JPS6157157A - Telephone set - Google Patents

Telephone set

Info

Publication number
JPS6157157A
JPS6157157A JP17983884A JP17983884A JPS6157157A JP S6157157 A JPS6157157 A JP S6157157A JP 17983884 A JP17983884 A JP 17983884A JP 17983884 A JP17983884 A JP 17983884A JP S6157157 A JPS6157157 A JP S6157157A
Authority
JP
Japan
Prior art keywords
circuit
impedance
line
voltage
balanced
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
Application number
JP17983884A
Other languages
Japanese (ja)
Inventor
Hisatoshi Kan
冠　久敏
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP17983884A priority Critical patent/JPS6157157A/en
Publication of JPS6157157A publication Critical patent/JPS6157157A/en
Pending 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
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/76—Compensating for differences in line impedance

Landscapes

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

Abstract

PURPOSE:To deleted the switching of a pat to simplify the handling by switching the impedance of a balanced circuit automatically so that the impedance may be balanced with the line impedance. CONSTITUTION:An FET 11 is used in the depression mode to always set it the on status. In a short distance to extension or an exchange, the line impedance is high so as to increase the voltage level between terminals 15a and 15b, which causes the voltage applied to a voltage change detecting circuit 17 to increase. This makes a zener diode 7 on and the FET 18 off because of reverse of reverse voltage. Then a resistance 21 in series resistances 21 and 22 is opened to have an equivalent circuit 20 high, which will be equivalent to the line impedance.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は良好な通話特性を得るための電話装置に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a telephone device for obtaining good communication characteristics.

従来例の構成とその問題点 第１図は従来の電話装置を示している。以下にこの従来
例の構成について第１図とともに説明する。第１図にお
いてＩａ、１ｂは回線端子、２は通話減衰回路、３は誘
導コイル、４は送話器、５は線路インピーダンスと平衡
させて防側音特性倉得るための平衡回路、６は直流防止
用コンデンサ、７は受話器である。誘導コイル３と平衡
回路５、直流防止用コンデンｉｒよシブースタ回路を構
成する。Structure of the conventional example and its problems FIG. 1 shows a conventional telephone device. The configuration of this conventional example will be explained below with reference to FIG. 1. In Fig. 1, Ia and 1b are line terminals, 2 is a call attenuation circuit, 3 is an induction coil, 4 is a transmitter, 5 is a balancing circuit for balancing the line impedance and obtaining sound protection characteristics, and 6 is a DC A prevention capacitor, 7 is a receiver. The induction coil 3, the balance circuit 5, and the direct current prevention capacitor IR constitute a booster circuit.

次に上記従来例の動作について説明する。第１図におい
て、回線の線路インピーダンスと平衡回路５のインピー
ダンスとが平衡状態になれば、防側音特性は良好な特性
を得られる。たとえば、交換機より近距離又は内線通話
の場合、回線の電圧レベルは高くなっておシ、線路イン
ピーダンスは、交換機よシ遠距離の場合に比べて高い。Next, the operation of the above conventional example will be explained. In FIG. 1, if the line impedance of the line and the impedance of the balance circuit 5 are in a balanced state, good side sound protection characteristics can be obtained. For example, when a call is made over a short distance from the exchange or by an internal line, the voltage level of the line is high, and the line impedance is higher than when the call is made over a long distance from the exchange.

平衡回路５のインピーダンスは一定なのでこの場合、平
衡状態は壊れ、側音が増加、音最が大きくなってハウリ
ングが起きる。これを防ぐために通話減衰回路２を使っ
て、回線の線路インピーダンスを低下させることで、平
衡回路５のインピーダンスと平衡状態にさせて防側音特
性を高める。Since the impedance of the balanced circuit 5 is constant, in this case, the balanced state is broken, the sidetone increases, the maximum sound becomes louder, and howling occurs. In order to prevent this, the call attenuation circuit 2 is used to lower the line impedance of the line, thereby bringing it into equilibrium with the impedance of the balance circuit 5, thereby improving the side sound protection characteristics.

しかしながら上記従来例においては、１つ１つの電話機
について通話減衰回路２をＯｄＢか３ｄＢに設定する必
要があり、内線又は交換機より近距離の場合と遠距離の
場合では線路インピーダンスが違うので通話減衰回路５
を場合に応じて設定するという操作しなければならない
という問題があるＯ 発明の目的 本発明は上記従来例の欠点を除去するもので、自動的に
通話レベルを変え良好な防側音特性を得、また、通話レ
ベルの切替え設定がなくなり取扱いが簡単な電話装置を
提供しようとするものである。However, in the above-mentioned conventional example, it is necessary to set the call attenuation circuit 2 to OdB or 3 dB for each telephone, and the line impedance is different depending on whether the line is close to the extension or the exchange or is far away, so the call attenuation circuit 2 is required for each telephone. 5
OBJECT OF THE INVENTION The present invention is intended to eliminate the drawbacks of the above-mentioned conventional examples, and to automatically change the speech level to obtain good side noise protection characteristics. Furthermore, the present invention aims to provide a telephone device that is easy to handle since there is no need to change the call level.

発明の構成 上記目的を達成するために、本発明の電話装置は、交換
機からの回線の極性を一定にするためのダイオードブリ
ッジ回路と、このダイオードブリッジ回路の出力電圧の
変化を検出する電圧変化検出回路と、この電圧変化検出
回路の出力によシ通話回路のインピーダンスが変化する
平衡回路からなり、回線の電圧レベル変化をダイオード
ブリッジの出力電圧の変化として検出し、この出力電圧
の変化に応じて通話回路のインピーダンスを変化させ、
良好な防側音特性を得るものである。Structure of the Invention In order to achieve the above object, the telephone device of the present invention includes a diode bridge circuit for keeping the polarity of the line from the exchange constant, and a voltage change detection device for detecting changes in the output voltage of the diode bridge circuit. It consists of a balanced circuit in which the impedance of the communication circuit changes depending on the output of this voltage change detection circuit, detects changes in the voltage level of the line as changes in the output voltage of the diode bridge, and responds accordingly to changes in the output voltage. Change the impedance of the communication circuit,
This provides good side sound protection characteristics.

実施例の説明 以下に、本発明の一実施例の構成について、図面ととも
に説明する。第２図において、１５ａ。DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, 15a.

１ｓｂは回線に接続される端子であシ、この端子１ｓａ
　、　１ｔｓｂはダイオードブリッジ回路１６と接続さ
れている。ダイオードブリッジ回路１６の出力端子間に
はその間の電圧変化を検出する電圧変化検出回路１７が
接続してあシ、電圧変化検出回路１７は抵抗２６、ツェ
ナーダイオード２７、抵抗２８が直列接続して構成しで
ある。ツェナーダイオード２７とＦＥＴ１８のゲートは
接続されている。２０は平衡回路であシ、ＦＥＴ１ａの
ドレインは抵抗２１を介して誘導コイル１９に接続され
ている。ＦＥＴ１ａのソースは抵抗２２と抵抗２３に接
続されておシ、抵抗２２は誘導コイル１ｅに接続してい
る。２４は直流防止用コンデンサ、２５は受話器、２６
′は送話器、２９はコンデンサ、３ｏは抵抗である。1sb is the terminal connected to the line, this terminal 1sa
, 1tsb are connected to the diode bridge circuit 16. A voltage change detection circuit 17 is connected between the output terminals of the diode bridge circuit 16 to detect voltage changes therebetween, and the voltage change detection circuit 17 is composed of a resistor 26, a Zener diode 27, and a resistor 28 connected in series. It is. The Zener diode 27 and the gate of the FET 18 are connected. 20 is a balance circuit, and the drain of the FET 1a is connected to the induction coil 19 via a resistor 21. The source of the FET 1a is connected to a resistor 22 and a resistor 23, and the resistor 22 is connected to the induction coil 1e. 24 is a DC prevention capacitor, 25 is a receiver, 26
' is a transmitter, 29 is a capacitor, and 3o is a resistor.

次に上記実施例の動作について説明する。第２図におい
て、ＦＥＴ１８をデグレッシランモードで使用し、常時
ＯＮ状態にしておく。たとえば、内線又は交換機までが
近距離の場合、回線のインピーダンスは高く、この場合
には、端子１５ａ。Next, the operation of the above embodiment will be explained. In FIG. 2, the FET 18 is used in degressive run mode and is always kept in the ON state. For example, if the extension line or exchange is short distance, the impedance of the line is high, and in this case, the terminal 15a.

１ｓｂ間の電圧レベルが上昇し、これに伴なって電圧変
化検出回路１７にかかる電圧が上昇する。The voltage level between 1sb increases, and the voltage applied to the voltage change detection circuit 17 increases accordingly.

これによシツェナーダイオード２７がＯＮ状態になり、
ＦＥＴ１ａに逆電圧が加わシＦＥＴ１ｓはＯＦＦ　　状
態になる。ＦＥＴ１８のＯＮ状態からＯＦＦ　状態に変
化することにより並列な抵抗２１゜２２のうち抵抗２１
が開放され、この並列回路のインピーダンスは抵抗２２
だけのインピーダンスになり、平衡回路２ｏのインピー
ダンスが高ぐなシ、回線インピーダンスと平衡状態にな
シ良好な側音防止特性を得ることができる。This turns the Schizener diode 27 ON,
A reverse voltage is applied to FET1a, and FET1s is turned off. By changing the FET 18 from the ON state to the OFF state, the resistor 21 of the parallel resistors 21°22
is open, and the impedance of this parallel circuit is the resistance 22
As long as the impedance of the balance circuit 2o is high, good sidetone prevention characteristics can be obtained unless the impedance of the balance circuit 2o is high and is in equilibrium with the line impedance.

本実施例においては、回線の電圧レベル又は線路インピ
ーダンスがいかなる状態であっても、回線インピーダン
スと平衡状態になるように平衡回路のインピーダンスを
自動的に切替えることができ、かつ、線路インピーダン
スの高低に関係なく良好な防側音特性を得ることができ
、また、従来の電話機の通話減衰回路と比べてパッドを
切替える必要がなぐなシ取扱いが簡単になる。　　゛発
明の効果 以上の説明から明らかなように、本発明の電話装置は回
線の線路インピーダンスの変化により回線の電圧レベル
が変化し、この変化は極性を一定にするダイオードブリ
ッジ回路を通ＤｔＥＥ変化を検出する電圧変化検出回路
で検知されこの電圧液、化検出回路の出力により平衡回
路のインピーダンスを調整するように構成したものであ
り、回線の線路インピーダンスがどんな状態でも平衡回
路が平衡状態を保つことができ良好な防側音特性を得ら
れる利点を有する。In this embodiment, the impedance of the balanced circuit can be automatically switched so as to be in balance with the line impedance, regardless of the line voltage level or line impedance, and It is possible to obtain good side sound protection characteristics regardless of the situation, and compared to the call attenuation circuit of a conventional telephone, there is no need to switch pads, making handling easier.゛Effects of the Invention As is clear from the above explanation, in the telephone device of the present invention, the voltage level of the line changes due to a change in the line impedance, and this change is caused to change in DtEE through a diode bridge circuit that keeps the polarity constant. The voltage change is detected by the voltage change detection circuit, and the impedance of the balanced circuit is adjusted by the output of the voltage change detection circuit, so that the balanced circuit maintains a balanced state no matter what the line impedance is. It has the advantage of providing good side sound protection characteristics.

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

第１図は従来の電話装置の回路図、第２図は本発明の一
実施例における電話装置の回路図である。 １ｓａ　、　１ｓｂ・・・・・・回線の端子、１６・・
・・・・ダイオードブリッジ回路、１７・・・・・・電
圧変化検出回路、２０・・・・・・平衡回路。FIG. 1 is a circuit diagram of a conventional telephone device, and FIG. 2 is a circuit diagram of a telephone device according to an embodiment of the present invention. 1sa, 1sb...Line terminal, 16...
... Diode bridge circuit, 17 ... Voltage change detection circuit, 20 ... Balance circuit.

Claims (1)

【特許請求の範囲】[Claims] 交換機からの回線の極性を一定にするためのダイオード
ブリッジ回路と、このダイオードブリッジ回路の出力電
圧の変化を検出する電圧変化検出回路と、この電圧変化
検出回路の出力によりインピーダンスが変化する平衡回
路とからなる電話装置。A diode bridge circuit to keep the polarity of the line from the exchange constant, a voltage change detection circuit to detect changes in the output voltage of this diode bridge circuit, and a balanced circuit whose impedance changes depending on the output of this voltage change detection circuit. A telephone device consisting of
JP17983884A 1984-08-29 1984-08-29 Telephone set Pending JPS6157157A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17983884A JPS6157157A (en) 1984-08-29 1984-08-29 Telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17983884A JPS6157157A (en) 1984-08-29 1984-08-29 Telephone set

Publications (1)

Publication Number Publication Date
JPS6157157A true JPS6157157A (en) 1986-03-24

Family

ID=16072779

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17983884A Pending JPS6157157A (en) 1984-08-29 1984-08-29 Telephone set

Country Status (1)

Country Link
JP (1) JPS6157157A (en)

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