JPS6220404A - Voltage amplifying circuit - Google Patents
Voltage amplifying circuitInfo
- Publication number
- JPS6220404A JPS6220404A JP15961185A JP15961185A JPS6220404A JP S6220404 A JPS6220404 A JP S6220404A JP 15961185 A JP15961185 A JP 15961185A JP 15961185 A JP15961185 A JP 15961185A JP S6220404 A JPS6220404 A JP S6220404A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- current
- measured
- input
- detector
- 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
Landscapes
- Measurement Of Current Or Voltage (AREA)
- Amplifiers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、電圧測定器、電圧増幅器、精度計測、微少
電圧取出用の初段増幅器等に用いる電圧増幅回路に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a voltage amplification circuit used in a voltage measuring device, a voltage amplifier, a precision measurement, a first-stage amplifier for extracting a minute voltage, and the like.
従来の増幅器は入力インピーダンスが有限のため有限電
流が入力端子に流入する。そのため、被測定系の内部抵
抗等に起因する電圧降下などにより精度のよい電圧測定
、電圧増幅等には限界があった・
〔発明が解決しようとする問題点〕
上記のように従来の増幅器では、入力インピーダンスが
有限のため、十分な精度のものが得られないという問題
点があった。Conventional amplifiers have a finite input impedance, so a finite current flows into the input terminal. Therefore, there was a limit to accurate voltage measurement, voltage amplification, etc. due to voltage drops caused by internal resistance of the system under test. [Problems to be solved by the invention] As mentioned above, conventional amplifiers However, since the input impedance is finite, there is a problem in that sufficient accuracy cannot be obtained.
この発明は上記の問題点を解決するためになされたもの
で、入力インピーダンスを無限大にした増幅器を提供す
ることを目的とする。This invention was made to solve the above problems, and an object thereof is to provide an amplifier with infinite input impedance.
この発明にかかる電圧増幅回路は、被測定電圧が印加さ
れる入力端子に、電流検出器と抵抗器の直列体と、電流
増幅器と外部抵抗器の直列体とをそれぞれ並列にｖｃ続
し、電流増幅器により電流検出器の検出電流とこの電流
増幅器の増幅電流間に正帰還をかけ被測定電圧と同一の
電圧を入力端子に発生させる構成としたものである。The voltage amplification circuit according to the present invention connects a series body of a current detector and a resistor and a series body of a current amplifier and an external resistor in parallel to an input terminal to which a voltage to be measured is applied, and The configuration is such that an amplifier applies positive feedback between the detected current of the current detector and the amplified current of this current amplifier to generate the same voltage as the voltage to be measured at the input terminal.
この発明においては、入力端子に被測定電圧と同一の電
圧が発生するので、入力インピーダンスが無限大になる
。In this invention, since the same voltage as the voltage to be measured is generated at the input terminal, the input impedance becomes infinite.
第１図はこの発明の一実施例を示す等価回路図であり、
１，２は入力端子、３，４は出力端子、５は電流増幅器
、６は電流検出器、７は抵抗値がＲＧの抵抗器で電流検
出器６と直列体をなしている。８は被測定電圧で、Ｖｘ
はその電圧値、９は前記被測定電圧８の内部抵抗で、Ｒ
ｘはその抵抗値、１０は外部抵抗器で、ＲＯはその抵抗
値である。なお、■はこの発明による電圧増幅回路、■
は被測定系、■は出力系を示す。FIG. 1 is an equivalent circuit diagram showing an embodiment of the present invention.
1 and 2 are input terminals, 3 and 4 are output terminals, 5 is a current amplifier, 6 is a current detector, and 7 is a resistor with a resistance value of RG, which is connected in series with the current detector 6. 8 is the voltage to be measured, Vx
is its voltage value, 9 is the internal resistance of the voltage to be measured 8, and R
x is its resistance value, 10 is an external resistor, and RO is its resistance value. In addition, ■ is a voltage amplification circuit according to the present invention, and ■
indicates the system under test, and ■ indicates the output system.
次に作用について説明する。回路方程式は下記のように
なる。Next, the effect will be explained. The circuit equation is as follows.
ただし、ＩＸは入力電流、ＩＧは前記電流検出器Ｇを流
れる電流、
ＩＯは出力電流、Ａは電流増幅器５の
増幅度である。Here, IX is the input current, IG is the current flowing through the current detector G, IO is the output current, and A is the amplification degree of the current amplifier 5.
これを解くと、 ただし、ＶＯは出力電圧である。Solving this, However, VO is the output voltage.
ここで、Ａ＝１と選ぶと、
を得る。第（７）式より入力電流工×が０、すなわち、
入力インピーダンスを無限大にすることができるのが分
る。また、第（９）式においてＲｏの値ことができる。Here, if we choose A=1, we get . From equation (7), input current factor x is 0, that is,
It can be seen that the input impedance can be made infinite. Furthermore, the value of Ro can be expressed in equation (9).
次にこの発明の他の実施例について説明する。Next, other embodiments of the invention will be described.
第２図は出力インピーダンスのマツチングをよりし易く
より一般的な実施例を示すものである。FIG. 2 shows a more general embodiment that makes it easier to match output impedances.
この図で第１図と同じ符号は同じものであり、１ｉ、１
２は抵抗器で、Ｒ１，Ｒ２はその抵抗値を示す。In this figure, the same symbols as in Figure 1 are the same, 1i, 1
2 is a resistor, and R1 and R2 indicate its resistance value.
この場合も回路方程式を立て、それを解くと、・・・・
・・・・・・・・・・・（１２）ここで、Ｒ，Ｒ２＋Ｒ
Ｇ −ＲＩ Ａ＝Ｏとなるように回路定数を選ぶと、
を得る。第（１３）式から入力インピーダンスが無限大
、第（１５）式からＲＯを適当に選ぶことにより第３図
は上記第１図に等価回路で示した実施例の実際回路の一
例を示すものである。In this case as well, if you create a circuit equation and solve it...
・・・・・・・・・・・・(12) Here, R, R2+R
If we choose the circuit constants so that G - RI A=O, we obtain. By appropriately selecting input impedance from Equation (13) and RO from Equation (15), Fig. 3 shows an example of the actual circuit of the embodiment shown as the equivalent circuit in Fig. 1 above. be.
この図で、６Ａは反射鏡で、吊線６Ｂにより支承されて
おり、電流検出器６の電流量に応じて回動し、光源６Ｃ
からの光を電流増幅器５に向けて反射する。８′は電池
で、被測定電圧Ｖ×を有する。この例では電流増幅器５
は２個の太陽電池５Ａ、５Ｂからなり、これらは差動的
に接続されている。従って、両太陽電池５Ａ、５Ｂが等
量の光照射を受けるときは出力は零であり、どちらが一
方だけが照射されたとき最大の出力となる。In this figure, 6A is a reflecting mirror, which is supported by a hanging wire 6B, rotates according to the amount of current from the current detector 6, and is rotated by the light source 6C.
The light from the current amplifier 5 is reflected toward the current amplifier 5. 8' is a battery having a voltage to be measured Vx. In this example, the current amplifier 5
consists of two solar cells 5A and 5B, which are differentially connected. Therefore, when both solar cells 5A and 5B are irradiated with the same amount of light, the output is zero, and when only one of them is irradiated, the output is maximum.
次に動作について説明する。Next, the operation will be explained.
今、電流検出器６に電流が流れないとき、つまり、電池
８′が接続されていないとき、反射鏡６Ａで反射される
光が太陽電池５Ａ 、５Ｂに等量入射するように調整し
であるとすると、この状態では電流増幅器５から出力は
出ない。Now, when no current flows through the current detector 6, that is, when the battery 8' is not connected, the adjustment is made so that the light reflected by the reflector 6A is equally incident on the solar cells 5A and 5B. In this case, no output is output from the current amplifier 5 in this state.
この状態で、電池８′を入力端子１，２に接続すると、
電流検出器６に電流ＩＧが流れる。この電流値は被測定
電圧ＶＸに比例する。一方、この電流ＩＧの大きさに比
例して反射鏡６Ａが回動する。この回動方向は被測定電
圧ＶＸの極性に応じて定まる。反射鏡６Ａの回動によっ
て光源６Ｃからの光は反射鏡６Ａで反射され太陽電池５
Ａ、５Ｂに等量に入射していたのが、どちらか一方へ多
く入射されるようになる。すなわち、被測定電圧ＶＸに
応じた起電力が発生し、これにより第１図に示すように
出力電流ＩＯが外部抵抗器１ｏに流れ、出力電圧ＶＯが
発生するとともに、抵抗器７と電流検出器６の直列体の
両端に被測定電圧Ｖ×と等しい電圧を発生させる。つま
り、入力端子１．２間の入力端子電圧Ｖｉ （＝Ｖｘ
、ただし電流を流さないとき）と等しい電圧を発生
させ、電池８′から電流を流さないようにする。このと
きの出力電圧Ｖｏを測定することにより被測定電圧Ｖχ
を正確に測定することができる。In this state, when battery 8' is connected to input terminals 1 and 2,
A current IG flows through the current detector 6. This current value is proportional to the voltage to be measured VX. On the other hand, the reflecting mirror 6A rotates in proportion to the magnitude of this current IG. This direction of rotation is determined depending on the polarity of the voltage to be measured VX. By rotating the reflecting mirror 6A, the light from the light source 6C is reflected by the reflecting mirror 6A and the solar cell 5
The same amount of light was incident on A and 5B, but now more light is incident on one of them. That is, an electromotive force is generated according to the voltage to be measured VX, and as a result, as shown in FIG. A voltage equal to the voltage to be measured Vx is generated across the series body of 6. In other words, the input terminal voltage Vi (=Vx
, but when no current is flowing), so that no current flows from the battery 8'. By measuring the output voltage Vo at this time, the voltage to be measured Vχ
can be measured accurately.
この発明は以上説明したとおり、電流検出器の検出電流
と電流増幅器の増幅電流との間に正帰還をかけ入力電圧
と同一の′電圧を入力端子に発生させる構成としたので
、入力インピーダンスを無限大にすることができ、精度
の高い電圧増幅回路が得られる利点がある。As explained above, this invention has a configuration in which positive feedback is applied between the detected current of the current detector and the amplified current of the current amplifier to generate the same voltage as the input voltage at the input terminal, so that the input impedance can be infinitely reduced. It has the advantage that it can be made larger and a highly accurate voltage amplification circuit can be obtained.
第１図はこの発明の一実施例の等価回路図、第２図はこ
の発明の他の実施例を示す等価回路図、第３図は第１図
の等価回路の実際回路の一例を示す図である。
図中、１，２は入力端子、３，４は出力端子。
５は電流増幅器、５Ａ 、５Ｂは太陽電池、６は電流検
出器、６Ａは反射鏡、６Ｂは吊線、６Ｃは光源、７は抵
抗器、８は被測定電圧、８′は電池、第１図
第２図
第３図Fig. 1 is an equivalent circuit diagram of one embodiment of the present invention, Fig. 2 is an equivalent circuit diagram showing another embodiment of the invention, and Fig. 3 is a diagram showing an example of an actual circuit of the equivalent circuit of Fig. 1. It is. In the figure, 1 and 2 are input terminals, and 3 and 4 are output terminals. 5 is a current amplifier, 5A, 5B are solar cells, 6 is a current detector, 6A is a reflector, 6B is a hanging wire, 6C is a light source, 7 is a resistor, 8 is a voltage to be measured, 8' is a battery, Fig. 1 Figure 2 Figure 3
Claims (1)
器の直列体と、電流増幅器と外部抵抗器の直列体とをそ
れぞれ並列に接続し、さらに前記電流増幅器により前記
電流検出器の検出電流とこの電流増幅器の増幅電流間に
正帰還をかけ前記被測定電圧と同一の電圧を前記入力端
子に発生させる構成としたことを特徴とする電圧増幅回
路。A series body of a current detector and a resistor, and a series body of a current amplifier and an external resistor are each connected in parallel to an input terminal to which a voltage to be measured is applied, and the current amplifier detects the current detector. 1. A voltage amplifying circuit characterized in that the circuit is configured to apply positive feedback between the current and the amplified current of the current amplifier to generate a voltage at the input terminal that is the same as the voltage to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15961185A JPS6220404A (en) | 1985-07-19 | 1985-07-19 | Voltage amplifying circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15961185A JPS6220404A (en) | 1985-07-19 | 1985-07-19 | Voltage amplifying circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6220404A true JPS6220404A (en) | 1987-01-29 |
| JPH0332922B2 JPH0332922B2 (en) | 1991-05-15 |
Family
ID=15697493
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15961185A Granted JPS6220404A (en) | 1985-07-19 | 1985-07-19 | Voltage amplifying circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6220404A (en) |
-
1985
- 1985-07-19 JP JP15961185A patent/JPS6220404A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0332922B2 (en) | 1991-05-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |