JP2002310758A - Bridge circuit - Google Patents
Bridge circuitInfo
- Publication number
- JP2002310758A JP2002310758A JP2001114717A JP2001114717A JP2002310758A JP 2002310758 A JP2002310758 A JP 2002310758A JP 2001114717 A JP2001114717 A JP 2001114717A JP 2001114717 A JP2001114717 A JP 2001114717A JP 2002310758 A JP2002310758 A JP 2002310758A
- Authority
- JP
- Japan
- Prior art keywords
- resistor
- temperature
- dependent
- electric
- circuit
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、熱式流量計など
の電橋回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bridge circuit such as a thermal flow meter.
【０００２】[0002]
【従来の技術】一般に、熱式流量計には、センサコイル
である第１の温度依存性電気抵抗体と、この温度依存性
電気抵抗体の温度を制御するための温度センサである第
２の温度依存性電気抵抗体と、所用の固定電気抵抗器で
構成される電橋回路を用い、センサコイルである第１の
温度依存性電気抵抗体の電圧、電流を測定し、所用の演
算を施して、目的とする物理量（流量）を測定するもの
がある。2. Description of the Related Art In general, a thermal flow meter has a first temperature-dependent electric resistor as a sensor coil and a second temperature sensor as a temperature sensor for controlling the temperature of the temperature-dependent electric resistor. Using a bridge circuit composed of a temperature-dependent electric resistor and a required fixed electric resistor, the voltage and current of the first temperature-dependent electric resistor as a sensor coil are measured, and the required operation is performed. In some cases, a target physical quantity (flow rate) is measured.
【０００３】この種の熱式流量計の従来の電橋回路及び
演算回路を図３に示している。図３において、電橋回路
は、抵抗値Ｒa の固定抵抗器１と抵抗値Ｒb の固定抵抗
器２の直列回路と、センサコイルである抵抗値Ｒs の温
度依存性電気抵抗体３と、抵抗値Ｒc の温度差発生用抵
抗器４、温度センサである抵抗値Ｒt の温度依存性抵抗
体５の直列回路が並列接続され、固定抵抗器１と固定抵
抗器２の接続点Ｐ3 と、温度依存性電気抵抗体３と温度
差発生用抵抗器４の接続点Ｐ4 が演算増幅器６の入力端
に接続されている。演算増幅器６の出力端が固定抵抗器
１と温度依存性電気抵抗体５の接続点Ｐ1 に接続され、
固定抵抗器２と温度依存性電気抵抗体３の接続点Ｐ2 が
接地接続されている。FIG. 3 shows a conventional electric bridge circuit and an arithmetic circuit of this type of thermal flow meter. 3, the bridge circuit includes a fixed resistor 1 of the resistance value R a series circuit of a fixed resistor 2 of the resistance value R b, and temperature dependence of the electrical resistance 3 of the resistance value R s is a sensor coil , the resistance R c the temperature difference generating resistor 4, the series circuit of the temperature-dependent resistor 5 of resistance R t is a temperature sensor are connected in parallel, the connection point of the fixed resistor 1 and the fixed resistor 2 P 3, the connecting point P 4 of the temperature dependence of the electrical resistance 3 and the temperature difference generating resistor 4 is connected to the input terminal of the operational amplifier 6. An output terminal of the operational amplifier 6 is connected to a connection point P 1 between the fixed resistor 1 and the temperature-dependent electric resistor 5,
Connection point P 2 of the fixed resistor 2 and the temperature-dependent electrical resistor 3 is connected to ground.
【０００４】そして、センサコイルである温度依存性電
気抵抗体３の両端電圧Ｅs は演算増幅器７を経て導出さ
れ、固定抵抗器４と温度依存性電気抵抗体５の接続点の
電位は、演算増幅器８によって導出される。また、演算
増幅器９によって接続点Ｐ1とＰ4 の電位差Ｅt が算出
され、出力される。また、演算増幅器７、８の出力が演
算増幅器１０に入力され、演算増幅器８の出力から演算
増幅器７の出力を減じた電圧、つまり温度差発生用抵抗
器４の両端電圧が演算増幅器１０より出力される。[0004] Then, the voltage across E s temperature dependency electric resistor 3 is a sensor coil is derived through an operational amplifier 7, the potential at the connection point between the fixed resistor 4 and the temperature dependence of the electric resistor 5, the operation Derived by the amplifier 8. Further, the potential difference E t of the connection point P 1 and P 4 are calculated and output by the operational amplifier 9. The outputs of the operational amplifiers 7 and 8 are input to the operational amplifier 10, and the voltage obtained by subtracting the output of the operational amplifier 7 from the output of the operational amplifier 8, that is, the voltage across the temperature difference generating resistor 4 is output from the operational amplifier 10. Is done.
【０００５】図４は、熱式流量計の従来の他の電橋回路
及び演算回路を示す回路図である。図４において、電橋
回路はセンサコイルである温度依存性電気抵抗体３と固
定抵抗器１の直列回路と、温度センサである温度依存性
電気抵抗体５、温度差発生用抵抗器４と固定抵抗器２の
直列回路が並列接続され、固定抵抗器１とセンサコイル
である温度依存性電気抵抗体３の接続点Ｐ3 と、固定抵
抗器２と温度差発生用抵抗器４の接続点Ｐ4 が演算増幅
器６に接続され、演算増幅器６の出力端が固定抵抗器１
と固定抵抗器２の接続点Ｐ1 に接続され、センサコイル
である温度依存性電気抵抗体３と温度センサである温度
依存性電気抵抗体５の接続点Ｐ2 が接地接続されて構成
されている。FIG. 4 is a circuit diagram showing another conventional bridge circuit and arithmetic circuit of the thermal type flow meter. In FIG. 4, the bridge circuit is a series circuit of a temperature-dependent electric resistor 3 as a sensor coil and a fixed resistor 1, and a temperature-dependent electric resistor 5 and a temperature difference generating resistor 4 as a temperature sensor. A series circuit of the resistor 2 is connected in parallel, and a connection point P 3 between the fixed resistor 1 and the temperature-dependent electric resistor 3 which is a sensor coil, and a connection point P between the fixed resistor 2 and the temperature difference generating resistor 4. 4 is connected to the operational amplifier 6, and the output terminal of the operational amplifier 6 is a fixed resistor 1
Fixed resistor connected second to the connection point P 1, the connecting point P 2 of the temperature-dependent electrical resistance element 3 and the temperature dependence of electric resistor 5 is a temperature sensor which is a sensor coil is configured by a ground connection and I have.
【０００６】また、この電橋回路からはセンサコイルで
ある温度依存性電気抵抗体３の両端電圧Ｅs が接続点Ｐ
3 より導出され、温度センサである温度依存性電気抵抗
体５の両端電圧Ｅt が接続点Ｐ5 より導出される。更
に、接続点Ｐ4 の電位が演算増幅器１１より導出され、
演算増幅器１２で接続点Ｐ1 の電位から接続点Ｐ4 の電
位を減じた電圧、つまり固定抵抗器２の両端電圧Ｅi を
導出する。Further, the voltage across E s of the temperature-dependent electrical resistance element 3 is a sensor coil from the conductive bridge circuit node P
3 is derived from the voltage across E t of the temperature-dependent electric resistor 5 is a temperature sensor is derived from the connection point P 5. Further, the potential of the connection point P 4 is derived from the operational amplifier 11, and
The operational amplifier 12 derives a voltage obtained by subtracting the potential at the connection point P 4 from the potential at the connection point P 1 , that is, a voltage E i across the fixed resistor 2.
【０００７】[0007]
【発明が解決しようとする課題】上記した従来の電橋回
路及び演算回路では、電圧供給端（Ｐ1 、Ｐ2 点）の両
方とも、また片方を基準電位としており、基準電位につ
ながる２個の抵抗体の電圧のみ基準電位からの電位とし
て取り出すことができ、他の抵抗体の電圧の測定は基準
電位につながる抵抗体の電圧の和として取り出した上、
他の抵抗体の電圧の測定は基準電位につながる抵抗体の
電圧を差し引いて取り出すものである。そのため、電橋
回路に接続する回路が複雑になるという問題があった。In the above-described conventional bridge circuit and arithmetic circuit, both of the voltage supply terminals (P 1 and P 2 ) and one of them are used as a reference potential. Only the voltage of the resistor can be taken out as a potential from the reference potential, and the measurement of the voltage of the other resistors is taken out as the sum of the voltages of the resistors connected to the reference potential,
The measurement of the voltage of another resistor is obtained by subtracting the voltage of the resistor connected to the reference potential. Therefore, there is a problem that a circuit connected to the electric bridge circuit becomes complicated.
【０００８】この発明は上記問題点に着目してなされた
ものであって、比較的簡単な回路構成で、測定に必要な
電圧、電流を導出し得る電橋回路を提供することを目的
としている。The present invention has been made in view of the above problems, and has as its object to provide an electric bridge circuit capable of deriving a voltage and a current required for measurement with a relatively simple circuit configuration. .
【０００９】[0009]
【課題を解決するための手段】この発明の電橋回路は、
第１の温度依存性電気抵抗体と、この第１の温度依存性
電気抵抗体の温度を制御するための第２の温度依存性電
気抵抗体を含む電橋回路において、前記第１の温度依存
性電気抵抗体と、この第１の温度依存性電気抵抗体に流
れる電流検出用抵抗の直列回路と、前記第２の温度依存
性電気抵抗体と、この第２の温度依存性電気抵抗体に流
れる電流検出用抵抗の直列回路とを並列接続して形成
し、前記第１の温度依存性電気抵抗体と電流検出用抵抗
の接続点と基準電位Ｅ0 の差と、第２の温度依存性電気
抵抗体と電流検出用抵抗の接続点と基準電気Ｅ0 の差を
増幅し、それぞれを回路の電圧供給点に供給し、前記第
１の温度依存性電気抵抗体に印加する電力による加熱に
よって、抵抗値を制御して、回路を平衡させ、第１と第
２の温度依存性抵抗体の各々の電圧と電流を基準電位差
Ｅ0 との電位差として出力する。The electric bridge circuit according to the present invention comprises:
In a bridge circuit including a first temperature-dependent electrical resistor and a second temperature-dependent electrical resistor for controlling the temperature of the first temperature-dependent electrical resistor, the first temperature-dependent electrical resistor is provided. A series circuit of a conductive electric resistor, a current detecting resistor flowing through the first temperature-dependent electric resistor, the second temperature-dependent electric resistor, and the second temperature-dependent electric resistor. A series connection of a series circuit of a flowing current detecting resistor and a difference between a reference potential E 0 and a connection point between the first temperature-dependent electric resistor and the current detecting resistor; Amplify the difference between the connection point of the electric resistor and the current detection resistor and the reference electricity E 0 , supply the difference to the voltage supply point of the circuit, and heat by the power applied to the first temperature-dependent electric resistor. , Controlling the resistance to balance the circuit and the first and second temperature dependent resistors Are output as a potential difference from the reference potential difference E 0 .
【００１０】[0010]
【発明の実施の形態】以下、実施の形態により、この発
明をさらに詳細に説明する。図１は、この発明の一実施
形態である熱式流量計の電橋回路を示す回路図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a circuit diagram showing an electric bridge circuit of a thermal flow meter according to an embodiment of the present invention.
【００１１】この実施形態電橋回路は、抵抗値Ｒa の固
定抵抗器２１と抵抗値Ｒb の固定抵抗器２２の直流回路
と、センサコイルである抵抗値Ｒs の温度依存性電気抵
抗体２３と、抵抗値Ｒc である温度差発生用抵抗器２
４、温度センサである抵抗値Ｒ t の温度依存性電気抵抗
体２５の直列回路が並列接続され、温度差発生用抵抗器
２４と温度依存性電気抵抗体２３の接続点Ｐ3 が演算増
幅器２６の入力の一端に接続され、この演算増幅器２６
の入力の他端が接地（基準電位）接続されている。この
演算増幅器２６の出力端が固定抵抗器２１と温度依存性
電気抵抗体２５の接続点Ｐ1 に接続されている。また、
固定抵抗器２１と固定抵抗器２２の接続点Ｐ4 が演算増
幅器２７の入力の一端に接続され、この演算増幅器２７
の入力の他端が接地接続されている。この演算増幅器２
７の出力端が固定抵抗器２２と温度依存性電気抵抗体２
３の接続点Ｐ2 に接続されている。In this embodiment, the bridge circuit has a resistance value RaSolid
Constant resistor 21 and resistance value RbDC circuit of fixed resistor 22
And the resistance value R of the sensor coilsTemperature-dependent electrical resistance
Antibody 23 and resistance value RcTemperature difference generating resistor 2
4. Resistance value R as temperature sensor tTemperature-dependent electrical resistance of
The series circuit of the body 25 is connected in parallel,
24 and the temperature dependent electrical resistor 23ThreeIs increased
The operational amplifier 26 is connected to one end of the input of the
The other end of the input is connected to ground (reference potential). this
Output terminal of operational amplifier 26 is fixed resistor 21 and temperature dependency
Connection point P of electric resistor 251It is connected to the. Also,
Connection point P between fixed resistor 21 and fixed resistor 22FourIs increased
The operational amplifier 27 is connected to one end of the input of the
The other end of the input is grounded. This operational amplifier 2
7 has a fixed resistor 22 and a temperature-dependent electric resistor 2.
Connection point P of 3TwoIt is connected to the.
【００１２】この実施形態電橋回路において、平衡電位
検出端Ｐ3 、Ｐ4 は、それぞれ基準電位Ｅ0 との差を検
出し、増幅した上、センサコイルである温度依存性電気
抵抗体２３の電圧を制御する。この温度依存性電気抵抗
体２３の電圧によって、その温度を制御し、平衡電位検
出端（Ｐ3 、Ｐ4 ）の電位を基準電位に等しくする。In this embodiment, the equilibrium potential detecting terminals P 3 and P 4 respectively detect the difference from the reference potential E 0 , amplify the difference, and detect the difference between the reference potential E 0 and the temperature-dependent electric resistor 23 as a sensor coil. Control the voltage. The temperature is controlled by the voltage of the temperature-dependent electric resistor 23, and the potentials at the equilibrium potential detection terminals (P 3 , P 4 ) are made equal to the reference potential.
【００１３】回路が平衡すると、接続点Ｐ2 より、セン
サコイルである温度依存性電気抵抗体２３の電圧Ｅs が
導出され、温度差発生用抵抗器２４と温度依存性電気抵
抗体２５の接続点Ｐ5 より、温度差発生用抵抗器２４両
端の電圧、つまり温度依存性電気抵抗体２３に流れる電
流Ｉs に応じた電圧Ｅi を導出し、接続点Ｐ1 より温度
依存性電気抵抗体２５の電圧Ｅt が導出される。このた
め、これらの電圧、電流を算出するための複雑な回路を
必要としない。When the circuit is balanced, the voltage E s of the temperature-dependent electric resistor 23 as a sensor coil is derived from the connection point P 2 , and the connection between the temperature difference generating resistor 24 and the temperature-dependent electric resistor 25 is established. the point P 5, the voltage of the temperature difference generating resistor 24 across, that is the temperature dependence of the voltage E i derived in accordance with the current I s flowing through the electric resistor 23, the temperature-dependent electrical resistor from the connection point P 1 25 of the voltage E t is derived. Therefore, a complicated circuit for calculating these voltages and currents is not required.
【００１４】図２は、この発明の他の実施形態である熱
式流量計の電橋回路を示す回路図である。FIG. 2 is a circuit diagram showing an electric bridge circuit of a thermal flow meter according to another embodiment of the present invention.
【００１５】この実施形態電橋回路は、抵抗値Ｒa の固
定抵抗器２１と、センサコイルである抵抗値Ｒs の温度
依存性電気抵抗体２３の直列回路と、抵抗値Ｒc である
温度差発生用抵抗器２４、温度センサである抵抗値Ｒt
の温度依存性電気抵抗体２５と抵抗値Ｒb である固定抵
抗器２２の直列回路が並列に接続され、温度差発生用抵
抗器２４と温度依存性電気抵抗体２３の接続点Ｐ3 が演
算増幅器２６の入力の一端に接続され、この演算増幅器
２６の入力の他端が接地（基準電位）接続されている。
この演算増幅器２６の出力端が固定抵抗器２１と固定抵
抗器２２の接続点Ｐ1 に接続されている。また、固定抵
抗器２２と温度依存性電気抵抗体２５の接続点Ｐ4 が演
算増幅器２７の入力の一端に接続され、この演算増幅器
２７の入力の他端が接地接続されている。この演算増幅
器２７の出力端が温度差発生用抵抗器２４と温度依存性
電気抵抗体２３の接続点Ｐ2 に接続されている。[0015] The embodiment the bridge circuit includes a fixed resistor 21 of resistance R a, the series circuit of the temperature-dependent electric resistor 23 of resistance R s is a sensor coil, the resistance value R c Temperature generating resistor 24, a temperature sensor resistance R t
A series circuit of the fixed resistors 22 and temperature-dependent electric resistor 25 of a resistance value R b are connected in parallel, connecting point P 3 of the temperature difference generating resistor 24 and the temperature-dependent electrical resistor 23 is operational The other end of the input of the operational amplifier 26 is connected to ground (reference potential).
The output terminal of the operational amplifier 26 is connected to a connection point P 1 between the fixed resistor 21 and the fixed resistor 22. The connection point P 4 of the fixed resistor 22 and the temperature-dependent electrical resistor 25 is connected to one end of the input of the operational amplifier 27, the other end of the input of the operational amplifier 27 is connected to ground. The output terminal of the operational amplifier 27 is connected to a connection point P 2 between the temperature difference generating resistor 24 and the temperature-dependent electric resistor 23.
【００１６】この実施形態回路において、次式の条件、
成立で回路が平衡し、点Ｐ3 、Ｐ4が基準電圧Ｅ0 とな
る。In the circuit of this embodiment, the following condition:
When it is established, the circuit is balanced, and the points P 3 and P 4 become the reference voltage E 0 .
【００１７】 Ｉs ×Ｒs ＝Ｉt ×（Ｒc ×Ｒt ） ……（１） Ｉs ×Ｒs ＝Ｉt ×Ｒb ……（２） Ｒs ＝Ｒc ＋Ｒtb ……（３） この実施形態電橋回路においても、平衡時において、点
Ｐ3 、Ｐ4 が基準電位Ｅ0 となるので、点Ｐ2 からセン
サコイルである温度依存性電気抵抗体２３の電圧Ｅs が
導出され、固定抵抗器２４と温度依存性電気抵抗体２５
の接続点から固定抵抗器２４の電圧、つまり温度センサ
である温度依存性電気抵抗体２５の電圧Ｅt が導出さ
れ、点Ｐ1 からは温度依存性電気抵抗体２５に流れる電
流Ｉt に応じた電圧Ｅi が導出できる。そのため、複雑
な演算回路を設ける必要がない。[0017] I s × R s = I t × (R c × R t) ...... (1) I s × R s = I t × R b ...... (2) R s = R c + R tb ...... ( 3) Also in this embodiment of the bridge circuit, at the time of equilibrium, the points P 3 and P 4 become the reference potential E 0 , so that the voltage E s of the temperature-dependent electric resistor 23 which is the sensor coil from the point P 2 becomes Derived fixed resistor 24 and temperature-dependent electric resistor 25
Voltage of the fixed resistor 24 from the connection point, i.e. the voltage E t of the temperature-dependent electric resistor 25 is a temperature sensor is derived, depending on the current I t flowing through the temperature-dependent electrical resistor 25 from the point P 1 voltage E i can be derived. Therefore, there is no need to provide a complicated arithmetic circuit.
【００１８】[0018]
【発明の効果】この発明によれば、第１の温度依存性電
気抵抗体と電流検出用抵抗の接続点と基準電位Ｅ0 の差
と、第２の温度依存性電気抵抗体と電流検出用抵抗の接
続点と基準電気Ｅ0 の差を増幅し、それぞれを回路の電
圧供給点に供給し、前記第１の温度依存性電気抵抗体に
印加する電力による加熱によって、抵抗値を制御して、
回路を平衡させ、第１と第２の温度依存性抵抗体の各々
の電圧と電流を基準電位差Ｅ0 との電位差として出力す
るようにしているので、電橋回路に後続する回路を簡単
な構成とすることができ、その分、各演算増幅器で発生
する誤差を軽減でき、精度の良い制御が可能となる。Effects of the Invention According to the present invention, the difference between the first temperature-dependent electrical resistor and the current detection resistor connecting point and a reference potential E 0, the second temperature-dependent electrical resistor and the current detection Amplify the difference between the connection point of the resistor and the reference electricity E 0 , supply each to the voltage supply point of the circuit, and control the resistance value by heating with the power applied to the first temperature-dependent electrical resistor. ,
Allowed to equilibrate circuit, since the outputs a first and respective voltage and current of the second temperature-dependent resistor as a potential difference between the reference potential E 0, simple circuits subsequent to the bridge circuit arrangement Therefore, the error generated in each operational amplifier can be reduced, and accurate control can be performed.
【図１】この発明の一実施形態である熱式流量計の電橋
回路を示す回路図である。FIG. 1 is a circuit diagram showing an electric bridge circuit of a thermal flow meter according to an embodiment of the present invention.
【図２】この発明の他の実施形態である熱式流量計の電
橋回路を示す回路図である。FIG. 2 is a circuit diagram showing an electric bridge circuit of a thermal flow meter according to another embodiment of the present invention.
【図３】従来の熱式流量計の電橋回路及び電橋回路に後
続する演算回路を思惟す回路図である。FIG. 3 is a circuit diagram of an electric bridge circuit of a conventional thermal flow meter and an arithmetic circuit subsequent to the electric bridge circuit.
【図４】従来の他の熱式流量計の電橋回路及び電橋回路
に後続する演算回路を思惟す回路図である。FIG. 4 is a circuit diagram for considering an electric bridge circuit and an arithmetic circuit subsequent to the electric bridge circuit of another conventional thermal flow meter.
２１、２２ 固定抵抗器 ２３ センサコイルである温度依存性電気抵
抗体 ２４ 温度差発生用抵抗器 ２５ 温度センサである温度依存性電気抵抗
体 ２６、２７ 演算増幅器21, 22 Fixed resistor 23 Temperature-dependent electrical resistor as sensor coil 24 Resistor for generating temperature difference 25 Temperature-dependent electrical resistor as temperature sensor 26, 27 Operational amplifier
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2F035 EA09 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2F035 EA09
Claims (1)
の温度依存性電気抵抗体の温度を制御するための第２の
温度依存性電気抵抗体を含む電橋回路において、 前記第１の温度依存性電気抵抗体と、この第１の温度依
存性電気抵抗体に流れる電流検出用抵抗の直列回路と、
前記第２の温度依存性電気抵抗体と、この第２の温度依
存性電気抵抗体に流れる電流検出用抵抗の直列回路とを
並列接続して形成し、 前記第１の温度依存性電気抵抗体と電流検出用抵抗の接
続点と基準電位Ｅ0 の差と、第２の温度依存性電気抵抗
体と電流検出用抵抗の接続点と基準電気Ｅ0 の差を増幅
し、それぞれを回路の電圧供給点に供給し、前記第１の
温度依存性電気抵抗体に印加する電力による加熱によっ
て、抵抗値を制御して、回路を平衡させ、第１と第２の
温度依存性抵抗体の各々の電圧と電流を基準電位差Ｅ0
との電位差として出力することを特徴とする電橋回路。A first temperature-dependent electrical resistor; and a first temperature-dependent electrical resistor.
An electrical bridge circuit including a second temperature-dependent electrical resistor for controlling the temperature of the temperature-dependent electrical resistor, wherein the first temperature-dependent electrical resistor and the first temperature-dependent electrical resistor A series circuit of a current detection resistor flowing through the resistor,
The second temperature-dependent electric resistor is formed by connecting a series circuit of a current detecting resistor flowing through the second temperature-dependent electric resistor in parallel, and the first temperature-dependent electric resistor is formed. The difference between the connection point of the current detection resistor and the reference potential E 0 , and the difference between the connection point of the second temperature-dependent electrical resistor and the connection point of the current detection resistor and the reference electricity E 0 are amplified, and each is amplified by the circuit voltage. The resistance is controlled by heating by electric power supplied to the supply point and applied to the first temperature-dependent electric resistor, the circuit is balanced, and each of the first and second temperature-dependent resistances is heated. The voltage and the current are set to the reference potential difference E 0
An electric bridge circuit characterized by outputting as a potential difference from the electric bridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001114717A JP2002310758A (en) | 2001-04-13 | 2001-04-13 | Bridge circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001114717A JP2002310758A (en) | 2001-04-13 | 2001-04-13 | Bridge circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002310758A true JP2002310758A (en) | 2002-10-23 |
Family
ID=18965732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001114717A Pending JP2002310758A (en) | 2001-04-13 | 2001-04-13 | Bridge circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002310758A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1541974A1 (en) * | 2003-12-08 | 2005-06-15 | Hitachi, Ltd. | Heating resistor type flow-measuring device |
-
2001
- 2001-04-13 JP JP2001114717A patent/JP2002310758A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1541974A1 (en) * | 2003-12-08 | 2005-06-15 | Hitachi, Ltd. | Heating resistor type flow-measuring device |
| US7010971B2 (en) | 2003-12-08 | 2006-03-14 | Hitachi Ltd. | Heating resistor type flow-measuring device having a heating resistor and a thermoresistance, whose resistance value varies in response to the ambient temperature |
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