JPH0572788B2 - - Google Patents
Info
- Publication number
- JPH0572788B2 JPH0572788B2 JP3553683A JP3553683A JPH0572788B2 JP H0572788 B2 JPH0572788 B2 JP H0572788B2 JP 3553683 A JP3553683 A JP 3553683A JP 3553683 A JP3553683 A JP 3553683A JP H0572788 B2 JPH0572788 B2 JP H0572788B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- current
- power supply
- feedback
- feedback loop
- 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 - Lifetime
Links
- 238000001514 detection method Methods 0.000 claims description 8
- 238000010586 diagram Methods 0.000 description 3
- 230000010354 integration Effects 0.000 description 1
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
- H04M19/005—Feeding arrangements without the use of line transformers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (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の供給回
路に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication current supply circuit in a telephone exchange.
従来この種の通話電流供給回路として第１図に
示すような回路が考えられている。１，２は加入
者回線に接続される端子であり加入者回線の線間
に直流負荷が接続されると直流電源１１の＋側→
抵抗３，５，７とトランジスタ９で構成される一
方の直流給電回路→端子１→加入者回線→直流負
荷→加入者回線→端子２→抵抗４，６，８とトラ
ンジスタ１０で構成される他方の直流給電回路→
直流電源１１の−側と電流（通話電流）が流れ
る。しかしながら、この回路構成は、通話電流が
小さくなるとトランジスタ９，１０のコレクタ−
ベース間電圧が小さくなり通話電流供給回路のダ
イナミツクレンジが狭くなるため低電流領域で
は、使用出来ない欠点があつた。 Conventionally, a circuit as shown in FIG. 1 has been considered as this type of communication current supply circuit. 1 and 2 are terminals connected to the subscriber line, and when a DC load is connected between the lines of the subscriber line, the + side of the DC power supply 11 →
One DC power supply circuit consisting of resistors 3, 5, 7 and transistor 9 → terminal 1 → subscriber line → DC load → subscriber line → terminal 2 → the other consisting of resistors 4, 6, 8 and transistor 10 DC power supply circuit→
A current (communication current) flows to the negative side of the DC power supply 11. However, in this circuit configuration, when the communication current becomes small, the collectors of transistors 9 and 10
This had the disadvantage that it could not be used in low current ranges because the voltage between the bases became smaller and the dynamic range of the communication current supply circuit became narrower.
本発明の目的は、上記欠点を解決し、集積化に
よる装置の小型化、経済化を図り、更に特性の向
上を図つた通話電流供給回路を提供することにあ
る。 SUMMARY OF THE INVENTION It is an object of the present invention to provide a communication current supply circuit which solves the above-mentioned drawbacks, makes the device smaller and more economical through integration, and further improves characteristics.
本発明は、２線式加入者回路を経由して端末に
直流電流を供給する通話電流供給回路において、
前記加入者回線の一方と前記直流電源の正側と
の間に接続された第１の直流給電回路と、前記加
入者回路の他方と前記直流電源の負側との間に接
続された第２の直流給電回路と、
前記加入者回路と電源間の電圧を検出して電流
に変換する一対の検出回路と、
前記一対の検出回路で変換された電流の和を得
る加算回路と、
一定電流を発生する定電流源の電流と前記加算
回路の出力電流を入力とする帰還ループを持つ帰
還回路と、
前記帰還ループを外部からの制御信号によつて
オン・オフする制御回路と、
前記帰還回路の出力を入力として前記第１およ
び第２の直流給電回路を駆動する電流を発生する
駆動回路と、
を備え、前記制御回路をオフして前記帰還回路の
帰還ループをオフすることにより定抵抗給電を行
い、また、前記制御回路をオンして前記帰還回路
の帰還ループをオンすることにより定電圧給電を
行うことを特徴とする。 The present invention provides a speech current supply circuit that supplies DC current to a terminal via a two-wire subscriber circuit, comprising: a first communication current supply circuit connected between one of the subscriber lines and the positive side of the DC power supply; a DC power supply circuit; a second DC power supply circuit connected between the other of the subscriber circuits and the negative side of the DC power supply; detecting a voltage between the subscriber circuit and the power supply and converting it into a current; a pair of detection circuits, an addition circuit that obtains the sum of the currents converted by the pair of detection circuits, and a feedback loop that receives as input the current of a constant current source that generates a constant current and the output current of the addition circuit. a control circuit that turns on and off the feedback loop according to an external control signal; and a drive circuit that uses the output of the feedback circuit as an input to generate a current that drives the first and second DC power supply circuits. A constant resistance power supply is performed by turning off the control circuit and the feedback loop of the feedback circuit, and a constant resistance power supply is performed by turning on the control circuit and turning on the feedback loop of the feedback circuit. It is characterized by supplying voltage power.
次に本発明の実施例を図面を参照して説明す
る。 Next, embodiments of the present invention will be described with reference to the drawings.
第２図は本発明の一実施例を示す回路図であ
る。１２，１３は加入者回線に接続される端子で
あり、１４，１５は加入者回線に接続される端末
に通話電流を供給する一対の直流給電回路であ
る。１６，１７は端子１２と直流電源２２の一方
の端子間の電圧および端子１３と直流電源２２の
他方の端子間の電圧を抵抗２３，２４とカレント
ミラー回路２５，２６で電流に変換する一対の検
出回路である。１８は前記検出回路で変換された
電流を加算（絶対値和）する加算回路である。２
０は一定電流を発生する定電流源１９の電流と加
算回路１８の出力電流を入力とする帰還ループを
持つ帰還回路でありカレントミラー回路２７，２
８で構成される。２９は帰還ループを制御信号に
よつてオン・オフする制御回路である。２１は帰
還回路２０の出力を入力として前記直流給電回路
１４，１５を駆動する電流を発生する駆動回路で
ある。直流給電回路１４，１５は駆動回路２１か
らの電流をｋ（任意の値）倍に増幅した電流を出
力する。 FIG. 2 is a circuit diagram showing one embodiment of the present invention. 12 and 13 are terminals connected to the subscriber line, and 14 and 15 are a pair of DC power supply circuits that supply speech current to terminals connected to the subscriber line. 16 and 17 are a pair of resistors 23 and 24 and current mirror circuits 25 and 26 that convert the voltage between the terminal 12 and one terminal of the DC power supply 22 and the voltage between the terminal 13 and the other terminal of the DC power supply 22 into current. It is a detection circuit. Reference numeral 18 denotes an addition circuit that adds (absolute value sum) the currents converted by the detection circuit. 2
0 is a feedback circuit having a feedback loop that inputs the current of a constant current source 19 that generates a constant current and the output current of the adder circuit 18, and is a current mirror circuit 27, 2.
Consists of 8. 29 is a control circuit that turns on and off the feedback loop according to a control signal. Reference numeral 21 denotes a drive circuit that receives the output of the feedback circuit 20 as an input and generates a current for driving the DC power supply circuits 14 and 15. The DC power supply circuits 14 and 15 output a current obtained by amplifying the current from the drive circuit 21 by k (an arbitrary value) times.
次に端子１２，１３に直流負荷RLを接続した
場合について定量的に説明する。直流電源２２の
電圧をVBB、端子１２，１３間の電圧をVL、直流
負荷RLを流れる通話電流をIL、抵抗２３，２４の
抵抗値をＲ、カレントミラー回路２５，２６，２
７，２８のミラー比（入力電流と出力電流の比）
をそれぞれ１：ｎ＝１：１、１：ｍ＝１：0.5、
１：ｐ：ｑ＝１：１：２、駆動回路２１の入出力
電流比を１：１、定電流源の出力電流を2I0とす
る。検出回路１６，１７の出力電流I1はカレント
ミラー回路２５，２６の電圧降下を無視するとI1
＝（VBB−VL）／2Rとなる。加算回路の出力電流
I2は絶対値和であるためI2＝（VBB−VL）／Ｒとな
る。制御信号によつて帰還ループがオフした場合
帰還回路２０の出力電流I3はI3＝I2／２となる。
直流給電回路１４，１５の出力電流はkI3である。
したがつてkI3≫I1とすると端子１２，１３間の
電圧VLは次式で示される。 Next, the case where a DC load R L is connected to the terminals 12 and 13 will be quantitatively explained. The voltage of the DC power supply 22 is V BB , the voltage between the terminals 12 and 13 is V L , the communication current flowing through the DC load R L is I L , the resistance value of the resistors 23 and 24 is R, and the current mirror circuits 25 , 26 , 2
Miller ratio (ratio of input current to output current) of 7.28
1:n=1:1, 1:m=1:0.5, respectively.
1:p:q=1:1:2, the input/output current ratio of the drive circuit 21 is 1:1, and the output current of the constant current source is 2I 0 . The output current I 1 of the detection circuits 16 and 17 is I 1 if the voltage drop of the current mirror circuits 25 and 26 is ignored.
=(V BB −V L )/2R. Adder circuit output current
Since I 2 is the sum of absolute values, I 2 =(V BB −V L )/R. When the feedback loop is turned off by the control signal, the output current I 3 of the feedback circuit 20 becomes I 3 =I 2 /2.
The output current of the DC power supply circuits 14 and 15 is kI 3 .
Therefore, if kI 3 >>I 1 , the voltage V L between terminals 12 and 13 is expressed by the following equation.
VL＝１／１＋2R／kRLVBB
この式は
VL＝RL／RL＋2R／ＫVBB
で表わされ、この式から明らかなように直流給電
回路の給電抵抗は2R／Ｋで常に一定の値となる
ため、通常行なわれている定抵抗給電となる。 V L = 1/1 + 2R/kR L V BB This formula is expressed as V L = R L /R L +2R/KV BB , and as is clear from this formula, the power supply resistance of the DC power supply circuit is always 2R/K. Since it is a constant value, it becomes a constant resistance power supply that is normally performed.
制御信号によつて帰還ループがオンした場合、
カレントミラー回路２８の出力ｑはミラー比１：
Ｐ：ｑ＝１：１：２より2I3であるので制御回路
２９を通過する電流は2I0−2I3となる。このた
め、カレントミラー回路２７の加算回路１８から
の入力はI2−（2I0−2I3）となり、この回路２７の
出力ｍはミラー比１：ｍ＝１：0.5より入力の1/2
ですなわち、｛I2−（2I0−2I3）｝／２となる。この
電流はそのままカレントミラー回路２８への入力
となるが、ここでこの回路２８の入力と出力Ｐ
（＝I3）とはミラー比から同じ値となるため、I3
＝｛I2−（2I0−2I3）｝／２の関係が成り立ち、端子
１２，１３間の電圧VLは次式で示される。 When the feedback loop is turned on by the control signal,
The output q of the current mirror circuit 28 has a mirror ratio of 1:
Since P:q=1:1:2, the current is 2I 3 , so the current passing through the control circuit 29 is 2I 0 -2I 3 . Therefore, the input from the adder circuit 18 of the current mirror circuit 27 becomes I 2 −(2I 0 −2I 3 ), and the output m of this circuit 27 is 1/2 of the input from the mirror ratio 1:m=1:0.5.
In other words, {I 2 −(2I 0 −2I 3 )}/2. This current becomes the input to the current mirror circuit 28 as it is, but here the input and output P of this circuit 28 are
(=I 3 ) is the same value from the mirror ratio, so I 3
The relationship = {I 2 −(2I 0 −2I 3 )}/2 holds true, and the voltage V L between the terminals 12 and 13 is expressed by the following equation.
VL＝VBB−2RI0
したがつて通話電流の小さい領域（I22I0）
では端子１２，１３間の電圧は一定となる定電圧
給電となる。この電圧は定電流源１９の電流を変
化することによつて任意な値に設定出来る。すな
わち、VBB−VLを直流給電回路のダイナミツクレ
ンジ以上の電圧に設定することによつて通話電流
の小さい領域でも十分安定に通話電流を供給でき
る。 V L = V BB −2RI 0 Therefore, the area where the talking current is small (I 2 2I 0 )
In this case, the voltage between the terminals 12 and 13 is constant, resulting in constant voltage power supply. This voltage can be set to any value by changing the current of the constant current source 19. That is, by setting V BB -V L to a voltage higher than the dynamic range of the DC power supply circuit, it is possible to supply a sufficiently stable communication current even in a region where the communication current is small.
本発明は以上説明したように、定電流と検出電
流を比較する帰還ループを制御信号でオン・オフ
することによつて通話電流の小さい領域でも安定
に通話電流を供給出来ると共に、集積化による装
置の小型化、経済化が図れる効果がある。 As explained above, the present invention is capable of stably supplying a communication current even in a small communication current range by turning on and off the feedback loop that compares a constant current and a detected current using a control signal, and also enables a device to be integrated. This has the effect of making it more compact and economical.
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図は本発明の一実施例を示す回路図
である。
１，２，１２，１３……加入者回線に接続され
る端子、３，４，５，６，７，８，２３，２４…
…抵抗、９……PNPトランジスタ、１０……
NPNトランジスタ、１１，２２……直流電源、
１４，１５……一対の直流給電回路、１６，１７
……１対の検出回路、１８……加算回路、１９…
…定電流源、２０……帰還回路、２１……駆動回
路、２５，２６，２７，２８……カレントミラー
回路、２９……制御回路。
FIG. 1 is a circuit diagram showing an example of a conventional communication current supply circuit, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 1, 2, 12, 13...Terminals connected to subscriber lines, 3, 4, 5, 6, 7, 8, 23, 24...
...Resistor, 9...PNP transistor, 10...
NPN transistor, 11, 22...DC power supply,
14, 15...Pair of DC power supply circuits, 16, 17
...Pair of detection circuits, 18... Addition circuit, 19...
... constant current source, 20 ... feedback circuit, 21 ... drive circuit, 25, 26, 27, 28 ... current mirror circuit, 29 ... control circuit.
Claims (1)
を供給する通話電流供給回路において、 前記加入者回線の一方と前記直流電源の正側と
の間に接続された第１の直流給電回路と、前記加
入者回路の他方と前記直流電源の負側との間に接
続された第２の直流給電回路と、 前記加入者回路と電源間の電圧を検出して電流
に変換する一対の検出回路と、 前記一対の検出回路で変換された電流の和を得
る加算回路と、 一定電流を発生する定電流源の電流と前記加算
回路の出力電流を入力とする帰還ループを持つ帰
還回路と、 前記帰還ループを外部からの制御信号によつて
オン・オフする制御回路と、 前記帰還回路の出力を入力として前記第１およ
び第２の直流給電回路を駆動する電流を発生する
駆動回路と、 を備え、前記制御回路をオフして前記帰還回路の
帰還ループをオフすることにより定抵抗給電を行
い、また、前記制御回路をオンして前記帰還回路
の帰還ループをオンすることにより定電圧給電を
行うことを特徴とする通話電流供給回路。[Scope of Claims] 1. In a speech current supply circuit that supplies direct current to a terminal via a two-wire subscriber circuit, the circuit is connected between one of the subscriber lines and the positive side of the DC power supply. a first DC power supply circuit; a second DC power supply circuit connected between the other of the subscriber circuits and the negative side of the DC power supply; detecting the voltage between the subscriber circuit and the power supply; a pair of detection circuits that convert the currents into a current, an addition circuit that obtains the sum of the currents converted by the pair of detection circuits, and a feedback loop that receives as input the current of a constant current source that generates a constant current and the output current of the addition circuit. a control circuit that turns on and off the feedback loop according to an external control signal; and a control circuit that uses the output of the feedback circuit as an input to generate a current that drives the first and second DC power supply circuits. a drive circuit that performs constant resistance power supply by turning off the control circuit and turning off the feedback loop of the feedback circuit, and turning on the feedback loop of the feedback circuit by turning on the control circuit. A telephone current supply circuit characterized by performing constant voltage power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58035536A JPS59161172A (en) | 1983-03-04 | 1983-03-04 | Call current supplying circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58035536A JPS59161172A (en) | 1983-03-04 | 1983-03-04 | Call current supplying circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59161172A JPS59161172A (en) | 1984-09-11 |
| JPH0572788B2 true JPH0572788B2 (en) | 1993-10-13 |
Family
ID=12444450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58035536A Granted JPS59161172A (en) | 1983-03-04 | 1983-03-04 | Call current supplying circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59161172A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07199592A (en) * | 1993-12-28 | 1995-08-04 | Nec Corp | Electrifying part for electrophotographic printing device |
-
1983
- 1983-03-04 JP JP58035536A patent/JPS59161172A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59161172A (en) | 1984-09-11 |
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