Current sensor

Abstract

To provide a current sensor for detecting a magnetic flux generated from a current to be detected, in which a conductor to which the current to be detected is applied is formed into a coil shape, to significantly increase a magnetic flux density detected by a magnetoelectric conversion element, thereby making it possible to reduce an amplification factor of an output signal.SOLUTION: End faces of a U-shaped magnetic core 1A having a gap 2A and a U-shaped magnetic core 1B having a gap 2B are arranged facing each other to form a core gap 5 between the end faces. Coil parts 6A, 6B formed by a conductor 3 to which a current A1 to be detected is applied are arranged so as to penetrate the gaps 2A, 2B at least once. A magnetic sensor 4 having a substrate on which a pair of magnetoelectric conversion elements are mounted, is arranged such that the pair of magnetoelectric conversion elements are within a width dimension of the core gap in an X direction, a thickness dimension of the magnetic cores 1A, 1B in a Y direction, and a width dimension of the magnetic cores 1A, 1B in a Z direction, and face each other and are spaced apart across a virtual center line between the end faces of the magnetic cores 1A, 1B in the Z direction.SELECTED DRAWING: Figure 1-1

Description

[Technical field]

[0001] The present invention relates to a current sensor using a magnetoelectric conversion element. [Background technology]

[0002] In current sensors used in conventional inverters, etc., a coil-type current sensor is known in which a conductor to which a current to be detected is applied is formed into a coil shape, and the magnetic flux generated from the current to be detected flowing through the coil-shaped portion is detected using a magnetoelectric conversion element such as a Hall element, thereby accurately detecting the current to be detected.

[0003] For example, Patent Document 1 shows a coil-type current sensor in which two coils are formed using a conductor to which the current to be detected is applied, and a Hall element is placed between the two coils, so that the detection sensitivity is not significantly affected even if there is variation in the mounting position accuracy of the Hall element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-221342 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the coil-type current sensor shown in Patent Document 1, the magnetoelectric conversion element directly detects the magnetic flux generated by the application of the current to be detected from the conductor, and therefore the amount of magnetic flux density that the magnetoelectric conversion element can detect is very small, and the output signal output in accordance with the amount of magnetic flux density detected by the magnetoelectric conversion element also becomes small, making it necessary to increase the amplification factor of the output signal.

[0006] In particular, when the current to be detected is a low current value, the magnetic flux density becomes even smaller, so the amplification factor is set very high. However, when the amplification factor of the output signal is set high, even slight changes in the magnetic flux density are significantly affected, so when a slight magnetic flux density is detected in an external magnetic field environment of the current sensor, the impact becomes large.

[0007] In consideration of the above problems, the present invention proposes a current sensor structure that can increase the magnetic flux density detected by a magnetoelectric conversion element and reduce the amplification factor of the output signal output in accordance with the amount of magnetic flux density detected by the magnetoelectric conversion element. [Means for solving the problem]

[0008] The current sensor of the present invention is a current sensor comprising a conductor to which a current to be detected is applied, first and second magnetic cores each having a substantially U-shape with two end faces, and a magnetic sensor having a substrate on which a pair of magnetoelectric conversion elements are mounted, the magnetoelectric conversion elements detecting the magnetic flux density in a predetermined magnetic sensing axis direction of the magnetic flux generated from the current to be detected and outputting an output signal according to the magnetic flux density, the first magnetic core having a first gap formed by the substantially U-shape and a first center line which is an imaginary center line of the dimension between the two end faces, and the second magnetic core having a second gap formed by the substantially U-shape and a second center line which is an imaginary center line of the dimension between the two end faces. the first and second magnetic cores are arranged with two end faces facing each other, and a core gap is formed between the two facing end faces; the pair of magnetoelectric conversion elements are mounted at a distance from each other on the substrate and their relative positions are fixed; the magnetic sensor is arranged so that the pair of magnetoelectric conversion elements face each other across the first center line and face each other across the second center line; the conductors pass through each of the first and second gaps at least once, and are arranged so that the directions of current application in the conductor portions passing through the first and second gaps are all the same. Effect of the Invention

[0009] According to the present invention, a current sensor is provided that can increase the magnetic flux density detected by a magnetoelectric conversion element and reduce the amplification factor of an output signal output in accordance with the amount of magnetic flux density detected by the magnetoelectric conversion element. [Brief description of the drawings]

[0010] [Figure 1] 1(a) is a schematic diagram of a current sensor according to a first embodiment of the present invention, FIG. 1(b) is a plan view of the current sensor, FIG. 1(c) is a front view of the current sensor, and FIG. 1(d) is a cross-sectional view. [Diagram 2] 2(a), (b), and (c) are plan views showing an example of a configuration in which the conductor of the current sensor shown in FIG. 1 is changed, and FIG. 2(d) is a perspective view showing an example of a configuration in which the conductor of the current sensor shown in FIG. 1 is changed. [Diagram 3] 2 is a plan view showing a configuration example in which the magnetic core of the current sensor shown in FIG. 1 is changed. [Figure 4] 2 is a schematic diagram showing a magnetic flux path when a current to be detected is applied to the current sensor according to the first embodiment of the present invention. FIG. [Diagram 5] 4A to 4C are diagrams illustrating examples of changes in the arrangement of conductors and magnetoelectric conversion elements of the current sensor according to the first embodiment of the present invention. [Figure 6] 6 is a table showing the amount of magnetic flux density detected by a magnetoelectric conversion element and its differential calculation value when a current to be detected is applied in the configuration examples (a), (b), (c), and (d) shown in FIG. [Figure 7] 7A to 7D are schematic diagrams of a current sensor according to a second embodiment of the present invention, where FIG. 7A is an oblique view of the current sensor, FIG. 7B is a plan view of the current sensor, FIG. 7C is a front view of the current sensor, and FIG. 7D is a cross-sectional view. [Figure 8] 8A and 8B are diagrams showing an example of a configuration in which the conductor of the current sensor shown in FIG. 1 is changed, FIG. 8A being a perspective view of the current sensor, and FIG. 8B being a plan view of the current sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

[0011] Fig. 1 is a schematic diagram of a current sensor 100 according to a first embodiment of the present invention, in which Fig. 1(a) is a perspective view of the current sensor 100 according to the first embodiment, Fig. 1(b) is a plan view of the current sensor 100 according to the first embodiment, Fig. 1(c) is a front view of the current sensor 100 according to the first embodiment, and Fig. 1(d) is a cross-sectional view of section BB in Fig. 1(c). Furthermore, unless otherwise specified in the present invention, the width direction of the core gap is the X direction, the core thickness direction is the Y direction, the direction perpendicular to the X and Y directions is the Z direction, and the direction of the illustrated arrow is the + (positive) direction, and each direction is defined similarly in the first embodiment.

[0012] 1, current sensor 100 according to the first embodiment of the present invention includes arm 1A1 having end surface 1a1 at its extending tip, arm 1A2 having end surface 1a2 at its extending tip, thickness dimension T1 in the Y direction, width dimension W1 in the Z direction, dimension W2 which is the distance dimension between the end surfaces in the Z direction, center line CL1 which is the imaginary center line of dimension W2, magnetic core 1A having gap 2A in a hollow portion formed in the center by arms 1A1 and 1A2 forming a U-shape, arm 1B1 which has the same shape as magnetic core 1A and has end surface 1b1 at its extending tip, and end The magnetic core 1B has an arm 1B2 having a surface 1b2, a center line CL2 which is an imaginary center line of the distance dimension between the end faces in the Z direction (a dimension corresponding to the dimension W2 of the magnetic core 1A), a U-shape formed by the arms 1B1 and 1B2 and having a gap 2B in a hollow portion formed in the center thereof, a conductor 3 to which a current to be detected A1 is applied from a current application surface 31 and which has a circular cross-sectional shape, a substrate 4B on which magnetoelectric conversion elements M1 and M2 which are detection elements for detecting magnetic flux are mounted, and a current sensor which detects an output signal outputted in accordance with the amount of magnetic flux density detected by the magnetoelectric conversion elements M1 and M2. The magnetic sensor 4 has a lead 4L which is a terminal for outputting to the outside of the sensor 100, the magnetic cores 1A and 1B are arranged in such a manner that the end faces 1a1 and 1b1 face each other, and the end faces 1a2 and 1b2 face each other, and a core gap 5 having a width dimension W3 in the X direction is formed between the respective facing end faces, the conductor 3 forms a coil portion 6A surrounding the periphery of the arm portion 1A1 so as to penetrate the gap 2A three times from the Y+ direction to the Y- direction, and the coil portion 6A surrounds the periphery of the arm portion 1B2 so as to penetrate the gap 2B three times from the Y+ direction to the Y- direction after passing through the connection portion 7. The magnetic sensor 4 is arranged so as to surround the core gap 5 to form a coil portion 6B, and the magnetoelectric conversion elements M1, M2 are in a range overlapping the range of dimension W3 in the X direction which is the width dimension in the X direction of the core gap 5, the range of dimension T1 in the Y direction which is the thickness dimension of the magnetic cores 1A, 1B, and the range of dimension W1 in the Z direction which is the width dimension of the magnetic cores 1A, 1B, and are arranged so as to face each other and be spaced apart across a center line CL1 in the Z direction, and also face each other and be spaced apart across a center line CL2 in the Z direction, with their magnetic sensing axes being in the X direction, and the current to be detected A1 applied from the current application surface 31 of the conductor 3 isSince conductor 3 is a conductive conductor made of a single material, current flows in the order of coil portion 6A, connection portion 7, and coil portion 6B, and current (not shown) flowing through conductor portions 3a, 3b, and 3c, which are conductor portions that penetrate gap 2A, flows in the Y-direction, while current (not shown) flowing through conductor portions 3d, 3e, and 3f, which are conductor portions that penetrate gap 2B, flows in the Y-direction, so that the currents flowing through conductive portions 3a, 3b, 3c, 3d, 3e, and 3f that penetrate gaps 2A and 2B are all configured to flow in the same direction.

[0013] In addition, the current sensor 100 relating to embodiment 1 of the present invention has a resin housing (not shown) and a printed circuit board (not shown) on which a connector (not shown) is mounted, the printed circuit board, magnetic cores 1A and 1B, and conductor 3 are fixed to the resin housing, and the magnetic sensor 4 is connected to the printed circuit board via a lead 4L.

[0014] The magnetic sensor 4 is a magnetic detection device such as an IC in which a portion of a lead 4L (not shown) and a substrate 4B on which magnetoelectric conversion elements M1 and M2 are mounted are sealed inside with thermosetting resin, and the lead 4L and the substrate 4B are connected inside the magnetic sensor 4 by a die bond (not shown) or the like.

[0015] The substrate 4B is a rectangular semiconductor chip, and the magnetoelectric conversion elements M1 and M2 are mounted on the substrate 4B at a distance from each other, and the relative positions of the magnetoelectric conversion elements M1 and M2 are fixed. In the current sensor 100 according to the first embodiment of the present invention, the substrate 4B has a plane parallel to the YZ plane, and the magnetoelectric conversion elements M1 and M2 are mounted on the plane at a distance from each other in the Z direction.

[0016] The substrate 4B also has a detection means (not shown) that amplifies the output signals output by the magnetoelectric conversion elements M1 and M2 in accordance with the amount of magnetic flux density detected, performs a differential calculation on the two amplified output signals, and has a differential calculation unit (not shown) that outputs the differential calculation value, and the differential calculation value is output to the outside of the current sensor 100 via the lead 4L of the magnetic sensor 4, the printed circuit board, and the connector.

[0017] The magnetic cores 1A, 1B are laminated cores, wound cores, or cast cores made of one or more magnetic materials such as silicon steel plate, ferrite, or permalloy, and in the current sensor 100 relating to the first embodiment of the present invention, they are made of a single magnetic material and have the same shape (U-shaped cross-sectional area shape) and are arranged with end face 1a1 facing end face 1b1 and end face 1a2 facing end face 1b2.

[0018] Conductor 3 has a circular cross-sectional shape and is a conductive conductor constructed by combining a single or multiple conductors made of non-magnetic materials such as copper or aluminum, and coil portions 6A and 6B are arranged surrounding arm portions 1A1 and 1B2 at a constant pitch, respectively.

[0019] The magnetoelectric conversion elements M1 and M2 are Hall effect elements, magnetoresistance effect elements, etc., and any type of detection element can be used as long as it is capable of detecting magnetic flux and outputting an output. In the current sensor 100 according to the first embodiment of the present invention, the magnetic sensor 4 having two magnetoelectric conversion elements (magnetoelectric conversion elements M1 and M2) is used, which has an effect of reducing the number of parts compared to using two magnetic sensors each having one magnetoelectric conversion element, and thus has a cost advantage.

[0020] Figures 2 and 3 show conductors and magnetic cores of different shapes, and Figures 2(a), (b), and (c) show an example configuration in which the conductor 3 of the current sensor 100 shown in Figure 1 is changed in a diagram corresponding to Figure 1(b). Figure 2(d) shows an example configuration in which the conductor 3 of the current sensor 100 shown in Figure 1 is changed in a diagram corresponding to Figure 1(a). Figures 3(a) and (b) show an example configuration in which the magnetic cores 1A and 1B of the current sensor 100 shown in Figure 1 are changed in a diagram corresponding to Figure 1(b).

[0021] In the current sensor 100 relating to the first embodiment of the present invention, the conductor 3 to which the detected current is applied has three conductor portions, 3a, 3b, and 3c, that penetrate gap 2A of magnetic core 1A, and three conductor portions, 3d, 3e, and 3f, that penetrate gap 2B of magnetic core 1B, and the number of conductor portions that penetrate gaps 2A and 2B is equal; however, this is not necessarily the case as long as the direction of the current flowing through the conductor portions that penetrate gaps 2A and 2B is all the same. As shown in FIG. 2(a), the coil portion 6C of conductor 3A may be configured to penetrate gap 2A three times, and then, after passing through connection portion 7A, the coil portion 6D may be configured to penetrate gap 2B twice. The number of conductor portions that penetrate gaps 2A and 2B does not have to be the same as long as it is at least once, and the number of times they penetrate is not important.

[0022] The more times the conductor passes through the gaps 2A, 2B, the greater the amount of magnetic flux density detected by the detection element when the current to be detected is applied. Therefore, for example, by insulating the surface of the conductor to which the current to be detected is applied and arranging the conductors so that they are in contact with each other, thereby increasing the number of times they pass through as much as possible, the amount of magnetic flux density detected by the magneto-electric conversion element can be increased, and the output signal output by the magneto-electric conversion element can be increased, making it possible to reduce the amplification factor of the output signal.

[0023] In the current sensor 100 according to the first embodiment of the present invention, the conductor 3 to which the current to be detected is applied is configured such that when the conductor portions 3a, 3b, and 3c pass through the gap 2A of the magnetic core 1A, the coil portion 6A surrounds the periphery of the arm portion 1A1, and when the conductor portions 3d, 3e, and 3f pass through the gap 2B of the magnetic core 1B, the coil portion 6B surrounds the periphery of the arm portion 1B2. However, this is not necessarily the case as long as the current flowing in the conductor portions passing through the gaps 2A and 2B is in the same direction. As shown in FIG. 2(b), the coil portion 6E of the conductor 3B is disposed so as to surround the periphery of the arm portion 1A1. Alternatively, as shown in FIG. 2(c), coil portion 6G of conductor 3C may be arranged so as to surround arm portion 1A1, and after passing through connection portion 7C, coil portion 6H may be arranged so as to surround arm portion 1B1, and after passing through connection portion 7D, coil portion 6J may be arranged so as to surround arm portion 1B2, and after passing through connection portion 7E, coil portion 6K may be arranged so as to surround arm portion 1A2; the number of points surrounding each arm is not important.

[0024] In the current sensor 100 according to the first embodiment of the present invention, the conductor 3 to which the current to be detected is applied has a circular cross-sectional shape, and when the conductor portions 3a, 3b, and 3c pass through the gap 2A of the magnetic core 1A, the coil portion 6A surrounds the arm portion 1A1, and when the conductor portions 3d, 3e, and 3f pass through the gap 2B of the magnetic core 1B, the coil portion 6B surrounds the arm portion 1B2. However, this is not necessarily the case as long as the current flowing in the conductor portions passing through the gaps 2A and 2B is in the same direction. As shown in FIG. 2(d), if the conductor passes through the gaps 2A and 2B at least once, the cross-sectional shape may be rectangular like the conductor 3D.

[0025] In the current sensor 100 according to the first embodiment of the present invention, two magnetic cores having the same U-shaped cross section made of a single magnetic material are arranged facing each other, but this is not limited thereto. As shown in FIG. 3(a), a U-shaped magnetic core made of multiple magnetic materials may be used, such as magnetic material 1C and magnetic material 1D forming magnetic material 1Aa. As shown in FIG. 3(b), magnetic material core 1A and magnetic material core 1B may not be the same shape, and for example, magnetic material core 1B may be magnetic material core 1Ba long in the X direction. In addition, the shape of the magnetic material core may have a convex portion, a concave portion, or the like as long as it is approximately U-shaped, as long as the current flowing in the conductor portion penetrating gaps 2A and 2B of conductor 3 is in the same direction.

[0026] The configurations of the conductor and magnetic core shown in FIGS. 2 and 3 are examples of shapes in the current sensor 100 according to the first embodiment of the present invention, and do not limit the configuration of the present invention.

[0027] In the current sensor 100 according to the first embodiment of the present invention configured as described above, a description will be given of the magnetic flux generated by the current when the detection current A1 is applied to the conductor 3 from the current application surface 31. Fig. 4 is a schematic diagram showing the magnetic flux path when the detection current A1 is applied to the conductor 3 from the current application surface 31 in the current sensor 100, in a diagram equivalent to the cross-sectional view of Fig. 1(d) B-B, and shows the magnetic flux path passing through the magnetic cores 1A and 1B and the core gap 5 when the detection current A1 is applied.

[0028] In the current sensor 100, when a current to be detected A1 is applied to the conductor 3 from the current application surface 31, the conductor 3 is a conductive conductor formed of a single material, so that the current flows through the coil portion 6A, the connection portion 7, and the coil portion 6B in that order. At this time, the current (not shown) flowing through the conductor portions 3a, 3b, and 3c that are conductor portions penetrating the gap 2A flows in the Y-direction, and the current (not shown) flowing through the conductor portions 3e, 3f, and 3g that are conductor portions penetrating the gap 2B flows in the Y-direction. Therefore, the current application directions flowing through the conductive portions 3a, 3b, 3c, 3d, 3e, and 3f that penetrating the gaps 2A and 2B are all the same direction, and the magnetic flux generated from the current flowing through the conductive portions 3a, 3b, 3c, 3d, 3e, and 3f is collected in the magnetic cores 1A and 1B, and most of the collected magnetic flux passes through the magnetic cores 1A and 1B in the direction of the arrows shown in the figure, as in the magnetic flux path 8. At that time, the magnetic flux path of the core gap 5 forms a magnetic flux path such as magnetic flux 8A.

[0029] The magnetoelectric conversion elements M1, M2 mainly detect the magnetic flux 8A, and the output signals output from the magnetoelectric conversion elements M1, M2 according to the detected magnetic flux density are amplified, subjected to differential calculation in a differential calculation unit (not shown) possessed by the substrate 4B, and then output to the outside via a connector (not shown).

[0030] The magnetic flux 8A detected by magnetoelectric conversion elements M1, M2 has a very large magnetic flux density because magnetic cores 1A, 1B collect most of the magnetic flux generated from the detected current A1 flowing through the conductor 3. Compared to a configuration that directly detects magnetic flux generated from a conductor, such as the coil-type current sensor shown in the prior art, magnetoelectric conversion elements M1, M2 are able to detect a very large magnetic flux density.

[0031] Furthermore, in FIG. 4, magnetic flux 8A on the upper side is in the X+ direction, while magnetic flux 8A on the lower side is in the opposite X- direction; the magnetic sensitivity axes of magnetoelectric conversion elements M1 and M2 are in the X direction, and they are arranged facing each other across center lines CL1 and CL2, spaced apart in the Z direction, and their magnetic sensitivity polarity is + in the X+ direction. As a result, the positive and negative signs of magnetic flux 8A on the upper and lower sides of the figure are reversed at the boundary between center lines CL1 and CL2, and the magnetic flux density amount in the X direction detected by magnetoelectric conversion element M1 is a positive value, and the magnetic flux density amount in the X direction detected by magnetoelectric conversion element M2 is a negative value; and when a differential operation is performed on the outputs of magnetoelectric conversion elements M1 and M2, the two are added together and output. Compared to conventional technology, the amount of magnetic flux density detected by magnetoelectric conversion elements M1 and M2 is large, so it is possible to lower the amplification factor of the output signal. In an external magnetic field environment of the current sensor, magnetoelectric conversion elements M1 and M2 detect magnetic flux due to an external magnetic field, and even if a minute output signal is generated, it is possible to reduce the influence of this.

[0032] Also, by making the dimension W3, which is the width dimension in the X direction of the core gap 5 of the magnetic cores 1A and 1B, smaller than the dimension W2, which is the distance dimension between the end faces in the Z direction, it is possible to increase the magnetic flux density of the magnetic flux 8A detected by the magnetoelectric conversion elements M1 and M2. If the dimension W2 is made smaller than the dimension W3, the magnetic resistance of the core gap 5 is reduced, so that the magnetic flux components that did not form the magnetic flux path 8 (the magnetic flux components of the magnetic flux path formed between the end faces 1a1 and 1a2 of the magnetic core 1A and the end faces 1b1 and 1b2 of the magnetic core 1A, not shown) are added to the magnetic flux path 8, and the magnetic flux 8A becomes larger. This makes it possible to increase the magnetic flux density detected by the magnetoelectric conversion elements M1 and M2. Therefore, it is preferable to form the dimension W3 to be smaller than the dimension W2.

[0033] Furthermore, an external magnetic field having a magnetic flux source outside the current sensor 100 mainly produces magnetic flux of the same direction and polarity for the nearby magnetoelectric conversion elements M1 and M2, and by performing differential calculation on the outputs of magnetoelectric conversion elements M1 and M2, the two are offset and the differential calculation output becomes small. Also, the magnetic cores 1A and 1B act as a shield, making the output extremely small and suppressing the influence of the external magnetic field, resulting in a configuration that is less susceptible to the influence of the external magnetic field than the coil-type current sensor shown in the prior art.

[0034] The amount of magnetic flux density detected by the current sensor 100 according to the first embodiment of the present invention will be described using a simulation. Fig. 5 shows a configuration example of the arrangement of the conductor 3 and the magnetoelectric conversion elements M1 and M2 according to this embodiment in a diagram equivalent to the cross-sectional view of Fig. 1(d) BB, and Fig. 5(a) shows a configuration example (a), in which the conductor 3 penetrates the gap 2A three times from the Y+ direction to the Y- direction, surrounding the periphery of the arm 1A1 to form a coil portion 6A, and the conductor portion penetrating the gap 2A has a conductor portion 3a, a conductor portion 3b, and a conductor portion 3c, and the coil portion 6A passes through the connection portion 7 and then penetrates the gap 2B three times from the Y+ direction to the Y- direction, surrounding the periphery of the arm 1B2 to form a coil portion. 5B is a diagram showing the example of the configuration (b), in which the conductor 3E penetrates the gap 2A from the Y+ direction, and the magnetoelectric conversion elements M1 and M2 are arranged so that they are within an area R (area R will be described later). The magnetoelectric conversion elements M1 and M2 are arranged so that they face each other and are spaced apart from each other across a center line CL1 in the Z direction, and are also spaced apart from each other in a posture in which they face each other across a center line CL2 in the Z direction. The magnetoelectric conversion elements M1 and M2 are arranged so that their magnetic sensing axes are in the X-direction. FIG. 5B is a diagram showing the example of the configuration (b), in which the conductor 3E penetrates the gap 2A from the Y+ direction, and the magnetoelectric conversion elements M1 and M2 are arranged so that they face each other across a center line CL2 in the Z direction. Coil portion 6L is formed by surrounding arm portion 1A1 so as to penetrate twice in the Y- direction, and the conductor portion that penetrates air gap 2A has conductor portion 3g and conductor portion 3h. Coil portion 6L passes through connection portion 7F and then penetrates air gap 2B twice from the Y+ direction to the Y- direction to form coil portion 6M by surrounding arm portion 1B2, and the conductor portion that penetrates air gap 2B has conductor portion 3j and conductor portion 3k. Magnetic sensor 4 is disposed such that magnetoelectric conversion elements M1 and M2 are within region R, and magnetoelectric conversion elements M1 and M2 are aligned along the center line in the Z direction. The magnetoelectric conversion elements M1 and M2 are arranged facing each other with CL1 in between and spaced apart in a facing position with center line CL2 in the Z direction, and the magnetoelectric conversion elements M1 and M2 are arranged so that their magnetic sensing axes are in the X direction. FIG. 5(c) is a diagram showing configuration example (c), in which a coil portion 6N is formed by surrounding the periphery of arm portion 1A1 so that conductor 3F passes through gap 2A once from the Y+ direction to the Y- direction, and the conductor portion that passes through gap 2A has conductor portion 3m, and coil portion 6N passes through connection portion 7G and then passes through gap 2B once from the Y+ direction to the Y- direction.The coil portion 6P is formed by surrounding the arm portion 1B2, and the conductor portion penetrating the air gap 2B has a conductor portion 3n. The magnetic sensor 4 is arranged such that the magnetoelectric conversion elements M1 and M2 are located within the region R, and the magnetoelectric conversion elements M1 and M2 are spaced apart facing each other across the center line CL1 in the Z direction, and are also spaced apart facing each other across the center line CL2 in the Z direction. The magnetoelectric conversion elements M1 and M2 are arranged such that their magnetic sensing axes are in the X direction. FIG. 5(d) shows a configuration example. FIG. 13 shows configuration example (d), in which the configurations of the magnetic cores 1A, 1B and the conductor 3 are the same as those of configuration example (a), and the magnetoelectric conversion elements M1 and M2 of the magnetic sensor 4A are arranged so that they are each located within the core gap 5, and the magnetoelectric conversion elements M1 and M2 are spaced apart and opposed to each other across a center line CL1 in the Z direction, and are also spaced apart and opposed to each other across a center line CL2 in the Z direction, and the magnetoelectric conversion elements M1 and M2 are arranged so that their magnetic sensing axes are in the X direction. As shown in Figures 5(a), (b), and (c), region R is a range that overlaps the range of dimension W3, which is the width dimension of core gap 5 in the X direction, the range of dimension T1 (see Figure 1(c)), which is the thickness dimension of magnetic cores 1A and 1B in the Y direction, and dimension W2, which is the distance dimension between the end faces of magnetic cores 1A and 1B in the Z direction.

[0035] Fig. 6 shows the magnetic flux density amount detected by the magnetoelectric conversion elements M1 and M2 in response to the current to be detected and the fluctuation of the differential calculation value of the magnetic flux density amount detected by the magnetoelectric conversion elements M1 and M2 when the magnetic sensor 4 is displaced in the Y direction in the configuration examples (a), (b), (c), and (d) shown in Fig. 5. Fig. 6(a) is a table showing the simulated magnetic flux density amount in the X+ direction at the arrangement points of the magnetoelectric conversion elements M1 and M2 when the current to be detected is applied in the configuration examples (a), (b), (c), and (d), and the differential calculation value, which is the difference between the two, is calculated. Fig. 6(b) is a graph showing the fluctuation rate of the differential calculation value when the magnetic sensor 4 is displaced in the Y direction in the configuration example (a) by changing the thickness dimension T1 (see Fig. 1(c)) of the magnetic cores 1A and 1B. (Details of Fig. 6(b) will be described later.) This simulation was performed using finite element method electromagnetic field analysis software, and the current to be detected was set to 10A.

[0036] In this simulation, as shown in FIG. 5, the width dimension W1 in the Z direction is 7.0 mm, the dimension W2 between the end faces in the Z direction is 3.0 mm, the width dimension W4 in the X direction is 7.75 mm, the extension dimension W5 of arms 1A1 and 1A2 in the X direction is 5.75 mm, the width dimension W6 in the Z direction of arm 1A1 is 2.0 mm, the core gap width dimension W3 in the X direction of core gap 5 is 1.5 mm, and the thickness dimension T1 in the Y direction of magnetic cores 1A and 1B (see FIG. 1(c)) is 3.0 mm. The cross-sectional shape of the conductors 3, 3E, 3F is a circle with a diameter of 1.0 mm, the coil portions 6A, 6N, 6L are spaced 1.0 mm from the arm portion 1A1 and have a spiral shape with a pitch of 1.5 mm, and the dimension W7 of the separation in the X direction from the end faces 1a1, 1a2 to the conductive portions 3a, 3g, 3m is 4.0 mm, and the coil portions 6B, 6M, 6P are spaced 1.0 mm from the arm portion 1B2 and have a spiral shape with a pitch of 1.5 mm, and the dimension W8 of the separation in the X direction from the end faces 1b1, 1b2 to the conductive portions 3f, 3k, 3n is 4.0 mm. In addition, the magnetoelectric conversion elements M1 and M2 are arranged on the center line of the dimension W3 and the dimension T1, and in Figures 5(a), (b), and (c), the Z-direction separation distance Mp1 between the magnetoelectric conversion elements M1 and M2 is 2.6 mm, and in Figure 5(d), the Z-direction separation distance Mp2 between the magnetoelectric conversion elements M1 and M2 is 5.0 mm (the center position of the core gap 5), and a detected current A1 (see Figure 1(a)) of 10 A is applied from the current application surface 31 (see Figure 1(a)). Furthermore, the magnetic cores 1A and 1B are set to be made of silicon steel plate, the conductors 3, 3E, and 3F are set to be made of copper, and the relative permeability of the surrounding air is 1.0. Since non-magnetic materials are generally used for the magnetic sensors 4, 4A and lead 4L, in the simulation the relative permeability was set to 1.0, the same as the surrounding air, and the magnetic flux density in the X+ direction at the placement points of the magneto-electric conversion elements M1 and M2 was simulated.

[0037] In configuration example (a), conductor 3 penetrates gap 2A three times by conductor portions 3a, 3b, and 3c, and conductor portions 3d, 3e, and 3f penetrate gap portion 2B three times. When current to be detected A1 is applied from current application surface 31, a current (not shown) flowing through conductor portions 3a, 3b, and 3c is in the Y-direction, a current (not shown) flowing through conductor portions 3d, 3e, and 3f is in the Y-direction, and the directions of currents (not shown) flowing through conductor portions 3a, 3b, 3c, 3d, 3e, and 3f are all the same. The magnetic flux density in the X-direction detected by magnetoelectric conversion element M1 is 17.5 mT, the magnetic flux density in the X-direction detected by magnetoelectric conversion element M2 is -15.9 mT, and the differential calculation value thereof is 33.4 mT.

[0038] In configuration example (b), conductor 3E penetrates gap 2A twice by conductor portions 3g and 3h, and conductor portions 3j and 3k penetrate gap portion 2B twice. When current to be detected A1 is applied from current application surface 31, a current not shown flowing through conductor portions 3g and 3h is in the Y-direction, a current not shown flowing through conductor portions 3j and 3k is in the Y-direction, and the directions of currents not shown flowing through conductor portions 3g, 3h, 3j, and 3k are all in the same direction. The magnetic flux density in the X-direction detected by magnetoelectric conversion element M1 is 11.5 mT, the magnetic flux density in the X-direction detected by magnetoelectric conversion element M2 is -10.4 mT, and the differential calculation value is 21.9 mT. Compared to configuration example (a), conductor portion 3E penetrates gaps 2A and 2B fewer times, and therefore the magnetic flux density in the X-direction detected by magnetoelectric conversion elements M1 and M2 is reduced.

[0039] In configuration example (c), conductor 3F passes through gap 2A once via conductor portion 3m and conductor portion 3n passes through gap 2B once, and when detected current A1 is applied from current application surface 31, a current (not shown) flowing through conductor portion 3m is in the Y-direction, a current (not shown) flowing through conductor portion 3n is in the Y-direction, and the directions of the currents (not shown) flowing through conductor portions 3m and 3n are all in the same direction. The magnetic flux density in the X-direction detected by magnetoelectric conversion element M1 is 5.7 mT, the magnetic flux density in the X-direction detected by magnetoelectric conversion element M2 is -5.2 mT, and the differential calculation value is 10.9 mT. Compared to configuration example (b), the number of times conductor portion 3F passes through gaps 2A and 2B is smaller, and therefore the magnetic flux density in the X-direction detected by magnetoelectric conversion elements M1 and M2 is further reduced.

[0040] In configuration example (d), conductor 3 penetrates gap 2A three times by conductor portions 3a, 3b, and 3c, and conductor portions 3d, 3e, and 3f penetrate gap portion 2B three times. When current to be detected A1 is applied from current application surface 31, a current (not shown) flowing through conductor portions 3a, 3b, and 3c is in the Y-direction, a current (not shown) flowing through conductor portions 3d, 3e, and 3f is in the Y-direction, and the directions of currents (not shown) flowing through conductor portions 3a, 3b, 3c, 3d, 3e, and 3f are all the same. The magnetic flux density in the X-direction detected by magnetoelectric conversion element M1 is 25.7 mT, the magnetic flux density in the X-direction detected by magnetoelectric conversion element M2 is -23.4 mT, and the differential calculation value is 49.1 mT. In this case, in configuration example (d), magnetoelectric conversion elements M1 and M2 are arranged in the upper and lower core gaps 5 in the figure, respectively, so it is possible to detect a larger magnetic flux density amount than in configuration example (a). This is because, when comparing magnetic flux 8A passing through region R with magnetic flux 8A passing through core gap 5, the magnetic resistance of core gap 5 is smaller, so the magnetic flux 8A component passing through core gap 5 is larger.

[0041] In the coil-type current sensor shown in the prior art, two coil sections (three turns) similar to configuration example (a) are constructed, and a magnetoelectric conversion element is placed between the coil sections. Even if the same current to be detected is applied, the magnetic flux density that the magnetoelectric conversion element can detect is, at the very least, 5.0 mT or less, and it is immediately clear how large a magnetic flux density the current sensor 100 can detect.

[0042] Furthermore, as shown in configuration examples (a), (b), and (c), the more conductor portions that penetrate the gaps 2A and 2B, the greater the magnetic flux density detected by the magnetoelectric conversion elements M1 and M2 can be, and the designer can freely design the amount of magnetic flux density required for the current sensor design.

[0043] Furthermore, as shown in configuration example (d), the magnetic flux density detected by magnetoelectric conversion elements M1 and M2 can be increased as they approach core gap 5, and the designer can freely design the magnetic flux density required for the current sensor design.

[0044] In addition, the current sensor 100 according to the first embodiment of the present invention, under its usage environment, Even if the magnetic sensor 4 is misaligned due to expansion and contraction of a resin housing (not shown), which in turn causes the magnetoelectric conversion elements M1 and M2 to be misaligned, and the magnetic flux density in the X direction of the magnetic flux 8A detected by each of the magnetoelectric conversion elements M1 and M2 fluctuates, the differential calculation value is unlikely to fluctuate, resulting in a characteristic that measurement errors are unlikely to occur.

[0045] For example, in the current sensor 100, when the magnetic sensor 4 is displaced in the Z+ direction, the magnetoelectric conversion elements M1 and M2 are mounted on the substrate 4B and configured inside the magnetic sensor 4, and therefore the relative positions of the magnetoelectric conversion elements M1 and M2 are fixed, so that the same distance of displacement occurs in the Z+ direction. At this time, as shown in the simulation results of the configuration examples (a) and (d) shown in FIG. 6, the closer the magnetoelectric conversion elements M1 and M2 are to the core gap 5, the greater the magnetic flux density amount. Therefore, since the magnetoelectric conversion element M1 approaches the upper core gap 5 in the figure, the magnetic flux density amount in the X direction of the magnetic flux 8A on the upper side in the figure detected by the magnetoelectric conversion element M1 increases. However, since the magnetoelectric conversion element M2 is farther away from the lower core gap 5 in the figure, the magnetic flux density amount in the X direction of the magnetic flux 8A on the lower side in the figure detected by the magnetoelectric conversion element M2 decreases. Therefore, the fluctuation amount of the magnetic flux density amount detected by the magnetoelectric conversion elements M1 and M2 is offset by differential calculation, so that it is possible to reduce the measurement error. (The same applies when the magnetic sensor 4 is misaligned in the Z-direction.)

[0046] Furthermore, when the magnetic sensor 4 is misaligned in the X direction, the magnetoelectric conversion elements M1 and M2 are mounted on the substrate 4B and configured inside the magnetic sensor 4, and therefore the relative positions of the magnetoelectric conversion elements M1 and M2 are fixed, so that the same distance of misalignment occurs in the X direction. However, the magnetic flux 8A detected by the magnetoelectric conversion elements M1 and M2 forms a magnetic flux path in the X direction, so the amount of variation in the magnetic flux density in the X direction is small, and the measurement error due to the misalignment is small. (The measurement error is small whether the misalignment occurs in the X+ direction or the X- direction.)

[0047] Furthermore, when the magnetic sensor 4 is misaligned in the Y direction, the magnetoelectric conversion elements M1 and M2 are mounted on the base material 4B and configured inside the magnetic sensor 4, and therefore the relative positions of the magnetoelectric conversion elements M1 and M2 are fixed, so that the same distance of misalignment occurs in the Y direction. At this time, the magnetic flux density amount in the X direction of the magnetic flux 8A detected by the magnetoelectric conversion elements M1 and M2 fluctuates, but the amount of this fluctuation can be reduced by increasing the thickness dimension T1 (see FIG. 1(b)) in the Y direction of the magnetic cores 1A and 1B, and the amount of fluctuation in the magnetic flux density amount can be controlled as desired by the designer.

[0048] 6(b) is a graph showing the rate of variation of the differential calculation value when the dimension T1 in the configuration example (a) is changed to 3.0 mm (the dimension value in the configuration example (a)), 2.0 mm, and 1.0 mm, and the magnetic sensor 4 is displaced in the Y direction by ±0.5 mm, and the graph plots the simulation results with the horizontal axis of the graph representing the amount of displacement of the magnetic sensor 4 in the Y direction and the vertical axis representing the rate of variation of the differential calculation value. The rate of variation was calculated for each dimension value of dimension T1 as (differential calculation value of the amount of magnetic flux density in the X direction detected by the magnetoelectric conversion elements M1 and M2 when a displacement occurs) / (differential calculation value of the amount of magnetic flux density in the X direction detected by the magnetoelectric conversion elements M1 and M2 when no displacement occurs)×100-100.

[0048] 6(b), when the dimension T1 is 3.0 mm, even if the magnetic sensor 4 is misaligned by ±0.5 mm, the rate of variation is 1.0% or less, but when the dimension T1 is 2.0 mm, the rate of variation is about 4.0%, and when the dimension T1 is 1.0 mm, the rate of variation is about 13%. This amount of variation in magnetic flux density is required to be as small as possible because it directly affects the output signal output by the current sensor 100, and since a rate of variation of 1.0% or less is considered to be an acceptable error, the dimension T1 needs to be 3.0 mm.

[0049] Therefore, even if the magnetic sensor 4 is misaligned in the X or Z direction, the current sensor 100 has the characteristic that the differential calculation value is unlikely to fluctuate because the magnetoelectric conversion elements M1 and M2 are mounted on the substrate 4B and their relative positions are fixed. Furthermore, by making the Y-direction thickness dimension T1 of the magnetic cores 1A and 1B 3.0 mm or more, a current sensor capable of stable current detection with little measurement error can be provided.

[0050] The current sensor 100 according to the first embodiment of the present invention is configured so that the conductor 3 passes through the gaps 2A and 2B at least once, but current detection itself is possible if the conductor 3 is configured to pass through either the gap 2A or the gap 2B at least once.

[0051] Figure 7 is a schematic diagram of a current sensor 200 relating to embodiment 2 of the present invention, where Figure 7(a) is an oblique view of the current sensor 200 relating to embodiment 2, Figure 7(b) is a plan view of the current sensor 200 relating to embodiment 1, Figure 1(c) is a front view of the current sensor 200 relating to embodiment 1, and Figure 7(d) is a cross-sectional view of section CC in Figure 7(c).

[0052] Current sensor 200 according to the second embodiment of the present invention includes arm 1A1 having end surface 1a1 at its extending tip, arm 1A2 having end surface 1a2 at its extending tip, thickness dimension T1 in the Y direction, width dimension W1 in the Z direction, dimension W2 which is the distance dimension between the end surfaces in the Z direction, center line CL1 which is the imaginary center line of dimension W2, magnetic core 1A having gap 2A in a hollow portion formed in the center by arms 1A1 and 1A2 forming a U-shape, arm 1B1 having the same shape as magnetic core 1A and having end surface 1b1 at its extending tip, and arm 1B2 having end surface 1b2 at its extending tip. The magnetic core 1B has an arm 1B2, a center line CL2 which is an imaginary center line of the distance dimension between the end faces in the Z direction (a dimension equivalent to the dimension W2 of the magnetic core 1A), and a U-shape formed by the arms 1B1 and 1B2, and has a gap 2B in a hollow portion formed in the center thereof, a conductor 3G to which a current to be detected A2 is applied from a current application surface 32 and which has a circular cross-sectional shape, and magnetoelectric conversion elements M1 and M2 which are detection elements that detect magnetic flux, and has leads 4L which are terminals for outputting to the outside an output signal that is output in accordance with the amount of magnetic flux density detected by the magnetoelectric conversion elements M1 and M2. The magnetic cores 1A and 1B are arranged such that end faces 1a1 and 1b1 face each other and end faces 1a2 and 1b2 face each other, and a core gap 5 having a width dimension W3 in the X direction is formed between the facing end faces. The conductor 3G forms a coil portion 6Q surrounding the periphery of the arm portion 1A1 so as to penetrate the air gap 2A three times from the Y+ direction to the Y- direction. The magnetic sensor 4 has magnetoelectric conversion elements M1 and M2 that are arranged within a range of dimension W3 that is the width dimension of the core gap 5 in the X direction and a range of dimension W4 that is the thickness dimension of the magnetic cores 1A and 1B in the Y direction. The range of dimension T1 overlaps with the range of dimension W1, which is the width dimension of magnetic cores 1A, 1B in the Z direction, and they are disposed opposite each other with a center line CL1 therebetween and a space therebetween in the Z direction, and also opposite each other with a center line CL2 therebetween, with their magnetic sensing axes being in the X direction. Since conductor 3 is a conductive conductor formed of a single material, a current to be detected A2 applied from current application surface 32 of conductor 3G flows in the Y-direction through conductor portions 3p, 3q, and 3r, which are conductor portions that penetrate gap 2A, and a current not shown in the figure flows in the Y-direction through conductive portions 3p, 3q, andThe current flowing through the 3r is configured to be in the same direction.

[0053] Moreover, the current sensor 200 relating to the embodiment 2 of the present invention has a resin housing (not shown) and a printed circuit board (not shown) on which a connector (not shown) is mounted, the printed circuit board, magnetic cores 1A, 1B, and conductor 3 are fixed to the resin housing, and the magnetic sensor 4 is connected to the printed circuit board via a lead 4L.

[0054] The magnetic sensor 4 is a magnetic detection device in which a portion of a lead 4L (not shown) and a base material 4B are sealed inside with thermosetting resin, and the lead 4L and the base material 4B are connected inside the magnetic sensor 4 by a die bond (not shown) or the like.

[0055] The substrate 4B is a rectangular semiconductor chip, and the magnetoelectric conversion elements M1 and M2 are mounted on the substrate 4B at a distance from each other, and the relative positions of the magnetoelectric conversion elements M1 and M2 are fixed. In the current sensor 200 according to the first embodiment of the present invention, the substrate 4B has a plane parallel to the YZ plane, and the magnetoelectric conversion elements M1 and M2 are mounted on the plane at a distance from each other in the Z direction.

[0056] The substrate 4B also has a detection means (not shown) that amplifies the output signals output by the magnetoelectric conversion elements M1 and M2 in accordance with the amount of magnetic flux density detected, performs a differential calculation on the two amplified output signals, and has a differential calculation unit (not shown) that outputs the differential calculation value, and the differential calculation value is output to the outside of the current sensor 200 via the lead 4L of the magnetic sensor 4, the printed circuit board, and the connector.

[0057] As in the current sensor 200 relating to the second embodiment of the present invention, if the magnetic flux density detected by the magnetoelectric conversion elements M1, M2 is smaller than that of the current sensor 100 relating to the first embodiment of the present invention, current detection is possible, and therefore as long as the magnetic flux density amount required by the designer can be detected by the magnetoelectric conversion elements M1, M2, the magnetic flux density may be configured to penetrate one or more times into the gaps 2A, 2B as in the current sensor 200. The more times the conductor portion penetrates the gap 2A or 2B, the more the amount of magnetic flux density detected by the magnetoelectric conversion elements M1, M2 can be increased, and the amplification factor of the output signal output according to the amount of magnetic flux density detected by the magnetoelectric conversion elements M1, M2 can be reduced.

[0058] In addition, in the current sensor 100 according to the first embodiment of the present invention, the conductors to which the current to be detected is applied are each made of a single material and are conductive conductors, but this is not limited thereto, and the conductors to which the current to be detected is applied may be made of multiple conductors and multiple materials.

[0059] Figure 8 shows an example of the configuration of a conductor of a different shape for the current sensor 100 according to embodiment 1 of the present invention, where Figure 8(a) is an oblique view in which the conductor 3 of the current sensor 100 shown in Figure 1 has been changed, and Figure 8(b) is a plan view.

[0060] In the current sensor 100 according to the first embodiment of the present invention, the conductor 3 to which the current to be detected is applied is a conductive conductor made of a single material, but this is not limited to the above. As shown in FIG. 8(a)(b), the conductor to which the current to be detected A3 is applied is formed of a plurality of conductors, including conductor portion 3H which is a board pattern formed of copper foil on printed board 9 and has a current application surface 33, conductor portion 3K which is also a board pattern formed of copper foil on printed board 9, conductor portion 3M, conductor 3J which forms coil portion 6R which passes through gap 2A three times, and conductor 3L which forms coil portion 6S which passes through gap 2B three times, and conductor 3J is joined to conductors 3H and 3K at the conductor terminals with solder 10 formed of a conductive material, and conductor 3L is formed so as to be joined to conductors 3K and 3M at the conductor terminals with solder 10 formed of a conductive material, and the conductors 3H, 3J, 3K, 3L, and 3M may be formed of a plurality of conductors as long as they are all conductive. (At this time, similarly to current sensor 100 according to the first embodiment of the present invention, when current to be detected A3 is applied from current application surface 33, current to be detected A3 applied in this order flows through conductor 3H, conductor 3J, conductor 3K, conductor 3L, and conductor 3M, and the current directions of the conductor portions through which coil portions 6R and 6S pass are the same in gaps 2A and 2B.)

[0061] In addition, Figure 8 shows an example of a configuration in which the conductor to which the detected current A3 is applied is composed of multiple conductors, namely coil sections 6R and 6S and conductor sections 3H, 3K, and 3M of the printed board 9, but the coil section may also be formed of multiple conductors.

[0062] The conductor configuration shown in Figure 8 is an example shape of current sensor 100 according to embodiment 1 of the present invention and is not intended to limit the configuration of the present invention. Although the configuration example shown in Figure 8 is shown using current sensor 100, it is the same for current sensor 200 according to embodiment 2 of the present invention. [Explanation of symbols]

[0063] 1A magnetic core 1Aa Magnetic core 1B Magnetic core 1Ba magnetic core 1C Magnetic core 1D magnetic core 1a1 end face 1a2 end face 1A1 Arm 1A2 Arm 1B1 Arm 1B2 Arm 1b1 End face 1b2 End face 2A void 2B void 3 Conductors 31 Current application surface 32 Current application surface 33 Current application surface 3A Conductor 3B conductor 3C Conductor 3D Conductor 3E Conductor 3F Conductor 3G Conductor 3H Conductor 3J Conductor 3K Conductor 3L Conductor 3M Conductor 3a Conductor 3b conductor 3c Conductor 3d conductor 3e Conductor 3f conductor 3g conductor 3h Conductor 3j Conductor 3k conductor 3m conductor 3n conductor 3p conductor 3q conductor 3r conductor 4 Magnetic Sensor 4A Magnetic Sensor 4B Base material 4L Lead 5 Core Gap 6A Coil section 6B Coil section 6C Coil section 6D Coil section 6E Coil section 6F Coil section 6G Coil section 6H Coil part 6J Coil section 6K coil part 6L Coil section 6M Coil section 6N Coil part 6P coil part 6Q Coil section 6R Coil section 6S Coil section 7 Connection 7A Connection 7B Connection 7C connection 7D Connection 7E Connection 7F Connection 7G connection 8 Magnetic flux path 8A magnetic flux 9 Printed circuit board 10 Solder A1 Current to be detected A2 Detected current A3 Detected current CL1 center line CL2 center line T1 Dimensions M1 Magnetoelectric conversion element M2 magnetoelectric conversion element Mp1 Dimensions Mp2 Dimensions W1 Dimension W2 Dimension W3 Dimensions W4 Dimensions W5 Dimensions W6 Dimensions W7 Dimensions W8 Dimensions

Claims

1. A current sensor comprising: a conductor to which a current to be detected is applied; first and second magnetic cores each having a substantially U-shape with two end faces; and a substrate on which a pair of magnetoelectric conversion elements are mounted, the magnetoelectric conversion elements detecting the magnetic flux density in a predetermined magnetic sensing axis direction of the magnetic flux generated from the current to be detected and outputting an output signal according to the magnetic flux density, wherein the first magnetic core has a first gap portion formed by the substantially U-shape and a first center line which is an imaginary center line of the dimension between the two end faces, and the second magnetic core has a second gap portion formed by the substantially U-shape and a second center line which is an imaginary center line of the dimension between the two end faces, and the first and a core gap is formed between the two opposing end faces of the two magnetic cores; the pair of magnetoelectric conversion elements are mounted at a distance from each other on the base material and their relative positions are fixed; the magnetic sensor is arranged such that the pair of magnetoelectric conversion elements face each other across the first center line and face each other across the second center line; the conductor passes through each of the first and second gaps one or more times and is arranged such that current application directions in the conductor portions passing through the first and second gaps are all the same.

2. A current sensor comprising: a conductor to which a current to be detected is applied; first and second magnetic cores each having a substantially U-shape with two end faces; and a substrate on which a pair of magnetoelectric conversion elements are mounted, the magnetoelectric conversion elements detecting the magnetic flux density in a predetermined magnetic sensing axis direction of the magnetic flux generated from the current to be detected and outputting an output signal according to the magnetic flux density, wherein the first magnetic core has a first gap portion formed by the substantially U-shape and a first center line which is an imaginary center line of the dimension between the two end faces, and the second magnetic core has a second gap portion formed by the substantially U-shape and a second center line which is an imaginary center line of the dimension between the two end faces, and the first and second magnetic cores the two end faces are arranged in a facing orientation, a core gap is formed between the two facing end faces, the pair of magnetoelectric conversion elements are mounted at a distance from each other on the base material, and their relative positions are fixed, the magnetic sensor is arranged such that the pair of magnetoelectric conversion elements are arranged in a facing orientation in the extension direction of the dimension between the end faces across the first center line and also in a facing orientation in the extension direction of the dimension between the end faces across the second center line, and the conductor passes through the first gap one or more times and is arranged such that all current application directions in the conductor portions passing through the first gap are the same.

3. The current sensor described in claim 1 or claim 2, characterized in that the magnetic sensor is arranged so that the pair of magnetoelectric conversion elements are arranged within an arrangement area bounded by the end face-to-end dimension and thickness direction dimension of the first and second magnetic cores and the width direction dimension of the core gap, and have the magnetic sensing axis in a direction horizontal to the width direction of the core gap.

4. 3. The current sensor according to claim 1, wherein the magnetic sensor is arranged such that the pair of magnetoelectric conversion elements are arranged within the core gap and have the magnetic sensing axis in a direction horizontal to the width direction of the core gap.

5. 3. The current sensor according to claim 1, wherein the conductor is formed by combining a plurality of conductive bodies that are electrically connected to each other.

6. 3. The current sensor according to claim 1, wherein a widthwise dimension of the core gap is smaller than a dimension between the end faces.

7. 3. The current sensor according to claim 1, wherein the first and second magnetic cores each have a thickness dimension of 3.0 mm or more.

Images