JP2000304629A - Strain gauge adjusting device - Google Patents

Strain gauge adjusting device

Info

Publication number
JP2000304629A
JP2000304629A JP11445299A JP11445299A JP2000304629A JP 2000304629 A JP2000304629 A JP 2000304629A JP 11445299 A JP11445299 A JP 11445299A JP 11445299 A JP11445299 A JP 11445299A JP 2000304629 A JP2000304629 A JP 2000304629A
Authority
JP
Japan
Prior art keywords
voltage
strain gauge
output voltage
adjusting
unit
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
Application number
JP11445299A
Other languages
Japanese (ja)
Inventor
Takatoshi Ono
貴敏 小野
Yoshiki Takeda
嘉樹 武田
Hiroshi Imada
博 今田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
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
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP11445299A priority Critical patent/JP2000304629A/en
Publication of JP2000304629A publication Critical patent/JP2000304629A/en
Pending legal-status Critical Current

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  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Analogue/Digital Conversion (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a strain gauge adjusting device capable of easily adjusting offset and span without using a potentiometer, by solving such conventional problem that adjustment of the offset and span of a fine output voltage from a strain gauge by using a potentiometer is delicate and apt to fluctuate. SOLUTION: Zero point adjustment and amplification factor adjustment can be done easily without using a potentiometer, by using a D/A conversion part 6 for adjusting the zero point of an output voltage of a strain gauge, an amplification factor setting part 4 for adjusting an amplification factor, and an A/D conversion part 5 for A/D-converting a previously set voltage for adjusting the zero point.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、歪みゲージからの
微小電圧を増幅・調整する歪みゲージ調整装置に関する
ものである。
[0001] 1. Field of the Invention [0002] The present invention relates to a strain gauge adjusting device for amplifying and adjusting a minute voltage from a strain gauge.

【0002】[0002]

【従来の技術】従来、歪みゲージからの微小電圧を増幅
・調整する歪みゲージ調整装置は、ポテンショメータを
用いた零点調整部や増幅度調整部より構成することが一
般的に知られている。その実施例としては図2に示すよ
うなポテンショメータを用いた歪みゲージ調整装置があ
る。
2. Description of the Related Art Conventionally, it is generally known that a strain gauge adjusting device for amplifying and adjusting a minute voltage from a strain gauge comprises a zero point adjusting unit using a potentiometer and an amplification degree adjusting unit. As an example, there is a strain gauge adjusting device using a potentiometer as shown in FIG.

【0003】この装置は歪みゲージからの出力信号を差
動増幅する差動増幅部10と、この差動増幅部10で得
られた電圧を零点調整するための零点設定部30、加減
算部20と、この結果を増幅・調整する増幅度設定部4
0と、増幅・調整した出力電圧をデジタル値に変換する
A/D変換部50から構成されている。
This device includes a differential amplifying unit 10 for differentially amplifying an output signal from a strain gauge, a zero point setting unit 30 for zero-adjusting a voltage obtained by the differential amplifying unit 10, and an addition / subtraction unit 20. Amplification degree setting unit 4 for amplifying and adjusting the result
It comprises an A / D converter 50 for converting the output voltage, which has been amplified and adjusted, to a digital value.

【0004】[0004]

【発明が解決しようとする課題】ロードセルでブリッジ
構成された歪みゲージからの出力電圧は一般的には数ミ
リボルトしかないうえに、オフセットとスパンが歪みゲ
ージ個々によって大きくばらつくき、このため大きく且
つ微妙にオフセットを調整する零点調整やスパンを調整
する増幅度調整は多回転型のポテンショメータで行われ
ることになる。
The output voltage from a strain gage bridged with load cells is typically only a few millivolts, and offsets and spans vary widely from strain gage to strain gage. Zero adjustment for adjusting the offset and amplification adjustment for adjusting the span are performed by a multi-rotation potentiometer.

【0005】しかしながら、多回転型ポテンショメータ
の調整は生産性にすぐれているとはいえず、また最初の
零点調整に誤差が発生すると増幅度調整後に零点が変動
し、零点調整と増幅度調整を2〜3度繰り返すことが必
要になるほど微妙であり、作業性を悪化させていた。
However, the adjustment of the multi-rotation potentiometer is not considered to be excellent in productivity, and when an error occurs in the initial zero adjustment, the zero point fluctuates after the amplification adjustment, and the zero adjustment and the amplification adjustment are performed by two times. It was delicate enough to need to be repeated up to three times, and the workability was deteriorated.

【0006】したがって、歪みゲージ調整装置の機能を
有する製品では、容易に零点調整・増幅度調整が出来な
いという課題があった。
Therefore, a product having the function of a strain gauge adjusting device has a problem that zero point adjustment and amplification degree adjustment cannot be easily performed.

【0007】本発明はこのような従来の課題を解決し、
ポテンショメータを用いることなく容易に零点調整・増
幅度調整ができる歪みゲージ調整装置を提供することを
目的とするものである。
The present invention solves such a conventional problem,
It is an object of the present invention to provide a strain gauge adjustment device capable of easily adjusting a zero point and an amplification degree without using a potentiometer.

【0008】[0008]

【課題を解決するための手段】この課題を解決するため
に本発明は、歪みゲージの出力電圧を差動増幅する差動
増幅部と、この差動増幅部の出力電圧と第1の所定電圧
を加減算する加減算部と、第2の所定電圧を設定する零
点設定部と、演算増幅器を用いた非反転増幅回路の増幅
度が外部信号により設定でき且つ前記零点設定部で設定
した第2の所定電圧を基準に前記加減算部の出力電圧を
増幅する増幅度設定部と、この増幅度設定部の出力電圧
か前記零点設定部で設定した第2の所定電圧かを選択で
きる電圧選択部と、この電圧選択部の出力電圧をデジタ
ル値に変換するA/D変換部と、所定のデジタル値を電
圧に変換し且つこの電圧が前記第1の所定電圧を生成す
るD/A変換部との構成を有するものである。この本発
明によれば、ポテンショメータを用いることなく容易に
零点調整・増幅度調整ができる歪みゲージ調整装置が得
られる。
According to the present invention, there is provided a differential amplifier for differentially amplifying an output voltage of a strain gauge, an output voltage of the differential amplifier and a first predetermined voltage. An addition / subtraction unit for adding / subtracting a second predetermined voltage, a zero point setting unit for setting a second predetermined voltage, and a second predetermined level set by the zero point setting unit, wherein the amplification degree of the non-inverting amplifier circuit using the operational amplifier can be set by an external signal. An amplification degree setting section for amplifying an output voltage of the addition / subtraction section based on a voltage; a voltage selection section for selecting between the output voltage of the amplification degree setting section and the second predetermined voltage set by the zero point setting section; An A / D converter for converting the output voltage of the voltage selector to a digital value, and a D / A converter for converting a predetermined digital value to a voltage and generating the first predetermined voltage based on the voltage. Have According to the present invention, it is possible to obtain a strain gauge adjustment device capable of easily adjusting the zero point and the amplification degree without using a potentiometer.

【0009】[0009]

【発明の実施の形態】本発明の請求項1に記載の発明
は、歪みゲージの出力電圧を差動増幅する差動増幅部
と、この差動増幅部の出力電圧と第1の所定電圧を加減
する加減算部と、第2の所定電圧を設定する零点設定部
と、演算増幅器を用いた非反転増幅回路の増幅度が外部
信号により設定でき且つ前記零点設定部で設定した第2
の所定電圧を基準に前記加減算部の出力電圧を増幅する
増幅度設定部と、この増幅度設定部の出力電圧か前記零
点設定部で設定した第2の所定電圧かを選択できる電圧
選択部と、この電圧選択部の出力電圧をデジタル値に変
換するA/D変換部と、所定のデジタル値を電圧に変換
し且つこの電圧が前記第1の所定電圧を生成するD/A
変換部との構成を有した歪みゲージ調整装置なので、ポ
テンショメータを用いることなく個々にばらつく歪みゲ
ージのオフセットとスパンを容易に調整できるという作
用を有する。
DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a differential amplifier for differentially amplifying an output voltage of a strain gauge, and an output voltage of the differential amplifier and a first predetermined voltage are provided. An adding / subtracting unit for adding and subtracting, a zero point setting unit for setting a second predetermined voltage, and a second degree set by the zero point setting unit.
An amplification setting unit that amplifies the output voltage of the addition / subtraction unit based on the predetermined voltage, and a voltage selection unit that can select the output voltage of the amplification setting unit or the second predetermined voltage set by the zero point setting unit. An A / D converter for converting the output voltage of the voltage selector to a digital value, and a D / A for converting a predetermined digital value to a voltage and generating the first predetermined voltage.
Since it is a strain gauge adjustment device having a configuration with a conversion unit, it has an effect that offsets and spans of strain gauges that vary individually can be easily adjusted without using a potentiometer.

【0010】以下、本発明の実施の形態について、図1
を用いて説明する。
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

【0011】(実施の形態1)図1は本発明の第1の実
施の形態における歪みゲージ調整装置の構成図であり、
図1において1は差動増幅部、2は加減算部、3は零点
設定部、4は増幅度設定部、5はA/D変換部、6はD
/A変換部、7は電圧選択部を示している。
(Embodiment 1) FIG. 1 is a configuration diagram of a strain gauge adjusting apparatus according to a first embodiment of the present invention.
In FIG. 1, 1 is a differential amplifier, 2 is an adder / subtractor, 3 is a zero setting unit, 4 is an amplification setting unit, 5 is an A / D converter, and 6 is D / D converter.
The / A converter 7 indicates a voltage selector.

【0012】以下、この歪みゲージ調整装置の動作につ
いて同図を用いて説明する。歪みゲージからの信号は通
常数ミリボルトであり、この電圧をVsとする。
Hereinafter, the operation of the strain gauge adjusting device will be described with reference to FIG. The signal from the strain gauge is usually several millivolts, and this voltage is Vs.

【0013】差動増幅部の増幅度がαのとき差動増幅部
出力電圧Vaは、 Va=α・Vs となり、D/A変換部の出力電圧をVbとすると加減算
部の出力Vcは、 Vc=Va+Vb =α・Vs+Vb となる。増幅度設定部でR2が選択されていると、増幅
度設定部の出力Vdは、 Vd=(1+R2/R1)・Vc−(R2/R1)・Vz ここで(1+R2/R1)=βとおくと、 =β・(Vc−Vz)+Vz =β・(α・Vs+Vb−Vz)+Vz … を得る。但しVzは零点設定部で設定した電圧である。
When the amplification degree of the differential amplifier is α, the output voltage Va of the differential amplifier becomes Va = α · Vs. When the output voltage of the D / A converter is Vb, the output Vc of the adder / subtractor becomes Vc = Va + Vb = α · Vs + Vb. If R2 is selected in the amplification degree setting section, the output Vd of the amplification degree setting section is as follows: Vd = (1 + R2 / R1) · Vc− (R2 / R1) · Vz (1 + R2 / R1) = β = Β · (Vc−Vz) + Vz = β · (α · Vs + Vb−Vz) + Vz. Here, Vz is a voltage set by the zero point setting unit.

【0014】今、歪みゲージがオフセット状態にあると
し、このときの歪みゲージ出力電圧Vs=Vsoとす
る。このオフセット状態でVd=Vzとするには、式
より Vz=β・(α・Vso+Vb−Vz)+Vz となり、 Vb=Vz−α・Vso を得る。
Now, it is assumed that the strain gauge is in an offset state, and the strain gauge output voltage Vs at this time is Vs = Vso. In order to make Vd = Vz in this offset state, Vz = β · (α · Vso + Vb−Vz) + Vz is obtained from the equation, and Vb = Vz−α · Vso is obtained.

【0015】以上より、歪みゲージがオフセット状態に
あるとき、D/A変換部からの出力電圧Vbを(Vz−
α・Vso)に設定すればよいことになる。そして本発
明の歪みゲージ調整装置の構成によれば、VzをA/D
変換部より取り込めるので容易にVbを調整できる。す
なわち歪みゲージがオフセット状態にあるとき、電圧選
択部で選択できる2つの電圧が等しくなるようにVbを
変えるだけでよい。
As described above, when the strain gauge is in the offset state, the output voltage Vb from the D / A converter is changed to (Vz-
α · Vso). According to the configuration of the strain gauge adjusting device of the present invention, Vz is set to A / D
Vb can be easily adjusted because it can be taken in from the converter. That is, when the strain gauge is in the offset state, it is only necessary to change Vb so that the two voltages selectable by the voltage selector become equal.

【0016】この求めたVbを式に代入すると、 Vd=α・β・(Vs−Vso)+Vz となる。When the obtained Vb is substituted into the equation, Vd = α · β · (Vs−Vso) + Vz.

【0017】歪みゲージのスパン調整は、歪みゲージを
最大スパンとなる状態にしVd値が最も大きく且つA/
D変換上限を超えないような値となるβを設定するだけ
でよい。
To adjust the span of the strain gauge, the strain gauge is set to the maximum span, the Vd value is the largest, and A / A
It is only necessary to set a value β that does not exceed the D conversion upper limit.

【0018】具体的な値として例をあげると、オフセッ
ト電圧Vso=−2mV、スパン電圧(Vs−Vso)
=4mVの特性を持つ歪みゲージを0.3〜4.3Vに
調整するためには例えばα=500、β=2とし、Vz
=0.3V、Vb=+1.3Vといった値にすればよい
ことになる。
For example, as specific values, offset voltage Vso = -2 mV, span voltage (Vs-Vso)
In order to adjust a strain gauge having a characteristic of = 4 mV to 0.3 to 4.3 V, for example, α = 500, β = 2, and Vz
= 0.3V, Vb = + 1.3V.

【0019】以上のように同実施の形態1によれば、ポ
テンショメータを用いることなく個々にばらつく歪みゲ
ージのオフセット・スパンを容易に調整できるという効
果が得られる。
As described above, according to the first embodiment, it is possible to easily adjust the offset span of the strain gauge that varies individually without using a potentiometer.

【0020】[0020]

【発明の効果】以上のように本発明による歪みゲージ調
整装置は、歪みゲージの出力電圧を差動増幅する差動増
幅部と、この差動増幅部の出力電圧と第1の所定電圧を
加減算する加減算部と、第2の所定電圧を設定する零点
設定部と、演算増幅器を用いた非反転増幅回路の増幅度
が外部信号により設定でき且つ前記零点設定部で設定し
た第2の所定電圧を基準に前記加減算部の出力電圧を増
幅する増幅度設定部と、この増幅度設定部の出力電圧か
前記零点設定部で設定した第2の所定電圧かを選択でき
る電圧選択部と、この電圧選択部の出力電圧をデジタル
値に変換するA/D変換部と、所定のデジタル値を電圧
に変換し且つこの電圧が前記第1の所定電圧を生成する
D/A変換部との構成を有しているので、ポテンショメ
ータを用いることなく個々にばらつく歪みゲージのオフ
セットを調整する零点調整やスパンを調整する増幅度調
整が容易にでき、生産性が向上するという有利な効果が
得られる。
As described above, the strain gauge adjusting apparatus according to the present invention comprises a differential amplifier for differentially amplifying the output voltage of the strain gauge, and adding / subtracting the output voltage of the differential amplifier and the first predetermined voltage. Adding / subtracting unit, a zero-point setting unit for setting a second predetermined voltage, and a second predetermined voltage set by the zero-point setting unit, wherein the amplification of the non-inverting amplifier circuit using the operational amplifier can be set by an external signal. An amplification setting section for amplifying the output voltage of the addition / subtraction section as a reference; a voltage selection section capable of selecting either the output voltage of the amplification setting section or the second predetermined voltage set by the zero point setting section; An A / D converter that converts an output voltage of the unit into a digital value; and a D / A converter that converts a predetermined digital value into a voltage and generates the first predetermined voltage. Use a potentiometer Ku can amplification degree is easily adjusted by adjusting the zero point adjustment and a span of adjusting the offset of the strain gauges varies individually, the advantageous effect of improving the productivity are obtained.

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

【図1】本発明の第1の実施の形態における歪みゲージ
調整装置の構成図
FIG. 1 is a configuration diagram of a strain gauge adjustment device according to a first embodiment of the present invention.

【図2】従来の歪みゲージ調整装置の構成図FIG. 2 is a configuration diagram of a conventional strain gauge adjustment device.

【符号の説明】[Explanation of symbols]

1 差動増幅部 2 加減算部 3 零点設定部 4 増幅度設定部 5 A/D変換部 6 D/A変換部 7 電圧選択部 10 差動増幅部 20 加減算部 30 零点設定部 40 増幅度設定部 50 A/D変換部 DESCRIPTION OF SYMBOLS 1 Differential amplification part 2 Addition and subtraction part 3 Zero point setting part 4 Amplification degree setting part 5 A / D conversion part 6 D / A conversion part 7 Voltage selection part 10 Differential amplification part 20 Addition and subtraction part 30 Zero point setting part 40 Amplification degree setting part 50 A / D converter

───────────────────────────────────────────────────── フロントページの続き (72)発明者 今田 博 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 Fターム(参考) 2F063 AA25 CA40 CB03 CB08 CC10 DA05 EC00 LA00 5J022 AA01 AB01 BA01 CB06 CC01 CF02 CF07  ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Imada 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 2F063 AA25 CA40 CB03 CB08 CC10 DA05 EC00 LA00 5J022 AA01 AB01 BA01 CB06 CC01 CF02 CF07

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 歪みゲージの出力電圧を差動増幅する差
動増幅部と、この差動増幅部の出力電圧と第1の所定電
圧を加減算する加減算部と、第2の所定電圧を設定する
零点設定部と、演算増幅器を用いた非反転増幅回路の増
幅度が外部信号により設定でき且つ前記零点設定部で設
定した第2の所定電圧を基準に前記加減算部の出力電圧
を増幅する増幅度設定部と、この増幅度設定部の出力電
圧か前記零点設定部で設定した第2の所定電圧かを選択
できる電圧選択部と、この電圧選択部の出力電圧をデジ
タル値に変換するアナログ・デジタル変換部と、所定の
デジタル値を電圧に変換し且つこの電圧が前記第1の所
定電圧を生成するデジタル・アナログ変換部との構成を
有する歪みゲージ調整装置。
1. A differential amplifier for differentially amplifying an output voltage of a strain gauge, an adder / subtractor for adding / subtracting an output voltage of the differential amplifier and a first predetermined voltage, and a second predetermined voltage are set. A zero-point setting unit, and an amplification degree which can set an amplification degree of a non-inverting amplifier circuit using an operational amplifier by an external signal and amplify an output voltage of the addition / subtraction unit based on a second predetermined voltage set by the zero-point setting unit. A setting unit, a voltage selection unit that can select the output voltage of the amplification degree setting unit or the second predetermined voltage set by the zero point setting unit, and an analog / digital converter that converts the output voltage of the voltage selection unit into a digital value A strain gauge adjustment device having a configuration of a conversion unit and a digital / analog conversion unit that converts a predetermined digital value into a voltage and generates the first predetermined voltage.
JP11445299A 1999-04-22 1999-04-22 Strain gauge adjusting device Pending JP2000304629A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11445299A JP2000304629A (en) 1999-04-22 1999-04-22 Strain gauge adjusting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11445299A JP2000304629A (en) 1999-04-22 1999-04-22 Strain gauge adjusting device

Publications (1)

Publication Number Publication Date
JP2000304629A true JP2000304629A (en) 2000-11-02

Family

ID=14638095

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11445299A Pending JP2000304629A (en) 1999-04-22 1999-04-22 Strain gauge adjusting device

Country Status (1)

Country Link
JP (1) JP2000304629A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006313096A (en) * 2005-05-06 2006-11-16 Tanita Corp Digital gravimeter
CN102087119A (en) * 2010-03-18 2011-06-08 上海海事大学 Remote zero setting circuit and method for resistance-type strain measurement
KR101059381B1 (en) 2009-08-19 2011-08-25 김지홍 Analog signal compensator to adjust zero and span
KR101128500B1 (en) * 2009-08-19 2012-03-27 김지홍 Measuring device for strain gage

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006313096A (en) * 2005-05-06 2006-11-16 Tanita Corp Digital gravimeter
KR101059381B1 (en) 2009-08-19 2011-08-25 김지홍 Analog signal compensator to adjust zero and span
KR101128500B1 (en) * 2009-08-19 2012-03-27 김지홍 Measuring device for strain gage
CN102087119A (en) * 2010-03-18 2011-06-08 上海海事大学 Remote zero setting circuit and method for resistance-type strain measurement

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