JPS62257223A - Transmission/recpetion signal branch circuit - Google Patents

Transmission/recpetion signal branch circuit

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Publication number
JPS62257223A
JPS62257223A JP10033986A JP10033986A JPS62257223A JP S62257223 A JPS62257223 A JP S62257223A JP 10033986 A JP10033986 A JP 10033986A JP 10033986 A JP10033986 A JP 10033986A JP S62257223 A JPS62257223 A JP S62257223A
Authority
JP
Japan
Prior art keywords
operational amplifier
signal
terminal
transmission
line
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.)
Granted
Application number
JP10033986A
Other languages
Japanese (ja)
Other versions
JPH0379893B2 (en
Inventor
Terumichi Kimura
照道 木村
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.)
Fuji Facom Corp
Original Assignee
Fuji Facom Corp
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 Fuji Facom Corp filed Critical Fuji Facom Corp
Priority to JP10033986A priority Critical patent/JPS62257223A/en
Publication of JPS62257223A publication Critical patent/JPS62257223A/en
Publication of JPH0379893B2 publication Critical patent/JPH0379893B2/ja
Granted legal-status Critical Current

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  • Small-Scale Networks (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To eliminate the attenuation of a transmission/reception signal and to attain the miniaturization and low cost by circuit integration by using a branch circuit comprising an operational amplifier and a resistor in place of a hybrid transfomer. CONSTITUTION:In connecting an output terminal of the 1st operational amplifier OP1 for transmission to a communication line via an impedance matching resistor R6, since the line impedance is known,a voltage across the resistor is decided. Thus, the voltage is extracted, fed to the 2nd operational amplifier OP2 for reception for proper operation, then a transmission signal component in an output terminal voltage of the 1 st operational amplifier OP1 is elimianted to obtain only a reception signal from a communication line. Since the impedance of a MODEM 15' is known, only the transmission signal eliminated with the reception signal component from the line is obtained by the operation using the 1st operational amplifier OP1 similarly.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、データ伝送装置において2線式または4線式
回線とモデム、保守用at話等の間に接続され、送・受
信信号の分岐および結合を行なうための送・受信信号分
岐回路に関する。
Detailed Description of the Invention (Field of Industrial Application) The present invention is a data transmission device that is connected between a 2-wire or 4-wire line and a modem, an AT line for maintenance, etc., and is used to branch out and receive signals. and a transmitting/receiving signal branching circuit for performing coupling.

(従来の技術) 従来、音声回線を用いたデータ伝送装置において2線式
回線とモデム、保守用電話等との間で送・受信信号を分
岐する場合、漏れインダクタンスを小さくできる等の利
点から一般にハイブリッド1−ランスを用いている。第
4図はこのような従来のデータ伝送装置を示すもので、
図において11は2線式の回線(単線図にて示す。以下
、同じ。)、12ハテータ伝送装置、 13はハイブリ
ッドトランス、14は保守用′fti話、15は4線式
のモデム、16は加τγ器をそれぞれ示している。
(Prior art) Conventionally, in a data transmission device using a voice line, when transmitting and receiving signals are branched between a two-wire line and a modem, a maintenance telephone, etc., it has been generally used because of its advantages such as reducing leakage inductance. A hybrid 1-lance is used. Figure 4 shows such a conventional data transmission device.
In the figure, 11 is a two-wire line (shown as a single line diagram. The same applies hereinafter), 12 is a hatter transmission device, 13 is a hybrid transformer, 14 is a maintenance cable, 15 is a 4-wire modem, and 16 is a 4-wire modem. Each figure shows the addition τγ device.

このデータ伝送装置12では、モデム15の送信(3号
は加算器16にて保守用電話14の送話信号と加算され
、ハイブリッドトランス13を介して2線式回線11に
送出される。この時、周知のようにハイブリッドトラン
ス13はこれに接続される回路との間でインピーダンス
マツチングがとられていると、加算器16の出力信号が
モデム15の受信回路側に回り込まないようになってい
る。
In this data transmission device 12, the transmission signal from the modem 15 (No. 3 is added to the transmission signal from the maintenance telephone 14 in the adder 16, and sent to the two-wire line 11 via the hybrid transformer 13. As is well known, if impedance matching is performed between the hybrid transformer 13 and the circuit connected to it, the output signal of the adder 16 will not go around to the receiving circuit side of the modem 15. .

一方1回線11からの受信信号は、ハイブリッドトラン
ス13を介してモデム15の受信回路および保守用電話
14の受話回路にのみ分岐されるものである。
On the other hand, the received signal from one line 11 is branched only to the receiving circuit of the modem 15 and the receiving circuit of the maintenance telephone 14 via the hybrid transformer 13.

(発明が解決しようとする問題点) ここで、ハイブリッドトランス13が損失のない理想ト
ランスであるとしても、その挿入により送・受信信号は
それぞれ一3dBの減衰を受ける。また。
(Problems to be Solved by the Invention) Here, even if the hybrid transformer 13 is an ideal transformer without loss, the transmitted and received signals are each attenuated by -3 dB due to its insertion. Also.

第5図に示す如くデータ伝送装置12′内のモデム15
′が2線式の場合には、送信信号と受信信号との分岐用
に別のハイブリッドトランス13′が必要となるため、
送・受信信号は更に一3dBの減衰を受けることとなる
As shown in FIG. 5, a modem 15 in the data transmission device 12'
If ' is a two-wire type, another hybrid transformer 13' is required for branching the transmitting signal and the receiving signal.
The transmitted and received signals will be further attenuated by -3 dB.

加えて、ハイブリッドトランス13.13’はIC等と
比べて小型化が困難であると共に、一般にコストか高い
という問題があった。
In addition, hybrid transformers 13, 13' are difficult to miniaturize compared to ICs, etc., and are generally expensive.

本発明は上記の問題点を解決するべく提案されたもので
、その目的とするところは、ハイブリッドトランスに代
えてオペアンプと抵抗からなる分岐回路を用いることに
より、送・受信信号の減衰をなくシ、シかもIC化によ
る小型化および低コスト化を可能にした送・受信信号分
岐回路を提供することにある。
The present invention was proposed to solve the above problems, and its purpose is to eliminate attenuation of transmitted and received signals by using a branch circuit consisting of an operational amplifier and a resistor instead of a hybrid transformer. Another object of the present invention is to provide a transmitting/receiving signal branching circuit that can be made smaller and lower in cost by using an IC.

(問題点を解決するための手段) 上記目的を達成するため1本発明は、データ伝送装置内
において、モデム等からの通信回線への送イ8信号と通
信回線からの受信信号の一部とを演算して前記送信信号
のみを取り出し、この送信信号を通信回線に送信する第
1のアンプと、通信回線からの受信信号と第1のアンプ
の出力信号すなわち送信信号の一部とを演算して前記受
信信号のみを得る第2のアンプとを備えたことを特徴と
している。
(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for transmitting a signal from a modem etc. to a communication line and a part of a received signal from the communication line in a data transmission device. A first amplifier that calculates only the transmission signal and transmits the transmission signal to a communication line, and calculates a reception signal from the communication line and an output signal of the first amplifier, that is, a part of the transmission signal. and a second amplifier that obtains only the received signal.

(作用) 本発明においては、ハイブリッドトランスを用いること
なく第1および第2のオペアンプによって送・受信信号
を分岐している。その際、本発明では回線のインピーダ
ンスおよびモデムのインピーダンスが既知であることに
着目して送信信号の受信回路への回り込みおよび受信信
号の送信回路への回り込みを防止している。
(Function) In the present invention, the transmission/reception signals are branched by the first and second operational amplifiers without using a hybrid transformer. In this case, the present invention focuses on the fact that the line impedance and the modem impedance are known, and prevents the transmitted signal from going around to the receiving circuit and the received signal from going around to the transmitting circuit.

すなわち、送信用の第1のオペアンプの出力端子をイン
ピーダンスマツチング用の抵抗を介して通信回線に接続
した場合、回線のインピーダンスが既知であるためこの
抵抗の両端の電圧が決定される。従って、この電圧を取
り出し、受信用の第2のオペアンプに加えて適宜な演算
を行なうことにより、第1のオペアンプの出力端子電圧
のうちの送信信号成分を除去して通信回線からの受信信
号のみを得ることができる。
That is, when the output terminal of the first operational amplifier for transmission is connected to a communication line via an impedance matching resistor, the voltage across this resistor is determined because the impedance of the line is known. Therefore, by extracting this voltage and adding it to the second operational amplifier for reception and performing appropriate calculations, the transmitted signal component of the output terminal voltage of the first operational amplifier is removed and only the received signal from the communication line is received. can be obtained.

また、モデムのインピーダンスも既知であるため、同様
にして第1のオペアンプによる演算により通信回線から
の受信信号成分を除去した送信信号のみを得ることがで
きる。
Further, since the impedance of the modem is also known, it is possible to similarly obtain only the transmission signal from which the received signal component from the communication line has been removed by calculation by the first operational amplifier.

更に、各オペアンプの人力抵抗および帰還抵抗の値を適
宜設定することで、送・受信信号の減衰を防止している
Furthermore, attenuation of transmitted and received signals is prevented by appropriately setting the values of the human resistance and feedback resistance of each operational amplifier.

(実施例) 以下、図に沿って本発明の詳細な説明する。(Example) The present invention will be described in detail below with reference to the drawings.

まず、第1図は本発明の第1実施例を示すもので、この
実施例は1本発明を2線式回線とモデム、保守用電話と
の間で送・受信信号を結合または分岐するデータ伝送装
置に適用したものである。図において、11は前記同様
に2W式の回線、12′はデータ伝送装置であり、本発
明にががる送・受信信号分岐回路1は回線11に接続さ
れる端子Aと、2線式のモデム15″に接続される端子
Cと、保守用′Ki話14の送話回路および受話回路に
それぞれ接続される端子B、Dとを備えている。
First of all, FIG. 1 shows a first embodiment of the present invention, and this embodiment is a first embodiment of the present invention. This is applied to transmission equipment. In the figure, 11 is a 2W type line as described above, and 12' is a data transmission device. It has a terminal C connected to the modem 15'', and terminals B and D connected to the transmitting circuit and receiving circuit of the maintenance Ki talk 14, respectively.

その回路構成を説明すると、まず、端子Cは差動増幅器
を構成する第1のオペアンプoP、の非反転入力端子に
接続されていると共に、インピーダンスマツチング用の
抵抗R7を介して同じく差動増幅器を構成する第2のオ
ペアンプOP2の出力端子に接続されている。このオペ
アンプoP2の出力端子は端子りに接続され、がっ抵抗
R4を介して第1のオペアンプOP□の反転入力端子に
接続されている。また、この反転入力端子は抵抗R2を
介して端子Bに接続されている。
To explain the circuit configuration, first, the terminal C is connected to the non-inverting input terminal of the first operational amplifier oP that constitutes the differential amplifier, and is connected to the same differential amplifier via an impedance matching resistor R7. The output terminal of the second operational amplifier OP2 is connected to the output terminal of the second operational amplifier OP2. The output terminal of this operational amplifier oP2 is connected to the terminal 1, and is connected to the inverting input terminal of the first operational amplifier OP□ via a resistor R4. Further, this inverting input terminal is connected to terminal B via resistor R2.

更に、第1のオペアンプ○P工の帰還ループには抵抗R
0が接続され、オペアンプOP□の出力端子はインピー
ダンスマツチング用の抵抗R,を介して端子Aに接続さ
れると共に抵抗R3を介して第2のオペアンプOP2の
反転入力端子に接続されている。また、端子Aはオペア
ンプoP2の非反転入力端子に接続され、オペアンプO
P2の帰還ループには抵抗R9が接続されている。
Furthermore, a resistor R is included in the feedback loop of the first operational amplifier ○P.
The output terminal of the operational amplifier OP□ is connected to the terminal A via an impedance matching resistor R, and is also connected to the inverting input terminal of the second operational amplifier OP2 via a resistor R3. In addition, terminal A is connected to the non-inverting input terminal of operational amplifier oP2, and terminal A is connected to the non-inverting input terminal of operational amplifier oP2.
A resistor R9 is connected to the feedback loop of P2.

なお、この回路において、各抵抗の値はR,=R,,R
,=R4とし、また抵抗Rsの値は既知である回1iA
11のインピーダンスに等しく、抵抗R7の値は同じく
既知であるモデム15′の入力インピーダンスに等しい
ものとする。
Note that in this circuit, the value of each resistor is R, = R,, R
, = R4, and the value of the resistance Rs is known.
11, and the value of resistor R7 is equal to the input impedance of modem 15', which is also known.

この動作を説明すると、まず、モデム15’からの送信
信号と保守用電話14からの送話信号とは第1のオペア
ンプOP1にて演算され、端子Aから送出される。また
、回線11からの受信信号とオペアンプOP□の出力信
号とは第2のオペアンプOP2にて演算され、端子りお
よび端子Cに出力される6 いま、オペアンプOP2による演算の結果、端子り、C
に現われる電圧Vd、Vcのうち、回allからの受信
信号による成分Vdr、 Verを求める。
To explain this operation, first, a transmission signal from the modem 15' and a transmission signal from the maintenance telephone 14 are calculated by the first operational amplifier OP1, and then sent from the terminal A. Also, the received signal from the line 11 and the output signal of the operational amplifier OP□ are calculated by the second operational amplifier OP2 and output to the terminals RI and C.
Of the voltages Vd and Vc appearing in the circuit, the components Vdr and Ver due to the received signal from the circuit all are determined.

第1図において、オペアンプ○P8の出カ端子rB圧■
工のうち送信信号による成分をVls、また端子へにお
ける電圧Vaのうち送信信号による成分をVasとする
と、抵抗R5が回線11のインピーダンスに等しいこと
から、これらの間には以下の関係が成立する。
In Figure 1, the output terminal rB voltage of operational amplifier ○P8
If the component of the voltage Va to the terminal due to the transmitted signal is Vls, and the component of the voltage Va to the terminal due to the transmitted signal is Vas, then since the resistor R5 is equal to the impedance of the line 11, the following relationship holds between them. .

Vas= V、s/ 2  ・・・・・・・・・・旧・
・・・・・・・・・・・旧・・(1)ここで、電圧■1
のうち回線11がらの受信信号による成分を■□r、電
圧Vaのうち同じく受信信号による成分をVarとする
と、■□rについてはオペアンプ○P1の出力インピー
ダンスが非常に小さいため、Vir=oとなる。従って
、VよおよびVaは次式にて表ねされる。
Vas= V, s/2 ・・・・・・・・・Old・
...... Old... (1) Here, voltage ■1
If the component due to the received signal from the line 11 is ■□r, and the component due to the received signal among the voltage Va is Var, then as for ■□r, since the output impedance of the operational amplifier ○P1 is very small, Vir=o. Become. Therefore, V and Va are expressed by the following formula.

V工=Vis+V1r=V、s  ・旧・・・旧・・・
旧・・(2)Va=Vas+Var=(V、s/2) 
十Var・・・(3)一方、オペアンプoP2の出力電
圧Vdrは次式にて表わされる。
V engineering = Vis + V1r = V, s ・Old...Old...
Old... (2) Va=Vas+Var=(V, s/2)
10 Var (3) On the other hand, the output voltage Vdr of the operational amplifier oP2 is expressed by the following equation.

Vdr=(1+Rs/R−)Va  (R−/R3)V
−・・・・・・・・・・・・・・・・・・(4)この(
4)式においてRs =R3であるがら、Vdr=2V
a−V□ ・・・・・・・・・・・・・・・・・・・・
団・・・・(5)(5)式に(2)、 (3)式を代入
すると。
Vdr=(1+Rs/R-)Va (R-/R3)V
−・・・・・・・・・・・・・・・・・・(4) This (
4) In the formula, Rs = R3, but Vdr = 2V
a-V□・・・・・・・・・・・・・・・・・・・・・
Group... (5) Substituting equations (2) and (3) into equation (5).

Vdr=2((V1g/2)+Var)−V1g= 2
 Var  ・・・・・団・・旧・・・・・・・・・・
・・・・・・・・・・(6)つまり、この(6)式から
明らがなように、端子りにはオペアンプOP工の出力端
子電圧V、のうち送信信号成分V□Sが現われず、送信
信号が回り込まないこととなり、回線llがらの受信信
号Varのみが2倍されて出方される。
Vdr=2((V1g/2)+Var)-V1g=2
Var...Dan...Old...
・・・・・・・・・・・・(6) In other words, as is clear from this equation (6), the transmission signal component V□S of the output terminal voltage V of the operational amplifier OP is at the terminal. Therefore, the transmitted signal does not go around, and only the received signal Var from the line 11 is doubled and outputted.

また、抵抗1り、はモデム15′のインピーダンスに等
しいから。
Also, the resistance 1 is equal to the impedance of the modem 15'.

Ver=Vdr/2  ・・・・・・・・・・・・・・
団・・・・・・・・・・・・・(7)となり、(6)式
および(7)式がら、Ver=Var  ・・・・・・
・旧・・・・・・旧・・・・・・・・・・・・・・・・
・(8)となって端子Aでの受信電圧は減衰することな
くモデム15′側の端子Cにそのまま呪われることとな
る。
Ver=Vdr/2 ・・・・・・・・・・・・・・・
Group・・・・・・・・・(7), and from equations (6) and (7), Ver=Var ・・・・・・
・Old・・・・・・Old・・・・・・・・・・・・・・・
- (8), the received voltage at terminal A is not attenuated and is directly transferred to terminal C on the modem 15' side.

送信信号についてもこれとほぼ同様であり、端子り、C
における電圧Vd、Vcのうち送信信号による成分Vd
s、 Vcsに関し、Vd5=Oであるがら。
The transmission signal is almost the same, and the terminal and C
Of the voltages Vd and Vc at , the component Vd due to the transmission signal
s, while Vcs is Vd5=O.

Vd=Vds+Vdr=Vdr  +・++++++H
H+”””(9)Vc=Vcs+Ver=Vcs+(V
dr/2)・・・(10)オペアンプOP□の出カ電圧
V工Sは、Vts: (1+ R,/ R,) Vc 
−(R0/ R4)Vd・・・・・・・・・・・・・・
・・・・(11)ここでR,=R,であるから、 VLs= 2 Ve −Vd  ・・・・・・・・・・
・・・1旧・・・・・(12)(12)式に(9)、 
(10)式を代入すると。
Vd=Vds+Vdr=Vdr +・++++++H
H+”””(9)Vc=Vcs+Ver=Vcs+(V
dr/2)...(10) The output voltage V of the operational amplifier OP□ is Vts: (1+ R, / R,) Vc
-(R0/R4)Vd・・・・・・・・・・・・・・・
・・・・・・(11) Here, since R,=R, VLs= 2 Ve −Vd ・・・・・・・・・・・・
...1 old... (12) (12) formula (9),
(10) By substituting the equation.

V、s= 2 ((Vdr/ 2 )+Vcs)  V
dr=2Vcs  ・旧・・・旧・・・・・・旧・・・
・団・・・・(13)となる。すなわち、オペアンプo
P□の出カ′市圧V、sにはオペアンプOP2の出力電
圧Vdのうち受信信号成分Vdrが回り込むことがない
。また、電圧V 、 sは端子Aでは1/2になるため
、端子AがらはVcsと等しい電圧が[す1線Ifに向
けて出力される。更に、保守用電話14の送話信号vb
は−(R□/ 2 R,)倍されて端子Aがら出力され
る。
V, s= 2 ((Vdr/ 2 )+Vcs) V
dr=2Vcs ・Old...Old...Old...
・Dan...(13). That is, the operational amplifier o
The received signal component Vdr of the output voltage Vd of the operational amplifier OP2 does not go around to the output voltage V, s of P□. Further, since the voltage V, s becomes 1/2 at the terminal A, a voltage equal to Vcs is output from the terminal A toward the line If. Furthermore, the transmission signal vb of the maintenance telephone 14
is multiplied by -(R□/2R,) and output from terminal A.

以上の各信号の流れを示すと、第2図のとおりとなる。The flow of each of the above signals is shown in FIG. 2.

この実施例にあっては、回線11およびモデム15’と
のインピーダンスマツチングを互いに別個の抵抗RいR
7によって行なっているため、本発明はインピーダンス
の異なる回線11およびモデム15′に対しても容易に
適用することができる。
In this embodiment, impedance matching between the line 11 and the modem 15' is performed using separate resistors R and R.
7, the present invention can be easily applied to lines 11 and modems 15' having different impedances.

次に、第3図は本発明の第2実施例を示している。この
実施例は、本発明を送信用回線11’および受信用回線
11”からなる4線式の回線と4線式のモデム15との
間に接続する場合であり、かかる送・受信信号分岐回路
1″には新たに端子E、Fがそれぞ扛設けられている。
Next, FIG. 3 shows a second embodiment of the present invention. In this embodiment, the present invention is connected between a 4-wire modem 15 and a 4-wire line consisting of a transmitting line 11' and a receiving line 11'', and such a transmitting/receiving signal branch circuit 1'' is newly provided with terminals E and F, respectively.

このうち、端子Eと抵抗1く□、R2の接続点との間に
は抵抗R,が接続されろと共に、端子Eには一端が接地
された抵抗R。
Among these, a resistor R is connected between the terminal E and the connection point of the resistors 1 and R2, and the resistor R has one end grounded to the terminal E.

の他端が接続される。また、端子Fと抵抗R3゜1(、
の接続点との間には抵抗R□。が接続されると共に、端
子Fには一端が接地された抵抗R□□の他端が接続され
ている。
The other end of is connected. Also, terminal F and resistor R3゜1 (,
There is a resistor R□ between the connection point and the connection point. is connected to the terminal F, and the other end of a resistor R□□ whose one end is grounded is connected to the terminal F.

この実施例においては、端子E、Fの入力インピーダン
スがそれぞれR工t R41R,、R9の合成抵抗、 
R,、R,、R,、、R□、の合成抵抗となるため、こ
れらとモデム15または受信用回線11”とのインピー
ダンスマツチングをとることにより、端子Eをモデム1
5の送信用端子、端子Cを同量4a用端子として、また
端子Aを4線式回線への送信用端子、端子Fを同受信用
端子として用いることができる。
In this example, the input impedance of terminals E and F is R41R, R9's combined resistance, respectively.
Since it becomes a composite resistance of R,, R,, R,,, R
Terminal C can be used as a terminal for transmitting 4a, terminal A can be used as a terminal for transmitting to a 4-wire line, and terminal F can be used as a receiving terminal for the same.

この実施例によれば1回線およびモデムが2線式または
4線式の何れであっても単一の回路構成により接続する
ことができ、汎用性、経済性に富むという利点がある。
According to this embodiment, it is possible to connect one line and the modem with a single circuit configuration regardless of whether the modem is a two-wire type or a four-wire type, and has the advantage of being highly versatile and economical.

(発明の効果) 以上詳述したように本発明によれば、ハイブリッドトラ
ンスを用いることなく送・受信信号の分岐を行なうこと
ができ、その際に信号が減衰することもない。
(Effects of the Invention) As described in detail above, according to the present invention, transmission and reception signals can be branched without using a hybrid transformer, and the signals are not attenuated at that time.

また、オペアンプ等を主体とした回路構成であるからI
C化が可能であり1回路装置の小型化および低コスト化
を図ることができる。
In addition, since the circuit configuration is mainly based on operational amplifiers, etc.
It is possible to reduce the size and cost of a single-circuit device.

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

第1図は本発明の第1実施例を示す回路図、第2図は同
じく信号の流れを示す説明図、第3図は本発明の第2実
施例を示す回路図、第4図および第5図は従来例を示す
回路図である。 1.1′・・・送・受信信号分岐回路 11.11’、11”・・・回線 12’、12”・・・データ伝送装置 14・・・保守用電話      15.15″・・・
モデム○P1.OR2・・・オペアンプ  R□〜R1
1・・・抵抗A−F・・・端子 特許出願人  富士ファコム制御株式会社第5図   
12゛ 、ノ
FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the flow of signals, FIG. 3 is a circuit diagram showing a second embodiment of the present invention, and FIGS. FIG. 5 is a circuit diagram showing a conventional example. 1.1'...Transmission/reception signal branch circuit 11.11', 11"...Line 12', 12"...Data transmission device 14...Maintenance telephone 15.15"...
Modem○P1. OR2... operational amplifier R□~R1
1...Resistors A-F...Terminal Patent applicant: Fuji Facom Control Co., Ltd. Figure 5
12゛、ノ

Claims (1)

【特許請求の範囲】 データ伝送装置内に設けられ、このデータ伝送装置に接
続された通信回線への送信信号と前記通信回線からの受
信信号とを分岐する送・受信信号分岐回路において、 前記通信回線への送信信号と前記受信信号の一部とを演
算して前記送信信号のみを前記通信回線に送信する第1
のアンプと、前記通信回線からの受信信号と前記送信信
号の一部とを演算して前記受信信号のみを得る第2のア
ンプとを備えたことを特徴とする送・受信信号分岐回路
[Scope of Claims] In a transmission/reception signal branching circuit provided in a data transmission device and branching a transmission signal to a communication line connected to the data transmission device and a reception signal from the communication line, the communication A first device that calculates a transmission signal to a line and a part of the received signal and transmits only the transmission signal to the communication line.
A transmitting/receiving signal branching circuit comprising: an amplifier; and a second amplifier that calculates a received signal from the communication line and a part of the transmitted signal to obtain only the received signal.
JP10033986A 1986-04-30 1986-04-30 Transmission/recpetion signal branch circuit Granted JPS62257223A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10033986A JPS62257223A (en) 1986-04-30 1986-04-30 Transmission/recpetion signal branch circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10033986A JPS62257223A (en) 1986-04-30 1986-04-30 Transmission/recpetion signal branch circuit

Publications (2)

Publication Number Publication Date
JPS62257223A true JPS62257223A (en) 1987-11-09
JPH0379893B2 JPH0379893B2 (en) 1991-12-20

Family

ID=14271368

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10033986A Granted JPS62257223A (en) 1986-04-30 1986-04-30 Transmission/recpetion signal branch circuit

Country Status (1)

Country Link
JP (1) JPS62257223A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5523683A (en) * 1978-08-08 1980-02-20 Nec Corp Bidirectional relay unit
JPS60171884A (en) * 1984-02-16 1985-09-05 Furukawa Electric Co Ltd:The Signal transmission system of two-way catv system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5523683A (en) * 1978-08-08 1980-02-20 Nec Corp Bidirectional relay unit
JPS60171884A (en) * 1984-02-16 1985-09-05 Furukawa Electric Co Ltd:The Signal transmission system of two-way catv system

Also Published As

Publication number Publication date
JPH0379893B2 (en) 1991-12-20

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