JPH07218560A - DC electrometer - Google Patents
DC electrometerInfo
- Publication number
- JPH07218560A JPH07218560A JP3430494A JP3430494A JPH07218560A JP H07218560 A JPH07218560 A JP H07218560A JP 3430494 A JP3430494 A JP 3430494A JP 3430494 A JP3430494 A JP 3430494A JP H07218560 A JPH07218560 A JP H07218560A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- value
- several
- capacitor
- insulator
- 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
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
(57)【要約】
【目的】 人体が絶縁物の上にいる時、人体が大地に対
して絶縁されている時は、絶縁物が殆ど静電容量となる
ため、触れた一瞬だけ検電するが無電圧状態に戻ってし
まう。この欠点を無くす。
【構成】 片手で持ち、電路の大地側に対し活線側の１
線又は絶縁電位の絶縁物の表面に触れるのみで、電路の
電圧を測定するポータブル１線接続式電位計において、
分圧用抵抗の後に数１０ＰＦのコンデンサと数１００Ｐ
Ｆのコンデンサを直列に接続し回路アースに接続する。
ここで数１０ＰＦのコンデンサの端子間の容量値と抵抗
値の積と数１００ＰＦのコンデンサの端子間の容量値の
積とが同じくなるようにする。
(57) [Summary] [Purpose] When the human body is on an insulator, or when the human body is insulated from the ground, the insulator has almost electrostatic capacitance, so the voltage is detected only for the moment it is touched. Will return to a non-voltage state. Eliminate this drawback. [Structure] Hold with one hand, 1 on the live line side to the earth side of the electric line
In a portable 1-wire connection type electrometer that measures the voltage of an electric circuit by simply touching the surface of a wire or an insulator of insulation potential,
After the voltage dividing resistor, several tens of PF capacitors and several hundreds of PFs
Connect the F capacitor in series and connect to circuit ground.
Here, the product of the capacitance value and the resistance value between the terminals of the capacitor of several 10 PF and the product of the capacitance value between the terminals of the capacitor of several 100 PF are set to be the same.
Description
【０００１】[0001]
【産業上の利用分野】本発明は、直流電路の導体又は絶
縁電線の絶縁物の表面に接触し、電圧を測定する直流電
位計ならびに検電器に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC electrometer and a voltage detector which contact a surface of a conductor of a DC electric path or an insulator of an insulated wire to measure a voltage.
【０００２】[0002]
【従来の技術】導体に電圧が印加された状態すなわち導
体の課電状態を表示する直流検電器は、内部に人体の抵
抗より充分大きな高抵抗を入れ、課電された導体から検
電器及び人体、大地を通して流れる微小電流から生じる
電圧降下分を検出する。従来の直流検電器の構成とその
動作原理について図１を用いて説明する。１は導電性ゴ
ム、２、３、４は分圧用抵抗、５はインピーダンス変換
用バッフア、６はコンパレータ、７は基準電圧、８は発
振器、９はブザーである。ここで導電性ゴム１を直流電
路の活線側に触れると、導電性ゴム１、分圧用抵抗２、
３、４及び人体を通り微小電流が流れ、分圧用抵抗４に
電圧が発生する。５のバッフアを通り基準電圧７で基準
電圧値より高い値になると発振回路が働きブザーが鳴
る。2. Description of the Related Art A DC detector which indicates a state in which a voltage is applied to a conductor, that is, a state in which a conductor is charged, has a high resistance which is sufficiently larger than the resistance of the human body, and the detector and the human body are connected to the conductor. , Detects voltage drop caused by minute current flowing through the earth. The structure of a conventional DC voltage detector and its operating principle will be described with reference to FIG. Reference numeral 1 is a conductive rubber, 2, 3, and 4 are resistors for voltage division, 5 is a buffer for impedance conversion, 6 is a comparator, 7 is a reference voltage, 8 is an oscillator, and 9 is a buzzer. Here, when the conductive rubber 1 is touched to the live line side of the direct current circuit, the conductive rubber 1, the voltage dividing resistor 2,
A minute electric current flows through 3, 4 and the human body, and a voltage is generated in the voltage dividing resistor 4. When the voltage passes through the buffer 5 and becomes higher than the reference voltage value at the reference voltage 7, the oscillation circuit operates and the buzzer sounds.
【０００３】[0003]
【発明が解決しようとする課題】従来の検電器は電路の
活線側より検電器の内部抵抗、人体を通り、大地に流れ
る検電器内部の抵抗で電圧降下させ検電するものであ
る。この方法では人体が絶縁物の上にいる時等、人体が
大地に対し絶縁されているときは、絶縁物が殆ど静電容
量となるため、触れた一瞬だけ検電するが無電圧状態に
戻ってしまう。本発明は上記の欠点を克服するために、
検電器内部の部品の定数を各相互間にある関係を持たせ
ることにより、改善させたものである。A conventional voltage detector is one in which the voltage is dropped by the internal resistance of the voltage detector from the live line side of the electric circuit and the resistance inside the voltage detector that flows through the human body to the ground. With this method, when the human body is insulated from the ground, such as when the human body is on an insulator, the insulator has almost electrostatic capacity. Will end up. The present invention, in order to overcome the above drawbacks,
The constants of the components inside the voltage detector are improved by having a relationship among them.
【０００４】[0004]
【課題を解決するための手段】従来の導電ゴム、分圧用
抵抗の後に数１０ＰＦのコンデンサと数１００ＰＦのコ
ンデンサを直列に接続し回路アースに接続する。ここで
数１０ＰＦのコンデンサの端子間の容量値と抵抗値の積
と数１００ＰＦのコンデンサの端子間の容量値の積とが
同じくなるようにする。Means for Solving the Problems After a conventional conductive rubber and a voltage dividing resistor, a capacitor of several tens of PF and a capacitor of several hundreds of PF are connected in series and connected to a circuit ground. Here, the product of the capacitance value and the resistance value between the terminals of the capacitor of several 10 PF and the product of the capacitance value between the terminals of the capacitor of several 100 PF are set to be the same.
【０００５】[0005]
【作用】以下、本発明の各構成部分の作用について説明
を行う。図２は本発明のブロック図である。１は導電性
ゴム、２は高周波電流抑制用抵抗、１０、１１は分圧用
インピーダンスでＣ1 ・Ｒ1 ＝Ｃ2 ・Ｒ2 となるように
各定数を決める。ここでＲ1 はＣ1 端子間の絶縁抵抗も
含まれた並列抵抗値、Ｒ2 は増幅器入力インピーダンス
を含んだＣ2 の端子間並列抵抗値である。１２は増幅
器、１３はアナログ値をデジタル値に変換するＡ／Ｄコ
ンバータ、１４は表示部である。ここで１の導電性ゴム
を直流電路の活線側に触れた時、Ｃ1 ・Ｒ1 とＣ2 ・Ｒ
2 との関係により図３（ａ）〜（ｃ）のように時間に対
し表示値が変わる。（ａ）はＣ1 ・Ｒ1 ＞Ｃ2 ・Ｒ2 の
時の例で、活線に導電性ゴムが触れた時は一瞬電圧値以
上の値を示すが、徐々に低下していく。（ｂ）はＣ1 ・
Ｒ1 ＝Ｃ2 ・Ｒ2の時の例で、活線に触れると即電圧値
を表示し、時間が経っても表示値は変化しない。（ｃ）
はＣ1 ・Ｒ1 ＜Ｃ2 ・Ｒ2 の時で、活線に触れると徐々
に表示値が上昇していき、活線の電圧値になるのに時間
を要する。ここで（ｂ）のように、Ｃ1 ・Ｒ1 ＝Ｃ2 ・
Ｒ2 の関係を維持した状態でＣ1を小さく、Ｒ1 を大き
くしていき、Ｃ1 を数１０ＰＦ、Ｒ1 を数１０００ＧΩ
程度に設定することにより、直流電圧測定時、絶縁被覆
の表面からでも電圧を計測することができる。Ｃ1 が数
１００ＰＦ程度にすると、被測定絶縁電線の静電容量の
方が小さくなり、検電計内の分圧電圧値が小さくなり測
定誤差が増加する。これとは逆に数１０ＰＦより小さく
すると、増幅器１２の内部静電容量が問題となり、Ｃ2
・Ｒ2 の値がある値より小さくならなくなる。その為Ｃ
1 ・Ｒ1 ＜Ｃ2 ・Ｒ2 となり応答性が悪くなる。The operation of each component of the present invention will be described below. FIG. 2 is a block diagram of the present invention. Reference numeral 1 is a conductive rubber, 2 is a resistance for suppressing high frequency current, and 10 and 11 are impedances for voltage division. Each constant is determined so that C 1 · R 1 = C 2 · R 2 . Here, R 1 is a parallel resistance value including the insulation resistance between the C 1 terminals, and R 2 is a parallel resistance value between the terminals of C 2 including the amplifier input impedance. Reference numeral 12 is an amplifier, 13 is an A / D converter for converting an analog value into a digital value, and 14 is a display unit. Here, when the conductive rubber of 1 is touched to the live line side of the direct current circuit, C 1 · R 1 and C 2 · R
Depending on the relationship with 2 , the display value changes with time as shown in FIGS. (A) is an example in the case of C 1 · R 1 > C 2 · R 2 , and when the conductive rubber touches the live wire, the voltage value momentarily exceeds the voltage value, but gradually decreases. (B) is C 1
In the example of R 1 = C 2 · R 2 , the voltage value is displayed immediately when the live line is touched, and the displayed value does not change even after a lapse of time. (C)
When C 1 · R 1 <C 2 · R 2 , the displayed value gradually rises when the live line is touched, and it takes time to reach the voltage value of the live line. Here, as in (b), C 1 · R 1 = C 2 ·
With the relationship of R 2 maintained, C 1 is decreased and R 1 is increased, C 1 is several tens of PF, and R 1 is several 1000 GΩ.
By setting the voltage to a certain level, it is possible to measure the voltage even from the surface of the insulating coating when measuring the DC voltage. When C 1 is about several hundreds of PF, the capacitance of the insulated wire to be measured becomes smaller, the divided voltage value in the electrometer becomes smaller, and the measurement error increases. On the contrary, if it is smaller than several tens of PFs, the internal capacitance of the amplifier 12 becomes a problem, and C 2
-The value of R 2 will not become smaller than a certain value. Therefore C
1 · R 1 <C 2 · R 2 , resulting in poor responsiveness.
【０００６】[0006]
【実施例】本発明の実施例を図４に示す。１は活線側に
接触時、付近の導体に接触しても短絡電流が流れないよ
うにする為の抵抗値をもった導電性ゴム、Ｚは高周波分
の電流流入防止用及び絶縁物の上からの測定においても
誤差を小さくする為の抵抗で数ＧΩ程度のもの、１５は
分圧用コンデンサで数１０ＰＦのもの、このコンデンサ
の沿面及び内部絶縁抵抗値をＲ1 、１６は分圧電圧検出
用コンデンサＣ2 で、１７は演算増幅器で入力抵抗がＦ
ＥＴのもので数１０００ＧΩのものを使用する。１８は
Ａ／Ｄコンバータ、１９は液晶表示。ここでコンデンサ
Ｃ1 を数１０ＰＦのセラミックコンデンサを使用すると
形状、定格電圧より絶縁抵抗値はほぼ決まる。このＣ1
Ｒ1 の値と等しくなるように（Ｃ2 ＋Ｃ3 ）・Ｒ2 の値
を決める。Ｃ3 Ｒ2 は演算増幅器の種類が決まるとほぼ
決定するので、それに合わせＣ2 を決める。１７の演算
増幅器で増幅度を変え活線側に導電性ゴム１を接触した
時、表示値が合うように調整する。このようにすること
により応答性がよくしかも絶縁電線の上からでも測定可
能なものができる。EXAMPLE An example of the present invention is shown in FIG. 1 is a conductive rubber having a resistance value so that a short-circuit current does not flow even when it comes into contact with a nearby conductor when it comes into contact with the live line side. The resistance for reducing the error is about several GΩ even in the measurement from 1., 15 is a voltage dividing capacitor of several tens of PF, and the creepage and internal insulation resistance values of this capacitor are R 1 and 16 are for detecting the divided voltage. The capacitor C 2 is an operational amplifier 17 and the input resistance is F.
Use an ET type with several 1000 GΩ. 18 is an A / D converter, 19 is a liquid crystal display. If a ceramic capacitor of several tens of PFs is used as the capacitor C 1 , the insulation resistance value is almost determined by the shape and rated voltage. This C 1
The value of (C 2 + C 3 ) R 2 is determined so that it becomes equal to the value of R 1 . Since C 3 R 2 is almost determined when the type of operational amplifier is determined, C 2 is determined accordingly. When the conductive rubber 1 is brought into contact with the live line side by changing the amplification degree with the operational amplifier 17 so that the displayed value is adjusted. By doing so, it is possible to obtain a product that has good responsiveness and can be measured even from above the insulated wire.
【０００７】[0007]
【発明の効果】測定時の応答性が早く、しかも絶縁電線
の上からでも、数Ｖの直流電圧が計測できるので、発変
電設備、制御盤内、車の電装回路、コンビナートの制御
回路等、直流電圧を使用している現場の保守、点検作業
時の安全性がより高まり、しかも作業の容易性から効率
向上が計れる。EFFECTS OF THE INVENTION Since the responsiveness at the time of measurement is fast and a DC voltage of several V can be measured even from above the insulated wire, it is possible to use the power generation and transformation equipment, the inside of the control panel, the electric circuit of the car, the control circuit of the complex, etc. The safety at the time of maintenance and inspection work at the site where DC voltage is used is further enhanced, and the efficiency is improved due to the ease of work.
【図１】図１は従来の検電器の回路ブロック図例であ
る。FIG. 1 is an example of a circuit block diagram of a conventional voltage detector.
【図２】図２は本発明の原理ブロック図例である。FIG. 2 is an example of a principle block diagram of the present invention.
【図３】図３（ａ）〜（ｃ）は本発明の回路内の部品定
数を変えたときの応答性のグラフである。FIG. 3A to FIG. 3C are graphs of responsiveness when the component constants in the circuit of the present invention are changed.
【図４】図４は本発明の実施回路例である。FIG. 4 is an example of an implementation circuit of the present invention.
Claims (1)
の１線又は絶縁電位の絶縁物の表面に触れるのみで電路
の電圧を測定するポータブル１線接続式電位計におい
て、電位計内部に使用される二つ以上の分圧静電容量の
各値と、これと等価的に並列に接続されている絶縁抵抗
値ないし並列抵抗値との掛け合わせた値が各々等しくな
いしは近似値とさせることにより、直流電圧測定時、す
みやかに電路電圧を表示することを特徴とする直流電位
計。1. A portable one-wire connection type electrometer for measuring the voltage of a circuit by holding it with one hand and only touching the surface of one line on the live line side or the surface of an insulator having an insulation potential with respect to the ground side of the circuit, and an electrometer. The value obtained by multiplying each value of two or more partial voltage electrostatic capacitances used internally by the insulation resistance value or parallel resistance value equivalently connected in parallel with this value is the same or an approximate value. By doing so, the DC electrometer is characterized in that the DC voltage is displayed promptly during DC voltage measurement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3430494A JPH07218560A (en) | 1994-02-08 | 1994-02-08 | DC electrometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3430494A JPH07218560A (en) | 1994-02-08 | 1994-02-08 | DC electrometer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07218560A true JPH07218560A (en) | 1995-08-18 |
Family
ID=12410425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3430494A Pending JPH07218560A (en) | 1994-02-08 | 1994-02-08 | DC electrometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07218560A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101721366B1 (en) * | 2016-05-25 | 2017-03-29 | 조병학 | hand-held voltmeter for electric fence |
-
1994
- 1994-02-08 JP JP3430494A patent/JPH07218560A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101721366B1 (en) * | 2016-05-25 | 2017-03-29 | 조병학 | hand-held voltmeter for electric fence |
| US9829515B1 (en) | 2016-05-25 | 2017-11-28 | Byung-Hak Cho | Hand-held voltmeter for electric fence |
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