JPS6111526B2 - - Google Patents
Info
- Publication number
- JPS6111526B2 JPS6111526B2 JP2816878A JP2816878A JPS6111526B2 JP S6111526 B2 JPS6111526 B2 JP S6111526B2 JP 2816878 A JP2816878 A JP 2816878A JP 2816878 A JP2816878 A JP 2816878A JP S6111526 B2 JPS6111526 B2 JP S6111526B2
- Authority
- JP
- Japan
- Prior art keywords
- output
- amplifier
- circuit
- voltage
- peak hold
- 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.)
- Expired
Links
- 238000009499 grossing Methods 0.000 claims description 7
- 239000003990 capacitor Substances 0.000 description 10
- 230000008878 coupling Effects 0.000 description 10
- 238000010168 coupling process Methods 0.000 description 10
- 238000005859 coupling reaction Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 238000001514 detection method Methods 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Landscapes
- Emergency Protection Circuit Devices (AREA)
Description
【発明の詳細な説明】
本発明は交流電路の漏電を検出しその電路をし
や断するために用いる漏電検出器に関し、その目
的とするところは高ゲインの漏電検出器を提供す
るにある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an earth leakage detector used for detecting electric leakage in an alternating current electric line and disconnecting the electric line, and an object thereof is to provide a high gain electric leakage detector.
第１図は此種漏電検出器の一従来例を示すもの
であるが、零相変流器ZCTと交流増幅器Ａの負
入力端子間を結合コンデンサＣを介して接続して
あることによつて、電源投入時交流増幅器Ａより
抵抗Rfを通して結合コンデンサＣが充電され、
誤動作を生じること、結合コンデンサＣのばらつ
きによりゲインが変化すること、50Hz、60Hzの周
波数の違いによりゲインが変化すること等の欠点
がある。即ち、同図において、交流増幅器Ａの正
入力端子は抵抗R2を介して整流平滑回路Ｄの両
端電圧を分圧する抵抗R3，R4の分圧点ａに接続
されており、Ｖ＝Ｒ４／Ｒ３＋Ｒ４ＶDDの電位を保持
し
ている。一方負入力端子の電位は結合コンデンサ
ＣがあるためにＣ（R1＋Rf）の時定数により、
ほゞ零電圧より徐々に上昇するため、その上昇の
間は第２図の如くＶがＶより電位が低く、し
たがつて、整流平滑回路Ｆの出力は第３図の如く
変化して、比較器Ｅの出力ＶOUTは、
ＶOUT＝（Ｖ−Ｖ）×Rf／R1＋Ｖ
となり、スイツチング回路ＧのサイリスタSCR
がトリガされる結果トリツプコイルTCが誤動作
を生じる。そして交流増幅器ＡのゲインAvは
Av＝Rf／（R1＋１／２πｆｃ′）
ｆ：周波数、C′：結合コンデンサＣの容量で
ある。したがつてゲインAvは50Hz、60Hzの周波
数によつてまた結合コンデンサＣのバラツキによ
つても変化することゝなる。 Figure 1 shows a conventional example of this type of earth leakage detector, which is constructed by connecting the zero-phase current transformer ZCT and the negative input terminal of the AC amplifier A via a coupling capacitor C. , when the power is turned on, the coupling capacitor C is charged from the AC amplifier A through the resistor Rf,
There are drawbacks such as malfunctions, gain changes due to variations in the coupling capacitor C, and gain changes due to differences in frequencies between 50 Hz and 60 Hz. That is, in the figure, the positive input terminal of AC amplifier A is connected via resistor R2 to the voltage division point a of resistors R3 and R4 that divide the voltage across the rectifier and smoothing circuit D, and V=R. 4 /R 3 +R 4 It holds the potential of V DD . On the other hand, the potential of the negative input terminal is due to the time constant of C (R 1 + Rf) due to the presence of the coupling capacitor C.
Since the voltage gradually rises from almost zero voltage, during the rise, the potential of V is lower than V as shown in Fig. 2. Therefore, the output of the rectifying and smoothing circuit F changes as shown in Fig. 3, and the comparison The output V OUT of the circuit E is V OUT = (V-V) x Rf/R 1 +V, and the thyristor SCR of the switching circuit G is
As a result, the trip coil TC malfunctions. The gain Av of the AC amplifier A is Av=Rf/(R 1 +1/2πfc') where f: frequency and C': the capacitance of the coupling capacitor C. Therefore, the gain Av changes depending on the frequency of 50 Hz and 60 Hz and also due to the dispersion of the coupling capacitor C.
以上従来の欠点は結合コンデンサＣがあること
によつて生じるものである。 The drawbacks of the conventional method described above are caused by the presence of the coupling capacitor C.
以下実施例として掲げた第５図乃至第９図を参
照して本発明漏電検出器を説明すると、交流電路
の不平衡電流を検出する零相変流器ZCTと、そ
の零相変流器ZCTの出力を入力信号とする直流
増幅器A1と、直流増幅器A1の出力をピークホー
ルドするピークホールド回路F1と、前記直流増
幅器A1の出力とピークホールド回路F1のレベル
を比較する差動増幅器E1と、その差動増幅器E1
の出力を整流平滑する整流平滑回路F2と整流平
滑回路F2のレベルを判定する比較器E2と、しや
断器のトリツプコイルTCとスイツチング素子
SCRよりなり前記比較器E2の出力によりスイツ
チング素子SCRを導通させるスイツチング回路
Ｇとを交流電路に接続する直流単電源回路Ｄに接
続してなる漏電検出器とするものである。 The earth leakage detector of the present invention will be explained below with reference to FIGS. 5 to 9 shown as examples. A DC amplifier A 1 whose input signal is the output of the DC amplifier A 1 , a peak hold circuit F 1 which peak-holds the output of the DC amplifier A 1 , and a differential circuit which compares the output of the DC amplifier A 1 and the level of the peak hold circuit F 1 Amplifier E 1 and its differential amplifier E 1
A rectifying and smoothing circuit F2 that rectifies and smoothes the output of F2 , a comparator E2 that determines the level of the rectifying and smoothing circuit F2 , and a trip coil TC and switching element of the breaker.
This is an earth leakage detector in which a switching circuit G consisting of an SCR is connected to a DC single power supply circuit D which is connected to an AC line.
而して、直流増幅器A1を使用するものである
から、従来の結合コンデンサを不要とし、その直
流増幅器A1によるオフセツト、ドリフトの問題
は次段に接続する差動増幅器E1の使用によつて
吸収される。 Since the DC amplifier A1 is used, the conventional coupling capacitor is not required, and the problem of offset and drift caused by the DC amplifier A1 can be solved by using the differential amplifier E1 connected to the next stage. It gets absorbed.
理想的に直流増幅器A1の出力V0は、第６図の
漏電発生にもとづく入力電圧Ｖの変化に対し
て、分圧抵抗R3，R4の分圧点ａのバイアス電圧
Ｖを基準にして第７図ａの如き波形で変化する
が、前記オフセツトやドリフトのために、また温
度変化やその他のバラツキで第７図ｂ，ｃのよう
にバイアス点にずれを生じる。そのため比較器
E2でレベル検知を行うことが非常に困難なもの
となる。したがつてゲイン倍された信号のみを正
確に把握するために次段にピークホールド回路
F1を設けそのピークホールド回路F1のレベル電
圧Vp（第８図）と直流増幅器A1の出力V0と比較
してその差だけを第９図の如く出力電圧V0cとし
て出す。 Ideally, the output V 0 of the DC amplifier A 1 is based on the bias voltage V at the voltage dividing point a of the voltage dividing resistors R 3 and R 4 with respect to the change in the input voltage V due to the occurrence of earth leakage in Fig. 6. However, due to the offset and drift, as well as temperature changes and other variations, the bias point shifts as shown in FIGS. 7b and 7c. Therefore the comparator
Level detection becomes very difficult with E 2 . Therefore, in order to accurately grasp only the gain multiplied signal, a peak hold circuit is installed at the next stage.
F 1 is provided, and the level voltage Vp (FIG. 8) of the peak hold circuit F 1 is compared with the output V 0 of the DC amplifier A 1 , and only the difference therebetween is outputted as the output voltage V 0 c as shown in FIG.
V0c（差動増幅器出力）＝Vp−V0
したがつて差動増幅器E1とピンクホールド回
路F1を用いるとバイアス点のずれに対して何の
影響も受けずに信号増幅分だけの出力を得ること
ができる。 V 0 c (differential amplifier output) = Vp - V 0 Therefore, if differential amplifier E 1 and pink hold circuit F 1 are used, the bias point shift will not affect the signal amplification amount. You can get the output.
上述するように本発明漏電検出装置によれば、
零相変流器ZCTの出力を直流増幅器A1でもつて
増幅することによつて従来の如き結合コンデンサ
を不要とし結合コンデンサのばらつきによつて起
るゲインの変化を無くすと共に、交流電路の周波
数の変化に基づくゲインの変化をなくし、また直
流増幅器A1にはピークホールド回路F1を次段に
接続して、各出力を差動増幅器E1でレベル判定
するために直流増幅器A1使用による誤動作を無
くすることができる等の本発明によつて高ゲイン
にして安定な特性をもつ漏電検出器が得られる。 As described above, according to the earth leakage detection device of the present invention,
By amplifying the output of the zero-phase current transformer ZCT with the DC amplifier A1 , the conventional coupling capacitor is not required, and the change in gain caused by variations in the coupling capacitor is eliminated, and the frequency of the AC line is In order to eliminate gain changes due to changes in gain, and to connect peak hold circuit F 1 to DC amplifier A 1 at the next stage, the level of each output is judged by differential amplifier E 1 . By the present invention, which can eliminate the problem, it is possible to obtain an earth leakage detector with high gain and stable characteristics.
第１図乃至第４図は従来の漏電検出器を示し、
第１図は回路図、第２図は交流増幅器の入力側電
圧を示す図、第３図はその出力側電圧を示す図、
第４図は比較器の出力電圧を示す図である。第５
図乃至第９図は本発明漏電検出器の実施例を示
し、第５図は回路図、第６図は直流増幅器の入力
電圧を示す図、第７図は直流増幅器の出力側電圧
を示す図、第８図はピークホールド回路の出力電
圧を示す図、第９図は差動増幅器の出力電圧を示
す図である。
ZCT……零相変流器、A1……直流増幅器、F1
……ピークホールド回路、E1……差動増幅器、
F2……整流平滑回路、E2……比較器、TC……ト
リツプコイル、SCR……スイツチング素子、Ｇ
……スイツチング回路、Ｄ……直流単電源回路。
Figures 1 to 4 show conventional earth leakage detectors,
Figure 1 is a circuit diagram, Figure 2 is a diagram showing the input side voltage of the AC amplifier, Figure 3 is a diagram showing its output side voltage,
FIG. 4 is a diagram showing the output voltage of the comparator. Fifth
9 to 9 show examples of the earth leakage detector of the present invention, FIG. 5 is a circuit diagram, FIG. 6 is a diagram showing the input voltage of the DC amplifier, and FIG. 7 is a diagram showing the output side voltage of the DC amplifier. , FIG. 8 is a diagram showing the output voltage of the peak hold circuit, and FIG. 9 is a diagram showing the output voltage of the differential amplifier. ZCT...Zero-phase current transformer, A 1 ...DC amplifier, F 1
……Peak hold circuit, E 1 ……Differential amplifier,
F 2 ... Rectifier and smoothing circuit, E 2 ... Comparator, TC ... Trip coil, SCR ... Switching element, G
...Switching circuit, D...DC single power supply circuit.
Claims (1)
と、その零相変流器の出力を入力信号とする直流
増幅器と、増幅出力をピークホールドするピーク
ホールド回路と、前記直流増幅器の出力とピーク
ホールド回路のレベルを比較する差動増幅器と、
その差動増幅器の出力を整流平滑する整流平滑回
路と、整流平滑回路のレベルを判定する比較器
と、しや断器のトリツプコイルとスイツチング素
子よりなる前記比較器の出力によりスイツチング
素子を導通させるスイツチング回路とを交流電路
に接続する直流単電源回路に接続してなる漏電検
出器。1. A zero-phase current transformer that detects unbalanced current in an AC line, a DC amplifier that uses the output of the zero-phase current transformer as an input signal, a peak hold circuit that holds the amplified output to a peak, and an output of the DC amplifier. and a differential amplifier that compares the levels of the peak hold circuit and
A rectifying and smoothing circuit that rectifies and smoothes the output of the differential amplifier, a comparator that determines the level of the rectifying and smoothing circuit, and a switching device that conducts a switching element by the output of the comparator, which is made up of a trip coil of a shield breaker and a switching element. An earth leakage detector that is connected to a DC single power supply circuit that connects the circuit to the AC line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2816878A JPS54120844A (en) | 1978-03-10 | 1978-03-10 | Leakage detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2816878A JPS54120844A (en) | 1978-03-10 | 1978-03-10 | Leakage detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54120844A JPS54120844A (en) | 1979-09-19 |
| JPS6111526B2 true JPS6111526B2 (en) | 1986-04-03 |
Family
ID=12241204
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2816878A Granted JPS54120844A (en) | 1978-03-10 | 1978-03-10 | Leakage detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54120844A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0266427U (en) * | 1988-11-05 | 1990-05-18 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2008280932B8 (en) | 2007-07-24 | 2011-02-24 | Panasonic Electric Works Co., Ltd. | Charging monitor |
-
1978
- 1978-03-10 JP JP2816878A patent/JPS54120844A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0266427U (en) * | 1988-11-05 | 1990-05-18 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54120844A (en) | 1979-09-19 |
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