JPS6216059B2 - - Google Patents
Info
- Publication number
- JPS6216059B2 JPS6216059B2 JP2685078A JP2685078A JPS6216059B2 JP S6216059 B2 JPS6216059 B2 JP S6216059B2 JP 2685078 A JP2685078 A JP 2685078A JP 2685078 A JP2685078 A JP 2685078A JP S6216059 B2 JPS6216059 B2 JP S6216059B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- current
- resistor
- communication
- terminal
- 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
Links
- 238000004804 winding Methods 0.000 claims description 9
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M19/00—Current supply arrangements for telephone systems
- H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Devices For Supply Of Signal Current (AREA)
Description
【発明の詳細な説明】
本発明は、電話交換機における通話電流供給回
路に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speech current supply circuit in a telephone exchange.
従来、電話交換機における加入者回線への通話
電流は、加入者回線に接続された直流電源より供
給している。一般に、通信端末の電話機と局内交
換機との間の加入者回線における線路抵抗は一定
ではない。しかし、通話電流は送受話器の伝送品
質上、所定の電流値以上流す必要があるため、線
路抵抗が規格内の最大値である場合に、所定の値
以上の通話電流を供給し得るような通話電流供給
回路を設けると、加入者回線の線路抵抗が規格内
の最小値である場合、必要以上の通話電流が流
れ、消費電力がそれだけ増大する。この問題を解
消するために加入者回線に定電流回路を挿入した
構成が用いられてきているが、定電流回路は多量
の熱放出を伴なうので周辺回路に悪影響を与え
る。 Conventionally, communication current to a subscriber line in a telephone exchange is supplied from a DC power supply connected to the subscriber line. Generally, line resistance in a subscriber line between a telephone of a communication terminal and a local exchange is not constant. However, due to the transmission quality of the handset, it is necessary for the communication current to flow at a predetermined value or higher, so if the line resistance is at the maximum value within the standard, it is difficult to make a call that can supply a communication current exceeding the predetermined value. When a current supply circuit is provided, if the line resistance of the subscriber's line is the minimum value within the standard, a communication current that is more than necessary will flow, and power consumption will increase accordingly. In order to solve this problem, a configuration in which a constant current circuit is inserted into the subscriber line has been used, but since the constant current circuit is accompanied by a large amount of heat emission, it has an adverse effect on peripheral circuits.
本発明は、これらの問題点を解消するためにな
されたものであり、互いに相異なる線路抵抗をそ
れぞれ有する複数の加入者回線に対して、熱放出
の増加を伴なうことなく常に所定の通話電流を供
給する通話電流供給回路を提供するものである。 The present invention has been made to solve these problems, and allows a plurality of subscriber lines, each having a different line resistance, to always carry out predetermined calls without increasing heat emission. A communication current supply circuit that supplies current is provided.
本発明は、一端を通話回路網との結合用トラン
スの１次側第１巻線に他端を通話電流供給用電源
の負極側に接続する第１の抵抗器と、一端を前記
トランスの１次側第２巻線に他端を前記電源の正
極側に接続する第２の抵抗器とを有する加入者回
線の通話電流供給回路において、前記第１および
第２の抵抗器の一方の両端に第３の抵抗器を含む
スイツチング回路を接続し、前記第１および第２
の抵抗器の他方のトランス接続側の電位と通話電
流の基準値を設定する回路から取出した電位とを
入力する通話電流比較回路の出力により前記スイ
ツチング回路を動作させることを特徴とする。 The present invention includes a first resistor having one end connected to a first winding on the primary side of a transformer for coupling with a communication circuit network and the other end connected to a negative electrode side of a power source for supplying communication current; In a communication current supply circuit for a subscriber line having a second winding on the next side and a second resistor whose other end is connected to the positive electrode side of the power supply, A switching circuit including a third resistor is connected to the first and second resistors.
The switching circuit is operated by the output of a communication current comparison circuit which inputs the potential of the other transformer-connected side of the resistor and the potential taken out from the circuit for setting the reference value of the communication current.
以下図面を参照して説明する。 This will be explained below with reference to the drawings.
第１図は、従来の通話電流供給回路の一例を示
す回路図である。第１図において、通話電流Ｉ
は、地気Ｅ―抵抗RO―トランスTRの１次側第２
巻線P2―線路抵抗RLO―電話機TEL―線路抵抗
RL1―トランスTRの１次側第１巻線P1―抵抗R1
―直流電源Ｖの経路によつて加入者回線に流れ
る。ところが、線路抵抗RLO，RL1が大きい場
合、加入者回線に流れる通話電流Ｉは減少する。
一方、線路抵抗RLO，RL1が小さい場合、加入者
回線に流れる通話電流Ｉは増加する。 FIG. 1 is a circuit diagram showing an example of a conventional communication current supply circuit. In Fig. 1, the communication current I
is the primary side 2nd of earth E-resistance RO-transformer TR
Winding P 2 - Line resistance RLO - Telephone TEL - Line resistance
RL 1 - Primary side first winding of transformer TR P 1 - Resistor R 1
- Flows to the subscriber line via the path of the DC power supply V. However, when the line resistances RLO and RL1 are large, the communication current I flowing through the subscriber line decreases.
On the other hand, when the line resistances RLO and RL 1 are small, the communication current I flowing through the subscriber line increases.
第２図は従来の通話電流供給回路の他の例とし
て定電流回路を用いた場合の回路図である。第２
図において通話電流Ｉは、地気Ｅ―抵抗RO―ト
ランスTRの１次側第２巻線P2―線路抵抗RLO―
電話機TEL―線路抵抗RL1―トランスTRの１次
側第１巻線P1―定電流回路CC―直流電源Ｖの経
路によつて加入者回線に流れる。定電流回路CC
において、ツエナーダイオードZDの両端には常
に定電圧が生じ、トランジスタＱのベースエミツ
タ電圧も一定であるため、抵抗R1に流れる電流
は定電流になる。従つて、線路抵抗RLO，RL1が
変化しても加入者回線に流れる通話電流Ｉは、常
に一定の値となる。 FIG. 2 is a circuit diagram using a constant current circuit as another example of the conventional communication current supply circuit. Second
In the figure, the communication current I is expressed as: Earth E - Resistance RO - Primary side second winding P 2 of transformer TR - Line resistance RLO -
Flows to the subscriber line through the telephone TEL - line resistance RL 1 - primary first winding P 1 of transformer TR - constant current circuit CC - DC power supply V. Constant current circuit CC
Since a constant voltage is always generated across the Zener diode ZD and the base-emitter voltage of the transistor Q is also constant, the current flowing through the resistor R1 becomes a constant current. Therefore, even if the line resistances RLO and RL1 change, the communication current I flowing through the subscriber line always remains at a constant value.
第３図は、本発明の通話電流供給回路の一実施
例を示す回路図である。 FIG. 3 is a circuit diagram showing an embodiment of the talking current supply circuit of the present invention.
図において、回路動作を説明する。加入者回線
の合成線路抵抗（抵抗R0，R1及び線路抵抗RLO
―RL1の総和）が規格内の標準値以下にある場
合、演算増幅器Ａの反転入力端子（−）への入力
電位は、通話電流基準回路THで設定された基準
電位（演算増幅器Ａの非反転入力端子（＋）への
入力電位）に比べて同レベル以下になるため、演
算増幅器Ａの出力端子にはOVもしくは＋Ｖの電
位が出力される。演算増幅器Ａの出力電位がOV
もしくは＋Ｖレベルであると、トランジスタＱは
OFF状態を継続する。従つて、通話電流Ｉは、
地気Ｅ―抵抗RO―トランスTRの１次側第２巻線
P2―線路抵抗RLO―電話機TEL―線路抵抗RL1
―トランスTRの１次側第１巻線P1―抵抗R1―直
流電源V1の経路を流れる。この通話電流Ｉは、
規格内の標準電流値である。ところが、加入者回
線の線路抵抗RLO，RL1が大きく合成線路抵抗が
規格内の標準値より大きい場合、通話電流Ｉは標
準電流値より小さくなるため、抵抗ROによる電
圧降下が小さくなる。従つて、演算増幅器Ａの反
転入力端子への入力電位は、通話電流基準回路
THで設定された基準電位に比べて大きくなるた
め、演算増幅器Ａの出力端子には、−Ｖの電位が
出力される。これにより、トランジスタＱがON
状態になり、抵抗ROの両端にトランジスタＱ及
び抵抗RBOよりなる閉回路が並列接続されるた
め、ＲＯ・ＲＢＯ／ＲＯ＋ＲＢＯ＋R1＋RLO＋RL1により
加入者回
線の合成線路抵抗は規格内の標準値以下になる。
従つて、加入者回線には標準電流値の通話電流Ｉ
が流れる。 The circuit operation will be explained with reference to the figure. Combined line resistance of subscriber line (resistance R 0 , R 1 and line resistance RLO
- RL 1 ) is below the standard value within the standard, the input potential to the inverting input terminal (-) of operational amplifier A will be lower than the reference potential set by the talk current reference circuit TH (the Since this level is lower than the same level as the input potential to the inverting input terminal (+), a potential of OV or +V is output to the output terminal of operational amplifier A. The output potential of operational amplifier A is OV
Or, if it is at +V level, transistor Q will be
Continues the OFF state. Therefore, the communication current I is
Earth E - Resistance RO - Primary side 2nd winding of transformer TR
P 2 - Line resistance RLO - Telephone TEL - Line resistance RL 1
- Flows through the primary winding P 1 of transformer TR - Resistor R 1 - DC power supply V 1 . This communication current I is
This is a standard current value within the specifications. However, if the line resistances RLO and RL 1 of the subscriber line are large and the combined line resistance is larger than the standard value within the specifications, the communication current I will be smaller than the standard current value, and therefore the voltage drop due to the resistor RO will be small. Therefore, the input potential to the inverting input terminal of operational amplifier A is
Since it is larger than the reference potential set by TH, a potential of -V is output to the output terminal of operational amplifier A. This turns transistor Q on.
Since the closed circuit consisting of the transistor Q and the resistor RBO is connected in parallel to both ends of the resistor RO, the combined line resistance of the subscriber line becomes less than the standard value within the standard due to RO・RBO/RO+RBO+R 1 +RLO+RL 1 . .
Therefore, the subscriber line has a standard current value of communication current I.
flows.
以上説明した如く、本発明によれば、多量な熱
放出を伴なわず線路抵抗の変化に対しても常に所
定の通話電流を供給することが可能な通話電流供
給回路が得られる。更に、本発明の通話電流供給
回路は、多量な熱放出を伴なわないため、実装密
度を増すことが可能であるので交換装置の小形化
をはかれる効果もある。 As described above, according to the present invention, it is possible to obtain a communication current supply circuit that can always supply a predetermined communication current even when line resistance changes without releasing a large amount of heat. Furthermore, since the communication current supply circuit of the present invention does not radiate a large amount of heat, it is possible to increase the packaging density, which has the effect of reducing the size of the switching device.
第１図は従来の通話電流供給回路の一例を示す
回路図、第２図は従来の通話電流供給回路の他の
例として定電流回路を用いた場合の回路図、第３
図は本発明の通話電流供給回路の一実施例を示す
回路図である。
RLO，RL1……線路抵抗、RO〜R5，RBO……
抵抗、Ｑ……トランジスタ、Ａ……演算増幅器、
TH……通話電流の基準値を設定する回路、Ｉ…
…加入者回線に流れる通話電流。
Fig. 1 is a circuit diagram showing an example of a conventional communication current supply circuit, Fig. 2 is a circuit diagram showing another example of the conventional communication current supply circuit using a constant current circuit, and Fig. 3 is a circuit diagram showing an example of a conventional communication current supply circuit.
The figure is a circuit diagram showing one embodiment of the talking current supply circuit of the present invention. RLO, RL 1 ...Line resistance, RO~ R5 , RBO...
Resistor, Q...transistor, A...operational amplifier,
TH...Circuit for setting the reference value of talking current, I...
...Talking current flowing through subscriber lines.
Claims (1)
の１次側第１巻線に第２の端子を通話電流供給用
電源の負極側に接続する第１の抵抗器と、第１の
端子を前記トランスの１次側第２巻線に第２の端
子を前記電源の正極側に接続する第２の抵抗器と
を有する加入者回線の通話電流供給回路におい
て、前記第１および第２の抵抗器のいずれか一方
の抵抗器と並列に第３の抵抗器を含むスイツチン
グ回路を接続し、前記スイツチング回路が接続さ
れた前記第１または第２の抵抗器の第１の端子の
電位と通話電流の基準値を設定する回路から取出
した電位とを入力する通話電流比較回路の出力に
より前記スイツチング回路を動作させることを特
徴とする通話電流供給回路。1. A first resistor whose first terminal is connected to the first winding on the primary side of a transformer for coupling with a communication circuit network, and whose second terminal is connected to the negative electrode side of a power supply for supplying communication current; and a second resistor connecting a second terminal to a positive terminal side of the power supply to a second winding on the primary side of the transformer, wherein the first and second A switching circuit including a third resistor is connected in parallel with one of the resistors, and the switching circuit is connected to the potential of the first terminal of the first or second resistor to which the switching circuit is connected. A speech current supply circuit characterized in that the switching circuit is operated by the output of a speech current comparison circuit inputted with a potential extracted from a circuit for setting a current reference value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2685078A JPS54118712A (en) | 1978-03-08 | 1978-03-08 | Call current supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2685078A JPS54118712A (en) | 1978-03-08 | 1978-03-08 | Call current supply circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54118712A JPS54118712A (en) | 1979-09-14 |
| JPS6216059B2 true JPS6216059B2 (en) | 1987-04-10 |
Family
ID=12204743
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2685078A Granted JPS54118712A (en) | 1978-03-08 | 1978-03-08 | Call current supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54118712A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56122569A (en) * | 1980-03-03 | 1981-09-26 | Fujitsu Ltd | Booster system |
| SE450677B (en) * | 1982-04-01 | 1987-07-13 | Ericsson Telefon Ab L M | SUPPLY CIRCUIT IN A DC MAGNETIZED FORK TRANSFORMER |
-
1978
- 1978-03-08 JP JP2685078A patent/JPS54118712A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54118712A (en) | 1979-09-14 |
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