplifier 3. .
発明の詳細
な説明した様に、本発明によればＳＡＰキャリア信号の
有無を信号の大小に関係なく検出でき、ノイズの量の大
小に対して安定に検出可能となる信号検出回路を得るこ
とができる。As described in detail, according to the present invention, it is possible to obtain a signal detection circuit that can detect the presence or absence of an SAP carrier signal regardless of the magnitude of the signal, and can stably detect the presence or absence of an SAP carrier signal regardless of the magnitude of the noise. can.
第１図は本発明の一実施例における音声多重信号検出回
路の回路図、第２図はその動作説明のだめの波形図、第
３図は従来例の音声多重信号検出回路の回路図、第４図
はその動作説明のための波形図である。
１１．１２，１３，１４，１５，１６，１７゜１８．１
９・・・・・・トランジスタ、２０，２１，２２゜２４
．２６・・・・・・抵抗、８．２６・・・・・・コンパ
レータ、２３．２７・・・・・・コンデンサ、１８・・
・・・・定電流源０代理人の氏名 弁理士 中 尾 敏
男 ほか１名第１図FIG. 1 is a circuit diagram of an audio multiplex signal detection circuit according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining its operation, FIG. 3 is a circuit diagram of a conventional audio multiplex signal detection circuit, and FIG. The figure is a waveform diagram for explaining the operation. 11.12,13,14,15,16,17゜18.1
9...Transistor, 20, 21, 22゜24
．． 26...Resistor, 8.26...Comparator, 23.27...Capacitor, 18...
...Name of constant current source 0 agent Patent attorney Toshio Nakao and one other person Figure 1
Claims (1)
るアンプと、このアンプを通過した信号の正又は負の期
間にコンデンサーに充電又は放電を行なう回路と、その
コンデンサーの出力を基準レベルと比較する比較回路と
、その比較出力を積分する積分器と、この積分器の出力
が規定レベルに達したか否かを判別して第２音声信号の
信号検出を行なう判別回路とを備えたことを特徴とする
音声多重信号検出回路。An amplifier that amplifies the carrier signal of the second audio signal in the audio multiplex signal, a circuit that charges or discharges a capacitor during the positive or negative period of the signal that has passed through this amplifier, and a comparison of the output of the capacitor with a reference level. A comparison circuit that integrates the comparison output, an integrator that integrates the comparison output, and a determination circuit that determines whether the output of the integrator has reached a specified level and detects the second audio signal. Characteristic audio multiplex signal detection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60148713A JPH0815327B2 (en) | 1985-07-05 | 1985-07-05 | Voice multiple signal detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60148713A JPH0815327B2 (en) | 1985-07-05 | 1985-07-05 | Voice multiple signal detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS628673A true JPS628673A (en) | 1987-01-16 |
| JPH0815327B2 JPH0815327B2 (en) | 1996-02-14 |
Family
ID=15458929
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60148713A Expired - Fee Related JPH0815327B2 (en) | 1985-07-05 | 1985-07-05 | Voice multiple signal detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0815327B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1118805A2 (en) | 2000-01-20 | 2001-07-25 | Teikoku Piston Ring Co., LTd. | Combined oil ring |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5844643U (en) * | 1981-09-17 | 1983-03-25 | 日本電気ホームエレクトロニクス株式会社 | Dettman timer |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5844643B2 (en) * | 1975-01-22 | 1983-10-04 | 日本曹達株式会社 | Shinkinadjiyosouzai |
-
1985
- 1985-07-05 JP JP60148713A patent/JPH0815327B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5844643U (en) * | 1981-09-17 | 1983-03-25 | 日本電気ホームエレクトロニクス株式会社 | Dettman timer |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1118805A2 (en) | 2000-01-20 | 2001-07-25 | Teikoku Piston Ring Co., LTd. | Combined oil ring |
| US6454271B2 (en) | 2000-01-20 | 2002-09-24 | Teikoku Piston Ring Co., Ltd. | Combined oil ring |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0815327B2 (en) | 1996-02-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |