JPS6129120Y2 - - Google Patents

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Publication number
JPS6129120Y2
JPS6129120Y2 JP6293878U JP6293878U JPS6129120Y2 JP S6129120 Y2 JPS6129120 Y2 JP S6129120Y2 JP 6293878 U JP6293878 U JP 6293878U JP 6293878 U JP6293878 U JP 6293878U JP S6129120 Y2 JPS6129120 Y2 JP S6129120Y2
Authority
JP
Japan
Prior art keywords
resistor
operational
operational amplifier
input terminal
resistance
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
Application number
JP6293878U
Other languages
Japanese (ja)
Other versions
JPS54164586U (en
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
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Priority to JP6293878U priority Critical patent/JPS6129120Y2/ja
Publication of JPS54164586U publication Critical patent/JPS54164586U/ja
Application granted granted Critical
Publication of JPS6129120Y2 publication Critical patent/JPS6129120Y2/ja
Expired legal-status Critical Current

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  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)

Description

【考案の詳細な説明】 本考案は、抵抗・電気信号変換装置に関するも
のであつて、測温抵抗体や半導体ストレンゲージ
等の抵抗体に電流を流すことによつて生ずる電圧
を検出して抵抗変化を電気信号に変換する装置に
おいて、抵抗体の導線抵抗の影響および交流ノイ
ズ成分を序去するようにしたものである。[Detailed description of the invention] The present invention relates to a resistance/electrical signal converter, which detects the voltage generated by passing a current through a resistor such as a resistance temperature detector or a semiconductor strain gauge, and In a device that converts changes into electrical signals, the influence of the conductor resistance of a resistor and AC noise components are eliminated.

一般に、この種の抵抗・電気信号変換装置にお
いては、抵抗体が遠隔の測定点に配置され、変換
用の電気回路とは導線によつて結ばれており、導
線の抵抗が抵抗体と直列になつている。したがつ
て、導線抵抗の値が抵抗体の抵抗値に対して無視
できなくなると、そのままでは変換結果に誤差を
生じることになる。また、抵抗体および導線を介
して変換用の電気回路に交流ノイズ成分が加えら
れて、変換動作に悪影響を及ぼすことがある。 Generally, in this type of resistance/electrical signal conversion device, a resistor is placed at a remote measurement point and connected to the conversion electric circuit by a conductor, so that the resistance of the conductor is in series with the resistor. It's summery. Therefore, if the value of the conductor resistance becomes no longer negligible compared to the resistance value of the resistor, an error will occur in the conversion result. Furthermore, AC noise components may be added to the conversion electric circuit via the resistor and conductive wire, which may adversely affect the conversion operation.

本考案は、このような抵抗・電気信号変換装置
における欠点を解決するものであつて、以下、図
面を用いて詳細に説明する。 The present invention solves the drawbacks of such a resistance/electrical signal converter, and will be described in detail below with reference to the drawings.

第１図は本考案の一実施例を示す回路図であつ
て、Rtは３線式の測温抵抗体、ａ，ｂ，ｃは各
導線の端子、r1〜r3は各導線の低抗を表わしてい
る。Ｉは電流源で、抵抗体Rtの両端の導線端子
ａ，ｃ間に接続され、低抗体Rtに一定の電流Isを
流すものである。OP1は演算増幅器、R1〜R4はそ
の演算抵抗体、C0，C2はコンデンサである。演
算増幅器OP1の反転入力端子（−）には抵抗R1を
介して抵抗体Rtの導線端子ａが接続されるとと
もに抵抗R2を介して出力端子が接続され、非反
転入力端子（＋）には抵抗R3を介して抵抗体Rt
の導線端子ｂが接続されるとともに抵抗R4とコ
ンデンサC2との直列回路を介して共通電位点が
接続されている。また、反転入力端子（−）と非
反転入力端子（＋）はコンデンサC2を介して接
続されている。ここで、演算抵抗R1〜R4はそれ
ぞれ等しい値に選定され、コンデンサC2はその
インピーダンスが演算抵抗の抵抗値に比べて充分
小さな値に選定されている。 FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which Rt is a three-wire resistance temperature detector, a, b, and c are terminals of each conductor, and r 1 to r 3 are low voltage terminals of each conductor. It represents resistance. I is a current source, which is connected between conductor terminals a and c at both ends of the resistor Rt, and causes a constant current Is to flow through the low antibody Rt. OP 1 is an operational amplifier, R 1 to R 4 are operational resistors thereof, and C 0 and C 2 are capacitors. The inverting input terminal (-) of the operational amplifier OP 1 is connected to the conductor terminal a of the resistor Rt via the resistor R 1 , and the output terminal is connected via the resistor R 2 , and the non-inverting input terminal (+) resistor Rt through resistor R3
The conductor terminal b is connected to the terminal b, and the common potential point is also connected through a series circuit of a resistor R4 and a capacitor C2 . Further, the inverting input terminal (-) and the non-inverting input terminal (+) are connected via a capacitor C2 . Here, the operational resistors R 1 to R 4 are each selected to have the same value, and the impedance of the capacitor C 2 is selected to be a value sufficiently smaller than the resistance value of the operational resistor.

このような構成の動作について説明する。 The operation of such a configuration will be explained.

まず、直流信号の場合、演算増幅器OP1の非反
転入力端子（＋）に接続された演算抵抗RR3，R4
は演算動作には寄与しない。したがつて、導線端
子ａの電圧をEa、導線端子ｂの電圧をEbとする
と、演算増幅器OP1の出力電圧Eoは、 Eo＝2Eb−Ea ＝2Is（Rt＋r3） −Is（r1＋Rt＋r3） (1) となる。ここで、抵抗体Rtの導線抵抗体r1〜r3は
ほぼ等しいので、r1＝r2＝r3＝ｒとすると、第(1)
式は、 Eo＝2Is（Rt＋ｒ）−Is（Rt＋2r） ＝IsRt (2) となり、導線抵抗体r1〜r3の影響は除去されるこ
とになる。また、(2)式から明らかなように、電流
Isの大きさとは無関係に導線抵抗ｒの影響を除去
できるので、抵抗体Rtを流れる電流Isを変えて、
たとえば温度変化に対する出力変化を直線化する
場合でも、導線抵抗ｒに無関係に関連出力を得る
ことができる。 First, in the case of a DC signal, the operational resistors RR 3 and R 4 connected to the non-inverting input terminal (+) of the operational amplifier OP 1
does not contribute to the calculation operation. Therefore, if the voltage at conductor terminal a is Ea and the voltage at conductor terminal b is Eb, the output voltage Eo of operational amplifier OP 1 is Eo = 2Eb - Ea = 2Is (Rt + r 3 ) - Is (r 1 + Rt + r 3 ) (1) becomes. Here, since the wire resistors r 1 to r 3 of the resistor Rt are almost equal, if r 1 = r 2 = r 3 = r, then (1)
The formula is Eo=2Is(Rt+r)-Is(Rt+2r)=IsRt (2), and the influence of the wire resistors r1 to r3 is removed. Also, as is clear from equation (2), the current
Since the influence of the conductor resistance r can be removed regardless of the magnitude of Is, by changing the current Is flowing through the resistor Rt,
For example, even when linearizing the output change with respect to temperature change, the relevant output can be obtained regardless of the conductor resistance r.

一方、交流信号の場合、演算増幅器OP1に接続
されたすべての演算抵抗体R1〜R4が演算に寄与
することになる。したがつて、各導線を介して伝
送される交流ノイズ成分をｅo1〜ｅo3、抵抗体Rt
自体に生じる交流ノイズ成分をｅotとし、導線端
子ａにおける交流ノイズ成分をｅa、導線端子ｂ
における交流ノイズｅbとすると、演算増幅器
OP1の出力電圧における交流ノイズ成分ｅpは、 ｅp＝ｅb−ｅa ＝（ｅo1＋ｅot＋ｅo3） −（ｅo2＋ｅot＋ｅo3） ＝ｅo2−ｅo1 (3) となる。ここで、導線はほぼ同一経路に配線され
ているので、各導線を介して伝送される交流ノイ
ズ成分は等しいものと考えることができる。すな
わち、第１図の回路によれば、抵抗体および導線
を介して変換用の電気回路に加えられる交流ノイ
ズ成分も除去することができる。 On the other hand, in the case of an AC signal, all the operational resistors R 1 to R 4 connected to the operational amplifier OP 1 contribute to the calculation. Therefore, the AC noise components transmitted through each conducting wire are e o1 to e o3 and the resistor Rt
Let e ot be the AC noise component generated at the terminal itself, e a be the AC noise component at the conductor terminal a, and let the AC noise component at the conductor terminal b be
If the AC noise e b is the operational amplifier
The AC noise component e p in the output voltage of OP 1 is as follows: e p = e b - e a = (e o1 + e ot + e o3 ) - (e o2 + e ot + e o3 ) = e o2 - e o1 (3) . Here, since the conducting wires are wired along substantially the same route, it can be considered that the AC noise components transmitted via each conducting wire are equal. That is, according to the circuit shown in FIG. 1, it is also possible to remove AC noise components that are applied to the conversion electric circuit via the resistor and conductive wire.

なお、演算増幅器OP1の反転入力端子（−）と
非反転入力端子（＋）間に接続されたコンデンサ
C1は、本考案の目的のためには直接寄与はしな
いが、回路の応等性の改善やキツクノイズ等高周
波成分除去等に効果を発揮するものである。 Note that the capacitor connected between the inverting input terminal (-) and non-inverting input terminal (+) of operational amplifier OP 1
Although C 1 does not directly contribute to the purpose of the present invention, it is effective in improving the compatibility of the circuit and removing high frequency components such as harsh noise.

第２図は、本考案の他の実施例を示す回路図、
第３図は第２図の等価回路図であつて、第１図と
同等部分には同一符号を付している。この実施例
において、測温抵抗体Rtの温度による抵抗値変
化を電流Isを流すことにより電圧変化として取り
出し、演算増幅器OP1を介して負荷Ｌに電流出力
として加えている。この出力電流は演算増幅器
OP3を介して帰還電圧Efとして演算増幅器OP2の
非反転入力端子に加えられ、演算増幅器OP2の入
力信号とが十分小さくなるように電流Isを変化さ
せて温度−出力電流の関係をリニアにしている。
ここで、１／Ｒ５＋１／Ｒ２≡１／Ｒ１，R3≡R4，R4≫
１／ωＣ２の条件 を満たすように演算抵抗体R1〜R5およびコンデ
ンサC2の値を選定することにより、第１図と同
様に、低抗体の導線低抗の影響および交流ノイズ
成分を除去することができる。 FIG. 2 is a circuit diagram showing another embodiment of the present invention;
FIG. 3 is an equivalent circuit diagram of FIG. 2, in which parts equivalent to those in FIG. 1 are given the same reference numerals. In this embodiment, a change in resistance value due to temperature of the temperature sensing resistor Rt is extracted as a voltage change by flowing a current Is, and is applied as a current output to a load L via an operational amplifier OP1 . This output current is an operational amplifier
It is applied to the non-inverting input terminal of operational amplifier OP 2 as a feedback voltage Ef via OP 3 , and the current Is is changed so that the input signal of operational amplifier OP 2 is sufficiently small to linearize the relationship between temperature and output current. I have to.
Here, 1/R 5 +1/R 2 ≡1/R 1 , R 3 ≡R 4 , R 4 ≫
By selecting the values of the operational resistors R 1 to R 5 and the capacitor C 2 so as to satisfy the condition of 1/ωC 2 , the influence of the low resistance of the conductor with low resistance and the AC noise component can be reduced, as in Fig. 1. Can be removed.

以上説明したように、本考案によれば、比較的
簡単な回路構成で、抵抗体に電流を流すことによ
つて生ずる電圧を検知して抵抗値変化を電気信号
に変換する装置における導線抵抗の影響および交
流ノイズ成分を除去することができ、抵抗温度測
定装置等に好適である。 As explained above, according to the present invention, the resistance of the conductor in a device that detects the voltage generated by passing a current through a resistor and converts the change in resistance value into an electrical signal with a relatively simple circuit configuration. It is possible to remove influences and alternating current noise components, making it suitable for resistance temperature measuring devices and the like.

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

第１図は本考案の一実施例を示す回路図、第２
図は本考案の他の実施例を示す回路図、第３図は
第２図の等価回路図である。 Rt……測温抵抗体、Ｉ……電流源、OP1〜OP3
……演算増幅器、R1〜R5……抵抗、C1，C2……
コンデンサ。 Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a circuit diagram showing another embodiment of the present invention, and FIG. 3 is an equivalent circuit diagram of FIG. 2. Rt...Resistance temperature detector, I...Current source, OP 1 to OP 3
...Operation amplifier, R1 to R5 ...Resistance, C1 , C2 ...
capacitor.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] ３線式の抵抗体と、抵抗体の両端の第１、第３
の導線間に電流を流す手段と、演算増幅器と、抵
抗体の両端の第１、第３の導線間の電圧を演算増
幅器の一方の入力端子に加えるための第１の演算
抵抗と、演算増幅器の出力信号に関連した信号を
一方の入力端子に帰還する第２の演算抵抗と、抵
抗体の第２、第３の導線間の電圧を演算増幅器の
他方の入力端子に加えるための第３の演算抵抗
と、演算増幅器の他方の入力端子を共通電位点に
接続する第４の演算抵抗とコンデンサとの直列回
路とからなり、前記各演算抵抗およびコンデンサ
の値を選定して抵抗体の導線抵抗の影響および交
流ノイズ成分を除去するようにした抵抗・電気信
号変換装置。 A three-wire resistor, and the first and third wires at both ends of the resistor.
an operational amplifier; a first operational resistor for applying a voltage between the first and third conductive wires at both ends of the resistor to one input terminal of the operational amplifier; and an operational amplifier. a second operational resistor for feeding back a signal related to the output signal of the operational amplifier to one input terminal; and a third operational resistor for applying a voltage between the second and third conductors of the resistor to the other input terminal of the operational amplifier. It consists of an operational resistor and a series circuit of a fourth operational resistor and a capacitor that connects the other input terminal of the operational amplifier to a common potential point, and the conductor resistance of the resistor is determined by selecting the values of each of the operational resistors and capacitors. A resistance/electrical signal converter that removes the effects of noise and alternating current noise components.
JP6293878U 1978-05-11 1978-05-11 Expired JPS6129120Y2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6293878U JPS6129120Y2 (en) 1978-05-11 1978-05-11

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6293878U JPS6129120Y2 (en) 1978-05-11 1978-05-11

Publications (2)

Publication Number Publication Date
JPS54164586U JPS54164586U (en) 1979-11-17
JPS6129120Y2 true JPS6129120Y2 (en) 1986-08-28

Family

ID=28965660

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6293878U Expired JPS6129120Y2 (en) 1978-05-11 1978-05-11

Country Status (1)

Country Link
JP (1) JPS6129120Y2 (en)

Also Published As

Publication number Publication date
JPS54164586U (en) 1979-11-17

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