JPS61154348A - Feeding current limit system - Google Patents

Feeding current limit system

Info

Publication number
JPS61154348A
JPS61154348A JP59276884A JP27688484A JPS61154348A JP S61154348 A JPS61154348 A JP S61154348A JP 59276884 A JP59276884 A JP 59276884A JP 27688484 A JP27688484 A JP 27688484A JP S61154348 A JPS61154348 A JP S61154348A
Authority
JP
Japan
Prior art keywords
power supply
voltage
reference voltage
current
operational amplifier
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
JP59276884A
Other languages
Japanese (ja)
Inventor
Kenji Takato
健司 高遠
Toshiro Tojo
敏郎 東條
Yozo Iketani
池谷　陽三
Mitsutoshi Ayano
綾野　光俊
Kiyoshi Shibuya
清 渋谷
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP59276884A priority Critical patent/JPS61154348A/en
Publication of JPS61154348A publication Critical patent/JPS61154348A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/001—Current supply source at the exchanger providing current to substations
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

PURPOSE:To decrease power consumption by decreasing a feeding current when no talking current flows in a subscriber circuit of a digital exchange. CONSTITUTION:When a subscriber telephone set 4 hooks on, since an output current of operational amplifiers 51, 52 is limited by resistors 71, 72, feeding currents I1, I2 are decreased than the specified value, voltages V1, V2 are decreased than those at hook-off state and lower than a reference voltage Vs. As a result, diodes 171, 172 are biased forward to decrease control voltages Vi1, Vi2 inputted to non-inverting inputs (+) of the operational amplifiers 51, 52 than the reference voltage Vs. Thus, the feeding currents I1, I2 of the feeding circuit are decreased.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明はディジタル交換機の加入者回路に使用される定
電流給電回路の消費電力を節減可能とする給電々流制限
方式に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply current limiting system that makes it possible to reduce the power consumption of a constant current power supply circuit used in a subscriber circuit of a digital exchange.

ディジタル交換機においては、通話路網を経由して高レ
ベルの電流を伝送出来ぬ為、加入者電話機に対し通話電
流を供給する給電回路は、各加入者回路に設けられてい
る。この種の給電回路には、加入者線路抵抗が変化した
場合にも略一定（例えば３０ミリアンペア程度）の通話
電流を供給し得る定電流給電回路が広く採用されている
。然し定電流給電回路を採用する場合にも、不要の消費
電力は極力削減させることが望まれる。In digital exchanges, since high-level current cannot be transmitted via the communication path network, each subscriber circuit is provided with a power supply circuit that supplies communication current to subscriber telephones. As this type of power supply circuit, a constant current power supply circuit that can supply a substantially constant talking current (for example, about 30 milliamperes) even when subscriber line resistance changes is widely used. However, even when employing a constant current power supply circuit, it is desirable to reduce unnecessary power consumption as much as possible.

〔従来の技術〕[Conventional technology]

第２図はこの種加入者回路における従来ある定電流給電
回路の一例を示す図である。FIG. 2 is a diagram showing an example of a conventional constant current power supply circuit in this type of subscriber circuit.

第２図において、Ｂ端子１およびＡ端子２間には、加入
者線路３を経由して加入者電話機４が接続されており、
演算増幅器５１、トランジスタ６１、抵抗７１および８
１から構成される第一の給電回路９１が地気ＧからＢ端
子ｌに接続される加入者線路３の一方の線条（以後Ｂ線
３１と称する）に正極性の給電電流■１が供給され、ま
た演算増幅器５２、トランジスタ６２、抵抗７２および
８２から構成される第二の給電回路９２が交換機上電源
の負極■、からＡ端子２に接続される加入者線路３の他
方の線条（以後ＡｖＡ３１と称する）に負極性の給電電
流Ｉ２が供給される。なお演算増幅器５１および５２、
並びにトランジスタ６１および６２はそれぞれ同一特性
を有し、また抵抗７１および７２は等しい抵抗値Ｒ１を
、また抵抗８１および８２は等しい抵抗値ＲＩｌを有す
る。In FIG. 2, a subscriber telephone 4 is connected between the B terminal 1 and the A terminal 2 via a subscriber line 3.
Operational amplifier 51, transistor 61, resistors 71 and 8
A first power supply circuit 91 consisting of 1 supplies a positive power supply current 1 to one wire of the subscriber line 3 (hereinafter referred to as the B line 31) connected from the earth G to the B terminal 1. In addition, a second power supply circuit 92 consisting of an operational amplifier 52, a transistor 62, and resistors 72 and 82 is connected to the other wire of the subscriber line 3 ( A negative power supply current I2 is supplied to the current AvA31 (hereinafter referred to as AvA31). Note that the operational amplifiers 51 and 52,
In addition, transistors 61 and 62 each have the same characteristics, resistors 71 and 72 have the same resistance value R1, and resistors 81 and 82 have the same resistance value RI1.

なお変成器ＩＯおよびコンデンサ１１は、二線式の加入
者線を四線式に変換する二線四線変換回路を構成する。The transformer IO and the capacitor 11 constitute a two-wire/four-wire conversion circuit that converts a two-wire subscriber line into a four-wire system.

一方、それぞれ抵抗値Ｒｔ□を有する抵抗１２１および
１２２、並びに抵抗値Ｒ１３を有する抵抗１３１および
１３２は交換機主電源電圧ｖＩｌを分圧し、抵抗１２１
および・１２２の両端にそれぞれ所定の電圧（以後基準
電圧Ｖｓと称する）を生成する。抵抗１２１の両端に生
じた基準電圧Ｖｓは演算増幅器５１の非反転入力端子（
＋）に制御電圧Ｖｉｌとして入力され、また抵抗１２２
の両端に生じた基準電圧Ｖｓは演算増幅器５２の非反転
入力端子（＋）に制御電圧Ｖ、として入力される。演算
増幅器５１の反転入力端子（−）はトランジスタ６１の
エミッタに接続され、また演算増幅器５１の出力端子は
抵抗７１を介してトランジスタ６１のベースに接続され
ている。かかる場合に演算増幅器５１は非反転入力端子
（＋）と反転入力端子（−）とが等電位（所謂イマジナ
リショート）となる如くトランジスタ６１を制御する。On the other hand, resistors 121 and 122 each having a resistance value Rt□ and resistors 131 and 132 having a resistance value R13 divide the main power supply voltage vIl of the exchanger,
A predetermined voltage (hereinafter referred to as reference voltage Vs) is generated at both ends of and 122, respectively. The reference voltage Vs generated across the resistor 121 is applied to the non-inverting input terminal of the operational amplifier 51 (
+) as the control voltage Vil, and the resistor 122
The reference voltage Vs generated across the operational amplifier 52 is input to the non-inverting input terminal (+) of the operational amplifier 52 as a control voltage V. The inverting input terminal (-) of operational amplifier 51 is connected to the emitter of transistor 61, and the output terminal of operational amplifier 51 is connected to the base of transistor 61 via resistor 71. In such a case, the operational amplifier 51 controls the transistor 61 so that the non-inverting input terminal (+) and the inverting input terminal (-) are at equal potential (so-called imaginary short).

その結果給電回路９１からＢ線３１に供給される給電電
流！、は、規定値（Ｖｓ／Ｒｇ）に維持される。As a result, the power supply current is supplied from the power supply circuit 91 to the B line 31! , is maintained at a specified value (Vs/Rg).

同様の構成を有する給電回路９２においても、演算増幅
器５２は非反転入力端子（＋）と反転入力端子（−）と
がイマジナリショートとなる如くトランジスタ６２を制
御し、給電回路９２からＡ線３２に供給される電流Ｉ２
は前記規定値（Ｖｓ／Ｒ，）に維持される。従って加入
者電話機Ｓが受話器を上げた状Ｓ（オフフック状ａ）に
おいては、加入者線路３の抵抗値に拘らず定電流（Ｖ　
ｓ　／　Ｒ８）が供給される。In the power supply circuit 92 having a similar configuration, the operational amplifier 52 controls the transistor 62 so that the non-inverting input terminal (+) and the inverting input terminal (-) are imaginary short-circuited, and connects the A line 32 from the power supply circuit 92. Current supplied I2
is maintained at the specified value (Vs/R,). Therefore, in state S where subscriber telephone S picks up the handset (off-hook state a), regardless of the resistance value of subscriber line 3, the constant current (V
s/R8) is supplied.

一方等しい抵抗値ＲＩ４を有する抵抗１４１およ、び１
４２、並びに利得＋１の増幅器１５は、Ｂ線３１および
Ａ！３２の中点電位を抵抗１３１および１３２の接続点
に帰還させることにより、給電回路９１および９２の特
性の偏差に基づく給電電流１１およびＩ２の偏差を補正
すると共に、Ｂ線３１およびＡ線３２に対する同相イン
ピーダンスを下げる役割を果たす。On the other hand, resistors 141 and 1 having the same resistance value RI4
42 and an amplifier 15 with a gain of +1 connects the B line 31 and the A! By feeding back the midpoint potential of 32 to the connection point of resistors 131 and 132, deviations in feed currents 11 and I2 based on deviations in characteristics of feed circuits 91 and 92 are corrected, and It plays the role of lowering the common mode impedance.

かかる状態で、加入者電話機４がオンフッタ状態になる
と、Ｂ端子１およびＡ端子２間には高抵抗値Ｒ１４を有
する抵抗１４１および１４２のみが接続されることとな
る。然し演算増幅器５１および５２は依然としてイマジ
ナリショートとなる様抵抗８１および８２に流れる電流
Ｉ＋およびＬを前記規定値（Ｖｓ／Ｒ＋＋）に維持し得
るベース電流をトランジスタ６１および６２に供給する
。In this state, when the subscriber telephone 4 enters the on-footer state, only the resistors 141 and 142 having a high resistance value R14 are connected between the B terminal 1 and the A terminal 2. However, the operational amplifiers 51 and 52 still supply base currents to the transistors 61 and 62 that can maintain the currents I+ and L flowing through the resistors 81 and 82 at the specified values (Vs/R++) so as to cause an imaginary short circuit.

その結果加入者電話機４は通話電流が不要であるにも拘
らず、給電回路９１および９２で加入者電話機４がオフ
フック状態にある場合と略変わらぬ電力が消費されるこ
ととなる。なお抵抗７１および７２は、かかるオンフッ
タ状態における演算増幅器５１および５２の出力電流を
極力削減する目的で挿入されているが、採用し得る抵抗
値にも限度があり、必ずしも充分な効果を挙げていない
。As a result, even though the subscriber telephone 4 does not require call current, the power supply circuits 91 and 92 consume approximately the same amount of power as when the subscriber telephone 4 is in an off-hook state. Note that the resistors 71 and 72 are inserted for the purpose of reducing the output current of the operational amplifiers 51 and 52 as much as possible in such an on-footer state, but there are limits to the resistance values that can be adopted, and they do not necessarily have a sufficient effect. .

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

以上の説明から明らかな如く、従来ある給電回路におい
ては、加入者電話機４がオンフック状態にある場合にも
、給電回路の特性で定まる規定値に近い電流が消費され
ることとなり、電力が無効消費される恐れがあった。As is clear from the above explanation, in a conventional power supply circuit, even when the subscriber telephone 4 is in an on-hook state, a current close to the specified value determined by the characteristics of the power supply circuit is consumed, and the power is ineffectively consumed. There was a risk of being exposed.

〔問題点を解決するための手段〕[Means for solving problems]

前記問題点は、それぞれ所定の基準電圧を制御電圧とし
て第一および第二の給電回路に入力し、該基準電圧によ
り定まる給電電流を加入者線の両線条に供給する第一お
よび第二の給電回路を具備する加入者回路において、前
記給電電流により前記第一および第二の給電回路の両端
に生ずる電圧と前記基準電圧とを比較し、該両端電圧が
前記基準電圧より低下した場合に前記各給電回路に入力
される制御電圧を前記基準電圧より低下させる手段を前
記各給電回路に設けることを特徴とする本発明により解
決される。The above problem is solved by inputting a predetermined reference voltage as a control voltage to the first and second power supply circuits, respectively, and supplying a power supply current determined by the reference voltage to both lines of the subscriber line. In a subscriber circuit equipped with a power supply circuit, a voltage generated across the first and second power supply circuits due to the power supply current is compared with the reference voltage, and if the voltage between the two ends is lower than the reference voltage, the This problem is solved by the present invention, characterized in that each power supply circuit is provided with means for lowering the control voltage input to each power supply circuit from the reference voltage.

〔作用〕[Effect]

加入者電話機がオフフック状態にある場合には、給電電
流により第一および第二の給電回路の両端に生ずる電圧
は前記基準電圧より大きい値を示している。加入者電話
機がオンフッタ状態となって通話電流が流れなくなると
、給電電流の減少に伴い第一および第二の給電回路の両
端に生ずる電圧は前記基準電圧より低下する。かかる状
態を前記手段が検出し、第一および第二の給電回路に入
力される制御電圧を低下させる為、前記第一および第二
の給電回路の給電電流は減少し、当該加入者回路におけ
る無効電力の消費は削減される。When the subscriber telephone is off-hook, the voltage produced across the first and second power supply circuits by the power supply current is greater than the reference voltage. When the subscriber telephone enters the on-footer state and no talking current flows, the voltages generated across the first and second power supply circuits drop below the reference voltage as the power supply current decreases. Since the means detects such a state and reduces the control voltage input to the first and second power supply circuits, the power supply currents of the first and second power supply circuits are reduced, and the invalidity in the subscriber circuit is reduced. Power consumption is reduced.

〔実施例〕〔Example〕

以下、本発明の一実施例を図面により説明する。 An embodiment of the present invention will be described below with reference to the drawings.

第１図は本発明の一実施例による給電々流制限方式を示
す図である。なお、企図を通じて同一符号は同一対象物
を示す。FIG. 1 is a diagram showing a feeding current limiting system according to an embodiment of the present invention. Note that the same reference numerals refer to the same objects throughout the plan.

第１図においては、給電電流Ｉ、により給電回路９１の
両端に生ずる電圧Ｖ、と基準電圧Ｖｓとを比較し、電圧
Ｖ、が基準電圧Ｖｓより低下した場合に給電回路９１に
入力される制御電圧Ｖ４．を低下させる手段として演算
増幅器１６１、ダイオード１７１および抵抗１８１が給
電回路９１に設けられ、また同様の手段として演算増幅
器１６２、ダイオード１７２および抵抗１８２が給電回
路９２に設けられている。演算増幅器１６１の非反転入
力端子（＋）には電圧ｖ１が入力され、また反転入力端
子（−）には基準電圧Ｖｓが入力され、出力端子はダイ
オード１７１を介して演算増幅器５１の非反転入力端子
（＋）に接続される。また演算増幅器１６２の非反転入
力端子（＋）には電圧ｖ２が人力され、また反転入力端
子（−）には基準電圧Ｖｓが入力され、出力端子はダイ
オード１７２を介して演算増幅器５２の非反転入力端子
（＋）に接続される。更に演算増幅器５１の非反転入力
端子（＋）には、基準電圧Ｖｓが抵抗１８１を介して入
力され、また演算増幅器５２の非反転入力端子（＋）に
は、基準電圧Ｖｓが抵抗１８２を介して入力される。In FIG. 1, the voltage V generated across the power supply circuit 91 due to the power supply current I is compared with the reference voltage Vs, and when the voltage V falls below the reference voltage Vs, the control is input to the power supply circuit 91. Voltage V4. An operational amplifier 161, a diode 171, and a resistor 181 are provided in the power supply circuit 91 as means for reducing the power, and an operational amplifier 162, a diode 172, and a resistor 182 are provided in the power supply circuit 92 as similar means. The voltage v1 is input to the non-inverting input terminal (+) of the operational amplifier 161, the reference voltage Vs is input to the inverting input terminal (-), and the output terminal is connected to the non-inverting input of the operational amplifier 51 via the diode 171. Connected to terminal (+). Further, the voltage v2 is input to the non-inverting input terminal (+) of the operational amplifier 162, the reference voltage Vs is input to the inverting input terminal (-), and the output terminal is connected to the non-inverting input terminal of the operational amplifier 52 via the diode 172. Connected to input terminal (+). Furthermore, the reference voltage Vs is input to the non-inverting input terminal (+) of the operational amplifier 51 via the resistor 181, and the reference voltage Vs is input to the non-inverting input terminal (+) of the operational amplifier 52 via the resistor 182. is input.

第１図において、加入者電話機４がオフフック状態にあ
る場合には、第２図におけると同様にして、給電回路５
１および５２よりＢ線３１およびＡ線３２に前記規定値
（Ｖｓ／Ｒ，）の給電電流■１およびＩｔが供給される
為、電圧Ｖ、およびｖ２はそれぞれ基準電圧Ｖｓにより
大となりる。In FIG. 1, when the subscriber telephone 4 is in an off-hook state, the power supply circuit 5
Since the power supply currents 1 and It of the specified value (Vs/R,) are supplied to the B line 31 and the A line 32 from 1 and 52, the voltages V and v2 are respectively larger than the reference voltage Vs.

かかる状態においては、演算増幅器１６１の非反転入力
端子（＋）が反転入力端子（−）より低電位に保たれる
為、比較器として作用する演算増幅器１６１は出力電圧
を基準電圧Ｖｓより低電圧に保つ。その結果ダイオード
１７１は逆バイアス状態となり、演算増幅器１６１は給
電回路９１に何等影響を与えない。同様に演算増幅器１
６２も非反転入力端子（＋）が反転入力端子（−）より
高電位に保たれる為、比較器として作用する演算増幅器
１６２は出力電圧を基準電圧Ｖｓより高電圧に保つ。そ
の結果ダイオード１７２は逆バイアス状態となり、演算
増幅器１６２は給電回路９２に何等影響を与えない。従
って加入者電話機４がオフフッタ状態にある場合には、
給電回路９１および９２は第２図におけると同様の給電
電流（＝Ｖｓ／Ｒｓ）を加入者電話機４に供給する。In such a state, the non-inverting input terminal (+) of the operational amplifier 161 is kept at a lower potential than the inverting input terminal (-), so the operational amplifier 161, which acts as a comparator, sets the output voltage to a voltage lower than the reference voltage Vs. Keep it. As a result, the diode 171 becomes reverse biased, and the operational amplifier 161 has no effect on the power supply circuit 91. Similarly, operational amplifier 1
Since the non-inverting input terminal (+) of 62 is kept at a higher potential than the inverting input terminal (-), the operational amplifier 162 acting as a comparator keeps the output voltage higher than the reference voltage Vs. As a result, diode 172 becomes reverse biased, and operational amplifier 162 has no effect on power supply circuit 92. Therefore, when the subscriber telephone 4 is in an off-footer state,
The power supply circuits 91 and 92 supply the same power supply current (=Vs/Rs) to the subscriber telephone 4 as in FIG.

次に加入者電話機４がオンフッタ状態になった場合にも
、演算増幅器５１および５２は前述の如くイマジナリシ
ョートを実現すべくトランジスタ６１および６２に略前
記規定値（Ｖｓ／Ｒｉ）に近いベース電流を供給する様
試みるが、前述の如く抵抗７１または７２により演算増
幅器５１および５２の出力電流は制限される為、給電電
流１゜およびＩ２は前記規定値（Ｖｓ／Ｒｓ）より減少
し、その結果電圧Ｖ、およびｖｔはオフフ７り状態の場
合より低下し、遂に基準電圧ｖｓより低くなる。かかる
状態においては、演算増幅器１６１の非反転入力端子（
＋）は反転入力端子（−）よや高電圧となり、演算増幅
器１６１の出方電圧は基準電圧Ｖｓより高くする。その
結果ダイオード１７１は順バイアス状態となり、演算増
幅器５１の非反転入力端子（＋）に入力される′Ｍ御電
圧Ｖｉ、を基準電圧Ｖｓより低下させる。その結果給電
回路９１の給電電流Ｉ、は前記規定値（Ｖｓ／Ｒ６）よ
り減少する。同様に演算増幅器１６２の非反転入力端子
（＋）も反転入力端子（−）より低電位となり、演算増
幅器１６２の出力電圧は基準電圧Ｖｓより低くする。そ
の結果ダイオード１７２は順バイアス状態となり、演算
増幅器５２の非反転入力端子（＋）に入力される制御電
圧Ｖ　ｉ　Ｚを基準電圧Ｖｓより低下させる。その結果
給電回路９２の給電電流■２は前記規定値（Ｖｓ／Ｒａ
）より減少する。減少を続ける給電電流１１およびＩ２
が抵抗１４１および１４２を経由して流れる微小電流に
達すると、電圧■、および■２は定常状態に達する。こ
の様にして、演算増幅器５１および５２の出力電流は、
トランジスタ６１および６２に微小なコレクタ電流を維
持させるだけのベース電流を供給するのみとなる。Next, when the subscriber telephone 4 enters the on-footer state, the operational amplifiers 51 and 52 supply base currents approximately close to the specified value (Vs/Ri) to the transistors 61 and 62 in order to realize an imaginary short circuit as described above. However, since the output currents of the operational amplifiers 51 and 52 are limited by the resistor 71 or 72 as described above, the power supply current 1° and I2 decrease from the specified value (Vs/Rs), and as a result, the voltage V and vt are lower than in the off-state, and finally become lower than the reference voltage vs. In such a state, the non-inverting input terminal (
+) has a higher voltage than the inverting input terminal (-), and the output voltage of the operational amplifier 161 is set higher than the reference voltage Vs. As a result, the diode 171 becomes forward biased, and the 'M control voltage Vi input to the non-inverting input terminal (+) of the operational amplifier 51 is lowered from the reference voltage Vs. As a result, the power supply current I of the power supply circuit 91 decreases from the specified value (Vs/R6). Similarly, the non-inverting input terminal (+) of the operational amplifier 162 also has a lower potential than the inverting input terminal (-), and the output voltage of the operational amplifier 162 is made lower than the reference voltage Vs. As a result, the diode 172 becomes forward biased and lowers the control voltage V i Z input to the non-inverting input terminal (+) of the operational amplifier 52 from the reference voltage Vs. As a result, the power supply current (2) of the power supply circuit 92 is the specified value (Vs/Ra
) decreases more. Supply currents 11 and I2 continue to decrease
When the current reaches a minute current flowing through the resistors 141 and 142, the voltages (1) and (2) reach a steady state. In this way, the output currents of operational amplifiers 51 and 52 are
Only a base current is supplied to transistors 61 and 62 to maintain a small collector current.

なおダイオード１９１および１９２は、演算増幅器１６
１および１６２の出力飽和電圧と、ダイオード１７１お
よび１７２による電圧降下を補償する為のバイアス電位
を与える。Note that the diodes 191 and 192 are connected to the operational amplifier 16.
1 and 162 and a bias potential to compensate for the voltage drop caused by the diodes 171 and 172.

以上の説明から明らかな如く、本実施例によれば、加入
者電話機４がオンフック状態になった場合に、演算増幅
器１６１および１６２が電圧Ｖ。As is clear from the above description, according to this embodiment, when the subscriber telephone 4 goes on-hook, the operational amplifiers 161 and 162 have a voltage of V.

および■２が基準電圧Ｖｓより低下することを検出して
給電電流１１およびＩ２を減少させる。and (2) detects that voltage 2 is lower than the reference voltage Vs, and reduces the power supply currents 11 and I2.

〔発明の効果〕〔Effect of the invention〕

以上、本発明によれば、前記加入者回路において、加入
者電話機がオンフック状態となって通話電流が流れ無く
なると、第一および第二の給電回路から供給される給電
電流は規定値より大幅に減少し、当該加入者回路の電力
消費は削減される。As described above, according to the present invention, in the subscriber circuit, when the subscriber telephone enters the on-hook state and no talking current flows, the power supply current supplied from the first and second power supply circuits becomes much larger than the specified value. and the power consumption of the subscriber circuit is reduced.

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

第１図は本発明の一実施例による給電々流制限方式を示
す図、第２図は従来ある定電流給電回路の一例を示す図
である。 図において、■ばＢ端子、２はＡ端子、３は加入者線路
、４は加入者電話機、ｌＯは変成器、１１はコンデンサ
、１５は増幅器、３１はＢ！、３２はＡ線、５１．５２
．９１および９２は給電回路、６１および６２はトラン
ジスタ、７１．７２．８■、８２．１２１．１２２．１
３１．１３２．１４１１４２．１８１および１８２は抵
抗、１６１および１６２は演算増幅、器、１７１．１７
２．１９１および１９２はダイオード、Ｇは地気、１１
およびＬは給電電流、■、および■２は電圧、■８は負
極電圧、Ｖｓは基準電圧、を示す。FIG. 1 is a diagram showing a feeding current limiting system according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a conventional constant current feeding circuit. In the figure, ■ is the B terminal, 2 is the A terminal, 3 is the subscriber line, 4 is the subscriber telephone, IO is the transformer, 11 is the capacitor, 15 is the amplifier, 31 is B! , 32 is A line, 51.52
．． 91 and 92 are power supply circuits, 61 and 62 are transistors, 71.72.8■, 82.121.122.1
31.132.141142.181 and 182 are resistors, 161 and 162 are operational amplifiers, 171.17
2.191 and 192 are diodes, G is earth, 11
and L indicate the feeding current, ■ and ■2 the voltage, ■8 the negative electrode voltage, and Vs the reference voltage.

Claims (1)

【特許請求の範囲】[Claims] それぞれ所定の基準電圧を制御電圧として第一および第
二の給電回路に入力し、該基準電圧により定まる給電電
流を加入者線の両線条に供給する第一および第二の給電
回路を具備する加入者回路において、前記給電電流によ
り前記第一および第二の給電回路の両端に生ずる電圧と
前記基準電圧とを比較し、該両端電圧が前記基準電圧よ
り低下した場合に前記各給電回路に入力される制御電圧
を前記基準電圧より低下させる手段を前記各給電回路に
設けることを特徴とする給電々流制限方式。The first and second power supply circuits each input a predetermined reference voltage as a control voltage to the first and second power supply circuits, and supply a power supply current determined by the reference voltage to both lines of the subscriber line. In the subscriber circuit, a voltage generated across the first and second power supply circuits due to the power supply current is compared with the reference voltage, and when the voltage at both ends is lower than the reference voltage, the voltage is input to each power supply circuit. A power supply current limiting system, characterized in that each of the power supply circuits is provided with means for lowering the control voltage to be lowered from the reference voltage.
JP59276884A 1984-12-27 1984-12-27 Feeding current limit system Pending JPS61154348A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59276884A JPS61154348A (en) 1984-12-27 1984-12-27 Feeding current limit system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59276884A JPS61154348A (en) 1984-12-27 1984-12-27 Feeding current limit system

Publications (1)

Publication Number Publication Date
JPS61154348A true JPS61154348A (en) 1986-07-14

Family

ID=17575738

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59276884A Pending JPS61154348A (en) 1984-12-27 1984-12-27 Feeding current limit system

Country Status (1)

Country Link
JP (1) JPS61154348A (en)

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