JPS5848597Y2 - Reference junction compensation circuit - Google Patents
Reference junction compensation circuitInfo
- Publication number
- JPS5848597Y2 JPS5848597Y2 JP16352379U JP16352379U JPS5848597Y2 JP S5848597 Y2 JPS5848597 Y2 JP S5848597Y2 JP 16352379 U JP16352379 U JP 16352379U JP 16352379 U JP16352379 U JP 16352379U JP S5848597 Y2 JPS5848597 Y2 JP S5848597Y2
- Authority
- JP
- Japan
- Prior art keywords
- reference junction
- resistor
- compensation circuit
- junction temperature
- junction compensation
- 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
Links
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
- Control Of Temperature (AREA)
Description
【考案の詳細な説明】
本考案は、熱電対温度測定器の基準接点補償回路の改良
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a reference junction compensation circuit for a thermocouple temperature measuring device.
第１図に従来のこの種の基準接点補償回路を示す。FIG. 1 shows a conventional reference junction compensation circuit of this type.
図において、熱電対１は端子板２に取り付けられ、熱電
対１の一端はコモンに接続されている。In the figure, a thermocouple 1 is attached to a terminal board 2, and one end of the thermocouple 1 is connected to a common.
熱電対１に生じた熱起電力は第１の増幅器３で増幅され
た後抵抗器４を介して帰還抵抗器１１を有する第３の増
幅器５の入力端に導かれている。The thermoelectromotive force generated in the thermocouple 1 is amplified by a first amplifier 3 and then led to an input terminal of a third amplifier 5 having a feedback resistor 11 via a resistor 4.
一方、端子板２の温度すなわち基準接点温度を測定する
ために、ダイオード接続されたトランジスタ６を熱的に
結合するように等温効果のある端子板２に埋設している
。On the other hand, in order to measure the temperature of the terminal board 2, that is, the reference junction temperature, a diode-connected transistor 6 is embedded in the terminal board 2, which has an isothermal effect, so as to be thermally coupled.
このトランジスタ６は第２の増幅器７の帰還路に挿入接
続されている。This transistor 6 is inserted into the feedback path of the second amplifier 7.
増幅器７の入力端には調整抵抗器８を介して基準電圧Ｅ
ｒｅｆが供給され、入力電流に実質的に等しい帰還電流
がトランジスタ６に流れる。A reference voltage E is connected to the input terminal of the amplifier 7 via an adjustment resistor 8.
ref is supplied and a feedback current substantially equal to the input current flows through transistor 6.
この場合のトランジスタ６のベース・エミッタ間電圧つ
まり増幅器７の出力電圧は基準接点温度に対応した値と
なる。In this case, the base-emitter voltage of the transistor 6, that is, the output voltage of the amplifier 7, has a value corresponding to the reference junction temperature.
この電圧は抵抗器９を介して第３の増幅器５の入力端に
導かれている。This voltage is led via a resistor 9 to the input of the third amplifier 5.
また、増幅器５の入力端には調整抵抗器１０を介して基
準電圧Ｅｒｅｆが供給されている。Further, a reference voltage Eref is supplied to the input terminal of the amplifier 5 via an adjustment resistor 10.
このような構成において、調整抵抗器８，１０及び抵抗
器４，９．１１の値を適切に選定することにより、基準
接点温度に応じた熱起電力が熱電対出力に加算され、い
わゆる基準接点補償の行なわれた熱起電力に関連した出
力が得られる。In such a configuration, by appropriately selecting the values of the adjustment resistors 8 and 10 and the resistors 4 and 9.11, a thermoelectromotive force according to the reference junction temperature is added to the thermocouple output, so that the so-called reference junction An output related to the compensated thermoelectromotive force is obtained.
しかし、増幅器の数が多く、小形軽量化に不向きで士か
も高価であるなどの欠点があった。However, it had drawbacks such as requiring a large number of amplifiers, making it unsuitable for miniaturization and weight reduction, and being expensive.
本考案の目的は、このような欠点を除去し、増幅器の個
数を減少し小形で安価な基準接点補償回路を実現しよう
とするものである。An object of the present invention is to eliminate such drawbacks, reduce the number of amplifiers, and realize a small and inexpensive reference junction compensation circuit.
以下図面を用いて本考案を詳しく説明する。The present invention will be explained in detail below using the drawings.
第２図は本考案に係る基準接点補償回路の一実施例を示
す構成国である。FIG. 2 shows the configuration of an embodiment of the reference junction compensation circuit according to the present invention.
第２図において、第１図と同等素子には同一符号を付し
その説明は省略する。In FIG. 2, elements equivalent to those in FIG. 1 are given the same reference numerals and their explanations will be omitted.
２１は零点調整手段、２２は基準接点温度検出手段、２
４．２５は第１及び第２の抵抗器、２６は演算増幅器で
ある。21 is a zero point adjustment means, 22 is a reference junction temperature detection means, 2
4.25 are first and second resistors, and 26 is an operational amplifier.
零点調整手段２１は、演算増幅器２６の零点を調整する
ものである。The zero point adjustment means 21 is for adjusting the zero point of the operational amplifier 26.
この調整手段２１としては、基準電圧Ｅｒｅｆを分圧し
て出力するポテンショメータなどを用いることかで゛き
、その出力は熱電対１を介して演算増幅器２６の非反転
入力端子に与えられている。As the adjustment means 21, a potentiometer or the like which divides the reference voltage Eref and outputs the divided voltage may be used, and the output thereof is applied to the non-inverting input terminal of the operational amplifier 26 via the thermocouple 1.
基準接点温度検出手段２２はダイオード接続されたトラ
ンジスタ６と抵抗器２３の直列回路で構成され、抵抗器
２３を介してトランジスタ６に基準電圧Ｅｒｅｆが印加
されている。The reference junction temperature detection means 22 is composed of a series circuit of a diode-connected transistor 6 and a resistor 23, and a reference voltage Eref is applied to the transistor 6 via the resistor 23.
トランジスタ６のベース・エミッタ間電圧■ＢＥは第１
の抵抗器２４を介して演算増幅器２６の反転入力端子に
導かれている。The base-emitter voltage of transistor 6 ■BE is the first
is led to the inverting input terminal of an operational amplifier 26 via a resistor 24 .
帰還抵抗器１１を有する演算増幅器２６の反転入力端子
はまた第２の抵抗器２５を介してコモンに接続されてい
る。The inverting input terminal of operational amplifier 26 with feedback resistor 11 is also connected via a second resistor 25 to common.
このような構成において、零点調整手段２１により、演
算増幅器２６のオフセット電圧並びにトランジスタ６及
び抵抗器２３のばらつきによる基準接点補償電圧のオフ
セットをまとめて調整している。In such a configuration, the zero point adjustment means 21 collectively adjusts the offset voltage of the operational amplifier 26 and the offset of the reference junction compensation voltage due to variations in the transistor 6 and the resistor 23.
ここで゛、トランジスタ６の出力インピーダンスが第１
の抵抗器２４の抵抗値Ｒ１に比べて十分小さいものとし
、第２の抵抗器２５及び帰還抵抗器１１の値をそれぞれ
Ｒ２，Ｒ３、ポテンショメータ２１の出力をＶｐおよび
熱電対１の熱起電力をＥｅｍｆとすれば、演算増幅器２
６の出力Ｖｏは
Ｖｏ ＝ （Ｅｅｍｆ＋ ｖｐ） −Ｒ３−となる。Here, the output impedance of the transistor 6 is the first
The values of the second resistor 25 and the feedback resistor 11 are R2 and R3, respectively, the output of the potentiometer 21 is Vp, and the thermoelectromotive force of the thermocouple 1 is set to be sufficiently small compared to the resistance value R1 of the resistor 24. If Eemf, operational amplifier 2
The output Vo of 6 becomes Vo = (Eemf+vp) -R3-.
また、（１）式において、端子板２の温度Ｔでの微少温
度変化に対して出力Ｖｏが変化しないものとすれば、
が成立する。Further, in equation (1), if it is assumed that the output Vo does not change with respect to a slight temperature change in the temperature T of the terminal board 2, then the following holds true.
したがって、（１）式の■０が熱電対１の０℃を基準と
する熱起電力に相当し、かつ（２）式が成立するように
Ｒ１，Ｒ２及びＲ３を適切に選定することによって、基
準接点温度Ｔおよびその近傍で基準接点補償がなされた
信号を得ることができる。Therefore, by appropriately selecting R1, R2, and R3 so that 0 in equation (1) corresponds to the thermoelectromotive force of thermocouple 1 with reference to 0°C, and equation (2) holds, A signal with reference junction compensation performed at and around the reference junction temperature T can be obtained.
更に高精度の補償を必要とする場合には抵抗器２３を調
整することにより遠戚することができる。If even more precise compensation is required, it can be further improved by adjusting the resistor 23.
なお、基準接点温度を検出するものとして実施例ではト
ランジスタ６を示したが、これに限らす測温抵抗体を用
いて所望の温度係数の得られるように構成することもで
きる。Although the transistor 6 is shown in the embodiment as a device for detecting the reference junction temperature, it is also possible to use a temperature-measuring resistor so as to obtain a desired temperature coefficient.
以上説明したように、本考案の基準接点補償回路によれ
ば、従来の回路のような多くの増幅器を必要とすること
なく、１個の増幅器を使用して基準接点補償を実質的に
高精度に行なうことができ、回路全体を小形で安価に構
成することができる効果がある。As explained above, according to the reference junction compensation circuit of the present invention, reference junction compensation can be performed with substantially high accuracy using one amplifier, without requiring many amplifiers unlike conventional circuits. This has the effect that the entire circuit can be made small and inexpensive.
第１図は従来の基準接点補償回路の構成図、第２図は本
考案に係る基準接点補償回路の一実施例を示す構成図で
ある。
１・・・・・・熱電対、２１・・・・・・零点調整手段
、２２・・・・・・基準接点温度検出手段、６・・・・
・・トランジスタ、２４・・・・・・第１の抵抗器、２
５・・・・・・第２の抵抗器、１１・・・・・・帰還抵
抗器、２６・・・・・・演算増幅器。FIG. 1 is a block diagram of a conventional reference junction compensation circuit, and FIG. 2 is a block diagram showing an embodiment of the reference junction compensation circuit according to the present invention. 1...Thermocouple, 21...Zero point adjustment means, 22...Reference junction temperature detection means, 6...
...Transistor, 24...First resistor, 2
5... Second resistor, 11... Feedback resistor, 26... Operational amplifier.
Claims (1)
接点補償回路において、零点調整手段と、基準接点温度
に応じて前記熱電灯の熱起電力に関連した信号を得る基
準接点温度検出手段と、非反転入力端子が前記熱電灯を
介して前記零点調整手段の出力端に接続され、反転入力
端子が第１の抵抗器を介して前記基準接点温度検出手段
の出力端に接続されると共に第２の抵抗器を介してコモ
ンに接続されかつ帰還抵抗器を介して出力端子に接続さ
れてなる演算増幅器を具備したことを特徴とする基準接
点補償回路。A reference junction compensation circuit that detects a reference junction temperature and compensates for the thermoelectromotive force of a thermocouple, comprising a zero point adjustment means and a reference junction temperature detection means for obtaining a signal related to the thermoelectromotive force of the thermoelectric lamp according to the reference junction temperature. and a non-inverting input terminal is connected to the output end of the zero point adjusting means via the thermoelectric lamp, an inverting input terminal is connected to the output end of the reference junction temperature detecting means via a first resistor, and A reference junction compensation circuit comprising an operational amplifier connected to a common via a second resistor and connected to an output terminal via a feedback resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16352379U JPS5848597Y2 (en) | 1979-11-26 | 1979-11-26 | Reference junction compensation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16352379U JPS5848597Y2 (en) | 1979-11-26 | 1979-11-26 | Reference junction compensation circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5679833U JPS5679833U (en) | 1981-06-29 |
| JPS5848597Y2 true JPS5848597Y2 (en) | 1983-11-07 |
Family
ID=29674491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16352379U Expired JPS5848597Y2 (en) | 1979-11-26 | 1979-11-26 | Reference junction compensation circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5848597Y2 (en) |
-
1979
- 1979-11-26 JP JP16352379U patent/JPS5848597Y2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5679833U (en) | 1981-06-29 |
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