JP3335648B2 - Call current supply device - Google Patents
Call current supply deviceInfo
- Publication number
- JP3335648B2 JP3335648B2 JP14105091A JP14105091A JP3335648B2 JP 3335648 B2 JP3335648 B2 JP 3335648B2 JP 14105091 A JP14105091 A JP 14105091A JP 14105091 A JP14105091 A JP 14105091A JP 3335648 B2 JP3335648 B2 JP 3335648B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- current
- power supply
- constant
- 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 - Fee Related
Links
Classifications
-
- 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
- Devices For Supply Of Signal Current (AREA)
- Interface Circuits In Exchanges (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電話交換機の加入者回
線に通話電流を供給する通話電流供給装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speech current supply device for supplying speech current to a subscriber line of a telephone exchange.
【０００２】[0002]
【従来の技術】従来、電話交換機において用いられてい
る電流供給装置は、図２に示すような回路構成となって
いる。図２において、１，２は加入者回線に接続される
端子であり、３，４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。６，７は
一対の検出回路であり、端子１と直流電源２０の一方の
端子間の電圧および端子２と直流電源２０の他方の端子
間の電圧を検出し、抵抗８，９とカレントミラー回路１
０，１１で電流に変換する。１２は前記検出回路で検出
された電流を加算（絶対値和）する加算回路である。１
３は加算回路１２の出力電流を入力とする帰還ループを
もつ定抵抗給電帰還回路であり、カレントミラー回路１
４，１５で構成されている。５は駆動回路であり、定抵
抗給電帰還回路１３の出力を入力として、前記直流給電
回路３，４の駆動電流を発生する。この駆動回路５から
の電流は、前記直流給電回路３，４に入力され、任意の
大きさ（ｋ倍）に増幅される。2. Description of the Related Art Conventionally, a current supply device used in a telephone exchange has a circuit configuration as shown in FIG. In FIG. 2, reference numerals 1 and 2 denote terminals connected to a subscriber line, and reference numerals 3 and 4 denote a pair of DC power supply circuits for supplying a call current to terminals connected to the subscriber line. Reference numerals 6 and 7 denote a pair of detection circuits which detect a voltage between the terminal 1 and one terminal of the DC power supply 20 and a voltage between the terminal 2 and the other terminal of the DC power supply 20, and connect the resistors 8 and 9 to the current mirror circuit. 1
It is converted to a current at 0,11. Reference numeral 12 denotes an addition circuit for adding (summing the absolute values) the currents detected by the detection circuit. 1
Reference numeral 3 denotes a constant-resistance feed-back circuit having a feedback loop to which the output current of the adder circuit 12 is input.
4 and 15. Reference numeral 5 denotes a drive circuit, which generates a drive current for the DC power supply circuits 3 and 4 using an output of the constant resistance power supply feedback circuit 13 as an input. The current from the drive circuit 5 is input to the DC power supply circuits 3 and 4 and is amplified to an arbitrary magnitude (k times).
【０００３】１７はスイッチ回路であり、端末に供給す
る直流給電電流を制限する場合に定抵抗給電帰還回路１
３と電流制御回路１８を接続する。電流制御回路１８
は、スイッチ回路１７が閉成したときに定抵抗給電帰還
回路１３の帰還電流を制御する。１９は電源回路であ
り、基準電圧ＶEEを定抵抗給電帰還回路１３へ供給す
る。２０は電源電圧ＶBBの電源であり、２１は電源電圧
ＶCCの電源である。Reference numeral 17 denotes a switch circuit, which is a constant-resistance feed-back circuit 1 for limiting a DC feed current supplied to a terminal.
3 and the current control circuit 18 are connected. Current control circuit 18
Controls the feedback current of the constant-resistance feed-back circuit 13 when the switch circuit 17 is closed. A power supply circuit 19 supplies the reference voltage V EE to the constant-resistance feed-back circuit 13. Reference numeral 20 denotes a power supply having a power supply voltage V BB , and reference numeral 21 denotes a power supply having a power supply voltage V CC .
【０００４】次に端子１，２に、加入者回線，電話機等
の負荷と等価の直流負荷ＲLを接続した場合について説
明する。端子１，２間の電圧をＶL、直流負荷ＲLに流れ
る通話電流をＩL、検出回路６，７における抵抗８，９
の抵抗値をＲ、カレントミラー回路１０，１１，１４，
１５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＝１：
１、駆動回路５の入出力電流比を１：１、抵抗１６の抵
抗値をＲCDC、抵抗１６の両端の電圧をＶCDCとする。Next, a case where a DC load RL equivalent to a load of a subscriber line, a telephone or the like is connected to the terminals 1 and 2 will be described. The voltage between the terminals 1 and 2 is V L , the call current flowing through the DC load RL is I L , and the resistors 8 and 9 in the detection circuits 6 and 7 are provided.
Is R, the current mirror circuits 10, 11, 14,
15 mirror ratios (ratio of input current to output current) of 1: n = 1: 1, 1: m = 1: 0.5, 1: p = 1:
1. The input / output current ratio of the drive circuit 5 is 1: 1, the resistance of the resistor 16 is R CDC , and the voltage across the resistor 16 is V CDC .
【０００５】このような条件下において、 （１）通話電流を制限しない場合 スイッチ回路１７は開き、電流制限回路１８を定抵抗給
電帰還回路１３から開放している。検出回路６，７の出
力電流Ｉ1は、カレントミラー回路１０，１１の電圧降
下を無視するとＩ1＝（ＶBB−ＶL）／２Ｒとなる。加算
回路１２の出力電流Ｉ2は、出力電流Ｉ1の絶対値和であ
るため、Ｉ2＝（ＶBB−ＶL）／Ｒとなる。また、定抵抗
給電帰還回路１３の出力電流Ｉ3は、Ｉ3＝Ｉ2／２とな
る。したがって、直流給電回路３，４の出力電流は駆動
電流のｋ倍、すなわちｋ・Ｉ3となる。よって、ｋ・
Ｉ3》Ｉ1とすると、端子１，２間の電圧は次式で示され
る。 ＶL＝１／１＋（２Ｒ／ｋＲL）・ＶBB すなわち、定抵抗帰還回路１３により、直流給電回路
３，４の給電抵抗が一定な定抵抗給電となる。[0005] Under such conditions, (1) When the call current is not limited The switch circuit 17 is opened, and the current limit circuit 18 is opened from the constant-resistance feed-back circuit 13. Output current I 1 of the detection circuit 6 and 7, I 1 = a (V BB -V L) / 2R and ignoring the voltage drop of the current mirror circuits 10 and 11. Output current I 2 of the adder circuit 12 are the absolute value sum of the output currents I 1, I 2 = a (V BB -V L) / R . Further, the output current I 3 of the constant resistance power feed feedback circuit 13 becomes I 3 = I 2/2. Therefore, the output current of the DC power supply circuits 3 and 4 is k times the drive current, that is, k · I 3 . Therefore, k
If I 3 >> I 1 , the voltage between the terminals 1 and 2 is expressed by the following equation. V L = 1/1 + (2R / kR L ) · V BB In other words, the constant-resistance feedback circuit 13 ensures that the power supply resistance of the DC power supply circuits 3 and 4 is constant-resistance power supply.
【０００６】（２）通話電流を制限する場合 スイッチ回路１７は閉じ、電流制限回路１８を定抵抗給
電帰還回路１３と接続している。電流制限回路１８は、
定抵抗給電帰還回路１３の帰還電流の制限を行う。これ
により、定抵抗給電帰還回路１３における抵抗１６の両
端の電圧ＶCDCは、ＶCLP以下に制限される。したがっ
て、Ｉ2ＲCDC＞ＶCLPとすると、定抵抗給電帰還回路１
３の出力電流Ｉ3は、Ｉ3＝ＶCLP／ＲCDCに制限される。
また、直流給電回路３，４の出力電流は、ｋ・Ｉ3とな
り、ｋ・Ｉ3）Ｉ1とすると、端子１，２間の電圧は次式
で示される。 ＶL＝ｋ・ＶCLP・ＲL／ＲCDC すなわち、電流制限回路１８により、直流給電回路３，
４の給電電流が一定な定電流給電となる。(2) Limiting the call current The switch circuit 17 is closed, and the current limit circuit 18 is connected to the constant-resistance feed-back circuit 13. The current limiting circuit 18
The feedback current of the constant-resistance feed-back circuit 13 is limited. As a result, the voltage V CDC across the resistor 16 in the constant-resistance feed-back circuit 13 is limited to V CLP or less. Therefore, if I 2 R CDC > V CLP , the constant-resistance feed-back circuit 1
Output current I 3 of 3 is limited to I 3 = V CLP / R CDC .
The output currents of the DC power supply circuits 3 and 4 are k · I 3 , and if k · I 3 ) I 1 , the voltage between the terminals 1 and 2 is expressed by the following equation. V L = k · V CLP · R L / R CDC That is, the DC limiting circuit 3
4 is a constant current supply.
【０００７】[0007]
【発明が解決しようとする課題】上述した通話電流供給
装置においては、通話電流を制御しない状態から通話電
流を制御する状態への移行時、電流制御回路から電源回
路へ急激に電流が流れる。このため、電源回路１９の出
力インピーダンスに比例して電源回路１９の出力電源が
振動し、定抵抗給電帰還回路１３の出力電流が振動する
ため加入者端末で可聴雑音が発生するという問題点があ
った。In the above-described communication current supply device, when the state changes from the state in which the communication current is not controlled to the state in which the communication current is controlled, the current suddenly flows from the current control circuit to the power supply circuit. Therefore, the output power is oscillation of the power supply circuit 19 in proportion to the output impedance of the power supply circuit 19, a problem that the output current of the constant resistance feed back circuit 13 is audible noise is generated in the subscriber terminal to vibrate Was.
【０００８】本発明は上記問題点にかんがみてなされた
ものであり、通話電流を制御しない状態から通話電流を
制御する状態への移行時に、定抵抗給電帰還回路１３の
出力電流を安定させ、加入者端末での可聴雑音の発生を
防止した通話電流供給装置の提供を目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and stabilizes the output current of the constant-resistance feed-back circuit 13 during the transition from a state in which the call current is not controlled to a state in which the call current is controlled. It is an object of the present invention to provide a communication current supply device that prevents generation of audible noise in a user terminal.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するた
め、電話交換機における加入者回線に通話電流を供給す
る本発明の通話電流供給装置は、２線式加入者回線を経
由して端末に直流電流を供給する通話電流供給装置にお
いて、前記加入者回線の一方に接続される一方の端子と
電源の一方の端子に接続される他方の端子とを有する直
流給電回路と、前記加入者回線の他方に接続される一方
の端子と電源の他方の端子に接続される他方の端子とを
有する直流給電回路と、この加入者回線と電源間の電圧
を検出して電流に変換する一対の検出回路と、この検出
回路の検出電流の和を得る加算回路と、この加算回路の
加算電流を入力とし前記直流給電回路を駆動する電流を
発生する定抵抗給電帰還回路と、この定抵抗給電帰還回
路の出力電流により前記給電回路を駆動する駆動回路
と、前記定抵抗給電帰還回路へ基準電圧を供給する電源
回路と、スイッチ回路の閉成により前記定抵抗給電帰還
回路の帰還電流を制御し、前記端末に供給する直流電流
を制御する電流制御回路と、エミッタが前記電流制御回
路の一端に接続され、コレクタが前記電源の一方に接続
され、ベースが、前記電流制御回路から前記電源回路に
流れる電流の高周波数成分を除去する低域ろ波器を経由
して前記電源回路に接続された、前記電流制御回路から
前記電源回路に流れる電流を低減するトランジスタを有
する構成としてある。In order to achieve the above object, the present invention provides a call current supply apparatus for supplying a call current to a subscriber line in a telephone exchange. in speech current supply device for supplying a current, straight with the other terminal connected to one terminal and one terminal of the power supply connected to one of said subscriber line
A power supply circuit and one connected to the other of the subscriber lines
Terminal and the other terminal connected to the other terminal of the power supply.
A DC power supply circuit, a pair of detection circuits for detecting a voltage between the subscriber line and the power supply and converting the voltage to a current, an addition circuit for obtaining a sum of detection currents of the detection circuit, and an addition current of the addition circuit. A constant-resistance feed-back circuit that generates a current for driving the DC feed circuit as an input; a drive circuit that drives the feed circuit by an output current of the constant-resistance feed-back circuit; and a reference voltage to the constant-resistance feed feedback circuit. A power supply circuit for supplying, a current control circuit for controlling a feedback current of the constant resistance power supply feedback circuit by closing a switch circuit to control a DC current supplied to the terminal, and an emitter for controlling the DC current supplied to the terminal. And a collector is connected to one of the power supplies, and a base is connected from the current control circuit to the power supply circuit .
The power supply circuit further includes a transistor connected to the power supply circuit via a low-pass filter that removes a high-frequency component of the flowing current and configured to reduce a current flowing from the current control circuit to the power supply circuit.
【００１０】[0010]
【実施例】次に、本発明について図面を参照して説明す
る。図１は本発明の一実施例を示す回路図である。な
お、。図１における、図２と同一符号のものは相当部分
を示す。したがって、その部分の説明は省略する。２３
は低域ろ波器であり、抵抗値ＲFの抵抗２４と、容量値
ＣFのコンデンサ２５で構成され、その出力側は電源回
路１９に接続されている。２２はＰＮＰ型トランジスタ
であり、エミッタが電流制御回路１８に接続され、コレ
クタが電源電圧ＶBBの電源２０に接続され、ベースが低
域ろ波器２３の入力に接続される。Next, the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing one embodiment of the present invention. In addition,. 1 in FIG. 1 indicate the same parts as those in FIG. Therefore, the description of that part is omitted. 23
Is a low-pass filter, which comprises a resistor 24 having a resistance value R F and a capacitor 25 having a capacitance value C F , and the output side of which is connected to the power supply circuit 19. Reference numeral 22 denotes a PNP transistor. The emitter is connected to the current control circuit 18, the collector is connected to the power supply 20 of the power supply voltage V BB , and the base is connected to the input of the low-pass filter 23.
【００１１】このように構成した実施例の動作を説明す
る。 （１）通話電流を制限しない場合 スイッチ回路１７は開き、電流制限回路１８を定抵抗給
電帰還回路１３から開放している。検出回路６，７の出
力電流Ｉ1は、カレントミラー回路１０，１１の電圧降
下を無視するとＩ1＝（ＶBB−ＶL）／２Ｒとなる。加算
回路１２の出力電流Ｉ2は、出力電流Ｉ1の絶対値和であ
るため、Ｉ2＝（ＶBB−ＶL）／Ｒとなる。また、定抵抗
給電帰還回路１３の出力電流Ｉ3は、Ｉ3＝Ｉ2／２とな
る。したがって、直流給電回路３，４の出力電流は駆動
電流のｋ倍、すなわちｋ・Ｉ3となる。よって、ｋ・
Ｉ3》Ｉ1とすると、端子１，２間の電圧は次式で示され
る。 ＶL＝１／１＋（２Ｒ／ｋＲL）・ＶBB すなわち、定抵抗帰還回路１３により、直流給電回路
３，４の給電抵抗が一定な定抵抗給電となる。The operation of the embodiment constructed as described above will be described. (1) When the call current is not limited The switch circuit 17 is opened, and the current limit circuit 18 is opened from the constant-resistance feed-back circuit 13. Output current I 1 of the detection circuit 6 and 7, I 1 = a (V BB -V L) / 2R and ignoring the voltage drop of the current mirror circuits 10 and 11. Output current I 2 of the adder circuit 12 are the absolute value sum of the output currents I 1, I 2 = a (V BB -V L) / R . Further, the output current I 3 of the constant resistance power feed feedback circuit 13 becomes I 3 = I 2/2. Therefore, the output current of the DC power supply circuits 3 and 4 is k times the drive current, that is, k · I 3 . Therefore, k
If I 3 >> I 1 , the voltage between the terminals 1 and 2 is expressed by the following equation. V L = 1/1 + (2R / kR L ) · V BB In other words, the constant-resistance feedback circuit 13 ensures that the power supply resistance of the DC power supply circuits 3 and 4 is constant-resistance power supply.
【００１２】（２）通話電流を制限する場合 スイッチ回路１７は閉じ、電流制限回路１８を定抵抗給
電帰還回路１３と接続している。電流制限回路１８は、
定抵抗給電帰還回路１３の帰還電流の制限を行う。これ
により、定抵抗給電帰還回路１３における抵抗１６の両
端の電圧ＶCDCは、ＶCLP以下に制限される。したがっ
て、Ｉ2ＲCDC＞ＶCLPとすると、定抵抗給電帰還回路１
３の出力電流Ｉ3は、Ｉ3＝ＶCLP／ＲCDCに制限される。
また、直流給電回路３，４の出力電流Ｉ3は、ｋ・Ｉ3と
なり、ｋ・Ｉ3）Ｉ1とすると、端子１，２間の電圧は次
式で示される。 ＶL＝ｋ・ＶCLP・ＲL／ＲCDC すなわち、電流制限回路１８により、直流給電回路３，
４の給電電流が一定な定電流給電となる。(2) Limiting the Call Current The switch circuit 17 is closed, and the current limit circuit 18 is connected to the constant-resistance feed-back circuit 13. The current limiting circuit 18
The feedback current of the constant-resistance feed-back circuit 13 is limited. As a result, the voltage V CDC across the resistor 16 in the constant-resistance feed-back circuit 13 is limited to V CLP or less. Therefore, if I 2 R CDC > V CLP , the constant-resistance feed-back circuit 1
Output current I 3 of 3 is limited to I 3 = V CLP / R CDC .
The output current I 3 of the DC power supply circuits 3 and 4 is k · I 3 , where k · I 3 ) I 1 , the voltage between the terminals 1 and 2 is expressed by the following equation. V L = k · V CLP · R L / R CDC That is, the DC limiting circuit 3
4 is a constant current supply.
【００１３】（３）通話電流を制御しない状態から通話
電流を制御する状態へ移行の場合 スイッチ回路１７が閉じて、電流制御回路１８を定抵抗
給電帰還回路１３と接続することにより、定抵抗給電帰
還回路１３の帰還電流の制御動作を開始する。このた
め、定抵抗給電帰還回路１３から電流制御回路１８を経
由して制御された定抵抗給電帰還電流Ｉ4が、ＰＮＰト
ランジスタ２２のエミッタからコレクタを経由して電源
ＶBBに流れる。このとき、ＰＮＰトランジスタ２２のベ
ースに流れる電流は、ＰＮＰトランジスタ２２の直流電
流増幅率をｈ FE とすると、１／（１＋ｈ FE ）に低減され
る。さらに、抵抗２４とコンデンサ２５で構成された低
域ろ波器２３で、高周波数成分の電流が除去されて電源
回路１９に流れる。これにより、電源回路１９の出力電
流の振動が抑制され、通話電流を制御しない状態から通
話電流を制御する状態への移行時にも定抵抗給電帰還回
路１３の出力電流Ｉ3が安定する。(3) In the case of transition from a state in which the call current is not controlled to a state in which the call current is controlled, the switch circuit 17 is closed, and the current control circuit 18 is connected to the constant-resistance feed-back circuit 13 so that the constant-resistance feed is performed. The control operation of the feedback current of the feedback circuit 13 is started. Therefore, constant resistance power feed feedback current I 4 that is controlled via the current control circuit 18 from the constant resistance feed back circuit 13, flows to the power source V BB through the collector from the emitter of the PNP transistor 22. At this time, the current flowing to the base of the PNP transistor 22 is reduced to 1 / (1 + h FE ), where the DC current gain of the PNP transistor 22 is h FE . Further, the low-pass filter 23 composed of the resistor 24 and the capacitor 25 removes the high frequency component current and flows to the power supply circuit 19. This will oscillation of the output current of the power supply circuit 19 is suppressed, even during the transition to state that controls the speech current from the state of not controlling the call current output current I 3 of the constant resistance feed back circuit 13 is stabilized.
【００１４】本発明は上記実施例に限定されるものでは
なく、要旨の範囲内での変形例を含むものであり、例え
ば、ＰＮＰトランジスタ以外のトランジスタを用いたも
のであってもよい。The present invention is not limited to the above embodiment, but includes modifications within the scope of the gist. For example, a transistor other than a PNP transistor may be used.
【００１５】[0015]
【発明の効果】以上説明したように、本発明の通話電流
供給装置によれば、電流制限回路を経由して電源回路に
流れ込む電流をトランジスタによって低減し、さらに低
域ろ波器によって高周波数成分を除去しているので、通
話電流を制限しない状態から通話電流を制限する状態へ
の移行時に、電流制限回路を経由して電源回路に急激に
流れ込む電流によって発生する電源回路の出力インピー
ダンスに比例した電圧の振動が抑制されるので、定抵抗
給電帰還回路の出力電流が安定し、加入者端末における
可聴雑音の発生を防止できるという効果を有する。As described above, according to the speech current supply device of the present invention, the current flowing into the power supply circuit via the current limiting circuit is reduced by the transistor, and the high frequency component is further reduced by the low-pass filter. When switching from the state where the call current is not limited to the state where the call current is limited, the output impedance is proportional to the output impedance of the power circuit generated by the current that suddenly flows into the power circuit via the current limiting circuit. Since the oscillation of the voltage is suppressed, the output current of the constant-resistance feed-back circuit is stabilized, and there is an effect that generation of audible noise in the subscriber terminal can be prevented.
【図１】本発明の通話電流供給装置一実施例のブロック
図である。FIG. 1 is a block diagram of a communication current supply device according to an embodiment of the present invention.
【図２】従来の通話電流供給装置一実施例のブロック図
である。FIG. 2 is a block diagram of one embodiment of a conventional communication current supply device.
３，４…直流給電回路 ５…駆動回路 ６，７…検出回路 １０，１１，１４，１５…カレントミラー回路 １２…加算回路 １３…定抵抗給電帰還回路 １７…スイッチ回路 １８…電流制御回路 １９…電源回路 ２０…電源 ２２…ＰＮＰ型トランジスタ ２３…低域ろ波器 3, 4 DC power supply circuit 5 Drive circuit 6, 7 Detection circuit 10, 11, 14, 15 Current mirror circuit 12 Addition circuit 13 Constant resistance power supply feedback circuit 17 Switch circuit 18 Current control circuit 19 Power supply circuit 20 Power supply 22 PNP transistor 23 Low-pass filter
Claims (1)
電流を供給する通話電流供給装置において、 前記加入者回線の一方に接続される一方の端子と電源の
一方の端子に接続される他方の端子とを有する直流給電
回路と、前記加入者回線の他方に接続される一方の端子と電源の
他方の端子に接続される他方の端子とを有する直流給電
回路と、 この加入者回線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、 この検出回路の検出電流の和を得る加算回路と、 この加算回路の加算電流を入力とし前記直流給電回路を
駆動する電流を発生する定抵抗給電帰還回路と、 この定抵抗給電帰還回路の出力電流により前記給電回路
を駆動する駆動回路と、 前記定抵抗給電帰還回路へ基準電圧を供給する電源回路
と、 スイッチ回路の閉成により前記定抵抗給電帰還回路の帰
還電流を制御し、前記端末に供給する直流電流を制御す
る電流制御回路と、 エミッタが前記電流制御回路の一端に接続され、コレク
タが前記電源の一方に接続され、ベースが、前記電流制
御回路から前記電源回路に流れる電流の高周波数成分を
除去する低域ろ波器を経由して前記電源回路に接続され
た、前記電流制御回路から前記電源回路に流れる電流を
低減するトランジスタを有することを特徴とした通話電
流供給装置。1. A direct current to a terminal via a two-wire subscriber line.
A call current supply device for supplying current, which is connected to one of the subscriber lines.OneTerminal and power supply
One terminalConnected toThe otherHaving terminalsDCFeeding
Circuit andOne terminal connected to the other side of the subscriber line and a power supply
DC power supply having the other terminal connected to the other terminal
Circuit and The voltage between this subscriber line and the power supply is detected and converted to a current.
A pair of detection circuits, an addition circuit for obtaining a sum of detection currents of the detection circuits, and
A constant-resistance feed-back circuit for generating a driving current; and
A power supply circuit for supplying a reference voltage to the constant-resistance feed-back circuit
And the return of the constant-resistance feed-back circuit by closing the switch circuit.
Control the return current and supply it to the terminalDC currentControl
A current control circuit, and an emitter connected to one end of the current control circuit.
A power supply is connected to one of the power supplies and a base is connected to the current
The power circuit from the control circuitFlow toHigh frequency components of the current
The power circuit via a low-pass filter to be removedConnect toIs
Further, a current flowing from the current control circuit to the power supply circuit is
Telecommunications telephone characterized by having a transistor to reduce
Flow supply device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14105091A JP3335648B2 (en) | 1991-05-16 | 1991-05-16 | Call current supply device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14105091A JP3335648B2 (en) | 1991-05-16 | 1991-05-16 | Call current supply device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04340851A JPH04340851A (en) | 1992-11-27 |
| JP3335648B2 true JP3335648B2 (en) | 2002-10-21 |
Family
ID=15283089
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14105091A Expired - Fee Related JP3335648B2 (en) | 1991-05-16 | 1991-05-16 | Call current supply device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3335648B2 (en) |
-
1991
- 1991-05-16 JP JP14105091A patent/JP3335648B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04340851A (en) | 1992-11-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0600175A1 (en) | Subscriber line interface circuit for controlling AC and DC output impedance | |
| JPH0713803B2 (en) | Battery feed integrated circuit | |
| CA1177986A (en) | Balanced current multiplier circuit for a subscriber loop interface circuit | |
| JPH0695715B2 (en) | DC voltage supply circuit | |
| US5420919A (en) | Telephone line current modulator | |
| JP3335648B2 (en) | Call current supply device | |
| JPS6014510A (en) | Transistor protecting circuit | |
| KR930002108B1 (en) | Power circuit for telephone apparatus | |
| JP3398950B2 (en) | Fieldbus interface circuit | |
| US6873705B2 (en) | Combine audio and ringing mode | |
| US4649235A (en) | Telephone circuit with a class-B amplifier output stage | |
| JP2573190B2 (en) | DC power supply circuit | |
| JPS62176290A (en) | Electronic choke circuit with electric current limit function | |
| KR19980040071A (en) | DC control differential base voltage generator circuit | |
| GB2132448A (en) | Telephone subscribers' line interface circuit | |
| KR100577621B1 (en) | Current distribution circuit having an additional parallel DC-current sinking branch | |
| JPS6390955A (en) | Electronic talking circuit device | |
| JP2618900B2 (en) | Ring signal circuit | |
| JPH071872Y2 (en) | Semiconductor integrated circuit | |
| JP2718762B2 (en) | Transmission signal injection circuit | |
| SE448662B (en) | SHUNTS VOLTAGE CONTROL CIRCUIT AND USE OF THE SAME IN A PHONE CONNECTOR DEVICE | |
| JP2993298B2 (en) | Telephone loudspeaker amplifier | |
| JPH11514828A (en) | Power circuit for electronic impedance | |
| JPH0572788B2 (en) | ||
| JPH0362065B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20070802 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080802 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080802 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090802 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090802 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100802 Year of fee payment: 8 |
|
| LAPS | Cancellation because of no payment of annual fees |