JPS63304123A - Temperature measuring circuit - Google Patents
Temperature measuring circuitInfo
- Publication number
- JPS63304123A JPS63304123A JP14055487A JP14055487A JPS63304123A JP S63304123 A JPS63304123 A JP S63304123A JP 14055487 A JP14055487 A JP 14055487A JP 14055487 A JP14055487 A JP 14055487A JP S63304123 A JPS63304123 A JP S63304123A
- Authority
- JP
- Japan
- Prior art keywords
- resistance
- terminal
- temperature measuring
- circuit
- amplifier
- 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
- 238000009529 body temperature measurement Methods 0.000 claims description 5
- 238000005259 measurement Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 1
- 102220110933 rs151253274 Human genes 0.000 description 1
- 102220079392 rs45524433 Human genes 0.000 description 1
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、５ｉｉ１抵抗体を用いた温度測定回路の改良
に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a temperature measuring circuit using a 5ii1 resistor.
１１２図は従来のこの種の温度測定回路の一例の接続図
である０図において、ＲＴは測温抵抗体で、３１１式の
接続方式により端子Ａ、Ｂ、ｂに接続されている。ｒは
各リード線の抵抗値を示すものである。Ｒ５は抵抗値が
既知の基準抵抗、■は電源、ＲＣは回路電流工を決定す
る抵抗、ＳＡ、ＳＢ。FIG. 112 is a connection diagram of an example of a conventional temperature measuring circuit of this type. In FIG. r indicates the resistance value of each lead wire. R5 is a reference resistor whose resistance value is known, ■ is a power supply, RC is a resistor that determines the circuit current, SA, SB.
Ｓｂ、Ｓｓはスイッチである。この構成において、電源
ＶよりＲＣ−＋ＲＴ−＋Ｒ８を通して電流■を流し、そ
の時の各電圧ＶＡ、ＶＢ、Ｖｂ及びＶｓをスイッチＳＡ
、ＳＢ、Ｓｂ及びＳｓを切換えて取り出したのち、アン
プＵを介してＡ／Ｄ変換器でディジタル信号に変換する
。その後、演算回路ＯＰＣで
ＲＴ＝ （（ＶＡ＋Ｖｂ−２ＶＢ）／ （Ｖｂ−ＶＳ）
）・Ｒｓ −（１）の演算を行なってＲＴの
抵抗値を求め、これを温度の単位に変換してその温度信
号を出カ端子○ＵＴより取り出すようになっている。Sb and Ss are switches. In this configuration, a current ■ is caused to flow from the power supply V through RC-+RT-+R8, and each voltage VA, VB, Vb, and Vs at that time is applied to the switch SA.
, SB, Sb and Ss are switched and taken out, and then converted into a digital signal by an A/D converter via an amplifier U. After that, in the arithmetic circuit OPC, RT= ((VA+Vb-2VB)/(Vb-VS)
).Rs - (1) to find the resistance value of RT, convert it into a temperature unit, and take out the temperature signal from the output terminal UT.
このような構成の温度測定回路においては、リード線の
抵抗に影響されずに温度測定が可能であるという特徴が
ある。ところで、測温抵抗体ＲＴとしては、一般に１０
Ω１０℃のものと１００Ω１０℃のものがある。しかし
、第２図の回路では両方の測温抵抗体を自動切換えで切
換えて測定することはできない。即ち、多くの抵抗値の
測温抵抗体に対応した測定ができないという問題がある
。A temperature measurement circuit having such a configuration has the feature that temperature measurement is possible without being affected by the resistance of the lead wire. By the way, the resistance temperature detector RT is generally 10
There are two types: one with Ω10℃ and one with 100Ω10℃. However, with the circuit shown in FIG. 2, it is not possible to automatically switch and measure both resistance temperature sensors. That is, there is a problem in that it is not possible to perform measurements corresponding to resistance temperature detectors having many resistance values.
本発明はこのような問題点を解決するためになされたも
ので、多くの抵抗値の測温抵抗体に対応した測定が自動
切換えで可能な温度測定回路を提供することを目的とし
たものである。The present invention has been made to solve these problems, and its purpose is to provide a temperature measurement circuit that can automatically switch to measure resistance temperature sensors with many resistance values. be.
本発明は上記の目的を達成するために複数個の基準抵抗
を設けこれを端子Ａに接続し、測温抵抗体の抵抗値に応
じてその基準抵抗より電圧を取り出すようにしたもので
ある。以下、実施例について詳細に説明する。In order to achieve the above object, the present invention provides a plurality of reference resistors, which are connected to terminal A, and a voltage is extracted from the reference resistors in accordance with the resistance value of the temperature-measuring resistor. Examples will be described in detail below.
第１図は本発明に係る温度測定回路の一実施例の回路図
である。図において、ＲＴは測温抵抗体、Ａ、Ｂ、ｂは
接続端子である。測温抵抗体ＲＴは第２図と同様に３線
式で端子Ａ、Ｂ、ｂに接続されている。ｒはそのリード
線の抵抗を示すものである。ＲＣは回路電流Ｉを決める
為の抵抗、Ｒ５１、Ｒ３２は基準抵抗である。電流値決
定用の抵抗ＲＣと基準抵抗Ｒ５Ｉ、Ｒ５２は直列に接続
され、その一端は電源Ｖに、他端は端子Ａに接続されて
いる。端子すは基準電位点ＣＯＭに接続されている。FIG. 1 is a circuit diagram of an embodiment of a temperature measuring circuit according to the present invention. In the figure, RT is a resistance temperature detector, and A, B, and b are connection terminals. The resistance temperature detector RT is connected to terminals A, B, and b in a three-wire system as in FIG. 2. r indicates the resistance of the lead wire. RC is a resistor for determining the circuit current I, and R51 and R32 are reference resistors. A resistor RC for determining a current value and reference resistors R5I and R52 are connected in series, one end of which is connected to a power supply V, and the other end connected to a terminal A. The terminal is connected to a reference potential point COM.
Ｓｓｌ、Ｓｓ２．ＳＡ、ＳＢ、Ｓｂは夫々スイッチ（リ
レー接点）、Ｕはアンプ、Ａ／Ｄはアナログ・ディジタ
ル変換器、ＯＰＣは演算回路、ＯＵＴは出力端子である
。スイッチＳｓｌの一端は抵抗ＲＣとＲ３Ｉの接続点に
、Ｓｓ２の一端は抵抗Ｒ３ＩとＲ５２の接続点に、ＳＡ
の一端は端子Ａに、ＳＨの一端は端子Ｂに、そしてｓｂ
の一端は端子すに夫々接続されている。各スイッチの他
端は共通にアンプＵの入力端に接続されている。Ssl, Ss2. SA, SB, and Sb are switches (relay contacts), U is an amplifier, A/D is an analog/digital converter, OPC is an arithmetic circuit, and OUT is an output terminal. One end of switch Ssl is connected to the connection point between resistors RC and R3I, one end of Ss2 is connected to the connection point between resistors R3I and R52, and SA is connected to the connection point between resistors RC and R3I.
One end of SH is connected to terminal A, one end of SH is connected to terminal B, and sb
One end of each is connected to a terminal. The other end of each switch is commonly connected to the input end of the amplifier U.
アンプＵの出力端はＡ／Ｄ変換器および演算回路○ＰＣ
を介して出力端子ＯＵＴに接続されている。The output terminal of amplifier U is A/D converter and arithmetic circuit ○PC
It is connected to the output terminal OUT via.
この回路においては、電ＢＶにより電流■が抵抗ＲＣ，
Ｒ３Ｉ、ＲＳ２．ＲＴおよび端子すを通して基準電位点
ＣＯＭに流れる。この電流■によりスイッチＳｓｌ、Ｓ
ｓ２．ＳＡ、ＳＢ、Ｓｂの各他端に生じる電位を夫々Ｖ
ｓ １．Ｖｓ ２．ＶＡ。In this circuit, the current ■ is caused by the voltage BV through the resistance RC,
R3I, RS2. It flows to the reference potential point COM through RT and the terminal. This current ■ causes switches Ssl and S
s2. The potentials generated at the other ends of SA, SB, and Sb are respectively V.
s1. Vs 2. V.A.
ＶＢ、Ｖｂとする。これらの各電圧降下は夫々アンプＵ
を介してＡ／Ｄ変換器でディジタル信号に変換されたの
ち、演算回路○ＰＣに加えられる。Let it be VB, Vb. Each of these voltage drops is
After being converted into a digital signal by an A/D converter, it is applied to an arithmetic circuit ○PC.
上記の回路は２種類の抵抗値の異なる測温抵抗体ＲＴが
使用可能な回路であるが、先ず１！Ｉ温抵抗抵抗Ｔの抵
抗値の大きな（１００Ω）レンジの場合について説明す
る。この場合、スイッチＳｓ２は開となっており、基準
抵抗としてＲ５ＩとＲ５２の合成値が用いられる。電源
Ｖにより電流工を流すことによって各抵抗に生じる電圧
降下と、各スイッチに生じる電圧との間には次の関係が
ある。The above circuit is a circuit that can use two types of resistance temperature detectors RT with different resistance values. A case where the I temperature resistance resistance T has a large resistance value (100Ω) will be explained. In this case, the switch Ss2 is open, and the combined value of R5I and R52 is used as the reference resistance. The following relationship exists between the voltage drop that occurs across each resistor when a current is applied by the power supply V and the voltage that occurs across each switch.
ｒ・Ｉ＝ＶＢ−Ｖｂ
（ｒ ＋ＲＴ） ・ Ｉ ＝ＶＡ−ＶＢ（Ｒ５１＋Ｒ
３２） ・ Ｉ＝Ｖｓｌ−ＶＡ演算回路ＯＰＣはこれ
らのデータをアンプＵを介して収集し、その収集した測
定データを基にして下記の演算を行なう。r・I=VB−Vb (r+RT)・I=VA−VB(R51+R
32) I=Vsl-VA calculation circuit OPC collects these data via amplifier U, and performs the following calculation based on the collected measurement data.
ＲＴＩ＝（（ＶＡ−２ＶＢ−Ｖｂ）／（Ｖｓｌ−ＶＡ）
）（Ｒ５ｌｌＲ５２） （Ｑ 〕・・・（２）
次に、測温抵抗体ＲＴの抵抗値が小さな（１０Ω）レン
ジの場合にはスイッチＳｓｌを開とし、基準抵抗として
Ｒ３２を用いる。この場合、ｒ弓＝ＶＢ−Ｖｂ
（ｒ＋ＲＴ） ・ｒ ＝ＶＡ−ＶＢ
Ｒ５２・Ｉ ＝Ｖｓ ２−ＶＡ
演算回路○ＰＣはこれらのデータを収集し、その取集し
た測定データを基にして下記の演算を行なう。RTI=((VA-2VB-Vb)/(Vsl-VA)
)(R5llR52) (Q]...(2) Next, when the resistance value of the resistance temperature detector RT is in the small (10Ω) range, the switch Ssl is opened and R32 is used as the reference resistance.In this case, r bow=VB-Vb (r+RT) ・r=VA-VB R52・I=Vs 2-VA Arithmetic circuit ○PC collects these data and performs the following calculations based on the collected measurement data. .
ＲＴ２＝（（ＶＡ−２ＶＢ−Ｖｂ）／（Ｖｓ２−ＶＡ）
）４５２ ［：Ωツー（３）（２）式及び（３）式で
表ねされる測温抵抗体ＲＴの抵抗値ＲＴＩ及びＲＴ２は
演算回路○ＰＣにおいて夫々抵抗値〔Ω〕→温度〔０Ｃ
〕変換され、その温度信号は出力端子ＯＵＴより取出さ
れる。スイッチＳｓｌ、Ｓｓ２の切換えは、図外の制御
回路の出力により使用する測温抵抗体ＲＴの値に応じて
自動的に行なわれる。（２）式及び（３）式から明らか
なように、第１図の回路においては測温抵抗体ＲＴを接
続するリード線の抵抗ｒは測定値に影響しないようにな
っている。RT2=((VA-2VB-Vb)/(Vs2-VA)
) 452 [: Ω2 (3) The resistance values RTI and RT2 of the resistance temperature detector RT expressed by equations (2) and (3) are calculated by the resistance value [Ω] → temperature [0C] in the arithmetic circuit ○PC, respectively.
] The temperature signal is taken out from the output terminal OUT. Switching of the switches Ssl and Ss2 is automatically performed according to the value of the temperature measuring resistor RT used by the output of a control circuit (not shown). As is clear from equations (2) and (3), in the circuit of FIG. 1, the resistance r of the lead wire connecting the resistance temperature detector RT does not affect the measured value.
ココテ、Ｖｓ １．Ｖｓ ２．ＶＡ、ＶＢ及びｖｂの電
圧値のスパンはアンプＵの入力に対して零ｖを基準値と
している為に、電流工をほぼ一定とした場合、小さなレ
ンジではそのアンプＵのゲインをあげることにより、そ
のまま分解能を一杯にとることができる。例えば、１０
０Ω測温抵抗体レンジにおいて、アンプＵを２００ｍＶ
フル・スケールで測定していた場合、１０Ωレンジに切
り換えたらアンプＵのゲインを２０ｍＶにすることによ
り、Ａ／Ｄ変換器出力の分解能は一定となる。Kokote, Vs 1. Vs 2. Since the span of the voltage values of VA, VB, and vb is based on 0 V with respect to the input of amplifier U, if the current is kept almost constant, in a small range, by increasing the gain of amplifier U, You can get the full resolution as is. For example, 10
In the 0Ω resistance thermometer range, the amplifier U is set to 200mV.
When measuring at full scale, when switching to the 10Ω range, the gain of amplifier U is set to 20mV, and the resolution of the A/D converter output becomes constant.
即ち、例えば１００Ωレンジの場合、Ｉ＝１ｍＡトシテ
、Ｒ３１＋Ｒ３２＝１００Ｑ、Ｒ５＝１０Ωとすると、
Ｖｓ １＝ （ＲＳ１＋Ｒ３２＋ＲＴ） ｅ
Ｉ＝２００ ・ Ｉ ＝２００ｍＶ
−（４）一方、１０Ωレンジの場合、Ｒ５２＝１０
Ω、ＲＴ＝１０Ωとすると、
Ｖｓ ２＝ （Ｒ３２＋ＲＴ） ・１＝２０・Ｉ ＝
２０ ｍ Ｖ ・・・（５）よって、
１００Ωレンジでは後段のアンプＵを２００ｍＶレンジ
に、又１０ΩレンジではアンプＵを２０ｍＶレンジで使
用するようにすれば、Ａ／Ｄ゛変換器の入力のフル・ス
ケールは同一となり、温度分解能は同一となる。That is, for example, in the case of 100Ω range, if I=1mA, R31+R32=100Q, and R5=10Ω, then Vs 1= (RS1+R32+RT) e
I=200・I=200mV
-(4) On the other hand, in the case of 10Ω range, R52=10
Ω, RT=10Ω, Vs 2= (R32+RT) ・1=20・I=
20 mV...(5) Therefore,
If you use the downstream amplifier U in the 200mV range for the 100Ω range, and the amplifier U in the 20mV range for the 10Ω range, the full scale of the A/D converter input will be the same, and the temperature resolution will be the same. Become.
なお、上述した実施例では２レンジの場合について説明
したが、多レンジの場合にはそのレンジの数に応じて基
準抵抗とそれに伴なうスイッチの数を増加するようにす
ればよい。In the above-mentioned embodiment, the case of two ranges has been described, but in the case of multiple ranges, the number of reference resistances and associated switches may be increased in accordance with the number of ranges.
以上説明したように、本発明においては３線式の特徴を
損なうことなく、複数個の抵抗値の測温抵抗体に対応し
て自動的に切換えて測定することができる温度測定回路
を極めて簡単な回路構成によって実現することができる
。As explained above, the present invention provides an extremely simple temperature measurement circuit that can automatically switch and measure temperature detectors with multiple resistance values without sacrificing the characteristics of the 3-wire system. This can be realized with a circuit configuration.
第１図は本発明に係る装置の一実施例の接続図、第２図
は従来のこの種の装置の一例の接続図である。
ＲＴ・・・測温抵抗体、Ａ、Ｂ、ｂ・・・端子、Ｒ５１
、Ｒ５２・・・基準抵抗、ＲＣ・・・電流決定用抵抗、
Ｓ ｓ １ 、 Ｓ ｓ ２ Ｓ Ａ 、 Ｓ Ｂ 、
Ｓ ｂ−スイッチ、Ｕ・・・アンプ、Ａ／Ｄ・・・ア
ナログ・ディジタル変換器、○ＰＣ・・・演算回路。
第１図
第２図FIG. 1 is a connection diagram of an embodiment of a device according to the present invention, and FIG. 2 is a connection diagram of an example of a conventional device of this type. RT...Resistance temperature sensor, A, B, b...Terminal, R51
, R52...Reference resistance, RC...Resistance for determining current,
S s 1 , S s 2 S A , S B ,
S b-switch, U...amplifier, A/D...analog-digital converter, ○PC...arithmetic circuit. Figure 1 Figure 2
Claims (1)
た測温抵抗体を温度検出素子とする温度測定回路におい
て、電源Ｖと前記端子Ａとの間に直列に接続された電流
値決定用抵抗と複数個の基準抵抗、前記端子Ａ、Ｂ、ｂ
と基準抵抗同志の接続点及び基準抵抗と電流値決定用抵
抗との接続点に夫々一端が接続された複数個のスイッチ
、この複数個のスイッチの他端がその入力端に接続され
たアンプ、このアンプの出力をディジタル変換するアナ
ログ・ディジタル変換器、このアナログ・ディジタル変
換器の出力端に接続され抵抗値をこれに対応した温度信
号に変換する演算回路、及びこの演算回路の出力を取出
す出力端子を備え、前記端子ｂを基準電位点に接続して
なる温度測定回路。In a temperature measurement circuit having terminals A, B, and b and having a temperature sensing element that is a resistance thermometer connected to these terminals in a 3-wire system, A current value determining resistor, a plurality of reference resistors, and the terminals A, B, and b.
a plurality of switches each having one end connected to the connection point between the reference resistor and the reference resistor and the current value determining resistor; an amplifier having the other end of the plurality of switches connected to its input end; An analog-to-digital converter that converts the output of this amplifier into digital data, an arithmetic circuit that is connected to the output end of this analog-to-digital converter and that converts a resistance value into a corresponding temperature signal, and an output that takes out the output of this arithmetic circuit. A temperature measuring circuit comprising a terminal, the terminal b being connected to a reference potential point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14055487A JPH076850B2 (en) | 1987-06-04 | 1987-06-04 | Temperature measurement circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14055487A JPH076850B2 (en) | 1987-06-04 | 1987-06-04 | Temperature measurement circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63304123A true JPS63304123A (en) | 1988-12-12 |
| JPH076850B2 JPH076850B2 (en) | 1995-01-30 |
Family
ID=15271377
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14055487A Expired - Lifetime JPH076850B2 (en) | 1987-06-04 | 1987-06-04 | Temperature measurement circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH076850B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0299331U (en) * | 1989-01-26 | 1990-08-08 | ||
| JPH05142061A (en) * | 1991-11-19 | 1993-06-08 | Mitsubishi Electric Corp | Multi-point temperature measuring apparatus |
| WO2003016920A1 (en) * | 2001-08-09 | 2003-02-27 | Matsushita Electric Industrial Co., Ltd. | Drop shock measurement system and acceleration sensor element used in the same |
| US7275412B2 (en) | 2001-08-09 | 2007-10-02 | Matsushita Electric Industrial Co., Ltd. | Drop shock measurement system and acceleration sensor element used in the same |
-
1987
- 1987-06-04 JP JP14055487A patent/JPH076850B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0299331U (en) * | 1989-01-26 | 1990-08-08 | ||
| JPH05142061A (en) * | 1991-11-19 | 1993-06-08 | Mitsubishi Electric Corp | Multi-point temperature measuring apparatus |
| WO2003016920A1 (en) * | 2001-08-09 | 2003-02-27 | Matsushita Electric Industrial Co., Ltd. | Drop shock measurement system and acceleration sensor element used in the same |
| US7275412B2 (en) | 2001-08-09 | 2007-10-02 | Matsushita Electric Industrial Co., Ltd. | Drop shock measurement system and acceleration sensor element used in the same |
| US7493818B2 (en) | 2001-08-09 | 2009-02-24 | Panasonic Corporation | Drop shock measurement system and acceleration sensor element used in the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH076850B2 (en) | 1995-01-30 |
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