JPH0772187A - Voltage measuring instrument - Google Patents
Voltage measuring instrumentInfo
- Publication number
- JPH0772187A JPH0772187A JP21974793A JP21974793A JPH0772187A JP H0772187 A JPH0772187 A JP H0772187A JP 21974793 A JP21974793 A JP 21974793A JP 21974793 A JP21974793 A JP 21974793A JP H0772187 A JPH0772187 A JP H0772187A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- integrator
- time
- switch
- measured
- 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.)
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- Measurement Of Current Or Voltage (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は被測定電圧を精度よく
測定する電圧測定装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage measuring device for accurately measuring a voltage to be measured.
【0002】[0002]
【従来の技術】一般にディジタル・マルチメータなど比
較的スピードが必要でない用途には積分型A/D変換器
が広く使われている。その理由としては積分型A/D変
換器は入力の積分時間を誘導雑音成分の周期の整数倍に
設定することにより誘導雑音周波数成分を除去できる特
性を持つためである。2. Description of the Related Art In general, an integral type A / D converter is widely used for applications such as digital multimeters where relatively high speed is not required. The reason is that the integration type A / D converter has a characteristic that the induction noise frequency component can be removed by setting the integration time of the input to an integral multiple of the period of the induction noise component.
【0003】図5に従来の積分型A/D変換器の構造を
示す。図中1は積分器、2はこの積分器1の入力端子を
示す。積分器1の入力端子2にはスイッチS1を通じて
被測定電圧EX を入力する入力端子3が接続される。更
に入力端子2にはスイッチS2を通じて基準電圧源4が
接続される。積分器1の出力側には電圧比較器5が接続
され、出力端子6に積分器1の積分電圧の極性に対応し
た論理信号VB を出力する。つまり積分器1の積分電圧
が0であれば0電位(H論理)を出力するが、積分電圧
がわずかでも負になると負の一定電圧(L論理)を出力
する。S3は積分器1の積分電圧を初期状態に戻すため
のリセットスイッチを示す。FIG. 5 shows the structure of a conventional integrating A / D converter. In the figure, 1 is an integrator, and 2 is an input terminal of the integrator 1. The input terminal 2 of the integrator 1 is connected to the input terminal 3 for inputting the measured voltage E X through the switch S1. Further, the reference voltage source 4 is connected to the input terminal 2 through the switch S2. The voltage comparator 5 is connected to the output side of the integrator 1, and outputs the logic signal V B corresponding to the polarity of the integrated voltage of the integrator 1 to the output terminal 6. That is, if the integrated voltage of the integrator 1 is 0, 0 potential (H logic) is output, but if the integrated voltage becomes negative even slightly, a constant negative voltage (L logic) is output. S3 is a reset switch for returning the integrated voltage of the integrator 1 to the initial state.
【0004】待機中はリセットスイッチS3がオンに制
御され、積分器1は初期状態(0電位)を出力する。測
定開始時にリセットスイッチS3をオフに制御し、スイ
ッチS1をオンに制御して被測定電圧EX を積分器1に
入力する。被測定電圧EX を図6Aに示すように一定時
間T1 (この時間を商用電源周波数の整数倍に採ると誘
導ノイズを除去できる)積分し、その時間T1 後にスイ
ッチS1をオフにし、代わってスイッチS2をオンに制
御して基準電圧源4を積分器1の入力端子2に接続す
る。During standby, the reset switch S3 is controlled to be turned on, and the integrator 1 outputs the initial state (0 potential). At the start of measurement, the reset switch S3 is turned off and the switch S1 is turned on to input the measured voltage E x to the integrator 1. As shown in FIG. 6A, the measured voltage E X is integrated for a fixed time T 1 (induction noise can be removed by taking this time as an integral multiple of the commercial power supply frequency), and after that time T 1 , the switch S1 is turned off and replaced. Then, the switch S2 is turned on to connect the reference voltage source 4 to the input terminal 2 of the integrator 1.
【0005】この切換のタイミングt1 から図6Cに示
すクロックCPの計数を開始する。積分器1の積分電圧
が0に戻り、出力端子6の論理値VB が反転するタイミ
ングt2 でクロックCPの計数を停止し、この計数値か
ら時間TX を計測する。時間TX は被測定電圧の値に対
応し、被測定電圧EX をクロックCPの周期の分解能で
AD変換したことになる。尚、AD変換の分解能を上げ
るには入力側に基準電圧源4の例えば1/100の電圧
を持つ第2の基準電圧源を設け、時点t 2 の終了電圧
(正側に行過ぎた電圧)を再度0に戻る方向に積分し、
この積分時間を加えることにより、時間TX の更に1/
100の分解能で端数部分をAD変換することができ
る。Timing of this switching t1Shown in Figure 6C
The counting of the clock CP is started. Integrated voltage of integrator 1
Returns to 0, and the logical value V of the output terminal 6BTaimi reverses
Ng t2Stop the counting of the clock CP at
From time TXTo measure. Time TXIs the value of the measured voltage
The measured voltage EXWith the resolution of the cycle of the clock CP
This means AD conversion. In addition, increase the resolution of AD conversion
Voltage on the input side of the reference voltage source 4, for example, 1/100
And a second reference voltage source having 2End voltage of
(Voltage that has passed too much on the positive side) is integrated in the direction of returning to 0 again,
By adding this integration time, the time TXFurther 1 /
The fractional part can be AD converted with a resolution of 100
It
【0006】[0006]
【発明が解決しようとする課題】従来の積分型AD変換
器を利用した電圧測定装置は入力切換用スイッチの数が
多く構成が複雑である。また基準電圧源を2個設け、時
間TX の端数部分をAD変換するように構成する場合は
基準電圧源の電圧比が正確である必要がある。また基準
電圧源の電圧比を定期的に測定し校正する必要がある。A voltage measuring device using a conventional integrating AD converter has a large number of input changeover switches and has a complicated structure. Also provided two reference voltage source, when constituting the fractional part of the time T X to AD conversion voltage ratio of the reference voltage source is required to be accurate. It is also necessary to periodically measure and calibrate the voltage ratio of the reference voltage source.
【0007】この発明の目的は入力切換用スイッチの数
を少なくし、構成を簡素化することができる積分型AD
変換器を利用して電圧測定装置を提供しようとするもの
である。また基準電圧源を複数設けなくても分解能の高
いAD変換を行なうことができる電圧測定装置を提供し
ようとするものである。An object of the present invention is to reduce the number of input changeover switches and to simplify the structure, thereby providing an integral type AD.
It is intended to provide a voltage measuring device using a converter. Another object of the present invention is to provide a voltage measuring device capable of performing high resolution AD conversion without providing a plurality of reference voltage sources.
【0008】[0008]
【課題を解決するための手段】この発明では被測定電圧
と、この被測定電圧と逆極性の既知の電圧の基準電圧と
を重畳した重畳電圧を積分器に与える状態と被測定電圧
のみを積分器に与える状態に切換る切換スイッチと、重
畳電圧を積分器に与える状態と被測定電圧のみを積分器
に与える状態を一定時間内に実行して1つの測定周期と
し、これを所定の回数繰返し実行させる制御器と、各測
定周期において各測定周期の終了時点における積分器の
積分電圧が可及的に予め予定した電圧に収歛するように
重畳電圧を積分器に与える時間を制御するスイッチ制御
手段と、重畳電圧を積分器に与える時間の累積値を
TRS、測定周期を加算した時間をTS 、基準電圧をES
としたとき被測定電圧EX をEX =ES ・TS /TS に
より算出する演算手段とによって構成するものである。SUMMARY OF THE INVENTION In the present invention, only the measured voltage and the measured voltage and a reference voltage of a known voltage having a polarity opposite to that of the measured voltage are applied to the integrator and only the measured voltage is integrated. Changeover switch for switching to the condition where the voltage is applied to the integrator, and the condition that the superimposed voltage is applied to the integrator and the condition that only the measured voltage is applied to the integrator are executed within a fixed time to make one measurement cycle, and this is repeated a predetermined number of times. The controller to be executed and the switch control to control the time to give the superposed voltage to the integrator so that the integrated voltage of the integrator at the end of each measurement cycle converges to the predetermined voltage as much as possible in each measurement cycle. Means, the cumulative value of the time for giving the superimposed voltage to the integrator is T RS , the time obtained by adding the measurement periods is T S , and the reference voltage is E S.
When that constitute the calculating means for calculating the measured voltage E X by E X = E S · T S / T S.
【0009】この発明では更に最終測定周期における積
分器の積分電圧をEAn、測定開始時における積分器の積
分電圧をEA1、積分器に基準電圧を与える積分時定数を
R・Cとしたとき(EAn−EA1)・R・C/TS によっ
て端数値を算出する端数値算出手段を設け、この端数値
を被測定電圧EX に加算する。この発明による電圧測定
装置によれば入力切換スイッチは1個でよく、構成を簡
素化することができる。また基準電圧源も1個で済むか
ら基準電圧相互の電圧値の比を管理する必要がない。よ
って取扱いも簡単になる利点が得られる。In the present invention, when the integrated voltage of the integrator in the final measurement cycle is E An , the integrated voltage of the integrator at the start of measurement is E A1 , and the integration time constant for giving the reference voltage to the integrator is R · C. (E An −E A1 ) · R · C / T S is provided with a fractional value calculating means for calculating a fractional value, and the fractional value is added to the measured voltage E X. According to the voltage measuring device of the present invention, only one input changeover switch is required, and the structure can be simplified. Further, since only one reference voltage source is required, it is not necessary to manage the ratio of the voltage values of the reference voltages. Therefore, there is an advantage that the handling is simple.
【0010】[0010]
【実施例】図1にこの発明の一実施例を示す。図中1は
積分器を示す。この例では積分器1に2本の積分抵抗器
R1とR2を設け、これら2つの積分抵抗器R1とR2
を入力端子2Aと2Bに接続し、2入力型の積分器を構
成した場合を示す。入力端子2Aに外部入力端子3を接
続し、被測定電圧EX を与える。これと共に入力端子2
Bには切換スイッチS2を通じて基準電圧源4を接続す
る。FIG. 1 shows an embodiment of the present invention. In the figure, 1 indicates an integrator. In this example, the integrator 1 is provided with two integrating resistors R1 and R2, and these two integrating resistors R1 and R2 are provided.
Is connected to the input terminals 2A and 2B to form a 2-input type integrator. The external input terminal 3 is connected to the input terminal 2A, and the measured voltage E X is applied. Along with this, input terminal 2
A reference voltage source 4 is connected to B through a changeover switch S2.
【0011】積分器1の出力側に瞬時変換型のAD変換
器7を接続し、制御器8から与えられる制御信号によ
り、その時点における積分器1の積分電圧をAD変換す
る。瞬時変換型AD変換器としては各種既存の構造のA
D変換器を用いることができる。制御器8は例えばマイ
クロコンピュータによって構成することができる。切換
スイッチS2は制御器8によってオンの状態と、オフの
状態に切換制御される。オンの状態に制御されることに
より積分器1には被測定電圧EX と基準電圧源4の基準
電圧ES が重畳して与えられる。また切換スイッチS2
がオフの状態では積分器1には被測定電圧EX だけが与
えられる。An instantaneous conversion type AD converter 7 is connected to the output side of the integrator 1, and the integrated voltage of the integrator 1 at that time is AD-converted by a control signal given from the controller 8. Instantaneous conversion type A / D converter with various existing structures
A D converter can be used. The controller 8 can be composed of, for example, a microcomputer. The changeover switch S2 is controlled by the controller 8 to be switched between an on state and an off state. By being controlled to the ON state, the voltage to be measured E X and the reference voltage E S of the reference voltage source 4 are applied to the integrator 1 in a superposed manner. In addition, the changeover switch S2
When is off, the integrator 1 is supplied with only the measured voltage E x .
【0012】図2を用いて動作を説明する。時点t1 で
積分器1の積分電圧を瞬時にAD変換器7でAD変換す
る。このAD変換値をEA1とし、制御器8に内蔵したメ
モリに記憶する。これと共に切換スイッチS2をオンに
制御し積分器1に重畳電圧を与える。初回の第1測定周
期では重畳電圧を積分する時間TR1は予め設定されてい
る或る一定時間に選定される。従って重畳電圧を積分す
る積分時間TR1を経過した時点で切換スイッチS2は制
御器8によりオフの状態に制御され、爾後時点t2 まで
被測定電圧EX のみが積分器1に与えられる。The operation will be described with reference to FIG. At time t 1 , the integrated voltage of the integrator 1 is instantly AD-converted by the AD converter 7. The AD conversion value is set as E A1 and stored in the memory built in the controller 8. At the same time, the changeover switch S2 is controlled to be turned on, and the superimposed voltage is given to the integrator 1. In the first measurement cycle of the first time, the time T R1 for integrating the superimposed voltage is selected to be a certain preset time. Therefore, when the integration time T R1 for integrating the superimposed voltage has elapsed, the changeover switch S2 is controlled to the off state by the controller 8, and only the measured voltage E X is given to the integrator 1 until the time t 2 after that.
【0013】時点t2 においてAD変換器7で積分器1
の積分電圧をAD変換する。そのAD変換値をEA2とす
る。EA2が正極性の値であれば制御器8は次回の測定周
期におけるスイッチS2のオン時間TR を長くする。負
極性の値であれば制御器8は次回の測定周期におけるス
イッチS2のオン時間を短かくする。この制御動作によ
り各測定周期の終了点における積分器1の積分電圧は予
め設定した、例えば共通電位に等しい0Vに収斂する。At time t 2 , the AD converter 7 causes the integrator 1
AD-converts the integrated voltage of. The AD conversion value is E A2 . If E A2 has a positive value, the controller 8 lengthens the ON time T R of the switch S2 in the next measurement cycle. If it is a negative value, the controller 8 shortens the on time of the switch S2 in the next measurement cycle. By this control operation, the integrated voltage of the integrator 1 at the end point of each measurement cycle converges to a preset voltage, for example, 0 V equal to the common potential.
【0014】測定周期を繰返し最終測定周期の時点tn
で積分器1の積分電圧をAD変換し、その値をEAn、時
点t1 〜tn までの間の時間(以下この時間を変換時間
と称す)をTS 、各測定周期におけるスイッチS2のオ
ン時間TR1,TR2,TR3…T Rnの総和TR1+TR2+TR3
…TRn=TRsとすると、被測定電圧EX は、 EX =ES ・TRs/TS +(EAn−EA1)・RC/TS …(1) で求められる。スイッチ2のオン時間の総和TRs及びE
X を算出する演算は制御器8で行なわれる。演算結果は
表示器9に表示される。(1)式において、第1項は被
測定電圧EX の主となる値、第2項は端数値である。第
2項の時定数R・Cは積分器1の積分抵抗器R2と積分
コンデンサC1の時定数を指す。The measurement cycle is repeated and the time t of the final measurement cycle is reached.n
AD-converts the integrated voltage of integrator 1 with the value EAn,Time
Point t1~ TnTime between (this time is converted time below
T)S, Switch S2 on in each measurement cycle
Time TR1, TR2, TR3… T RnSum of TR1+ TR2+ TR3
… TRn= TRsThen, the measured voltage EXIs EX= ES・ TRs/ TS+ (EAn-EA1) ・ RC / TS… It is calculated by (1). Total time T of switch 2 onRsAnd E
XThe controller 8 performs the calculation for calculating The calculation result is
It is displayed on the display unit 9. In equation (1), the first term is
Measuring voltage EXThe second term is the fractional numerical value. First
The time constant R · C of the second term is integrated with the integration resistor R2 of the integrator 1.
Refers to the time constant of the capacitor C1.
【0015】オン時間TR を計測する分解能を1μs、
変換時間TS を100mgとした場合、TRSは0〜10
0msの範囲で変化することになる。100msを1μ
sの分解能で計測した場合、105 カウント、つまり5
桁の計測が可能である。AD変換器7として8ビットの
AD変換器を用いるものとした場合、第2項として2桁
を採る設計は可能である。この結果として変換時間を1
00msに採った場合は第1項は5桁、第2項は2桁、
計7桁。The resolution for measuring the on-time T R is 1 μs,
When the conversion time T S is 100 mg, T RS is 0 to 10
It will change in the range of 0 ms. 1 ms for 100 ms
When measured with a resolution of s, 10 5 counts, that is, 5
Digits can be measured. When an 8-bit AD converter is used as the AD converter 7, it is possible to design the second term with two digits. As a result, the conversion time is 1
If it is set to 00 ms, the first term is 5 digits, the second term is 2 digits,
7 digits in total.
【0016】変換時間を20msに採った場合は第1項
は4桁、第2項は2桁、計6桁。変換時間を2msに採
った場合は第1項は3桁、第2項は2桁、計5桁。のA
D変換器が得られる。変換時間TS を100msに採っ
た場合は図3に示すように基本波Wが10Hzのノーマ
ルモードの雑音除去特性を得ることができる。つまり1
0Hz間隔で雑音除去特性を得ることができる。この結
果5W=50Hzと6W=60Hzの双方で雑音除去特
性を得ることができ、50Hzと60Hzの双方に共用
することができる。また変換時間TS を100msに採
った場合は測定周期の回数nは例えばn=33回に選定
することができ、1測定周期は3.03ms程度とな
る。変換時間TS の他の例としては20msと16.6
6msとが考えられる。20msは50Hz用、16.
66msは60Hz用として用いられる。When the conversion time is set to 20 ms, the first term has 4 digits, the second term has 2 digits, and a total of 6 digits. When the conversion time is set to 2 ms, the first term is 3 digits, the second term is 2 digits, and 5 digits in total. Of A
A D converter is obtained. When the conversion time T S is set to 100 ms, it is possible to obtain the normal mode noise elimination characteristics in which the fundamental wave W is 10 Hz as shown in FIG. That is 1
Noise removal characteristics can be obtained at 0 Hz intervals. As a result, the noise elimination characteristics can be obtained at both 5W = 50Hz and 6W = 60Hz, and can be shared for both 50Hz and 60Hz. When the conversion time T S is set to 100 ms, the number of measurement cycles n can be selected to be n = 33, for example, and one measurement cycle is about 3.03 ms. Other examples of the conversion time T S are 20 ms and 16.6.
6 ms is considered. 20 ms is for 50 Hz, 16.
66 ms is used for 60 Hz.
【0017】この発明による電圧測定装置の誤差要因は
積分抵抗器R1とR2の抵抗比だけである。積分コンデ
ンサC1の容量比値は(1)式の下位桁のみで容量値が
1%を越える変化をしなければ誤差は生じない。切換ス
イッチS2は1μsの1/100の10nsのオン・オ
フの繰返しが同じであればよい。例えばCMOSのスイ
ッチ素子を用いることができる。よって安価なスイッチ
素子を用いることができる。The only error factor of the voltage measuring device according to the present invention is the resistance ratio of the integrating resistors R1 and R2. The capacitance ratio value of the integrating capacitor C1 is only the lower digit of the equation (1), and no error occurs unless the capacitance value changes by more than 1%. It suffices that the change-over switch S2 has the same on / off repetition for 10 ns which is 1/100 of 1 μs. For example, a CMOS switch element can be used. Therefore, an inexpensive switch element can be used.
【0018】尚、図4はこの発明の変形実施例を示す。
この実施例では正と負の基準電圧源4Aと4Bを設け、
被測定電圧EX の極性に応じて自動的に逆極性の基準電
圧を選択する構造とした場合を示す。但し実用上は被測
定電圧EX の入力の向を選択して基準電圧と被測定電圧
を逆極性となるようにすればよいから、必ずしも正と負
の基準電圧を必要とするものではない。Incidentally, FIG. 4 shows a modified embodiment of the present invention.
In this embodiment, positive and negative reference voltage sources 4A and 4B are provided,
The case where the reference voltage having the opposite polarity is automatically selected according to the polarity of the measured voltage E X is shown. However, in practice, it is sufficient to select the input direction of the measured voltage E X so that the reference voltage and the measured voltage have opposite polarities, so that the positive and negative reference voltages are not necessarily required.
【0019】[0019]
【発明の効果】以上説明したように、この発明によれば
1個の切換スイッチS2をオン、オフ制御するだけで積
分型AD変換器を利用した電圧測定装置を構成できる。
従って従来の積分型AD変換器の構造より簡素化され安
価に作ることができる。然も基準電圧源は基本的に1個
で済むから、基準電圧源の電圧比を計測し、校正を行な
う等のわずらわしい作業を必要としない。よって取扱も
簡単となり、初期の性能を長期にわたって維持すること
ができる利点も得られる。As described above, according to the present invention, it is possible to construct the voltage measuring device using the integral type AD converter by simply turning on and off the single changeover switch S2.
Therefore, the structure is simpler and cheaper than the structure of the conventional integral AD converter. However, since only one reference voltage source is basically required, no troublesome work such as measuring the voltage ratio of the reference voltage source and performing calibration is required. Therefore, it is easy to handle, and there is an advantage that the initial performance can be maintained for a long time.
【図1】この発明の一実施例を示す接続図。FIG. 1 is a connection diagram showing an embodiment of the present invention.
【図2】図1の実施例の動作を説明するための波形図。FIG. 2 is a waveform diagram for explaining the operation of the embodiment of FIG.
【図3】積分型AD変換器のノーマルモード雑音除去特
性を説明するためのグラフ。FIG. 3 is a graph for explaining a normal mode noise elimination characteristic of the integral type AD converter.
【図4】この発明の変形実施例を示す接続図。FIG. 4 is a connection diagram showing a modified embodiment of the present invention.
【図5】従来の技術を説明するための接続図。FIG. 5 is a connection diagram for explaining a conventional technique.
【図6】図5の動作を説明するための波形図。6 is a waveform diagram for explaining the operation of FIG.
1 積分器 2A,2B 積分器の入力端子 3 外部入力端子 4 基準電圧源 S2 切換スイッチ 7 瞬時変換型のAD変換器 8 制御器 1 integrator 2A, 2B input terminal of integrator 3 external input terminal 4 reference voltage source S2 changeover switch 7 instantaneous conversion type AD converter 8 controller
Claims (2)
の電圧を持つ基準電圧とを重畳した重畳電圧を積分器に
与える状態及び被測定電圧のみを積分器に与える状態に
切換る切換スイッチと、重畳電圧を積分器に与える状態
と被測定電圧のみを積分器に与える状態を一定時間内に
実行して1測定周期とし、これを所定の回数繰返し実行
させる制御器と、各測定周期において各測定周期の終了
時点における積分器の積分電圧が可及的に予定した電圧
に収歛するように重畳電圧を上記積分器に与える時間を
制御するスイッチ制御手段と、重畳電圧を積分器に与え
る時間の累積値をTRS、測定周期の時間を加算した時間
をTS 、基準電圧をESとしたとき、被測定電圧EX を
EX =ES ・TRS/TS によって算出する演算手段とに
よって構成したことを特徴とする電圧測定装置。1. A switch for switching a state in which a superposed voltage obtained by superposing a measured voltage and a reference voltage having a voltage having a polarity opposite to that of the measured voltage is applied to an integrator and a state in which only the measured voltage is applied to the integrator. A switch, a controller that applies the superimposed voltage to the integrator and a condition that only the measured voltage is applied to the integrator within a fixed time to make one measurement cycle, and repeatedly executes this for a predetermined number of times, and each measurement cycle. In, the switch control means for controlling the time to give the superimposed voltage to the integrator so that the integrated voltage of the integrator at the end of each measurement period converges to the scheduled voltage as much as possible, and the superimposed voltage to the integrator. When the cumulative value of the given time is T RS , the time obtained by adding the time of the measurement cycle is T S , and the reference voltage is E S , the measured voltage E X is calculated by E X = E S · T RS / T S Comprised of arithmetic means and Voltage measuring device according to claim.
測定開始時点における積分器の積分電圧をEA1、最終測
定周期の終了時点における積分器の積分電圧をEAn、積
分器の基準電圧に対する積分時定数をCRとした場合
(EA1−EAn)・C・R/TS により補正値を算出し、
請求項1で算出した被測定電圧EX に加算するように構
成したことを特徴とする電圧測定装置。2. The voltage measuring device according to claim 1, wherein
When the integrated voltage of the integrator at the start of measurement is E A1 , the integrated voltage of the integrator at the end of the final measurement cycle is E An , and the integration time constant for the reference voltage of the integrator is CR (E A1 −E An ).・ Calculate the correction value by C ・ R / T S ,
A voltage measuring device configured to be added to the measured voltage E X calculated in claim 1.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21974793A JPH0772187A (en) | 1993-09-03 | 1993-09-03 | Voltage measuring instrument |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21974793A JPH0772187A (en) | 1993-09-03 | 1993-09-03 | Voltage measuring instrument |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0772187A true JPH0772187A (en) | 1995-03-17 |
Family
ID=16740364
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP21974793A Withdrawn JPH0772187A (en) | 1993-09-03 | 1993-09-03 | Voltage measuring instrument |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0772187A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009034319A (en) * | 2007-08-01 | 2009-02-19 | Ito Choutanpa Kk | Potential treatment device |
JP2012060350A (en) * | 2010-09-08 | 2012-03-22 | Mitsubishi Electric Corp | Analog input device |
-
1993
- 1993-09-03 JP JP21974793A patent/JPH0772187A/en not_active Withdrawn
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009034319A (en) * | 2007-08-01 | 2009-02-19 | Ito Choutanpa Kk | Potential treatment device |
JP2012060350A (en) * | 2010-09-08 | 2012-03-22 | Mitsubishi Electric Corp | Analog input device |
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Legal Events
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A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20001107 |