JPS6338905B2 - - Google Patents

Info

Publication number
JPS6338905B2
JPS6338905B2 JP20158582A JP20158582A JPS6338905B2 JP S6338905 B2 JPS6338905 B2 JP S6338905B2 JP 20158582 A JP20158582 A JP 20158582A JP 20158582 A JP20158582 A JP 20158582A JP S6338905 B2 JPS6338905 B2 JP S6338905B2
Authority
JP
Japan
Prior art keywords
vac
output
comparator
circuit
level
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.)
Expired
Application number
JP20158582A
Other languages
Japanese (ja)
Other versions
JPS5991765A (en
Inventor
Eiji Kawade
Hideaki Takahashi
Yoshuki 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.)
Tamura Electric Works Ltd
Original Assignee
Tamura Electric Works 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 Tamura Electric Works Ltd filed Critical Tamura Electric Works Ltd
Priority to JP20158582A priority Critical patent/JPS5991765A/en
Publication of JPS5991765A publication Critical patent/JPS5991765A/en
Publication of JPS6338905B2 publication Critical patent/JPS6338905B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/64—Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
    • H04M1/65—Recording arrangements for recording a message from the calling party
    • H04M1/654—Telephone line monitoring circuits therefor, e.g. ring detectors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/82—Line monitoring circuits for call progress or status discrimination

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)

Description

【発明の詳細な説明】 本発明は、留守番電話装置におけるVAC検出
回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a VAC detection circuit in an answering machine.

留守番電話装置は、通常その最低限の機能とし
て、一定の応答専用メツセージを吹き込んだ録音
テープをセツトしておき、着信があつた時にこの
テープを再生して発呼者側に上記メツセージを聴
かせる自動応答機能を有している。ところでこの
場合、何らかの手違いもしくは事故のために上記
応答専用メツセージが記録されているべきテープ
が無音であつたり切断している等の事情がある場
合、発呼者側の無用の出費を避ける等の観点から
テープを止め、着信状態のラインを強制的に開放
して以後の着信も受け付けないようにするように
しており、このような無音状態を検出するための
回路をVAC検出回路と称している。同様のこと
はライン側から入力される音声信号に関しても考
えられ、一定時間無音状態が続いた場合（これに
は発呼者が故意に発声しない場合と既に発呼者が
フツクオンされたにもかかわらずクリツク音を検
出し損ねて装置が復旧しないような場合とがあ
る）、何らかの事故と判断してライン開放する。
また、発呼者側のフツクオン後に無音ではなく交
換機側から連続音を送出するシステムもあるが、
この場合はクリツク音を検出し損ねて装置が復旧
しない場合の対策として一定時間連続音が続いた
場合にライン開放する。そこで、応答専用メツセ
ージについての上記制御をOGMVAC（OGMは
Out Goign Message）、ライン側からの音声信号
についての制御をラインVAC、無音についての
制御を無音VAC、連続音についての制御を連続
音VACとして区別する。 The minimum function of an answering machine is usually to set up a recording tape with a certain response-only message, and when a call is received, this tape is played back so that the caller can hear the message. It has an automatic response function. By the way, in this case, if there is a situation where the tape on which the above-mentioned response-only message is supposed to be recorded is silent or cut off due to some kind of mistake or accident, there is a need to avoid unnecessary expense on the part of the caller. From this point of view, the tape is stopped and the incoming call line is forcibly opened to prevent further calls from being accepted.The circuit for detecting this silent state is called the VAC detection circuit. . The same thing can be said about the audio signal input from the line side, and if there is silence for a certain period of time (this includes cases where the caller intentionally does not speak, and cases where the caller has already been turned on). (There are cases where the equipment does not recover due to a failure to detect the clicking sound), it is determined that this is some kind of accident and the line is opened.
There are also systems in which the exchange sends a continuous tone instead of silence after the caller turns on the caller.
In this case, as a measure against the failure to detect the clicking sound and the equipment not being restored, the line is opened if the sound continues for a certain period of time. Therefore, the above control for response-only messages is changed to OGMVAC (OGM is
Out Goign Message), control for audio signals from the line side is called line VAC, control for silence is called silent VAC, and control for continuous sound is called continuous sound VAC.

ところで、上記VAC検出回路は、増幅器を経
た音声信号を比較器に入力し、当該比較器の出力
によつて、無音もしくは連続音の継続を検出する
構成をとつているが、その場合、VAC検出レベ
ル、すなわちどの程度で無音もしくは発呼者側の
フツクオン後の連続音と判断するかの音声信号の
入力レベルは、同じ無音VACに関しても一般に
OGMVACとラインVACの場合とで異なるレベ
ルに設定されるが、ラインVACの無音VACと連
続VACについては当然に異ならせる必要がある。
すなわち、この両者が同一レベルであるとすれ
ば、無音でなければ直ちに上記連続音とされ、通
常の音声信号でも一定時間連続すれば直ちに強制
切断ということになる。 By the way, the VAC detection circuit described above is configured to input the audio signal that has passed through the amplifier to the comparator and detect silence or continuous sound based on the output of the comparator. The level, that is, the input level of the audio signal at which it is determined to be silence or continuous sound after the caller's call-on is generally the same for the same silent VAC.
Different levels are set for OGMVAC and line VAC, but it is naturally necessary to set them to different levels for line VAC's silent VAC and continuous VAC.
That is, assuming that both are at the same level, if there is no silence, it will immediately be treated as the continuous sound, and even if it is a normal audio signal, if it continues for a certain period of time, it will immediately be forcibly cut off.

本発明はこのような事情に鑑みてなされたもの
で、その目的は、ライン側における無音VACと
連続VACの検出をひとつの検出回路で行なえる
VAC検出回路を提供することにある。 The present invention was made in view of these circumstances, and its purpose is to detect silent VAC and continuous VAC on the line side with a single detection circuit.
The purpose of the present invention is to provide a VAC detection circuit.

このような目的を達成するために、本発明は、
比較器の出力段と当該比較器の基準電圧端子間に
出力の一部を帰還するインピーダンス素子を接続
し、当該出力がある時に比較器の基準レベルを上
昇させるものである。 In order to achieve such an objective, the present invention
An impedance element that feeds back part of the output is connected between the output stage of the comparator and the reference voltage terminal of the comparator, and the reference level of the comparator is raised when the output is present.

以下、実施例を用いて本発明を詳細に説明す
る。 Hereinafter, the present invention will be explained in detail using Examples.

図は、本発明の一実施例を示す回路図である。
図において、再生ヘツドから得られる応答専用メ
ツセージ再生信号（以下OGMと略記する）も、
ライン側からの音声信号も、同様に増幅器１１を
経て比較器１２に入力し、基準レベルより大きけ
れば出力が送出される。この比較器の出力は積分
回路１３および波形整形回路１４を経て、パルス
状の論理出力として論理回路１５からCPUに送
出される。そこでCPUはこの出力の論理が一定
時間、例えばラインVACの場合なら８秒間、
OGMVACの場合なら３秒間「０」であつた時、
およびラインVACの場合で上記論理が８秒間
「１」であつた時に事故と判断してVACをかけ
る。 The figure is a circuit diagram showing one embodiment of the present invention.
In the figure, the response-only message playback signal (hereinafter abbreviated as OGM) obtained from the playback head is also
The audio signal from the line side is similarly input to the comparator 12 via the amplifier 11, and if it is greater than the reference level, the output is sent out. The output of this comparator passes through an integrating circuit 13 and a waveform shaping circuit 14, and is sent from a logic circuit 15 to the CPU as a pulsed logic output. Therefore, the CPU uses this output logic for a certain period of time, for example 8 seconds in the case of line VAC.
In the case of OGMVAC, when it is "0" for 3 seconds,
In the case of line VAC, when the above logic is "1" for 8 seconds, it is determined that an accident has occurred and VAC is applied.

ここで、上記増幅器１１の利得は、抵抗器R1
および可変抵抗器R2の抵抗値の和と抵抗器R3の
抵抗値との比で決まるが、本実施例では可変抵抗
器R2に並列にトランジスタTr1が接続してある
が、これは、無音VACについて、OGMVACと
ラインVACの検出をひとつの回路で行なえるよ
うにするためである。すなわち、応答専用メツセ
ージ録音テープを回してOGMをラインに送出す
る時、CPUから同一タイミングで“Ｈ”の制御
信号を送出し、このトランジスタTr1を導通させ
る。この結果、上記利得は抵抗器R1と抵抗器R3
との比で決まることとなり、その値はライン
VACの検出の場合に比較して大きくなる。した
がつて、比較器１２の基準レベルは同一としたま
まで、ラインVACの検出レベルをOGMVACの
検出レベルより高くすることができる。このよう
にラインVACの検出レベルを高くしたのは、
OGMの方がライン側からの信号に比較してＳ／
Ｎ比が良いためで、ラインVACの場合に雑音を
正常な音声信号の入力があるものとして検出する
ことを避けるためである。両検出レベルの差を何
dBにとるかは、可変抵抗器R2によつて調整する。 Here, the gain of the amplifier 11 is determined by the resistor R 1
It is determined by the ratio of the sum of the resistance values of the variable resistor R 2 and the resistance value of the resistor R 3. In this embodiment, the transistor Tr 1 is connected in parallel to the variable resistor R 2 ; This is to enable detection of OGMVAC and line VAC for silent VAC using one circuit. That is, when the response-only message recording tape is rotated and the OGM is sent out to the line, the CPU sends out an "H" control signal at the same timing to turn on the transistor Tr1 . As a result, the above gain is equal to resistor R 1 and resistor R 3
The value is determined by the ratio of the line
This is larger compared to the case of VAC detection. Therefore, the detection level of line VAC can be made higher than the detection level of OGMVAC while the reference level of comparator 12 remains the same. The reason for increasing the line VAC detection level in this way is
Compared to the signal from the line side, OGM is S/
This is because the N ratio is good, and in the case of line VAC, to avoid detecting noise as normal audio signal input. What is the difference between both detection levels?
The value in dB is adjusted by variable resistor R2 .

このようにして無音VACについて、
OGMVACとラインVACの検出を同一回路で行
うことができるが、ここで、ラインVACの場合、
上述した検出レベルが固定されていると、連続音
VACについては不都合が生じる。すなわち、
CPUは論理回路１５の出力が８秒間連続して
「１」であれば発呼者側のオンフツクがあつたも
のと判断してVACをかけるのであるが、その検
出レベルが無音VACの検出レベルと同一である
とすれば、無音でなければすなわち「１」で、正
常な音声信号の入力があつた場合には常に「１」
となり、それが音楽等でたまたま８秒間連続した
場合には直ちにライン開放ということになりかね
ない。そこで、発呼者側のフツクオン後の連続音
は、通常の音声信号に比較して高レベルであるこ
とに着目し、論理回路１５の出力端子と比較器１
２の基準電圧端子との間に抵抗器R4を接続し、
上記出力の一部を帰還し、論理回路１５の出力が
「１」、すなわち“Ｈ”の出力がある場合、上記帰
還によつて比較回路１２の基準電圧を上昇させる
ようにしている。この場合、入力の音声信号がな
い無音時には、比較回路１２の基準電圧は可変抵
抗器R5の調整により設定された所定値の無音
VAC検出レベルにあり、比較回路１２は無音入
力によりその出力は「０」になり、論理回路１５
の出力も「０」となる。この出力「０」が一定時
間持続すれば無音VAC検出信号となる。 In this way, regarding silent VAC,
OGMVAC and line VAC can be detected using the same circuit, but in the case of line VAC,
If the detection level described above is fixed, continuous sound
There are some inconveniences regarding VAC. That is,
If the output of the logic circuit 15 is "1" for 8 consecutive seconds, the CPU determines that there is an on-hook from the caller and applies VAC, but the detection level is the same as the silent VAC detection level. If they are the same, it will be "1" unless there is no sound, and it will always be "1" if a normal audio signal is input.
If this happens to continue for 8 seconds due to music, etc., the line may be immediately opened. Therefore, we focused on the fact that the continuous sound after the caller's caller was at a higher level than a normal voice signal, and connected the output terminal of the logic circuit 15 and the comparator 1.
Connect resistor R 4 between the reference voltage terminal of 2 and
A part of the output is fed back, and when the output of the logic circuit 15 is "1", that is, "H", the reference voltage of the comparator circuit 12 is increased by the feedback. In this case, when there is no input audio signal and there is no sound, the reference voltage of the comparator circuit 12 is set to a predetermined value of silence, which is set by adjusting the variable resistor R5 .
is at the VAC detection level, and the comparator circuit 12 outputs "0" due to silent input, and the logic circuit 15
The output of is also "0". If this output "0" continues for a certain period of time, it becomes a silent VAC detection signal.

次に、音声入力がある場合には、比較回路１２
の入力はレベルは上記基準電圧である無音VAC
検出レベルより高くなり、比較回路１２の出力は
「１」になり、論理回路１５の出力も「１」にな
る。このとき、上記基準電圧端子と接地端子間に
コンデンサC1が接続してあるため、上記基準電
圧はその時定数にしたがつて緩やかに上昇して行
く。やがて、当該基準電圧が入力の音声信号のレ
ベルを越えると、論理回路１５からは「１」の出
力が送出されなくなるため上記基準電圧はやはり
コンデンサの作用によつて緩やかに下降して来
る。そこで再び入力の音声信号のレベルが基準電
圧レベルを越えると基準電圧は再度上昇を開始す
る。このようにして無音VACの検出レベルより
は大きく、かつ連続音VACの検出レベルよりは
小さい正常な音声信号の入力がある場合には、比
較器の基準電圧の上昇・下降、および論理回路１
５の出力のオン・オフが繰り返される。そして実
際に発呼者側のフツクオン後の連続音が入力した
場合には、連続音の入力レベルが基準電圧より大
きくなるために比較回路１２の出力は「１」にな
り、論理回路１５の出力も「１」になる。この出
力「１」が一定時間持続すれば連続音VAC検出
信号となる。なお、このとき比較回路１２の基準
電圧は、可変抵抗器R5によつて調整される無音
VACの検出レベルに対応した基準電圧よりも高
い、連続音VACの検出レベルに対応した基準電
圧に固定される。この場合両検出レベルの差は、
予め抵抗器R4の値を規定して帰還量を適当な値
に設定しておくことにより所望の値に設定でき
る。 Next, if there is an audio input, the comparison circuit 12
The input is silent VAC whose level is the reference voltage above
It becomes higher than the detection level, the output of the comparison circuit 12 becomes "1", and the output of the logic circuit 15 also becomes "1". At this time, since the capacitor C1 is connected between the reference voltage terminal and the ground terminal, the reference voltage gradually increases according to its time constant. Eventually, when the reference voltage exceeds the level of the input audio signal, the logic circuit 15 no longer outputs an output of "1", so the reference voltage gradually falls due to the action of the capacitor. Then, when the level of the input audio signal exceeds the reference voltage level again, the reference voltage starts rising again. In this way, when there is a normal audio signal input that is higher than the detection level of silent VAC and lower than the detection level of continuous sound VAC, the reference voltage of the comparator rises and falls, and the logic circuit 1
The output of No. 5 is repeatedly turned on and off. When a continuous tone is actually input after the caller's hook-on, the input level of the continuous tone becomes higher than the reference voltage, so the output of the comparator circuit 12 becomes "1", and the output of the logic circuit 15 becomes "1". also becomes "1". If this output "1" continues for a certain period of time, it becomes a continuous sound VAC detection signal. Note that at this time, the reference voltage of the comparison circuit 12 is a silent voltage adjusted by the variable resistor R5 .
It is fixed at a reference voltage corresponding to the detection level of the continuous sound VAC, which is higher than the reference voltage corresponding to the detection level of the VAC. In this case, the difference between both detection levels is
A desired value can be set by defining the value of the resistor R4 in advance and setting the feedback amount to an appropriate value.

なお、本実施例ではライン側からの音声信号
は、図上省略したがAGC回路を経てこのVAC検
出回路に入力するように構成してありこれにより
音声信号に比較的大きな連続ノイズが重畳し、音
声信号が断の時にも上記ノイズが連続してそのた
めに発呼者側のフツクオン後の連続音として誤検
出されることを防ぐ効果を高めることができる。
すなわち、AGC回路によつて音声信号のレベル
が抑圧される場合、ノイズは通常音声信号よりも
小さいため、再び低レベルに抑圧される。音声信
号が途切れると、AGC回路による抑圧も解除さ
れて上記ノイズのレベルは上昇して来るが、引続
き入力する音声信号のレベルによつて再びAGC
回路による抑圧がかかる。したがつて音声信号の
入力が正常に続く限り、上記ノイズは有効に抑圧
され続ける。 Note that in this embodiment, the audio signal from the line side is configured to be input to this VAC detection circuit via an AGC circuit, although it is omitted in the diagram, and as a result, relatively large continuous noise is superimposed on the audio signal. Even when the voice signal is cut off, the noise continues, thereby increasing the effect of preventing erroneous detection as a continuous sound after the caller's call is turned on.
That is, when the level of the audio signal is suppressed by the AGC circuit, since the noise is normally smaller than the audio signal, it is suppressed to a low level again. When the audio signal is interrupted, the suppression by the AGC circuit is also released and the level of the above-mentioned noise rises, but depending on the level of the audio signal that continues to be input, the AGC circuit is activated again.
Suppression is applied by the circuit. Therefore, as long as the input of audio signals continues normally, the above-mentioned noise continues to be effectively suppressed.

以上説明したように、本発明よれば、比較器の
出力段と当該比較器の基準電圧端子間に出力の一
部を帰還するインピーダンス素子を接続し、当該
出力がある時に比較器の基準レベルを上昇させる
ようにしたことにより、ライン側にける無音
VACと連続VACの検出をひとつの検出回路で有
効に行なうことが可能となつた。 As explained above, according to the present invention, an impedance element that feeds back part of the output is connected between the output stage of the comparator and the reference voltage terminal of the comparator, and the reference level of the comparator is adjusted when the output is present. By raising it up, there is no sound on the line side.
It has become possible to effectively detect VAC and continuous VAC with a single detection circuit.

【図面の簡単な説明】[Brief explanation of drawings]

図は本発明の一実施例を示す回路図である。 １２……比較器、R4……出力帰還用の抵抗器。 The figure is a circuit diagram showing one embodiment of the present invention. 12... Comparator, R 4 ... Resistor for output feedback.

Claims (1)

【特許請求の範囲】 １ 発呼者側からの音声信号を比較器に入力し、
当該比較器の出力の有無によつて無音および発呼
者側のフツクオン後の連続音の継続を検出する留
守番電話装置におけるVAC検出回路において、 比較器の出力段と当該比較器の基準電圧端子間
に出力の一部を帰環するインピーダンス素子を接
続し、当該出力がある時に比較器の基準レベルを
上昇させることを特徴とする留守番電話装置にお
けるVAC検出回路。[Claims] 1. A voice signal from the calling party is input to a comparator,
In a VAC detection circuit in an answering machine that detects silence and the continuation of a continuous tone after the caller's call-on based on the presence or absence of the output of the comparator, the voltage between the output stage of the comparator and the reference voltage terminal of the comparator is 1. A VAC detection circuit in an answering machine, characterized in that an impedance element is connected to the circuit to return a part of the output to the circuit, and the reference level of the comparator is raised when the output is present.
JP20158582A 1982-11-17 1982-11-17 Vac detecting circuit in automatic answering telephone set Granted JPS5991765A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20158582A JPS5991765A (en) 1982-11-17 1982-11-17 Vac detecting circuit in automatic answering telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20158582A JPS5991765A (en) 1982-11-17 1982-11-17 Vac detecting circuit in automatic answering telephone set

Publications (2)

Publication Number Publication Date
JPS5991765A JPS5991765A (en) 1984-05-26
JPS6338905B2 true JPS6338905B2 (en) 1988-08-02

Family

ID=16443491

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20158582A Granted JPS5991765A (en) 1982-11-17 1982-11-17 Vac detecting circuit in automatic answering telephone set

Country Status (1)

Country Link
JP (1) JPS5991765A (en)

Families Citing this family (1)

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Publication number Priority date Publication date Assignee Title
JP3409781B2 (en) 2000-09-05 2003-05-26 住友電気工業株式会社 Method for manufacturing optical semiconductor module

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