JPS60167564A - Subscriber circuit - Google Patents

Subscriber circuit

Info

Publication number
JPS60167564A
JPS60167564A JP59021662A JP2166284A JPS60167564A JP S60167564 A JPS60167564 A JP S60167564A JP 59021662 A JP59021662 A JP 59021662A JP 2166284 A JP2166284 A JP 2166284A JP S60167564 A JPS60167564 A JP S60167564A
Authority
JP
Japan
Prior art keywords
current
circuit
winding
voltage
primary winding
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
JP59021662A
Other languages
Japanese (ja)
Inventor
Yoshihisa Saito
斉藤　芳久
Hiroyuki Matsuda
博之 松田
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP59021662A priority Critical patent/JPS60167564A/en
Publication of JPS60167564A publication Critical patent/JPS60167564A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/18—Automatic or semi-automatic exchanges with means for reducing interference or noise; with means for reducing effects due to line faults with means for protecting lines
    • 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
    • H04M19/003—Arrangements for compensation of the DC flux in line transformers
    • 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)
  • Power Engineering (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

PURPOSE:To obtain a subscriber circuit which can protect more assuredly the parts having low pressure resistance to the surge and has a simple circuit constitution with high eliminating accuracy of DC magnetic field and low power consumption, by short-circuiting the primary winding of a transformer with a Zener diode having the Zener voltage higher than the peak level of an AC signal to absorb the surge voltage sent from a subscriber line and at the same time supplying a DC magnetic field eliminating current of the transformer by a single power supply. CONSTITUTION:The surge voltage applied to call lines A and B from a communication terminal is clamped less than the Zener voltage by Zener diodes D0-D3 which are inserted to a primary winding L01 of a transformer L0. The current flowing to the winding L01 undergoes the voltage/current conversion by a current converting circuit 6. The current is flowed to a 3rd winding L03 of the transformer L03. This eliminates a DC magnetic field which is produced by a DC current flowing to the winding L01.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は電子交換機の通信端末に対して直流電流を供給
するためのトランスを中心とした加入者回路に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a subscriber circuit centered around a transformer for supplying direct current to communication terminals of an electronic exchange.

〔発明の背景〕[Background of the invention]

従来の電子交換機における加入者回路の一例を第１図に
示す。同図に於て、通信端末からの通詰線Ａ、Ｂはトラ
ンスＬＯの１次巻線り、０１および電流検出用抵抗ＲＯ
，Ｒ１を介して、通信端末への直流電流供給用電源Ｅ（
通常４８Ｖ）に接続されている。コンデンサＣＯは通話
線Ａ、Ｂからの交流信号を通過させる通話回路用カップ
リングコンデンサであり、これをパスして１次巻線ＬＯ
１に流れる交流信号は２次巻線ＬＯ２から交換スイッチ
回路１１へ入力される。An example of a subscriber circuit in a conventional electronic exchange is shown in FIG. In the figure, the connecting wires A and B from the communication terminal are the primary winding of the transformer LO, 01, and the current detection resistor RO.
, R1, the power supply E(
Usually connected to 48V). Capacitor CO is a coupling capacitor for the communication circuit that passes AC signals from communication lines A and B, and passes this to the primary winding LO.
The AC signal flowing through the secondary winding LO2 is input to the exchange switch circuit 11 from the secondary winding LO2.

電流検出用抵抗Ｒｏ、凡１およびこれらにブリッジ回路
形式で接続された抵抗ｌ（，２〜Ｒ５は、トランスＬＯ
の１次巻線ＬＯ１に流れる直流電流を検出するための電
流検出回路１を形成している。抵抗Ｒ６〜Ｒ９は電流検
出回路１からの出力電圧を減衰させる抵抗減衰回路２を
形成しており、これによって電流検出回路の出力電圧は
通常ＩＣ回路である演算増幅器■ＣＯの動作可能な電圧
レベルの信号に変換される。演算増幅器ＩＣ０１抵抗Ｒ
１０〜Ｒ１２はバッファ３を形成し、抵抗減衰回路２の
出力電圧なハイインピーダンスで受け、その増幅率はＲ
１２／Ｒ。The current detection resistor Ro, 1 and the resistor l connected to these in a bridge circuit form (2 to R5 are the transformer LO
A current detection circuit 1 for detecting the direct current flowing through the primary winding LO1 is formed. Resistors R6 to R9 form a resistor attenuation circuit 2 that attenuates the output voltage from the current detection circuit 1, so that the output voltage of the current detection circuit is set to a voltage level at which the operational amplifier CO, which is usually an IC circuit, can operate. signal. Operational amplifier IC01 resistance R
10 to R12 form a buffer 3, which receives the output voltage of the resistive attenuation circuit 2 with high impedance, and its amplification factor is R.
12/R.

１１の比に比例する。抵抗Ｒ１５，コンデンサＣ１はロ
ーパスフィルタａｙｘ形成し、バッファ回路３の出力電
圧に含複れる高周波信号成分を除去する役目をもつ。演
算増幅器ＩＣ１は電圧フォロア型のバッファ回路５を形
成し、ローパスフィルタ回路４からの出力電圧をハイイ
ンピーダンスで受け、演算増幅器ＩＣ１の出力端子に同
電圧レベルで出力する。トランジスタＴ４０、抵抗Ｒ１
４はバッファ回路５の出力電圧を電流に変換し、トラン
スＬＯの６次巻線ＬＯ３に直流磁界打消し用の電流を供
給するという電流変換回路６を形成している。以上に述
べた抵抗減衰回路２．２段のバッファ回路６，５．ロー
パスフィルタ回路４．そして電流変換回路６は、通信端
末へ供給する直流電流が１次巻１Ｌ０１を流れることに
よってトランスＬＯのコアが磁気飽和状態へ近づくのを
防止するために、３次巻線ＬＯ５に電流検出回路１の出
力電圧に応じた直流磁界打消し電流を供給するという電
流制御回路１０を形成している。そしてトランスＬＯの
３次巻線ＬＯ３への電流供給電源は通話電流供給用電源
Ｅを併用（図では別個に示しているが）している。また
通信ＭＡ、Ｂからのサージ電圧に対しては、サージ電圧
によってトランスＬＯに大電流が流れて磁気飽和が生じ
、このためトランスＬＯの２次巻線および３次巻線には
大きな電圧が出ないという性質を利用して２次及び３次
巻線に接続されている低耐圧部品を保護するという回路
形式となっている。It is proportional to the ratio of 11. The resistor R15 and the capacitor C1 form a low-pass filter ayx, which serves to remove high-frequency signal components contained in the output voltage of the buffer circuit 3. The operational amplifier IC1 forms a voltage follower type buffer circuit 5, receives the output voltage from the low-pass filter circuit 4 at high impedance, and outputs it at the same voltage level to the output terminal of the operational amplifier IC1. Transistor T40, resistor R1
4 forms a current conversion circuit 6 which converts the output voltage of the buffer circuit 5 into a current and supplies a current for canceling the DC magnetic field to the sixth winding LO3 of the transformer LO. The above-described resistance attenuation circuit 2.2-stage buffer circuit 6, 5. Low pass filter circuit 4. In order to prevent the core of the transformer LO from approaching a magnetic saturation state due to the direct current supplied to the communication terminal flowing through the primary winding 1L01, the current converter circuit 6 connects a current detection circuit 1 to the tertiary winding LO5. A current control circuit 10 is formed to supply a DC magnetic field canceling current according to the output voltage of. The current supply power to the tertiary winding LO3 of the transformer LO is also provided by the communication current supply power supply E (although it is shown separately in the figure). In addition, in response to surge voltages from communication MA and B, a large current flows through the transformer LO due to the surge voltage, causing magnetic saturation, and therefore a large voltage is generated in the secondary and tertiary windings of the transformer LO. This circuit type utilizes this property to protect low voltage components connected to the secondary and tertiary windings.

しかし、以上に述べた従来の加入者回路では、加入者線
からのサージ電圧保護をトランスの磁気飽和のみに依存
しているため、サージ電圧の波形または波高によっては
十分に保護できないという欠点がある。また、電流制御
回路１０に２段のバッファ回路を用いているため回路が
複雑であるうえ、電流変換回路６と接続するバッファ回
路５は電圧フォロワ型であるから演算増幅器１ｃＯ、ｌ
ｃｌの電源として通話電流供給用電源Ｅ以外に２個の電
源＋Ｖ、−Ｖを必要とする欠点があり、かつ演算増幅器
を２個使用しているために１次善＠ＬＯ１に流れる直流
電流に比例する直流磁界打消し電流の精度が演算増幅器
個有のオフセット電圧による誤差の影譬な多く受けると
いう欠点がある。更に、トランスＬＯの６次巻線ＬＯ３
に接続する直流磁界打消し用電源として通話電流供給用
電源Ｅを使用しているが、一般にこの電源Ｅは一４８Ｖ
と高電圧であるため直流磁界・打消し電流が流れること
による余分の消費電力が犬さくなると同時に、トランジ
スタＴＲ０ＩＣ印加する電圧が高いたへトランジスタの
発熱室が大きいという欠点があった。However, the conventional subscriber circuit described above relies only on the magnetic saturation of the transformer to protect against surge voltage from the subscriber line, and therefore has the disadvantage that it cannot provide sufficient protection depending on the waveform or wave height of the surge voltage. . Furthermore, since the current control circuit 10 uses two stages of buffer circuits, the circuit is complicated, and the buffer circuit 5 connected to the current conversion circuit 6 is a voltage follower type, so the operational amplifiers 1cO, 1
There is a disadvantage that two power supplies +V and -V are required in addition to the power supply E for supplying communication current as a power supply for CL, and since two operational amplifiers are used, the DC current flowing to the first-order best @LO1 is The drawback is that the accuracy of the proportional DC magnetic field cancellation current is greatly affected by errors due to the offset voltage inherent in operational amplifiers. Furthermore, the sixth winding LO3 of the transformer LO
A power supply E for supplying communication current is used as a power supply for canceling the DC magnetic field connected to the
Since the voltage is high, the excess power consumption due to the flow of a DC magnetic field and canceling current is low, and at the same time, the heat generation chamber of the transistor is large due to the high voltage applied to the transistor TR0IC.

〔発明の目的〕[Purpose of the invention]

本発明の目的は、上記従来技術の欠点を除去し、サージ
に対して低耐圧部品をより確実に保護でき、また回路構
成が簡単で直流磁界打消しの精度が高く、消費電力も少
い加入者回路を提供するにある。It is an object of the present invention to eliminate the drawbacks of the prior art described above, to more reliably protect low-voltage components against surges, to have a simple circuit configuration, high accuracy in canceling DC magnetic fields, and low power consumption. It is to provide user circuit.

〔発明の概要） 本発明は、加入者線路からのサージ電圧を交流信号のピ
ーク値以上のツェナー電圧を有したツェナーダイオード
でトランスの１次巻線を短絡することによって吸収する
とともに、従来のローパスフィルタ及びこれの前、後段
に用イラれたバッファ回路を単一電源で動作可能な１個
の演算増幅器とフィルタ回路で実現しかつこの単一電源
によってトランスの直流磁界打消し用電流を供給するよ
うにしたことを特徴とするものである。[Summary of the Invention] The present invention absorbs surge voltage from a subscriber line by short-circuiting the primary winding of a transformer with a Zener diode having a Zener voltage higher than the peak value of an AC signal, and The filter and the buffer circuits used before and after the filter are realized by a single operational amplifier and filter circuit that can be operated with a single power supply, and this single power supply supplies current for canceling the DC magnetic field of the transformer. It is characterized by the following.

〔発明の実施例〕[Embodiments of the invention]

本発明による加入者回路の１実施例を牙２図に示す。牙
２図の回路には、トランスＬＯの２次巻線ＬＯ２，３次
巻線ＬＯ３に接続される低耐圧部品を通話線路からのサ
ージ電圧から保循するために、音声電圧（交流信号）を
クランプせずかつ低耐圧部品を保護できる電圧にクラン
プするためのツェナーダイオードＤＯ〜Ｄ３が１次巻線
ＬＯ１に並列に挿入されており、また矛１図のバッファ
回路３．５及びローパスフィルタ回路４に代って演算増
幅器ＩＣ２、抵抗Ｒ１０〜凡１３．コンデンサＣＩ、Ｃ
２から成るローパスフィルタ回路（バッファ回路モ兼ネ
る）７が設ゆられており、抵抗減衰回路２からの出力電
圧をハイインピーダンスで受け、筒周波信号成分を除去
して、演算増幅器ＩＣ２の出力端子にＲ１３／　Ｒ１１
倍の電圧を出力する。更に３次巻線ＬＯ３への電流は、
演算増幅器ＩＣ２の電源−Ｖから供給されており、演算
増幅器■Ｃ２は、通話電流供給用電源ＥのアースＧを共
通とした単電源−■のみで作動する型のものである。An embodiment of a subscriber circuit according to the invention is shown in FIG. In the circuit shown in Figure 2, an audio voltage (AC signal) is applied in order to protect the low voltage components connected to the secondary winding LO2 and tertiary winding LO3 of the transformer LO from surge voltage from the communication line. Zener diodes DO to D3 are inserted in parallel to the primary winding LO1 to clamp to a voltage that can protect low voltage components without clamping, and the buffer circuit 3.5 and low-pass filter circuit 4 in Figure 1 are also connected to the primary winding LO1. In place of , operational amplifier IC2 and resistors R10 to 13. Capacitor CI, C
A low-pass filter circuit 7 (also serving as a buffer circuit) consisting of 2 is provided, which receives the output voltage from the resistive attenuation circuit 2 at high impedance, removes the cylindrical frequency signal component, and filters the output voltage from the operational amplifier IC2. R13/R11 to the terminal
Outputs twice the voltage. Furthermore, the current to the tertiary winding LO3 is
It is supplied from the power source -V of the operational amplifier IC2, and the operational amplifier (2) C2 is of a type that operates only from a single power source (-2) that shares the ground G of the power source E for supplying communication current.

今、通信端末からの通話線Ａ、Ｈにサージ電圧が印加さ
れると、このサージ電圧はトランスＬＯの１次巻線Ｌ０
１に挿入されたツェナーダイオードＤＯ〜Ｄ６により、
ツェナー電圧以下にクランプされる。このツェナー電圧
は、トランスＬＯの２次巻線ＬＯ２、５次巻線ＬＯ３に
接続される低耐圧部品の耐圧よりは低（、かつ通信端末
からの音声電圧よりは大きい値に選定される。このため
、トランスＬＯのサージ電圧に対する磁気飽和を利用す
ることな（、低耐圧部品の保護を人力サージ波形のいか
んにかかわらず確実に行なうことができ、通信端末から
の音声信号については、波形クランプしたり減衰を与え
ることなくトランスＬＯに伝送される。Now, when a surge voltage is applied to the communication lines A and H from the communication terminal, this surge voltage is applied to the primary winding L0 of the transformer LO.
By the Zener diodes DO~D6 inserted in 1,
Clamped below Zener voltage. This Zener voltage is selected to be lower than the withstand voltage of the low voltage components connected to the secondary winding LO2 and the fifth winding LO3 of the transformer LO (and higher than the audio voltage from the communication terminal. Therefore, low-voltage components can be reliably protected regardless of the waveform of human power surges without using the magnetic saturation of the transformer LO against surge voltages. and is transmitted to the transformer LO without any attenuation.

次に、トランスＬＯの１次巻線ＬＯ１に流れる直流電流
により直流磁界を打消すための動作は従来と同様であり
、１次巻１ｆｌＪＬ０１に流れる電流が電流検出回路１
で検出され、抵抗減衰回路２でローパスフィルタ回路７
内の演算増幅器ＩＣ２の動作可能電圧レベルまで減衰さ
れ、ローパスフィルタ回路７で出力電圧に含まれる高周
波信号成分が除去され、電流変換回路６で電圧−電流変
換されて、トランスＬＯの３次巻線ＬＯ３に電流を流し
、これによって１次巻線に流れる直流電流によって生ず
る直流磁界を打消す。Next, the operation for canceling the DC magnetic field by the DC current flowing through the primary winding LO1 of the transformer LO is the same as the conventional one, and the current flowing through the primary winding 1flJL01 is transmitted to the current detection circuit 1.
is detected by the resistance attenuation circuit 2 and the low-pass filter circuit 7
The output voltage is attenuated to the operable voltage level of the operational amplifier IC2 in the transformer LO, high-frequency signal components included in the output voltage are removed by the low-pass filter circuit 7, voltage-to-current is converted by the current conversion circuit 6, and the tertiary winding of the transformer LO is attenuated. A current is passed through LO3, thereby canceling the DC magnetic field generated by the DC current flowing through the primary winding.

以上の実施例によると、従来は加入者線路からのサージ
電圧に対するトランス２次側の低耐圧部品の保映のため
、トランスの磁気飽和特性を利用していたものを、トラ
ンスの１次側に挿入したツェナーダイオードにより保護
することでサージ電圧波形の如何にかかわらず確実に保
護することがａＪ能となり、回路のサージ耐圧を高める
ことかでさる。また従来は２個の電源を使用し、演算増
幅器２個を必要とした複雑な電流制御回路を単電源動作
による演算増幅器１個の簡単な回路で構成することが可
能となり、回路の小型化、経済化及び信頼度の向上をは
かることができ、特に演算増幅器の数を減少させたため
演算増幅器のオフセット電圧分の誤差が減少し、精度を
高めることができる。このことは、トランスの１次電流
による直流磁界を打消すための直流磁界打消し電流を、
従来の回路よりさらに正確に供給できるため、本発明の
回路に使用するトランスは従来のトランスより飽和磁界
を小さく選定でき、従って小型化することが可能である
。その上、従来の回路では直流磁界打消し用の電源に比
較的高電圧である通話電流供給用電源を使用していたた
め、回路の消費電力および発熱が大きかったのに対して
、本発明の回路では、直流磁界打消し用の電源に比較的
低電圧である電流制御回路用の単電源を使用しているた
め、消費電力および発熱を減少させることが可能である
。According to the above embodiment, the magnetic saturation characteristics of the transformer were used to protect the low-voltage components on the secondary side of the transformer against surge voltage from the subscriber line, whereas the magnetic saturation characteristics of the transformer were used on the primary side of the transformer. By providing protection with the inserted Zener diode, it is possible to reliably protect the circuit regardless of the waveform of the surge voltage, thereby increasing the surge withstand voltage of the circuit. In addition, a complex current control circuit that conventionally required two power supplies and two operational amplifiers can now be configured with a simple circuit of one operational amplifier operating on a single power supply, resulting in smaller circuits and Economic efficiency and reliability can be improved. In particular, since the number of operational amplifiers is reduced, errors due to the offset voltage of the operational amplifiers are reduced, and accuracy can be improved. This means that the DC magnetic field cancellation current for canceling the DC magnetic field due to the primary current of the transformer is
Since it can be supplied more accurately than conventional circuits, the transformer used in the circuit of the present invention can be selected to have a smaller saturation magnetic field than conventional transformers, and therefore can be made smaller. Furthermore, in the conventional circuit, a relatively high-voltage power supply for supplying communication current was used as a power supply for canceling the DC magnetic field, resulting in large power consumption and heat generation, whereas the circuit of the present invention In this case, since a relatively low voltage single power supply for the current control circuit is used as the power supply for canceling the DC magnetic field, it is possible to reduce power consumption and heat generation.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、加入者線路からのサージ電圧に対する
回路内低耐圧部品の保護を確実に行え、また回路の小型
化、経済化、高性能化、信頼性の向上及び回路の消費電
力の低域に効果がある。According to the present invention, it is possible to reliably protect low-voltage components in the circuit against surge voltages from subscriber lines, and also to reduce the size, economy, performance, and reliability of the circuit, and to reduce the power consumption of the circuit. effective in the area.

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

牙１図は従来技術による加入者回路の一例を１ 示す図、矛２図は本発明の１実施例の回路図である。 １・・・電流検出回路、２・・・抵抗減衰回路、６・・
・電流変換回路、７・・・ローパスフィルタ回路、２０
・・・電流制御回路、Ａ、Ｂ・・・通話路、ＬＯ・・・
トランス、ＬＯｌ・・・１次巻線、ＬＯ２・・・２次巻
線、ＬＯ３・・・６次巻線、Ｅ・・・通話電流供給用電
源、−Ｖ・・・演算増幅器用電源、ＣＤ、Ｃ２・・・コ
ンデンサ、ＲＯ〜Ｒ１４用抵抗、Ｄｏ〜Ｄ３・・・ツェ
ナーダイオード、ＩＣ２・・・演算増幅器、ＴＲｏ・・
・トランジスタ。 ・　１２Figure 1 is a diagram showing an example of a subscriber circuit according to the prior art, and Figure 2 is a circuit diagram of an embodiment of the present invention. 1... Current detection circuit, 2... Resistance attenuation circuit, 6...
・Current conversion circuit, 7...Low pass filter circuit, 20
...Current control circuit, A, B...Communication path, LO...
Transformer, LOl...primary winding, LO2...secondary winding, LO3...sixth winding, E...power supply for communication current, -V...power supply for operational amplifier, CD , C2... Capacitor, RO to R14 resistor, Do to D3... Zener diode, IC2... Operational amplifier, TRo...
・Transistor.・12

Claims (1)

【特許請求の範囲】 １、　その１次巻線と２次巻線の交流結合により通信端
末よりの交流信号を中継し、また１次巻線を介して通信
端末に対し直流電流を供給し、更に該１次巻線の直流電
流により生ずる直流磁界をその３次巻線へ別の直流電流
を流すことにより打消すように構成したトランスと、上
記１次巻線の直流電流を検出する電流検出回路と、該電
流検出回路の検出した電流値に対応して上記３次巻線に
流す電流値を制′御する電流制御回路とを備えた交換機
の加入者回路に於て、上記交流信号より太き（かつ２次
及び３次巻線に接続された低耐圧部品が破壊されること
のない電圧に１次巻線の入力電圧をクランプするたぬの
ツェナーダイオードを上記トランスの１次巻線を短絡す
るように挿入したことを特徴とする加入者回路。 ２、　その１次巻線と２次巻線の交流結合により通信端
末よりの交流信号を中継し、また１次巻線を介して通信
端末に対し直流電流を供給し、更に該１次巻線の直流電
流により生ずる直流磁界をその３次巻線へ別の直流電流
を流すことにより打消すように構成したトランスと、上
記１次巻線の直流電流を検出する電流検出回路と、該電
流検出回路の検出した゛電流値に対応して上記３次巻線
に流す電流値を制御する電流制御回路とを備えた交換機
の加入者回路に於て、上記電流制御回路を、上記電流検
出回路の出力電圧を減衰させるための抵抗減衰回路と、
単一電源で動作する１個の演算増幅器及び高周波成分を
除去するたぬのローパスフィルタを用いたローパスフィ
ルタ回路と、該回路の出力電圧に応じた電流を６次巻勝
に流すための電流変換回路とから構成するとともに、上
記６次巻線への電流を上記演算増幅器の単一電源から供
給するように構成したことを特徴とする加入者回路。[Claims] 1. Relays an AC signal from a communication terminal through AC coupling between the primary winding and the secondary winding, and supplies DC current to the communication terminal via the primary winding; Furthermore, a transformer configured to cancel the DC magnetic field generated by the DC current of the primary winding by flowing another DC current to the tertiary winding, and a current detector for detecting the DC current of the primary winding. and a current control circuit that controls the current value flowing through the tertiary winding in accordance with the current value detected by the current detection circuit, A thick Zener diode (which clamps the input voltage of the primary winding to a voltage that does not destroy low-voltage components connected to the secondary and tertiary windings) is connected to the primary winding of the transformer. 2. An AC signal from a communication terminal is relayed by AC coupling between the primary winding and the secondary winding, and the AC signal is connected via the primary winding. A transformer configured to supply a direct current to a communication terminal and further cancel out a direct current magnetic field generated by the direct current in the primary winding by flowing another direct current to its tertiary winding; A subscriber of an exchange equipped with a current detection circuit that detects a direct current in a winding, and a current control circuit that controls a current value flowing through the tertiary winding in response to the current value detected by the current detection circuit. In the circuit, the current control circuit includes a resistance attenuation circuit for attenuating the output voltage of the current detection circuit;
A low-pass filter circuit that uses one operational amplifier that operates on a single power supply and a Tanu low-pass filter that removes high-frequency components, and a current conversion that allows a current corresponding to the output voltage of the circuit to flow through the sixth order winding. What is claimed is: 1. A subscriber circuit characterized in that the subscriber circuit comprises a circuit and a current to the sixth winding is supplied from a single power supply of the operational amplifier.
JP59021662A 1984-02-10 1984-02-10 Subscriber circuit Pending JPS60167564A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59021662A JPS60167564A (en) 1984-02-10 1984-02-10 Subscriber circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59021662A JPS60167564A (en) 1984-02-10 1984-02-10 Subscriber circuit

Publications (1)

Publication Number Publication Date
JPS60167564A true JPS60167564A (en) 1985-08-30

Family

ID=12061250

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59021662A Pending JPS60167564A (en) 1984-02-10 1984-02-10 Subscriber circuit

Country Status (1)

Country Link
JP (1) JPS60167564A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015142388A (en) * 2014-01-27 2015-08-03 サンケン電気株式会社 Switching power unit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015142388A (en) * 2014-01-27 2015-08-03 サンケン電気株式会社 Switching power unit

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