JPH0255960A - Photoelectric current sensor - Google Patents
Photoelectric current sensorInfo
- Publication number
- JPH0255960A JPH0255960A JP20715588A JP20715588A JPH0255960A JP H0255960 A JPH0255960 A JP H0255960A JP 20715588 A JP20715588 A JP 20715588A JP 20715588 A JP20715588 A JP 20715588A JP H0255960 A JPH0255960 A JP H0255960A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- magnetic
- magneto
- optical material
- magnetic flux
- 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
- 230000005291 magnetic effect Effects 0.000 claims abstract description 34
- 239000000463 material Substances 0.000 claims abstract description 25
- 230000003287 optical effect Effects 0.000 claims abstract description 21
- 230000004907 flux Effects 0.000 claims abstract description 16
- 239000000382 optic material Substances 0.000 claims description 10
- 239000013307 optical fiber Substances 0.000 abstract description 9
- 230000035945 sensitivity Effects 0.000 abstract description 8
- 230000005389 magnetism Effects 0.000 abstract description 3
- 238000000926 separation method Methods 0.000 description 7
- 230000010287 polarization Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 238000004079 fireproofing Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
Description
この発明は、磁気光学効果を利用した光電流センサの改
良に関する。The present invention relates to improvements in photocurrent sensors that utilize magneto-optic effects.
従来より、ＢＧＯ，ＢＳＯなとの磁気光学材料を用いた
光電流センサが知られている。このような光を利用した
電流センサは、無誘導性、防火・防爆性等の基本的な利
点があるため、とくに電力等のエネルギー産業において
実用ｆヒが待たれている。
ところで、ここで用いられる磁気光学材料は磁気に対す
る感度が低いため、電流により発生する磁場を鉄心によ
って補足させて効率を高める必要がある。そこで、従来
では第４図のような構造が考えられている。電流通路１
に対して、それを取り囲むようにリング型のコア２を配
置する。このリング型コア２は閉ループを形成するもの
ではなく、一部が切断されて開ループ状にされたもので
ある。この切断された部分により形成された空隙２１の
中に磁気光学材料３が配置される。こうして、電流通路
１に流れる電流により形成される磁場をコア２に補足さ
せ、空隙２１中に形成される磁束の密度を高めて、電流
による磁場が磁気光学材料３に作用する効率を高めるの
である。
そして、偏光分離プリズム６．７を磁気光学材料３の両
端に配置して光路をそれぞれ９０”曲げるようにして、
磁束と同方向に磁気光学材料３を通った光の検出ができ
るようにしている。この例では、光ファイバ４から出射
した光は光学系５を経て偏光分離プリズム６に入射し、
ここで方向変換されて磁気光学材料３に磁束と同方向に
入射させられる。こうして、磁気光学材料３を磁束と同
方向に通った光が光学バイアス（波長板）１０を介して
出射し、この出射光が偏光分離プリズム７で方向変換さ
れて光学系８を介して光ファイバ９に入射する。Photocurrent sensors using magneto-optical materials such as BGO and BSO are conventionally known. Current sensors that utilize such light have fundamental advantages such as non-inductive properties, fireproofing, and explosion-proofing properties, and are therefore expected to be put to practical use, particularly in the energy industry such as electric power. By the way, since the magneto-optical material used here has low sensitivity to magnetism, it is necessary to increase the efficiency by supplementing the magnetic field generated by the current with an iron core. Therefore, conventionally, a structure as shown in FIG. 4 has been considered. Current path 1
A ring-shaped core 2 is arranged so as to surround it. This ring-shaped core 2 does not form a closed loop, but is partially cut to form an open loop. The magneto-optical material 3 is placed in the gap 21 formed by the cut portion. In this way, the core 2 captures the magnetic field formed by the current flowing through the current path 1, increasing the density of the magnetic flux formed in the air gap 21, and increasing the efficiency with which the magnetic field caused by the current acts on the magneto-optical material 3. . Then, the polarization separation prisms 6.7 are arranged at both ends of the magneto-optic material 3 so that the optical paths are bent by 90'', respectively.
The light passing through the magneto-optical material 3 in the same direction as the magnetic flux can be detected. In this example, the light emitted from the optical fiber 4 passes through the optical system 5 and enters the polarization separation prism 6.
Here, the direction is changed and the beam is made to enter the magneto-optical material 3 in the same direction as the magnetic flux. In this way, the light that passes through the magneto-optical material 3 in the same direction as the magnetic flux is emitted via the optical bias (wave plate) 10, and the direction of this emitted light is changed by the polarization separation prism 7 and sent to the optical fiber via the optical system 8. 9.
しかしながら、従来では、上記のようにリング型コア２
の空隙２１内に磁気光学材料３のみならず偏光分離プリ
ズム６．７をも挿入しなければならないため、空隙２１
の間隔が大きくなるという問題がある。このように空隙
２１の間隔が大きくなればなるほど、磁気効率が悪くな
る。また、磁気光学材料３として強磁性体系のものを使
用した場合、コア２の端面との間隔が大きいと、磁気光
学材料３自体の表面に発生する磁荷による反磁場が生じ
、これによって電流により発生した磁場の一部が打ち消
されるため、磁気光学材料３の感度が低下する。
この発明は、リング型コアの空隙間隔を極力小さくする
ことが可能で、その結果磁気効率を高くし、且つ感度を
高くするよう改善できる、光電流センサを提供すること
を目的とする。However, conventionally, as described above, the ring-shaped core 2
Since it is necessary to insert not only the magneto-optical material 3 but also the polarization separation prism 6.7 into the air gap 21, the air gap 21
There is a problem that the interval between the two becomes large. As described above, the larger the distance between the air gaps 21, the worse the magnetic efficiency becomes. In addition, when a ferromagnetic material is used as the magneto-optical material 3, if the distance from the end face of the core 2 is large, a demagnetizing field is generated due to the magnetic charge generated on the surface of the magneto-optic material 3 itself, which causes the current to Since a part of the generated magnetic field is canceled out, the sensitivity of the magneto-optical material 3 is reduced. SUMMARY OF THE INVENTION An object of the present invention is to provide a photocurrent sensor in which the air gap of a ring-shaped core can be made as small as possible, resulting in improved magnetic efficiency and sensitivity.
【課題を解決するための手段１
上記目的を達成するため、この発明によれば、被検出電
流通路を囲むように配置される、一部が切断されて開ル
ープとなっているリング型コアと、該リング型コアの上
記切断部分の空隙中に配置される磁気光学材料とを有す
る光電流センサにおいて、上記リング型コア内に、切断
部分の空隙中に配置される磁気光学材料を通る磁束の軸
の延長上に位置するような光通路を設けたことが特徴と
なっている。
【作 用】
リング型コア内に光通路が設けられているため、この光
通路分介することにより磁気光学材料に対して、それを
通る磁束と同方向に光を通すことができる。
そのため、従来のように光の方向を変換するためのプリ
ズム等を空隙内において磁気光学材料の両端に配置する
必要がなくなる。その結果、リング型コアに設ける切断
部分の空隙間隔は、磁気光学材料を配置するための寸法
でよくなり、最小限のものとなる。
したがって、リング型コアの空隙間隔は極限まで狭くで
き、磁気効率が向上するとともに、反磁場による感度低
下も防げるので、光電流センサ全体として感度を改善す
ることができる。[Means for Solving the Problems 1] In order to achieve the above object, according to the present invention, a ring-shaped core with a part cut off to form an open loop, which is arranged so as to surround the current path to be detected. , a magneto-optical material disposed in the gap of the cut portion of the ring-shaped core, in which a magnetic flux passing through the magneto-optic material disposed in the gap of the cut portion of the ring-shaped core is provided. It is characterized by the provision of an optical path located on an extension of the axis. [Function] Since an optical path is provided in the ring-shaped core, by dividing the optical path, light can be passed through the magneto-optic material in the same direction as the magnetic flux passing through it. Therefore, it is no longer necessary to arrange prisms or the like for converting the direction of light at both ends of the magneto-optical material within the gap as in the conventional case. As a result, the gap between the cut portions provided in the ring-shaped core can be reduced to a size sufficient for arranging the magneto-optic material, and can be minimized. Therefore, the gap between the ring-shaped cores can be made as narrow as possible, improving the magnetic efficiency and preventing a decrease in sensitivity due to the demagnetizing field, thereby improving the sensitivity of the photocurrent sensor as a whole.
つぎにこの発明の一実施例について図面を参照しながら
説明する。第１図において、電流通路１の周囲を囲むよ
うにリング型コア２が配置される。
このリング型コア２は一部が切断されて開ループ状とな
っており、切断部分によって形成された空隙２１内に磁
気光学材料３が配置される。第２図にも示すように、こ
の空隙２１に対して直角な貫通孔２２．２３がリング型
コア２に設けられている。この貫通孔２２．２３を介し
て磁気光学材料３に対する光の透過が行なわれる。すな
わち、この貫通孔２２．２３を通るように光を透過させ
れば、この光は、磁束と同方向に磁気光学材料３を通過
する。
この実施例では、貫通孔２２．２３の中心軸の延長上に
、光ファイバ４、光学系５、漏光分離プリズム６と、偏
光分離プリズム７、光学系８、光ファイバ９とが１直線
状に配置されている。
したがって、第１図に示すように、電流通路１に紙面の
表面から裏面の方向へ電流が流れてリング型コア２に矢
印方向の磁束が生じると、この磁束は空隙２１を横切る
ように生じる。この磁束は空隙２１中に置かれた磁気光
学材料３中を透過する。光ファイバ４がら出て光ファイ
バ９に入る光は貫通孔２２．２３を通るため、この光は
上記の磁束と同方向に磁気光学材料３中を通ることにな
る。そのため、空隙２１中に光の方向を変換するための
プリズム等を配置する必要なく、磁気により変化した磁
気光学材料３の光学特性を検出することができる。
なお、上記ではリング型コア２内に光通路を形成するた
め、貫通孔２２．２３を設けているが、第３図に示すよ
うな満２４のようなものでもよいことは勿論である。
このように、リング型コア２に形成する空隙２１には磁
気光学材料３のみを配置するため、空隙２１の間隔は磁
気光学材料３を配置するために必要な寸法でよくなり、
その間隔を極限まで狭くすることができる。したがって
、空隙２１の間隔が従来のものに比較して狭くなるので
磁気効率が潰れる。また、磁気光学材料３とリング型コ
ア２の端面との間の間隔はほとんどなくなり、磁気の閉
回路に近い状態とすることができるため、磁気光学材料
の表面に発生する磁荷による反磁場を低減することがで
きる。これらのため、光電流センサとしての感度を向上
させることができる。Next, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a ring-shaped core 2 is arranged to surround a current path 1. A portion of the ring-shaped core 2 is cut to form an open loop, and the magneto-optical material 3 is disposed within a gap 21 formed by the cut portion. As also shown in FIG. 2, through holes 22, 23 are provided in the ring-shaped core 2, which are perpendicular to this gap 21. Light is transmitted through the magneto-optical material 3 through the through holes 22,23. That is, if light is transmitted through the through holes 22, 23, this light will pass through the magneto-optic material 3 in the same direction as the magnetic flux. In this embodiment, the optical fiber 4, the optical system 5, the leakage separation prism 6, the polarization separation prism 7, the optical system 8, and the optical fiber 9 are arranged in a straight line on the extension of the central axis of the through hole 22, 23. It is located. Therefore, as shown in FIG. 1, when a current flows through the current path 1 from the front side to the back side of the paper and a magnetic flux is generated in the ring-shaped core 2 in the direction of the arrow, this magnetic flux is generated across the air gap 21. This magnetic flux is transmitted through the magneto-optical material 3 placed in the air gap 21. Since the light coming out of the optical fiber 4 and entering the optical fiber 9 passes through the through holes 22, 23, this light passes through the magneto-optic material 3 in the same direction as the above-mentioned magnetic flux. Therefore, it is possible to detect the optical properties of the magneto-optical material 3 that have been changed by magnetism without the need to arrange a prism or the like for changing the direction of light in the air gap 21. In the above description, the through holes 22 and 23 are provided in order to form an optical path within the ring-shaped core 2, but it goes without saying that the through holes 22 and 23 as shown in FIG. 3 may also be used. In this way, since only the magneto-optic material 3 is placed in the gap 21 formed in the ring-shaped core 2, the spacing between the gaps 21 can be set to the size necessary for arranging the magneto-optic material 3.
The interval can be made as narrow as possible. Therefore, since the spacing between the air gaps 21 is narrower than in the conventional case, the magnetic efficiency is reduced. In addition, the gap between the magneto-optical material 3 and the end face of the ring-shaped core 2 is almost eliminated, creating a state close to a magnetic closed circuit. can be reduced. For these reasons, the sensitivity as a photocurrent sensor can be improved.
この発明の光電流センサによれば、電流により発生した
磁場を補足するためのリング型コアの空隙ｒｒＲ隔を極
力小さくすることが可能である。そのため、磁気効率の
向上、及び磁気光学材料の表面に発生する磁荷による反
磁場の低減が達成でき、光電流センサの感度を改善でき
る。According to the photocurrent sensor of the present invention, it is possible to minimize the gap rrR of the ring-shaped core for capturing the magnetic field generated by the current. Therefore, it is possible to improve the magnetic efficiency and reduce the demagnetizing field due to magnetic charges generated on the surface of the magneto-optical material, thereby improving the sensitivity of the photocurrent sensor.
第１図はこの発明の一実施例の正面より見た模式図、第
２図は同実施例のリング型コアのみを側面より見た模式
図、第３図は変形例にかかるものでリング型コアのみを
側面より見た模式図、第４図は従来例の正面より見た模
式図である。
１・・・電流通路、２・・・リング型コア、２１・・・
空隙、２２．２３・・・貫通孔、２４・・・溝、３・・
・磁気光学材料、４．９・・光ファイバ、５．８・・・
光学系、６．７・・・偏光分離プリズム、１０・・・光
学バイアス（波長板）。Fig. 1 is a schematic diagram of an embodiment of the present invention seen from the front, Fig. 2 is a schematic diagram of only the ring-shaped core of the same embodiment seen from the side, and Fig. 3 is a modification of the ring-shaped core. FIG. 4 is a schematic diagram of only the core seen from the side, and FIG. 4 is a schematic diagram of the conventional example seen from the front. 1... Current path, 2... Ring-shaped core, 21...
Gap, 22.23...Through hole, 24...Groove, 3...
・Magneto-optical materials, 4.9... Optical fibers, 5.8...
Optical system, 6.7... Polarization separation prism, 10... Optical bias (wave plate).
Claims (1)
切断されて開ループとなっているリング型コアと、該リ
ング型コアの上記切断部分の空隙中に配置される磁気光
学材料とを有する光電流センサにおいて、上記リング型
コア内に、切断部分の空隙中に配置される磁気光学材料
を通る磁束の軸の延長上に位置するような光通路を設け
たことを特徴とする光電流センサ。(1) A ring-shaped core with a portion cut off to form an open loop, which is arranged to surround the current path to be detected, and a magneto-optical material arranged in the gap between the cut portions of the ring-shaped core. A photocurrent sensor having a photocurrent sensor, characterized in that an optical path is provided in the ring-shaped core so as to be located on an extension of the axis of magnetic flux passing through the magneto-optic material disposed in the gap of the cut portion. Photocurrent sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20715588A JPH0255960A (en) | 1988-08-20 | 1988-08-20 | Photoelectric current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20715588A JPH0255960A (en) | 1988-08-20 | 1988-08-20 | Photoelectric current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0255960A true JPH0255960A (en) | 1990-02-26 |
Family
ID=16535137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20715588A Pending JPH0255960A (en) | 1988-08-20 | 1988-08-20 | Photoelectric current sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0255960A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8348891B2 (en) | 2009-09-22 | 2013-01-08 | Olympus Corporation | Surgical method and medical device |
| US8747297B2 (en) | 2009-03-02 | 2014-06-10 | Olympus Corporation | Endoscopic heart surgery method |
| US8808173B2 (en) | 2009-09-22 | 2014-08-19 | Olympus Corporation | Space ensuring device |
| US8900123B2 (en) | 2009-03-02 | 2014-12-02 | Olympus Corporation | Endoscopy method and endoscope |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56140263A (en) * | 1980-04-03 | 1981-11-02 | Fuji Electric Co Ltd | Electric current measuring apparatus |
| JPS5847773B2 (en) * | 1977-09-09 | 1983-10-25 | 松下電器産業株式会社 | magnetic recording and reproducing device |
| JPS61200477A (en) * | 1985-03-01 | 1986-09-05 | Mitsubishi Electric Corp | Current measuring apparatus |
-
1988
- 1988-08-20 JP JP20715588A patent/JPH0255960A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5847773B2 (en) * | 1977-09-09 | 1983-10-25 | 松下電器産業株式会社 | magnetic recording and reproducing device |
| JPS56140263A (en) * | 1980-04-03 | 1981-11-02 | Fuji Electric Co Ltd | Electric current measuring apparatus |
| JPS61200477A (en) * | 1985-03-01 | 1986-09-05 | Mitsubishi Electric Corp | Current measuring apparatus |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8747297B2 (en) | 2009-03-02 | 2014-06-10 | Olympus Corporation | Endoscopic heart surgery method |
| US8900123B2 (en) | 2009-03-02 | 2014-12-02 | Olympus Corporation | Endoscopy method and endoscope |
| US8348891B2 (en) | 2009-09-22 | 2013-01-08 | Olympus Corporation | Surgical method and medical device |
| US8808173B2 (en) | 2009-09-22 | 2014-08-19 | Olympus Corporation | Space ensuring device |
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