JPH05145957A - Subscriber circuit - Google Patents
Subscriber circuitInfo
- Publication number
- JPH05145957A JPH05145957A JP3329587A JP32958791A JPH05145957A JP H05145957 A JPH05145957 A JP H05145957A JP 3329587 A JP3329587 A JP 3329587A JP 32958791 A JP32958791 A JP 32958791A JP H05145957 A JPH05145957 A JP H05145957A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- line
- power supply
- sum
- comparator
- 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
Links
Landscapes
- Devices For Supply Of Signal Current (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、加入者回路に関し、特
にループ検出回路に関する。FIELD OF THE INVENTION The present invention relates to subscriber circuits, and more particularly to loop detection circuits.
【0002】[0002]
【従来の技術】従来の加入者回路のループ検出回路は、
チップ線及びリング線の各々を流れる電流の値の和(以
下、和電流という)を検出し、この和電流が予め設定し
た一定値を越えるか否かで、ループ検出の判定を行って
いた。2. Description of the Related Art A conventional loop detection circuit for a subscriber circuit is
The sum of the values of the currents flowing through the tip line and the ring line (hereinafter referred to as the sum current) is detected, and the loop detection is determined by whether the sum current exceeds a preset constant value.
【0003】[0003]
【発明が解決しようとする課題】上述した従来のループ
検出回路では、ループ検出の判定を和電流が一定値を越
えるか否かで行っているため、給電用電源が変動した場
合に、ループ検出の閾値となる線路抵抗が変動するとい
う欠点があった。In the above-mentioned conventional loop detection circuit, since the loop detection is determined by whether the sum current exceeds a certain value, the loop detection is performed when the power supply for power supply changes. There is a drawback that the line resistance, which is the threshold value of, fluctuates.
【0004】本発明の目的は、給電用電源の変動に基づ
くループ検出の閾値となる線路抵抗の変動をなくした加
入者回路を提供することにある。An object of the present invention is to provide a subscriber circuit in which fluctuations in line resistance, which is a threshold for loop detection based on fluctuations in power supply for power supply, are eliminated.
【0005】[0005]
【課題を解決するための手段】上記目的を達成するた
め、本発明による加入者回路においては、和電流検出回
路と、基準電圧発生回路と、比較器とを有し、チップ線
及びリング線を介して端末装置に通話電流を供給する加
入者回路であって、和電流検出回路は、チップ線とリン
グ線との各々に流れる電流の和を電圧に変換して検出し
て比較器に出力するものであり、基準電圧発生回路は、
給電用電源の値に比例した電圧を比較器に出力するもの
であり、比較器は、和電流検出回路の出力電圧と、基準
電圧発生回路の出力電圧を比較して結果を出力するもの
である。In order to achieve the above object, a subscriber circuit according to the present invention has a sum current detection circuit, a reference voltage generation circuit, and a comparator, and has a tip line and a ring line. A subscriber circuit for supplying a call current to a terminal device via a sum current detection circuit, which converts a sum of currents flowing in each of a tip line and a ring line into a voltage, detects the voltage, and outputs the voltage to a comparator. The reference voltage generation circuit is
It outputs to the comparator a voltage proportional to the value of the power supply, and the comparator compares the output voltage of the sum current detection circuit with the output voltage of the reference voltage generation circuit and outputs the result. ..
【0006】[0006]
【作用】電話機がオフフックし、通話電流が加入者回路
から電話機に供給されると、チップ線と、リング線とに
流れている電流の和を和電流検出回路により検出する。
この和電流検出回路出力電圧V1と、基準電圧発生回路
により作られた給電用電源VBBに比例した電圧V2とを
比較器により比較し、ループ検出の判定を行うことで、
ループ検出の閾値となる線路抵抗の値を給電用電源VBB
に依存せずに設定することが可能となる。When the telephone goes off-hook and the call current is supplied to the telephone from the subscriber circuit, the sum of the currents flowing through the tip line and the ring line is detected by the sum current detection circuit.
By comparing the output voltage V 1 of the sum current detection circuit and the voltage V 2 proportional to the power supply V BB for power supply generated by the reference voltage generation circuit by the comparator and determining the loop detection,
The value of the line resistance, which is the threshold for loop detection, is the power supply V BB
It becomes possible to set it without depending on.
【0007】[0007]
【実施例】次に本発明の実施例を図面を参照して説明す
る。図1は、本発明の一実施例の回路図である。図にお
いて、電話機1は、チップ線2及びリング線3を介して
加入者回路4に接続されている。チップ線2は、抵抗器
R1と給電回路5とを介して接地し、リング線3は、抵
抗器R2と給電回路6とを介して給電用電源VBBに接続
されている。給電回路5は、抵抗器R9とインダクタン
スL1、給電回路6は、抵抗器R10とインダクタンスL2
との直列回路で構成されている。ここで、抵抗器R1と
R2及び抵抗器R9とR10の抵抗値は等しい値をとるもの
とする。Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention. In the figure, a telephone 1 is connected to a subscriber circuit 4 via a tip line 2 and a ring line 3. The tip line 2 is grounded via the resistor R 1 and the power supply circuit 5, and the ring line 3 is connected to the power supply V BB via the resistor R 2 and the power supply circuit 6. The power feeding circuit 5 has a resistor R 9 and an inductance L 1 , and the power feeding circuit 6 has a resistor R 10 and an inductance L 2.
And a series circuit. Here, it is assumed that the resistors R 1 and R 2 and the resistors R 9 and R 10 have the same resistance value.
【0008】抵抗器R1及び抵抗器R2の両端子は、演算
増幅器OPAと、抵抗器R3,R4,R5,R6,R7,R8
からなる和電流検出回路7に接続し、抵抗器R1からチ
ップ線2に流れる電流ITと、リング線3から抵抗器R2
に流れる電流IRとの和電流に比例した電圧を演算増幅
器OPAから出力している。抵抗器R3,R4,R5,
R6,R7,R8は、すべて等しく、かつ抵抗器R1,R2
に対して十分大きな抵抗値をとるものとする。演算増幅
器OPAの出力端子は、比較器9の入力端子に接続され
ている。Both terminals of the resistor R 1 and the resistor R 2 are connected to an operational amplifier OPA and resistors R 3 , R 4 , R 5 , R 6 , R 7 and R 8 respectively.
Connect the sum current detection circuit 7 composed of a resistor and a current I T flows from R 1 to the chip line 2, a resistor R 2 from the ring line 3
The voltage that is proportional to the sum of the current I R flowing through the operational amplifier OPA is output from the operational amplifier OPA. Resistors R 3 , R 4 , R 5 ,
R 6 , R 7 and R 8 are all equal and resistors R 1 and R 2 are
It is assumed that the resistance value is sufficiently large. The output terminal of the operational amplifier OPA is connected to the input terminal of the comparator 9.
【0009】基準電圧発生回路8では、抵抗器R11とR
12との直列回路のR12側の端子が接地され、R11側の端
子には、給電用電源VBBが接続され、また抵抗器R11と
R12の中点は、整流回路RECを介して比較器9のもう
一方の入力端子に接続されている。比較器9は、ループ
検出を行うと、ループ検出信号を出力するループ検出信
号出力端子を持っている。In the reference voltage generating circuit 8, resistors R 11 and R
The grounded terminal of R 12 side of the series circuit of the 12, to the terminal of R 11 side, the midpoint of the power supply source V BB is connected and a resistor R 11 and R 12 are, via a rectifier circuit REC And is connected to the other input terminal of the comparator 9. The comparator 9 has a loop detection signal output terminal that outputs a loop detection signal when performing loop detection.
【0010】図2(a),(b),(c)は、電話機1
がオフフックされ加入者回路4から電話機1に通話電流
が供給された場合の各部の給電用電源VBBに対する変化
を示したものである。2A, 2B and 2C show a telephone 1
Shows the change with respect to the power supply V BB of each unit when the call current is supplied from the subscriber circuit 4 to the telephone 1 by the above.
【0011】図2(a)は、チップ線2に流れる電流I
T及びリング線3に流れる電流IRを示し、図2(b)
は、和電流検出回路7の出力電圧V1を示し、図2
(c)は、基準電圧発生回路8の出力電圧V2を示す。FIG. 2A shows a current I flowing through the chip line 2.
The current I R flowing through T and the ring line 3 is shown in FIG.
Shows the output voltage V 1 of the sum current detection circuit 7, and FIG.
(C) shows the output voltage V 2 of the reference voltage generation circuit 8.
【0012】次に動作について説明する。今、電話機1
がオフフック状態で電話機1に加入者回路4から通話電
流が供給されており、チップ線及びリング線の線路抵抗
はRLとする。Next, the operation will be described. Phone 1 now
In the off-hook state, the telephone line 1 is supplied with the call current from the subscriber circuit 4, and the line resistance of the tip line and the ring line is RL .
【0013】チップ線及びリング線に流れる電流IT,
IRは、R1+R9=R2+R10=RBとすると、(1)式
で表わされる。 IT=IR=|VBB|/(RL+2RB) …(1)The current I T flowing through the tip line and the ring line,
I R is represented by the equation (1), where R 1 + R 9 = R 2 + R 10 = R B. I T = I R = | V BB | / (R L + 2R B ) (1)
【0014】また和電流検出回路出力電圧V1は、R1+
R2=RAとすると、(2)式で表わされる。 V1=RA・(IT+IR)=2RA・|VBB|/(RL+2RB) …(2)The output voltage V 1 of the sum current detection circuit is R 1 +
When R 2 = RA , it is represented by the equation (2). V 1 = R A · (I T + I R) = 2R A · | V BB | / (R L + 2R B) ... (2)
【0015】また基準電圧発生回路出力電圧V2は、
(3)式で表わされる。 V1=R12/(R11+R12)・|VBB| …(3)The output voltage V 2 of the reference voltage generating circuit is
It is expressed by equation (3). V 1 = R 12 / (R 11 + R 12 ) · | V BB | (3)
【0016】ループ検出の判定の閾値の条件は、和電流
検出回路7の出力電圧V1と、基準電圧発生回路8の出
力電圧が等しくなったときであるから(4)式で表わさ
れる。 V1=V2 …(4)The condition of the threshold value for the loop detection judgment is expressed by the equation (4) because the output voltage V 1 of the sum current detection circuit 7 and the output voltage of the reference voltage generation circuit 8 become equal. V 1 = V 2 (4)
【0017】(2),(3),(4)式より、ループ検
出の判定の閾値となる線路抵抗R1は、(5)式で表わ
される。 2RA・|VBB|/(RL+2RB)=R12・|VBB|/(R12+R11) RL=2・RA・(R12+R11)/R12−2RB …(5)From the equations (2), (3) and (4), the line resistance R 1 which is the threshold value for the loop detection determination is expressed by the equation (5). 2R A · | V BB | / (R L + 2R B) = R 12 · | V BB | / (R 12 + R 11) R L = 2 · R A · (R 12 + R 11) / R 12 -2R B ... (5)
【0018】(5)式より、ループ検出の判定の閾値と
なる線路抵抗RLは、抵抗器R1,R2,R9,R10,
R11,R12の抵抗値により決定され、給電用電源VBBに
依存しない。From the equation (5), the line resistance RL, which is the threshold value for the loop detection judgment, is determined by the resistors R 1 , R 2 , R 9 , R 10 ,
It is determined by the resistance values of R 11 and R 12 , and does not depend on the power supply V BB for power supply.
【0019】[0019]
【発明の効果】以上説明したように本発明によれば、ル
ープ検出の基準となる閾値電圧に給電用電源に比例した
電圧を用いることで、ループ検出の閾値となる線路抵抗
が給電用電源に依存せず設定できるという効果がある。As described above, according to the present invention, by using a voltage proportional to the power supply for power supply as the threshold voltage that serves as a reference for loop detection, the line resistance that becomes the threshold for loop detection is used as the power supply for power supply. The effect is that it can be set independently.
【図1】図1は本発明の一実施例の回路図である。FIG. 1 is a circuit diagram of an embodiment of the present invention.
【図2】(a)は、チップ線,リング線に流れる電流の
給電用電源による変化を示し、(b)は、和電流検出回
路出力電圧の給電用電源による変化を示し、(c)は、
基準電圧発生回路の出力電圧の給電用電源による変化を
示す図である。FIG. 2A shows a change in current flowing through a tip line and a ring line due to a power supply power supply, FIG. 2B shows a change in output voltage of a sum current detection circuit due to a power supply power supply, and FIG. ,
It is a figure which shows the change by the power supply for electric power feeding of the output voltage of a reference voltage generation circuit.
【符号の説明】 1 電話機 2 チップ線 3 リング線 4 加入者回路 5,6 給電回路 7 和電流検出回路 8 基準電圧発生回路 9 比較器 REC 整流回路 IT チップ線に流れる電流 IR リング線に流れる電流 R1,R2,R3,R4,R5,R6,R7,R8,R9,
R10,R11,R12 抵抗器 OPA 演算増幅器 L1,L2 コイル VBB 給電用電源[Explanation of Codes] 1 Telephone 2 Chip line 3 Ring line 4 Subscriber circuit 5,6 Power supply circuit 7 Sum current detection circuit 8 Reference voltage generation circuit 9 Comparator REC rectifier circuit I T Current flowing in chip line I R Ring line Flowing currents R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 ,
R 10 , R 11 , R 12 resistor OPA operational amplifier L 1 , L 2 coil V BB power supply for power supply
Claims (1)
と、比較器とを有し、チップ線及びリング線を介して端
末装置に通話電流を供給する加入者回路であって、 和電流検出回路は、チップ線とリング線との各々に流れ
る電流の和を電圧に変換して検出して比較器に出力する
ものであり、 基準電圧発生回路は、給電用電源の値に比例した電圧を
比較器に出力するものであり、 比較器は、和電流検出回路の出力電圧と、基準電圧発生
回路の出力電圧を比較して結果を出力するものであるこ
とを特徴とする加入者回路。1. A subscriber circuit having a sum current detection circuit, a reference voltage generation circuit, and a comparator, which supplies a call current to a terminal device via a chip line and a ring line, the sum current detection circuit comprising: The circuit converts the sum of the currents flowing in each of the tip line and ring line into a voltage and detects it, and outputs it to a comparator.The reference voltage generation circuit outputs a voltage proportional to the value of the power supply A subscriber circuit, which outputs to a comparator, and the comparator compares the output voltage of the sum current detection circuit with the output voltage of the reference voltage generation circuit and outputs the result.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3329587A JPH05145957A (en) | 1991-11-18 | 1991-11-18 | Subscriber circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3329587A JPH05145957A (en) | 1991-11-18 | 1991-11-18 | Subscriber circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH05145957A true JPH05145957A (en) | 1993-06-11 |
Family
ID=18223021
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3329587A Pending JPH05145957A (en) | 1991-11-18 | 1991-11-18 | Subscriber circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH05145957A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008516211A (en) * | 2004-10-20 | 2008-05-15 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method, apparatus and circuit for detecting roll surface defects, such as cracks, depressions, etc., in rolling equipment |
-
1991
- 1991-11-18 JP JP3329587A patent/JPH05145957A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008516211A (en) * | 2004-10-20 | 2008-05-15 | エス・エム・エス・デマーク・アクチエンゲゼルシャフト | Method, apparatus and circuit for detecting roll surface defects, such as cracks, depressions, etc., in rolling equipment |
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