JPH02148955A - Polarity detection circuit - Google Patents
Polarity detection circuitInfo
- Publication number
- JPH02148955A JPH02148955A JP63303132A JP30313288A JPH02148955A JP H02148955 A JPH02148955 A JP H02148955A JP 63303132 A JP63303132 A JP 63303132A JP 30313288 A JP30313288 A JP 30313288A JP H02148955 A JPH02148955 A JP H02148955A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- polarity detection
- emitter
- transistor
- resistor
- 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
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 28
- 238000006243 chemical reaction Methods 0.000 abstract description 12
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000011664 signaling Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 1
Landscapes
- Measurement Of Current Or Voltage (AREA)
- Monitoring And Testing Of Exchanges (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は極性検出回路に関し、特に電話交換機における
２線式信号方式をＰＣＭ回線で用いられるデジタル信号
方式へ変換する信号変換回路の極性検出回路に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polarity detection circuit, and particularly to a polarity detection circuit for a signal conversion circuit that converts a two-wire signaling system in a telephone exchange to a digital signaling system used in a PCM line. Regarding.
従来、この種の極性検出回路は、第２図の回路図に示す
ように、交換機の制御電圧Ｖｃが入力端子１．２間に入
力され、この制御電圧Ｖｃが全波整流回路９を経由して
ループ形成回路１０によりループバックされる。また、
この制御電圧Ｖｃの極性を検出する回路は、トランジス
タ５、ダイオード１１、抵抗３、極性検出端子７からな
る第１の電圧電流変換回路と、トランジスタ６、ダイオ
ード１２、抵抗４、極性検出端子８からなる第２の電圧
電流変換回路とから構成されている。ここで第１の電圧
電流変換回路は入力端子２側の制御電圧が高い場合、外
部検出回路（図示せず）から極性検出端子７に流れる電
流をトランジスタ５により制御する。また、第２の電圧
電流変換回路は入力端子１側の制御電圧が高い場合、外
部検出回路（図示せず）から極性検出端子８に流れる電
流をトランジスタ６により制御する。この回路構成にお
いて、ダイオード９．１０はトランジスタ５゜６のベー
スエミッタ間に逆電圧がかかるのを防止するために接続
されている。Conventionally, in this type of polarity detection circuit, as shown in the circuit diagram of FIG. and is looped back by the loop forming circuit 10. Also,
The circuit for detecting the polarity of the control voltage Vc includes a first voltage-current conversion circuit consisting of a transistor 5, a diode 11, a resistor 3, and a polarity detection terminal 7; A second voltage-current conversion circuit is constructed. Here, when the control voltage on the input terminal 2 side is high, the first voltage-current conversion circuit controls the current flowing from the external detection circuit (not shown) to the polarity detection terminal 7 using the transistor 5. Further, when the control voltage on the input terminal 1 side is high, the second voltage-current conversion circuit controls the current flowing from the external detection circuit (not shown) to the polarity detection terminal 8 using the transistor 6. In this circuit configuration, diodes 9,10 are connected to prevent reverse voltages from being applied between the bases and emitters of transistors 5.6.
上述した従来の極性検出回路は、トランジスタのペース
エミッタ間の逆電圧保護のために、ダイオードを必要と
しているので、回路部品が多くなる欠点がある。The above-mentioned conventional polarity detection circuit requires a diode to protect against reverse voltage between the pace emitters of the transistors, and therefore has the disadvantage of requiring a large number of circuit components.
本発明の目的は、このような逆電圧保護用のダイオード
を必要とせず、トランジスタの接続方法のみで逆電圧の
保護を実現した極性検出回路を提供することにある。An object of the present invention is to provide a polarity detection circuit that does not require such a diode for reverse voltage protection and achieves reverse voltage protection only by connecting transistors.
本発明の極性検出回路は、２線式通信回線において、前
記２線の一方の線に抵抗を経由してエミッタを接続し、
コレクタを第１の極性検出端子とする第１のトランジス
タと、前記２線の他方の線に抵抗を経由してエミッタを
接続し、コレクタを第２の極性検出端子とする第２のト
ランジスタとを備え、前記第１のトランジスタのベース
が前記第２のトランジスタのエミッタに接続され、前記
第２のトランジスタのベースが前記第１のトランジスタ
のエミッタに接続されている。The polarity detection circuit of the present invention connects an emitter to one of the two wires via a resistor in a two-wire communication line,
A first transistor whose collector serves as a first polarity detection terminal, and a second transistor whose emitter is connected to the other of the two lines via a resistor and whose collector serves as a second polarity detection terminal. The base of the first transistor is connected to the emitter of the second transistor, and the base of the second transistor is connected to the emitter of the first transistor.
次に本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例の回路図である。第１図の実
施例は、極性を検出する回路である第１の電圧電流変換
回路として、トランジスタ５、抵抗３、極性検出端子７
から構成され、第２の電圧電流変換回路として、トラン
ジスタ６、抵抗４、極性検出端子８から構成される。こ
の第１および第２の電圧電流変換回路の極性検出機能は
従来例と同様である。今、制御電圧Ｖｃの端子１の電位
が端子２の電位よりも高い場合抵抗３を経由してトラン
ジスタ６のベースに電流を流し、端子１゜２間の電圧Ｖ
ｃは抵抗３、トランジスタ６のベース・エミッタ、抵抗
４の経路で電流を流し、極性検出端子８からのコレクタ
電流を制御する。この動作と同時にトランジスタ６のベ
ース・エミッタ間のＰＮ接合は、その電圧が極めて小さ
くなり、トランジスタらのベースエミッタに対して逆電
圧保護のダイオードとして動作する。同様に端子２の電
位が端子１の電位よりも高い場合、逆にトランジスタ５
のペースエミッタ間のＰＮ接合は、トランジスタ６のペ
ースエミッタ間の逆電圧保護のダイオードとして動作す
る。このようにトランジスタ５．．６のエミッターペー
ス間を相互に接続するのみで、保護ダイオードの不要な
極性検出回路が実現できる。FIG. 1 is a circuit diagram of an embodiment of the present invention. The embodiment shown in FIG. 1 includes a transistor 5, a resistor 3, and a polarity detection terminal 7 as a first voltage-current conversion circuit which is a circuit for detecting polarity.
The second voltage-current conversion circuit includes a transistor 6, a resistor 4, and a polarity detection terminal 8. The polarity detection functions of the first and second voltage-current conversion circuits are similar to those of the conventional example. Now, when the potential of terminal 1 of control voltage Vc is higher than the potential of terminal 2, current flows through the resistor 3 to the base of transistor 6, and the voltage between terminals 1 and 2 increases
A current is caused to flow through a path of the resistor 3, the base/emitter of the transistor 6, and the resistor 4, and the collector current from the polarity detection terminal 8 is controlled. At the same time as this operation, the voltage of the PN junction between the base and emitter of the transistor 6 becomes extremely small, and it operates as a diode for reverse voltage protection with respect to the base and emitter of the transistors. Similarly, if the potential of terminal 2 is higher than the potential of terminal 1, conversely, transistor 5
The PN junction between the pace emitters of transistor 6 acts as a diode for reverse voltage protection between the pace emitters of transistor 6. In this way, transistor 5. ．． A polarity detection circuit that does not require a protection diode can be realized by simply connecting the emitter paces of No. 6 to each other.
以上説明したように本発明は、電圧電流変換回路を構成
する２個のトランジスタのベース・エミッタ間のＰＮ接
合を相互に逆電圧保護用として利用することにより、従
来の逆電圧防止用のダイオードを必要とせず、少ない部
品数で極性検出回路を実現できる効果がある。As explained above, the present invention utilizes the PN junction between the base and emitter of two transistors constituting a voltage-current conversion circuit for reverse voltage protection, thereby replacing the conventional reverse voltage prevention diode. This has the effect of realizing a polarity detection circuit with a small number of parts.
従来の極性検出回路の回路図である。FIG. 2 is a circuit diagram of a conventional polarity detection circuit.
１．２・・・入力端子、３．４・・・抵抗、５，６・・
・トランジスタ、７，８・・・極性検出端子、９・・・
全波整流回路、１０・・・ループ形成回路、１１．１２
・・・ダイオード。1.2...Input terminal, 3.4...Resistor, 5,6...
・Transistor, 7, 8...Polarity detection terminal, 9...
Full wave rectifier circuit, 10... loop forming circuit, 11.12
···diode.
Claims (1)
経由してエミッタを接続しコレクタを第１の極性検出端
子とする第１のトランジスタと、前記２線の他方の線に
抵抗を経由してエミッタを接続しコレクタを第２の極性
検出端子とする第２のトランジスタとを備え、前記第１
のトランジスタのベースが前記第２のトランジスタのエ
ミッタに接続され、前記第２のトランジスタのベースが
前記第１のトランジスタのエミッタに接続されたことを
特徴とする極性検出回路。In a two-wire communication line, a first transistor whose emitter is connected to one of the two wires via a resistor and whose collector serves as a first polarity detection terminal, and a resistor is connected to the other of the two wires. a second transistor whose emitter is connected via the transistor and whose collector serves as a second polarity detection terminal;
A polarity detection circuit characterized in that the base of the transistor is connected to the emitter of the second transistor, and the base of the second transistor is connected to the emitter of the first transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63303132A JP2669014B2 (en) | 1988-11-29 | 1988-11-29 | Polarity detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63303132A JP2669014B2 (en) | 1988-11-29 | 1988-11-29 | Polarity detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02148955A true JPH02148955A (en) | 1990-06-07 |
| JP2669014B2 JP2669014B2 (en) | 1997-10-27 |
Family
ID=17917269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63303132A Expired - Lifetime JP2669014B2 (en) | 1988-11-29 | 1988-11-29 | Polarity detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2669014B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2899511A1 (en) | 2014-01-28 | 2015-07-29 | BEI Sensors & Systems Company Inc. | Polarity insensitive sensor |
-
1988
- 1988-11-29 JP JP63303132A patent/JP2669014B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2899511A1 (en) | 2014-01-28 | 2015-07-29 | BEI Sensors & Systems Company Inc. | Polarity insensitive sensor |
| US9465088B2 (en) | 2014-01-28 | 2016-10-11 | Sensata Technologies, Inc. | Polarity insensitive hall effect sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2669014B2 (en) | 1997-10-27 |
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