JP2015184175A - current sensor and current sensor set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of improving sensitivity of a current sensor including an elongated tabular metal plate and a magnetoelectric transducer, without using a magnetism collecting core.SOLUTION: A current sensor 2 includes a magnetoelectric transducer 6, an air core coil 3, and a pair of lead sections 4, 5. The air core coil 3 is formed of an elongated tabular metal plate. A wide side of the metal plate faces the magnetoelectric transducer 6. The air core coil is curved so as to surround the magnetoelectric transducer 6 in parallel with a magnetic sensitive surface normal N of the magnetoelectric transducer. The pair of lead sections 4, 5 are formed of the elongated tabular metal plate, and each extend from side ends of the wide side of the metal plate of the air core coil 3, which are both ends of the air core coil 3.

Description

  The present invention relates to a current sensor.

  A system that performs current feedback control of a three-phase AC motor includes a current sensor that monitors a three-phase output current. When the output of the motor is large, an elongated metal bar or metal plate called a bus bar is used to transmit the three-phase AC output. Three-phase AC power is transmitted by a bus bar extending in parallel. The current sensor is provided in at least one bus bar. The current sensor is typically a magnetoelectric conversion element and detects a magnetic field caused by a current flowing through the bus bar. The magnitude of the current flowing through the bus bar can be understood from the magnitude of the detected magnetic field.

  Conventionally, a bus bar to be measured is surrounded by a C-shaped magnetic collecting core, and a magnetoelectric conversion element is arranged at a C-shaped break. In recent years, the sensitivity of the magnetoelectric conversion element has been improved, and a current sensor that measures current with only the magnetoelectric conversion element without a magnetic collecting core has appeared. Since a magnetic core is not required, it is small and low cost. However, since the magnetic collecting core is not provided, the magnetoelectric conversion element detects a magnetic field caused by the current flowing through the bus bar other than the measurement target. That is, the S / N ratio is not high.

  In view of this, a technique for improving the sensitivity of a current sensor that is not provided with a magnetism collecting core and that is constituted by an elongated flat plate-like metal plate (bus bar) through which a current to be measured flows and a magnetoelectric conversion element has been studied (Patent Documents 1-3). ). The technique of patent document 1 is as follows. Three slits are provided alternately on both sides of the wide surface of an elongated flat metal plate through which a current to be measured passes. Then, a U-shaped air core coil is formed on the metal plate between the slits at both ends. A magnetoelectric conversion element is disposed inside the air-core coil. The magnetoelectric transducer is arranged so that the normal line of the magnetosensitive surface coincides with the slit penetration direction. When a current flows, the magnetic field generated by the air-core coil penetrates the magnetoelectric transducer in the direction of the normal to the magnetic sensitive surface inside the air-core coil. Since magnetic flux concentrates inside the air-core coil, magnetic flux measurement sensitivity, that is, current detection sensitivity is improved.

  The techniques of Patent Documents 2 and 3 are as follows. A part of an elongated flat plate-like metal plate through which a current to be measured passes is bent into a U shape to form an air core coil. A magnetoelectric conversion element is disposed inside the air-core coil. The magnetoelectric conversion element is arranged so that the normal line of its magnetosensitive surface coincides with the axial direction of the air-core coil. This current sensor has the same shape as that of the current sensor disclosed in Patent Document 1 when viewed from the axial direction of the air-core coil, and the function and effect thereof are also the same.

Japanese Patent Laid-Open No. 5-223849 JP 2008-241678 A JP 2008-216230 A

  For convenience of explanation, an elongated flat plate-like metal portion other than the air-core coil in the current sensor of Patent Documents 1-3 is referred to as a lead portion. In the current sensor of Patent Document 1, three slits are provided in an elongated metal plate to form an air core coil. The thickness of the air core coil in the axial direction is the same as that of the elongated metal plate, and the magnetic field generated by the air core coil is not strong. In the current sensors of Patent Documents 2 and 3, the width direction of the wide surface of the lead portion coincides with the normal direction of the magnetosensitive surface of the magnetoelectric transducer. This means that the magnetic flux generated at the lead portion penetrates the magnetosensitive surface of the magnetoelectric conversion element. Therefore, when the current sensor is applied to a plurality of parallel bus bars, the magnetic field generated by the adjacent bus bars penetrates the magnetosensitive surface of the magnetoelectric transducer, which affects the S / N ratio.

  The present specification also provides a current sensor including an elongated flat plate-like metal plate and a magnetoelectric conversion element without including a magnetic flux collecting core. The technology disclosed in this specification aims to improve the sensitivity of a current sensor composed of such an elongated flat plate-like metal plate and a magnetoelectric conversion element.

  One aspect of the current sensor disclosed in the present specification includes a magnetoelectric conversion element, an air-core coil, and a pair of lead portions. The air-core coil is made of an elongated flat plate-like metal plate, the wide surface of the metal plate faces the magnetoelectric conversion element, and the magnetoelectric conversion element is parallel to the normal of the magnetosensitive surface of the magnetoelectric conversion element. It is curved in a U-shape so as to surround. Each of the pair of lead portions is made of an elongated flat plate-like metal plate, and extends from both ends of the air core coil and from the side ends of the wide surface of the metal plate forming the air core coil.

  In the current sensors disclosed in Patent Documents 1 and 2, the lead portion extends from the tip of the U shape forming the air-core coil, and the current sensor disclosed in this specification is wide at both ends of the U shape. It differs in that it extends from the side edge of the surface. In other words, in the current sensors disclosed in Patent Documents 1 and 2, the width direction of the wide surface of the lead portion coincides with the axial direction of the air-core coil, whereas in the current sensor disclosed in this specification, The difference is that the width direction of the wide surface of the lead portion is orthogonal to the axial direction of the air-core coil.

  Due to the above difference, in the current sensor disclosed in the present specification, the magnetic field generated by the lead portion penetrates the magnetoelectric conversion element substantially perpendicular to the normal of the magnetosensitive surface of the magnetoelectric conversion element. Difficult to affect magnetic flux measurements. Since only the magnetic flux generated by the air-core coil penetrates the magnetosensitive surface vertically, the sensitivity is increased. Therefore, the S / N ratio can be improved when the technique of this specification is applied to parallel bus bars. Note that the lead portion and the air-core coil may be made of a single metal plate, or may be joined to separate components later.

  In the current sensor disclosed in the present specification, a printed circuit board is fixed by providing a slit extending from the U-shaped bottom side of the air-core coil toward the leading end of the U-shape at a connection portion between the lead portion and the air-core coil. It is convenient for.

  In the current sensor disclosed in this specification, there are two possible relations between the extending direction of the lead portion and the normal direction of the magnetic sensitive surface (this direction coincides with the axial direction of the air-core coil). One is a form in which the respective lead portions extend in opposite directions in parallel to the normal line of the magnetic sensitive surface. The other is a form in which the respective lead portions extend in directions opposite to each other in a direction orthogonal to the normal line of the magnetosensitive surface. Any form may be sufficient.

  As described above, the current sensor disclosed in the present specification is suitable for application to a plurality of bus bars extending in parallel. In particular, two types of current sensors having different relationships between the extending direction of the lead portion and the magnetic sensitive surface normal direction may be arranged. That is, the first current sensor whose lead portion is parallel to the magnetic sensitive surface normal line and the second current sensor whose lead portion is orthogonal to the magnetic sensitive surface normal direction may be arranged in the following manner. The first current sensor and the second current line are arranged so that all the lead portions are parallel. The air core coil of the first current sensor and the air core coil of the second current sensor are arranged so as to be aligned in a direction orthogonal to the extending direction of the lead portion. And each magnetoelectric conversion element is arrange | positioned so that the magnetic sensitive surface normal line of the magnetoelectric conversion element of a 1st current sensor and the magnetic sensitive surface normal line of the magnetoelectric conversion element of a 2nd current sensor may orthogonally cross. In this current sensor set, since the magnetosensitive surface normals of the two magnetoelectric transducers are orthogonal, the magnetic flux penetrating through one of the magnetosensitive surfaces is parallel to the other magnetosensitive surface. That is, since the magnetic field affecting one of the magnetic sensitive surfaces is unlikely to affect the other magnetic sensitive surface, the influence of the two current sensors on each other is reduced. That is, it becomes possible to measure each current of two parallel bus bars with a high S / N ratio.

  The following aspect is also suitable for the current sensor disclosed in this specification. The air core coil and the lead portion are made of a single metal flat plate, and the overall shape when the air core coil is flatly developed is a crank shape. Here, the whole shape means a shape in which the above-described slit is ignored. Further, it is preferable that a slit is provided from the bottom of the U-shape of the air-core coil toward the tip, an insulating plate is inserted into the slit, and a magnetoelectric conversion element is attached to the plate. The former is suitable for manufacturing a plurality of current sensors at low cost. The latter is easy to support the magnetoelectric conversion element.

  According to the technology disclosed in this specification, it is possible to increase the sensitivity of a current sensor that does not require a magnetic core. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a perspective view of the current sensor of the first embodiment. It is the perspective view which decomposed | disassembled the current sensor of 1st Example for description. It is an expanded view of the lead part and air-core coil of the current sensor of 1st Example. It is a perspective view of the current sensor of 2nd Example. It is a perspective view of the current sensor of 3rd Example. It is a perspective view of a current sensor set (fourth embodiment). It is a figure explaining the suitable relationship between a magnetoelectric conversion element and a lead part. It is a perspective view of the current sensor of 5th Example.

  (First Embodiment) A current sensor 2 of the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of the current sensor 2, and FIG. 2 is an exploded perspective view of the current sensor 2 for convenience of explanation. The current sensor 2 includes a magnetoelectric conversion element 6, an air-core coil 3 obtained by bending an elongated flat plate-like metal plate into a U shape, and a pair of lead portions 4 and 5 extending from both ends thereof. In FIG. 2, the air-core coil 3 and the lead portions 4 and 5 are drawn separately so that they can be easily understood, but they are made of a single metal plate. That is, the lead part 4 (5) and the air-core coil 3 are continuous. Moreover, the broken line shown in FIG. 1 represents the boundary (explanatory boundary) between the lead parts 4 and 5 and the air-core coil 3. The axial direction of the air-core coil 3 is parallel to the X axis in the figure.

  The magnetoelectric conversion element 6 is disposed inside the air-core coil 3. An arrow indicated by a symbol N in the drawing indicates a normal line of the magnetosensitive surface 7 of the magnetoelectric transducer 6. That is, the magnetoelectric conversion element 6 is arranged so that the normal line N of the magnetosensitive surface 7 is parallel to the axis of the air core coil 3 inside the air core coil 3. In other words, the air-core coil 3 is made of an elongated flat plate-like metal plate, the wide surface of the metal plate faces the magnetoelectric conversion element 6, and the magnetosensitive surface 7 of the magnetoelectric conversion element 6 It is curved in a U shape so as to surround the magnetoelectric conversion element 6 in parallel to the normal line N.

  As well shown in FIG. 2, the pair of lead portions 4 and 5 are made of an elongated flat plate-like metal plate, and are the both ends of the air core coil 3 and the wide surface of the metal plate of the air core coil. Respectively extending from the side ends (locations indicated by reference numerals 3a and 3b in the figure).

  The lead parts 4 and 5 and the air-core coil 3 are conductors that pass the current to be measured. The current to be measured flows through one lead portion 4 toward the air-core coil 3 as indicated by the arrow A1, and in the air-core coil 3, as indicated by the arrow A2, from one end of the U-shape toward the other end. The lead portion 5 moves away from the air-core coil 3 as indicated by an arrow A3.

  As shown by the arrow A2 in FIG. 1, the current flowing through the U-shaped air-core coil 3 flows so as to surround the normal line N of the magnetosensitive surface 7 of the magnetoelectric transducer 6. The magnetic flux generated by the current flowing through the air-core coil 3 is concentrated at the position of the magnetoelectric transducer 6 and penetrates the magnetosensitive surface 7 vertically. With this structure, the magnetoelectric conversion element 6 can measure the magnetic flux with high sensitivity. That is, the current sensor 2 has high sensitivity.

  Further, the magnetic flux generated by the current flowing through the lead portions 4 and 5 is generated so as to surround the arrows A1 and A3 in FIG. The lead portions 4 and 5 are positioned so that the width direction of the wide surface (Z-axis direction in the figure) is perpendicular to the normal line N of the magnetic sensitive surface 7, and the magnetic flux generated by the lead portions 4 and 5 is , And parallel to the magnetosensitive surface 7 of the magnetoelectric transducer 6. Therefore, the magnetic flux generated by the lead portions 4 and 5 does not affect the measurement of the magnetic flux of the magnetoelectric transducer 6. This means that when a plurality of current sensors 2 are arranged in parallel, the magnetic flux generated by the lead portion of one current sensor does not affect the magnetoelectric conversion element of the other current sensor. This advantage is suitable for applying the current sensor of this embodiment to three parallel bus bars that supply three-phase AC motor power.

  FIG. 3 is a diagram in which the lead portions 4 and 5 and the air-core coil 3 which are integrally formed are developed on a plane. A broken line indicates a boundary for explanation of a portion where the air-core coil 3 is formed and the lead portion. It is often shown that the air-core coil 3 is made of an elongated flat plate-like metal plate. As shown in FIG. 3, when the lead portions 4 and 5 and the air-core coil 3 are deployed, the overall shape is a crank shape. This shape is convenient for manufacturing a plurality of current sensors (excluding magnetoelectric transducers) from one wide metal plate.

  (Second Embodiment) FIG. 4 is a perspective view of a current sensor 12 according to a second embodiment. The current sensor 12 is also composed of a magnetoelectric conversion element 6, an air core coil 13, and a pair of lead portions 14 and 15. The air core coil 13 is equivalent to the air core coil 3 of the first embodiment. That is, the air-core coil 13 is made of an elongated flat plate-like metal plate, the wide surface of the metal plate faces the magnetoelectric conversion element 6, and is parallel to the normal line N of the magnetosensitive surface of the magnetoelectric conversion element 6. Are bent in a U shape so as to surround the magnetoelectric conversion element 6. However, since the air-core coil 13 has a slit 8 which will be described later, the height of the U-shape (the length from the bottom to the tip of the U-shape and the length in the Z-axis direction in the figure) is that of the first embodiment. It is lower than the height of the air-core coil 3.

  The pair of lead portions 14 and 15 are the same as those in the first embodiment. The pair of lead portions 14 and 15 are made of an elongated flat plate-like metal plate, and extend from both ends of the air core coil 13 and from the side ends of the wide surface of the metal plate of the air core coil 13.

  In the current sensor 12 of the second embodiment, the U-shaped bottom side of the air-core coil 13 (the positive direction of the Z-axis in the figure) is connected to the connecting portion between the lead portion 14 (15) and the air-core coil 13. A slit 8 extending in the direction of the tip of the character (the negative direction of the Z axis) is provided. The current flowing through the one lead portion 14 by the slit 8 is concentrated at one end of the U-shape of the air-core coil 13 as indicated by an arrow A4, and flows while being curved along the U-shape. (Arrow A2). Then, as indicated by an arrow A <b> 5, after flowing to the other end of the U-shaped air core coil, it flows to the lead portion 15. In the current sensor 12 of the second embodiment, by providing the slit 8, current flows in a U shape from end to end of the U-shaped air-core coil 3, so that the magnetic flux penetrating the magnetosensitive surface 7 can be increased. . Accordingly, for example, in order to obtain the same sensitivity as that of the current sensor 2 of the first embodiment, the height of the U-shape can be made lower than that of the first embodiment. That is, the size of the current sensor can be reduced.

  (Third Embodiment) FIG. 5 shows a perspective view of a current sensor 22 according to a third embodiment. The current sensor 22 is also composed of the magnetoelectric transducer 6, the air-core coil 23, and a pair of lead portions 24 and 25. The air core coil 23 is equivalent to the air core coil 3 of the first embodiment. That is, the air-core coil 23 is made of an elongated flat plate-like metal plate, the wide surface of the metal plate faces the magnetoelectric conversion element 6, and is parallel to the normal line N of the magnetosensitive surface of the magnetoelectric conversion element 6. Are bent in a U shape so as to surround the magnetoelectric conversion element 6.

  The pair of lead portions 24 and 25 are the same as those in the first embodiment. The pair of lead portions 24 and 25 are made of an elongated flat plate-like metal plate, and extend from both ends of the air core coil 23 and from the side ends of the wide surface of the metal plate of the air core coil 23. Similarly to the current sensor 12 of the second embodiment, the U-shaped bottom side of the air-core coil 23 (the Z-axis positive in the figure) is connected to the connecting portion between the lead portion 24 (25) and the air-core coil 23. A slit 8 extending from the direction) to the leading end of the U-shape (the negative direction of the Z axis) is provided. Therefore, the height of the U-shape (the length from the bottom to the tip of the U-shape) is lower than the height of the air-core coil 3 of the first embodiment.

  The current sensor 12 of the second embodiment and the current sensor 22 of the third embodiment are different in the relationship between the direction of the air-core coil (that is, the direction of the magnetoelectric transducer) and the extending direction of the lead portion. In the current sensor 12 of the second embodiment, the respective lead portions 14 and 15 extend in opposite directions in parallel to the magnetic sensitive surface normal line N. On the other hand, in the current sensor 22 of the third embodiment, the lead portions 24 and 25 extend in directions opposite to each other in a direction orthogonal to the magnetic sensitive surface normal line N. The current sensor of the third embodiment has the same advantages as the current sensor of the second embodiment. The current sensor 12 of the second embodiment and the current sensor 22 of the third embodiment are sensitive to the width direction (Z-axis direction in the drawing) of the wide surface of the lead portion made of an elongated flat plate-like metal plate. This is common in that it is perpendicular to the magnetic surface normal N.

  (Fourth Embodiment) FIG. 6 is a perspective view of a current sensor set 32 in which two current sensors are arranged in parallel. This current sensor set 32 is a combination of the current sensor 12 of the second embodiment and the current sensor 22 of the third embodiment. 6 is a perspective view similar to FIGS. 4 and 5, but it should be noted that the viewpoint for the U-shaped air-core coil is different. That is, the air-core coil of FIGS. 4 and 5 is drawn with a U-shaped downward, while the air-core coil of FIG. 6 is drawn with a U-shaped upward.

  In the current sensor set 32, for convenience of explanation, the current sensor 12 of the second embodiment is referred to as a first current sensor 12, and the current sensor of the third embodiment is referred to as a second current sensor 22. As well shown in FIG. 6, in the current sensor set 32, the first current sensor 12 and the second current sensor 22 are arranged so that all the lead portions 14, 15, 24, 25 are parallel to each other. The air core coil 13 of the first current sensor 12 and the air core coil 23 of the second current sensor 22 are arranged in a direction orthogonal to the extending direction of the lead portion. In other words, the air-core coils 13 and 23 are arranged in the YZ plane in the drawing. Further, the magnetosensitive surface normal line N1 of the magnetoelectric transducer 6 of the first current sensor 12 and the magnetosensitive surface normal line N2 of the magnetoelectric transducer 6 of the second current sensor 22 are orthogonal to each other.

  In the arrangement of the current sensor set 32, the magnetic flux passing through the magnetosensitive surface of the magnetoelectric transducer 6 of the first current sensor 12 is parallel to the magnetosensitive surface of the magnetoelectric transducer 6 of the second current sensor 22. Similarly, the magnetic flux passing through the magnetosensitive surface of the magnetoelectric transducer 6 of the second current sensor 22 is parallel to the magnetosensitive surface of the magnetoelectric transducer 6 of the first current sensor 12. Further, the magnetic flux generated due to the current (arrows A6 and A7) flowing through any lead portion is also parallel to the magnetic sensitive surface of each magnetoelectric transducer. Therefore, in each current sensor 12, 22, each magnetoelectric conversion element 6 measures only the magnetic flux generated by each air-core coil. Therefore, a high S / N ratio can be maintained even if two current sensors are arranged close to each other.

  Next, with reference to FIG. 7, a preferable relationship between the magnetoelectric transducer 6 of one current sensor and the lead portion of the other current sensor will be described. Here, the relationship between the magnetoelectric transducer 6 of the second current sensor 22 and the lead part 14 (15) of the first current sensor 12 will be described. FIG. 7 is a plan view for explaining the relationship between the magnetoelectric conversion element 6 of the second current sensor 22 and the lead portion 14 (15) of the first current sensor 12. The air core coil 23 and the lead parts 24 and 25 of the second current sensor 22 are not shown.

  FIG. 7 is a view of the current sensor set 32 of FIG. 6 as viewed in the YZ plane. However, in FIG. 7, the position in the X-axis direction where the magnetoelectric conversion element 6 of the second current sensor 22 is located is different from the position in the X-axis direction of the cross section of the lead portion 14 (15) shown in FIG. 7. Please note that.

  The magnetoelectric conversion element 6 is a straight line perpendicular to the wide surface of the lead portion 14 (15) of the adjacent current sensor, and is disposed on an extension of the straight line CL passing through the center in the width direction (Z-axis direction in the drawing). It is good to do. According to such an arrangement, as shown in FIG. 7, the magnetic flux P1 caused by the current flowing through the lead portion 14 (15) is parallel to the magnetic sensitive surface 7 of the magnetoelectric transducer 6 (arrow P2 in the figure). ). That is, the magnetic flux P <b> 1 generated in the lead portion 14 (15) does not penetrate the magnetosensitive surface 7. Therefore, the magnetoelectric conversion element 6 of the second current sensor 22 is not affected by the magnetic field generated by the lead portion 14 (15) of the adjacent first current sensor 12. Suppose that the magnetoelectric transducer 6 is located at the point Q and deviates from the straight line CL. In this case, the magnetic flux at the point Q where the lead portion 14 (15) is generated is in the direction of the arrow P3, and a component penetrating the magnetoelectric transducer 6 is generated. The component becomes noise in the magnetoelectric conversion element 6 of the second current sensor 22. Thus, it is desirable to arrange the magnetoelectric conversion element 6 of the current sensor 22 at a position passing through the center line CL of the wide surface of the lead portion of the adjacent current sensor. This is the same even when other metal wires (for example, other bus bars) pass in the vicinity of the magnetoelectric transducer 6.

  (Fifth Embodiment) FIG. 8 is a perspective view of a current sensor 42 according to a fifth embodiment. The current sensor 42 also includes an air-core coil 43, a magnetoelectric conversion element 6, and a pair of lead portions 4 and 5, as in the case of conventional current sensors. In FIG. 8, a plate 49 (described later) removed from the air core coil 43 is drawn with a solid line, and the plate 49 inserted into the slit 48 of the air core coil 43 is drawn with a virtual line. The magnetoelectric conversion element 6 is located inside the U-shaped air-core coil 43 in the state of being assembled to the air-core coil 43, as in the current sensor 2 of FIG.

  The air core coil 43 is made of an elongated flat plate-like metal plate. The air-core coil 43 has the wide surface of the metal plate facing the magnetoelectric conversion element 6 (the magnetoelectric conversion element 6 indicated by the phantom line in FIG. 8), and the normal line of the magnetosensitive surface of the magnetoelectric conversion element 6. It is curved in a U shape so as to surround the magnetoelectric transducer parallel to N. Similar to the current sensor 2 of the first embodiment, the lead portions 4 and 5 are made of an elongated flat plate-like metal plate, and are wide ends of the metal plate of the air-core coil 43 at both ends of the air-core coil 43. It extends from the side edge of each. The air-core coil 43 is provided with a slit 48 extending from the bottom of the U shape toward the tip. An insulating plate 49 is inserted into the slit 48, and the magnetoelectric transducer 6 is attached to the plate 49. The plate 49 may be a sensor substrate on which a chip that applies a voltage to the magnetoelectric conversion element 6 and receives an electric signal of the magnetoelectric conversion element 6 is mounted. The insulating plate 49 is suitable for supporting the magnetoelectric transducer 6.

  Points to be noted regarding the technology described in the embodiments will be described. The air-core coil is curved in a U shape, but may be substantially C-shaped. The lead portions extend from both ends of the air-core coil and from the side ends of the wide surface of the metal plate of the air-core coil. In other words, the lead portion is connected to both ends of the air-core coil and side ends in the coil axial direction.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2, 42: Current sensor 12: Current sensor (first current sensor)
22: Current sensor (second current sensor)
32: Current sensor set 3, 13, 23, 43: Air-core coil 4, 5, 14, 15, 24, 25: Lead part 6: Magnetoelectric conversion element 7: Magnetosensitive surface 8, 48: Slit 49: Plate

Claims (7)

A magnetoelectric conversion element;
It is made of an elongated flat plate-like metal plate, and the wide surface of the metal plate faces the magnetoelectric conversion element and surrounds the magnetoelectric conversion element in parallel to the normal line of the magnetosensitive surface of the magnetoelectric conversion element. An air-core coil curved in a U-shape,
A pair of lead portions each made of an elongated flat plate-like metal plate and extending from both ends of the air core coil and from the side ends of the wide surface of the metal plate of the air core coil;
A current sensor comprising:   2. The current according to claim 1, wherein a slit extending from a U-shaped bottom side of the air-core coil toward a leading end of the U-shape is provided at a connection portion between the lead portion and the air-core coil. Sensor.   3. The current sensor according to claim 1, wherein each lead portion extends in a direction opposite to each other in parallel with the normal line.   3. The current sensor according to claim 1, wherein the respective lead portions extend in directions opposite to each other in a direction orthogonal to the normal line. A first current sensor according to claim 3 and a second current sensor according to claim 4;
The first current sensor and the second current sensor are arranged so that all the lead portions are parallel,
The air core coil of the first current sensor and the air core coil of the second current sensor are arranged in a direction orthogonal to the extending direction of the lead portion, and the normal line of the magnetosensitive surface of the magnetoelectric transducer of the first current sensor The current sensor set is characterized in that the normal lines of the magnetosensitive surfaces of the magnetoelectric transducers of the second current sensor are orthogonal.   5. The air core coil and the lead portion are made of a single metal flat plate, and the entire shape when the air core coil is flattened is a crank shape. The current sensor according to item 1.   A slit is provided from the bottom of the U-shape of the air-core coil toward the tip, an insulating plate is inserted into the slit, and a magnetoelectric conversion element is attached to the plate. Item 5. The current sensor according to any one of Items 1 to 4.

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