JPH04337428A - Temperature measurement device - Google Patents
Temperature measurement deviceInfo
- Publication number
- JPH04337428A JPH04337428A JP13710691A JP13710691A JPH04337428A JP H04337428 A JPH04337428 A JP H04337428A JP 13710691 A JP13710691 A JP 13710691A JP 13710691 A JP13710691 A JP 13710691A JP H04337428 A JPH04337428 A JP H04337428A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- power supply
- thermistor
- series
- temperature
- 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
- 238000009529 body temperature measurement Methods 0.000 title abstract description 4
- 238000001514 detection method Methods 0.000 claims abstract description 8
- 230000000694 effects Effects 0.000 abstract description 4
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】この発明は、サーミスタの抵抗変
化を測定温度信号として取出す温度測定装置に関するも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature measuring device that extracts a change in resistance of a thermistor as a measured temperature signal.
【０００２】0002
【従来の技術】図２は従来の温度測定回路を示す温度測
定装置を示し、図において、Ｒ１，Ｒ２は互いに直並列
接続されて抵抗変化を電圧に変換する直並列抵抗、Ｒ４
，ＴＲ１は抵抗Ｒ２に定電流を流す抵抗およびトランジ
スタ、Ｒ３，ＴＲ２は定電流回路の温度補償を行う抵抗
およびトランジスタ、ＴＨはサーミスタである。また、
抵抗Ｒ１，Ｒ２およびサーミスタＴＨは温度検出回路Ｐ
を構成している。2. Description of the Related Art FIG. 2 shows a temperature measuring device showing a conventional temperature measuring circuit. In the figure, R1 and R2 are series-parallel resistors connected in series and parallel to each other to convert resistance changes into voltage;
, TR1 are a resistor and a transistor that cause a constant current to flow through the resistor R2, R3 and TR2 are a resistor and a transistor that perform temperature compensation for the constant current circuit, and TH is a thermistor. Also,
Resistors R1, R2 and thermistor TH are temperature detection circuit P
It consists of
【０００３】次に動作について説明する。まず、図示し
ない温度測定対象に取付けられたサーミスタＴＨは温度
変化により、自身の抵抗値が変化する。この抵抗変化は
、端子Ａ，Ｃを介してサーミスタＴＨに並列に接続され
た抵抗Ｒ１および直列抵抗Ｒ２により電圧に変換される
。そこで、端子Ｂに得られる出力電圧Ｖｏ は、抵抗Ｒ
２に流れる電流をＩ、Ｖｐ を正側の電源電圧、サーミ
スタＴＨの抵抗値をＲＴとすれば、出力電圧Ｖｏ は、
Ｖｏ ＝Ｖｐ−［｛Ｒ１×ＲＴ／（Ｒ１＋ＲＴ）｝＋Ｒ
２］×Ｉ＝Ｖｐ −（ＲＺ＋Ｒ２）×Ｉとなる。なお、
ここでＲＺはＲ１×ＲＴ／（Ｒ１＋ＲＴ）とする。また
、上記の電流Ｉは、定電流回路のトランジスタＴＲ１の
ベース電圧Ｖｂ ，ベース・エミッタ間電圧Ｖｂｅおよ
び抵抗Ｒ４で決まり、Ｉ＝（Ｖｂ −Ｖｎ −Ｖｂｅ）
／Ｒ４のようになる。ここで、Ｖｎ は負の電源電圧で
ある。従って、被測定対象に取り付けたサーミスタＴＨ
の抵抗値ＲＴが、温度変化に応じて変わるとき、端子Ｂ
よりその変化に対応した電圧出力が取り出せる。つまり
、サーミスタＴＨによる検出温度が上昇すると、出力電
圧Ｖｏ は大きくなり、下降すると出力電圧Ｖｏ が小
さくなる。Next, the operation will be explained. First, the resistance value of the thermistor TH attached to a temperature measurement target (not shown) changes due to temperature changes. This resistance change is converted into a voltage by a resistor R1 and a series resistor R2 connected in parallel to the thermistor TH via terminals A and C. Therefore, the output voltage Vo obtained at terminal B is the resistance R
If the current flowing through 2 is I, Vp is the positive power supply voltage, and the resistance value of thermistor TH is RT, then the output voltage Vo is
Vo =Vp-[{R1×RT/(R1+RT)}+R
2]×I=Vp−(RZ+R2)×I. In addition,
Here, RZ is R1×RT/(R1+RT). Furthermore, the above current I is determined by the base voltage Vb of the transistor TR1 of the constant current circuit, the base-emitter voltage Vbe, and the resistor R4, and I=(Vb - Vn - Vbe).
/R4. Here, Vn is a negative power supply voltage. Therefore, the thermistor TH attached to the object to be measured
When the resistance value RT of terminal B changes depending on the temperature change,
A voltage output corresponding to the change can be obtained. That is, when the temperature detected by the thermistor TH increases, the output voltage Vo increases, and when it decreases, the output voltage Vo decreases.
【０００４】0004
【発明が解決しようとする課題】従来の温度測定装置は
以上のように構成されているので、上記の各式からも明
らかなように、電源電圧Ｖｐ ，Ｖｎ の変動に伴って
、出力電圧Ｖｏ が変化し、正しい温度測定が行えない
などの課題があった。なお、このような温度測定装置に
類似する技術が、ＪＩＳＣ１６１１に示されている。[Problem to be Solved by the Invention] Since the conventional temperature measuring device is constructed as described above, as is clear from the above equations, the output voltage Vo changes as the power supply voltages Vp and Vn change. There were issues such as changes in temperature, making it impossible to measure temperature correctly. Note that a technology similar to such a temperature measuring device is shown in JISC1611.
【０００５】この発明は上記のような課題を解消するた
めになされたもので、正側の電源電圧の変動による出力
電圧への影響を少なくできるとともに、負側の電源電圧
の変動による出力電圧への影響も無視できる程度に小さ
くでき、結果的に温度測定の精度の向上を図ることがで
きる温度測定装置を得ることを目的とする。This invention has been made to solve the above-mentioned problems, and it is possible to reduce the influence on the output voltage due to fluctuations in the positive side power supply voltage, and to reduce the influence on the output voltage due to fluctuations in the negative side power supply voltage. It is an object of the present invention to provide a temperature measuring device in which the influence of the temperature can be reduced to a negligible extent, and the accuracy of temperature measurement can be improved as a result.
【０００６】[0006]
【課題を解決するための手段】この発明に係る温度測定
装置は、サーミスタの抵抗変化に応じた電圧を出力する
直並列抵抗と、この直並列抵抗およびサーミスタを含む
温度検出回路と負側電源との間に接続された定電流供給
用のトランジスタとを設けて、正側の電源および負側の
電源の各電圧の変化を検出する分圧抵抗に、上記各電圧
の変化分に応じた電流をトランジスタのベースに入力さ
せるようにしたものである。[Means for Solving the Problems] A temperature measuring device according to the present invention includes a series-parallel resistor that outputs a voltage according to a change in resistance of a thermistor, a temperature detection circuit including the series-parallel resistor and the thermistor, and a negative side power supply. A constant current supply transistor is connected between the voltage divider resistors that detect changes in the voltages of the positive power supply and the negative power supply, and a current corresponding to the change in each voltage is supplied to the voltage dividing resistor that detects changes in the voltages of the positive power supply and the negative power supply. It is designed to be input to the base of the transistor.
【０００７】[0007]
【作用】この発明における分圧抵抗は、正側の電源電圧
および負側の電源電圧の変動（変化）を、これらの正，
負電圧のアンバランスとして検出し、この検出した電圧
の変化に応じて、上記トランジスタの定電流特性を制御
し、上記各電源電圧の変動による出力の変化を抑えるよ
うにする。[Operation] The voltage dividing resistor in this invention handles fluctuations (changes) in the positive side power supply voltage and the negative side power supply voltage.
A negative voltage imbalance is detected, and the constant current characteristics of the transistor are controlled in accordance with the detected voltage change, thereby suppressing changes in the output due to fluctuations in the power supply voltages.
【０００８】[0008]
【実施例】以下、この発明の一実施例を図について説明
する。図１において、Ｒ１，Ｒ２は互いに直並列接続さ
れて抵抗変化を電圧に変換する直並列抵抗、Ｒ４，ＴＲ
１は抵抗Ｒ２に定電流を流す抵抗およびトランジスタ、
Ｒ３，ＴＲ２は定電流回路の温度補償を行う抵抗および
トランジスタ、ＴＨはサーミスタ、Ｒ５，Ｒ６は各一端
が接続された分圧抵抗で、これらの各他端は上記の正側
の電源および負側の電源にそれぞれ接続されている。各
分圧抵抗Ｒ５，Ｒ６の接続点は、増幅回路ＡＭＰを介し
て、上記トランジスタのＴＲ２のベースに接続されてい
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, R1 and R2 are series-parallel resistors that are connected in series and parallel to each other to convert resistance changes into voltage, and R4 and TR
1 is a resistor and a transistor that causes a constant current to flow through resistor R2;
R3 and TR2 are resistors and transistors that perform temperature compensation for the constant current circuit, TH is a thermistor, R5 and R6 are voltage dividing resistors connected at one end, and the other ends are connected to the above positive power supply and negative side. each connected to a power source. The connection point of each voltage dividing resistor R5, R6 is connected to the base of the transistor TR2 via the amplifier circuit AMP.
【０００９】次に動作について説明する。まず、被測定
対象の温度が変化したときの出力電圧Ｖｏ および抵抗
Ｒ２に流れる電流Ｉは、上記従来と同様であり、このと
き、トランジスタＴＲ１のベースに印加される電圧Ｖｂ
は、上記分圧抵抗Ｒ５，Ｒ６，正側の電源電圧Ｖｐ
，負側の電源電圧Ｖｎ から、Ｖｂ ＝［｛（Ｖｐ −
Ｖｎ ）×Ｒ６／（Ｒ５＋Ｒ６）｝＋Ｖｎ ］×Ｇとな
る。ここで、Ｇはアンプゲインであり、Ｒ５，Ｒ６《Ｒ
３の関係にある。Next, the operation will be explained. First, when the temperature of the object to be measured changes, the output voltage Vo and the current I flowing through the resistor R2 are the same as in the conventional case, and at this time, the voltage Vb applied to the base of the transistor TR1.
are the voltage dividing resistors R5 and R6, the positive side power supply voltage Vp
, from the negative side power supply voltage Vn, Vb = [{(Vp −
Vn )×R6/(R5+R6)}+Vn ]×G. Here, G is the amplifier gain, and R5, R6《R
There is a relationship of 3.
【００１０】また、電源電圧の変動は、正側の電源電圧
Ｖｐ と負側の電源電圧Ｖｎ についてそれぞれ出力電
圧Ｖｏ に対する影響が異なる。すなわち、正側の電源
電圧Ｖｐ が変動した場合には、その変化分をΔＶｐ
とすると、出力電圧Ｖｏ の変化分ΔＶｏは、ΔＶｏ
＝ΔＶＰ ［１−｛（ＲＺ＋Ｒ２）／Ｒ４｝×｛Ｒ６／
（Ｒ５＋Ｒ６）｝］となる。従って、サーミスタＴＨを
（ＲＺ＋Ｒ２）／Ｒ４≒１付近で使用し、アンプゲイン
Ｇを２，分圧比をＲ６／（Ｒ５＋Ｒ６）＝１／２とすれ
ば、変化分ΔＶｐ は０に近づき、出力電圧Ｖｏ の変
動を小さく抑えることができる。Furthermore, fluctuations in the power supply voltage have different effects on the output voltage Vo for the positive power supply voltage Vp and the negative power supply voltage Vn. In other words, when the positive side power supply voltage Vp fluctuates, the change is expressed as ΔVp.
Then, the change ΔVo in the output voltage Vo is ΔVo
=ΔVP [1-{(RZ+R2)/R4}×{R6/
(R5+R6)}]. Therefore, if the thermistor TH is used near (RZ+R2)/R4≒1, the amplifier gain G is 2, and the voltage division ratio is R6/(R5+R6)=1/2, the variation ΔVp approaches 0, and the output voltage Vo fluctuations can be suppressed to a small level.
【００１１】また、負側の電源電圧Ｖが変化したときに
は、上記式の定電流Ｉのみ変化する。そこで、その定電
流Ｉの変化分ΔＩは、トランジスタＴＲ１のベース電圧
変化分をΔＶｂ 、負側の電圧変化分をΔＶｎ として
、ΔＩ＝（−ΔＶｂ −ΔＶｎ ）／ΔＶｎ ＝［−Δ
Ｖｎ ×｛Ｒ６／（Ｒ５＋Ｒ６）｝×Ｇ］−ΔＶｎ ／
Ｒ４となる。そこで、上記同様に分圧比をＲ６／（Ｒ５
＋Ｒ６）＝１／２，アンプゲインをＧとすれば、電流の
変化分ΔＩは計算上０にでき、結局、出力電圧Ｖｏ の
変動を小さく抑えたり、なくすることができる。Further, when the negative side power supply voltage V changes, only the constant current I in the above equation changes. Therefore, the change ΔI in the constant current I is calculated as follows: ΔI = (-ΔVb - ΔVn ) / ΔVn = [-Δ
Vn×{R6/(R5+R6)}×G]−ΔVn/
It becomes R4. Therefore, as above, the partial pressure ratio is set to R6/(R5
+R6)=1/2 and the amplifier gain is G, the change in current ΔI can be calculated to be 0, and as a result, the fluctuation in the output voltage Vo can be suppressed or eliminated.
【００１２】0012
【発明の効果】以上のように、この発明によればサーミ
スタの抵抗変化に応じた電圧を出力する直並列抵抗と、
この直並列抵抗およびサーミスタを含む温度検出回路と
負側電源との間に接続された定電流供給用のトランジス
タとを設けて、正側の電源および負側の電源の各電圧の
変化を検出する分圧抵抗に、上記各電圧の変化分に応じ
た電流をトランジスタのベースに入力させるように構成
したので、電源電圧の変動を受けずに、安定した検出温
度対応の出力電圧を出力でき、信頼性の高い温度検出デ
ータを得ることができるものが得られる効果がある。[Effects of the Invention] As described above, according to the present invention, a series-parallel resistor that outputs a voltage according to a change in resistance of a thermistor;
A constant current supply transistor connected between the temperature detection circuit including the series-parallel resistor and thermistor and the negative power supply is provided to detect changes in each voltage of the positive power supply and the negative power supply. Since the voltage dividing resistor is configured to input current to the base of the transistor according to the change in each of the voltages mentioned above, it is possible to output a stable output voltage corresponding to the detected temperature without being affected by fluctuations in the power supply voltage, making it reliable. This has the effect of allowing highly accurate temperature detection data to be obtained.
【図１】この発明の一実施例による温度測定装置を示す
回路図である。FIG. 1 is a circuit diagram showing a temperature measuring device according to an embodiment of the present invention.
【図２】従来の温度測定装置を示す回路図である。FIG. 2 is a circuit diagram showing a conventional temperature measuring device.
ＴＨ サーミスタ Ｒ１ 直並列抵抗（抵抗） Ｒ２ 直並列抵抗（抵抗） Ｐ 温度検出回路 Ｒ５ 分圧抵抗（抵抗） Ｒ６ 分圧抵抗（抵抗） ＴＲ１ トランジスタ TH Thermistor R1 Series parallel resistance (resistance) R2 Series parallel resistance (resistance) P Temperature detection circuit R5 Voltage dividing resistance (resistance) R6 Voltage dividing resistor (resistance) TR1 transistor
Claims (1)
ミスタに直並列接続されて、該サーミスタの抵抗変化に
応じた電圧を出力する直並列抵抗と、該直並列抵抗およ
び上記サーミスタを含む温度検出回路と負側の電源との
間に接続されて、該温度検出回路に定電流を供給するト
ランジスタと、上記正側の電源および負側の電源の各電
圧の変化を検出し、該電圧の変化分に応じた電流を上記
トランジスタのベースに入力する分圧抵抗とを備えた温
度測定装置。1. A series-parallel resistor that is connected in series and parallel to a thermistor that operates in response to a positive power supply voltage and outputs a voltage according to a change in resistance of the thermistor, and a temperature that includes the series-parallel resistor and the thermistor. A transistor is connected between the detection circuit and the negative power supply to supply a constant current to the temperature detection circuit, and detects changes in the voltages of the positive power supply and the negative power supply. A temperature measuring device comprising a voltage dividing resistor that inputs a current corresponding to the amount of change to the base of the transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13710691A JPH04337428A (en) | 1991-05-14 | 1991-05-14 | Temperature measurement device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13710691A JPH04337428A (en) | 1991-05-14 | 1991-05-14 | Temperature measurement device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04337428A true JPH04337428A (en) | 1992-11-25 |
Family
ID=15190994
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13710691A Pending JPH04337428A (en) | 1991-05-14 | 1991-05-14 | Temperature measurement device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04337428A (en) |
-
1991
- 1991-05-14 JP JP13710691A patent/JPH04337428A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5753815A (en) | Thermo-sensitive flow sensor for measuring flow velocity and flow rate of a gas | |
| US4910455A (en) | Non-intrusive current measuring circuit | |
| EP0566160B1 (en) | Bridge type measuring device with output compensating circuit | |
| US4060715A (en) | Linearized bridge circuitry | |
| US4109196A (en) | Resistance measuring circuit | |
| US5426364A (en) | Linear hall circuit for measuring magnetic field strength | |
| US5554927A (en) | Electrical quantity measurement device | |
| US4528499A (en) | Modified bridge circuit for measurement purposes | |
| KR940002188B1 (en) | Thermal-type flowometer | |
| US4294116A (en) | Temperature detecting circuit | |
| JPH04337428A (en) | Temperature measurement device | |
| US5096303A (en) | Electronic circuit arrangement for temperature measurement based on a platinum resistor as a temperature sensing resistor | |
| US20060021444A1 (en) | Method of operating a resistive heat-loss pressure sensor | |
| US3021480A (en) | Voltage compensation | |
| JPS6347999Y2 (en) | ||
| JPH03128513A (en) | Automatic gain control method | |
| JP2576235Y2 (en) | Voltage or current measuring device | |
| JPS6221958Y2 (en) | ||
| JPS58127134A (en) | Detecting circuit for temperature | |
| JPH053989Y2 (en) | ||
| JPH065635Y2 (en) | Flow velocity sensor | |
| JP2938657B2 (en) | Current detection circuit | |
| KR100355381B1 (en) | Current-controlled power amplifier | |
| JPH044980Y2 (en) | ||
| JP2514235Y2 (en) | Amplifier circuit |