JP2013002974A - Current measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current measuring device capable of easily measuring a current in an arbitrary electric wire including a plurality of conductors.SOLUTION: A current measuring device 1, which measures a current flowing through an electric wire 10 including a plurality of conductors 11A to 11C, includes a plurality of current detection elements 22A to 22C which are separately arranged on an outer periphery of an arbitrary cross section of the electric wire 10 and which detect the current on the basis of a magnetic flux caused by the current flowing through the conductors 11A, 11B, and current measuring means 50 for measuring the current flowing through the electric wire 10 on the basis of an output value of one current detection element having the largest output value among the current detection elements 22A to 22C.

Description

  The present invention relates to a current measuring device, and more particularly, to a current measuring device that measures a current flowing in an electric wire including a plurality of conductive wires.

  For example, Patent Document 1 below discloses a current measuring device according to the background art. The current measuring device is a device for measuring a current flowing in a flat parallel cord including two conductive wires. By sandwiching the parallel cord by the magnetic detector having one Hall element, the Hall element is arranged between the two conductors. And the electric current which flows into a parallel cord is measured by detecting the magnetic flux which generate | occur | produces between two conducting wires with a Hall element.

Japanese Patent Laid-Open No. 9-189723

  However, according to the current measuring device disclosed in Patent Document 1, the measurement target is limited to a flat parallel cord including two conductive wires. Therefore, there is a problem that current measurement cannot be performed on a round electric wire or an electric wire including three or more conducting wires.

  The present invention has been made to solve such a problem, and an object of the present invention is to obtain a current measuring device capable of easily measuring a current for an arbitrary electric wire including a plurality of conductive wires. It is.

  The current measuring device according to the first aspect of the present invention is a current measuring device for measuring a current flowing in an electric wire containing a plurality of conducting wires, and is arranged separately on an outer periphery of an arbitrary cross section of the electric wire, A plurality of current detection elements that detect the current based on a magnetic flux generated due to a current flowing through the conducting wire, and the output value of one current detection element having the maximum output value among the plurality of current detection elements And measuring means for measuring the current flowing through the electric wire.

  According to the current measuring device concerning the 1st mode, a plurality of current detecting elements are arranged apart on the perimeter of the arbitrary section of an electric wire. The magnetic flux at the position where the current detection element is arranged becomes smaller as the distance between the current detection element and the conductor increases. Therefore, even when the direction of the magnetic flux generated around one conductor and the direction of the magnetic flux generated around another conductor are opposite to each other, the distance between the two conductors is arranged at a large position. A relatively large output value can be obtained from the current detection element. Therefore, based on the output value of one current detection element having the maximum output value among the plurality of current detection elements, the current flowing through the electric wire can be measured by the measuring means. In addition, according to the current measuring device according to the first aspect, the measurement target is not limited to a flat parallel cord including two conductive wires, and is arbitrary such as a round electric wire or an electric wire including three or more conductive wires. Current measurement can be performed on an electric wire.

  The current measurement device according to the second aspect of the present invention is arranged in correspondence with each of the plurality of current detection elements, particularly in the current measurement device according to the first aspect. It further includes a plurality of magnetic bodies guided to the element, and a predetermined gap is provided between the adjacent magnetic bodies.

  According to the current measurement device according to the second aspect, a plurality of magnetic bodies are arranged corresponding to each of the plurality of current detection elements, and a predetermined gap is provided between adjacent magnetic bodies. Yes. By providing a gap between adjacent magnetic materials and leaking a part of the magnetic flux generated around the conducting wire from the gap to the outside, the total of the magnetic flux in one direction and the total of the magnetic flux in the opposite direction Can be intentionally different. As a result, it is possible to avoid a situation in which the opposite magnetic fluxes completely cancel each other.

  The current measurement device according to a third aspect of the present invention is characterized in that, in the current measurement device according to the first or second aspect, the plurality of current detection elements include at least three current detection elements. Is.

  According to the current measurement device according to the third aspect, the plurality of current detection elements include at least three current detection elements. By arranging at least three current detection elements, the situation in which the opposite magnetic fluxes completely cancel each other out of all the current detection elements does not occur, so that current measurement can be performed appropriately.

  The current measurement device according to a fourth aspect of the present invention is the current measurement device according to the third aspect, in particular, wherein the plurality of current detection elements are composed of three current detection elements arranged at equal intervals. It is what.

  According to the current measurement device according to the fourth aspect, the plurality of current detection elements are composed of three current detection elements arranged at equal intervals. Therefore, compared to the case of using four or more current detection elements, the manufacturing cost can be reduced and the magnetic flux leaking from the gap can be minimized, so that the current measurement accuracy can be improved. Become.

  The current measurement device according to a fifth aspect of the present invention is the current measurement device according to any one of the first to fourth aspects, in particular, the unit including the plurality of current detection elements is an arrangement of the current detection elements. A plurality of the sensors are arranged at different positions.

  According to the current measurement device according to the fifth aspect, a plurality of units including a plurality of current detection elements are arranged with the arrangement positions of the current detection elements being shifted. Therefore, the possibility that any one of the current detection elements is arranged at a position where the difference in distance from the plurality of conductive wires is larger is increased. Therefore, since the possibility that a larger maximum output value can be obtained increases, the current measurement accuracy can be improved.

  The current measurement device according to a sixth aspect of the present invention is the current measurement device according to any one of the first to fifth aspects, and in particular, the measurement means is connected to outputs of the plurality of current detection elements. A plurality of amplifier circuits; and a signal processing device connected to outputs of the plurality of amplifier circuits.

  According to the current measurement device according to the sixth aspect, the amplifier circuit is connected to the output of each current detection element, so that the output value of each current detection element is amplified by each amplifier circuit and input to the signal processing device. Is done. Therefore, it is possible to input the output values of the plurality of current detection elements to the signal processing device in real time.

  In the current measurement device according to the seventh aspect of the present invention, in particular, in the current measurement device according to any one of the first to fifth aspects, the measurement means is connected to outputs of the plurality of current detection elements, A switching circuit that sequentially switches and outputs output values from the plurality of current detection elements; an amplifier circuit connected to the output of the switching circuit; and a signal processing device connected to the output of the amplifier circuit. It is characterized by.

  According to the current measuring device according to the seventh aspect, the output of each current detection element is connected to the switching circuit, and the output of the switching circuit is connected to the amplifier circuit. Therefore, compared with the case where an amplifier circuit is connected to the output of each current detection element, the number of amplifier circuits can be reduced, so that the cost can be reduced.

  The current measurement device according to an eighth aspect of the present invention is characterized in that, in the current measurement device according to any one of the first to seventh aspects, the electric wire has a circular cross-sectional shape. .

  According to the current measuring device concerning the 8th mode, the electric wire which is a measuring object has circular section shape. As described above, the current measuring apparatus according to the present invention can perform current measurement on not only a flat cable but also a round cable by using a plurality of current detection elements.

  ADVANTAGE OF THE INVENTION According to this invention, the electric current measuring apparatus which can measure an electric current easily about the arbitrary electric wires which contain several conducting wire as object can be obtained.

It is a figure showing roughly the composition of the current measuring device concerning an embodiment of the invention. It is sectional drawing which shows the cross-section of an electric wire. It is sectional drawing which shows the state in which the current sensor unit was attached to the circumference | surroundings of an electric wire. It is a figure which shows the specific example of the attachment structure of the current sensor unit to an electric wire. It is a figure which shows the magnetic flux which generate | occur | produces through a current detection element, when an electric current flows into a conducting wire. It is a block diagram which shows the 1st example of an electric current measurement means. It is a block diagram which shows the 2nd example of an electric current measurement means. It is sectional drawing which shows the state in which the additional current sensor unit was attached to the circumference | surroundings of an electric wire. It is a figure which shows the state in which the some current sensor unit was attached to the circumference | surroundings of an electric wire. It is sectional drawing which shows the modification of the structure of an electric wire and a current sensor unit. It is sectional drawing which shows the modification of the structure of an electric wire and a current sensor unit. It is sectional drawing which shows the modification of the structure of an electric wire and a current sensor unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the element which attached | subjected the same code | symbol in different drawing shall show the same or corresponding element.

  FIG. 1 is a diagram schematically showing a configuration of a current measuring apparatus 1 according to an embodiment of the present invention. FIG. 1A shows a side view, and FIG. 1B shows a front view. The current measuring device 1 has a lower housing 3 in which a circuit board 5 is built, and an upper housing 2 that is detachably attached to the lower housing 3. The electric wire 10 to be measured is sandwiched and fixed between the lower housing 3 and the upper housing 2 via the current sensor unit 4 from above and below. As shown in FIG. 1C, the current sensor unit 4 is disposed on the outer periphery of an arbitrary cross section in the length direction of the electric wire 10. In the example of the present embodiment, the electric wire 10 is a round power cable having a circular cross-sectional shape. As shown in FIG. 1B, a display unit 6 such as an LED or LCD and a communication unit 7 such as a wireless LAN or USB are arranged on the front surface of the lower housing 3.

  FIG. 2 is a cross-sectional view showing a cross-sectional structure of the electric wire 10. The electric wire 10 includes a plurality (three in this example) of conductive wires 11A to 11C. The conducting wires 11A to 11C are respectively covered with insulators 12A to 12C such as vinyl insulators, and the periphery thereof is covered with an insulator 13 such as a vinyl sheath. The conducting wire 11A is a conducting wire for L terminal connected to the non-ground side of the commercial power source. The conducting wire 11B is a conducting wire for an N terminal connected to the ground side of the commercial power source. The conducting wire 11C is a conducting wire for an FG terminal connected to the ground. A current having the same current value and a reverse direction flows through the conducting wire 11A and the conducting wire 11B. No electric current flows through the conducting wire 11C in the normal state.

  FIG. 3 is a cross-sectional view showing a state where the current sensor unit 4 is attached around the electric wire 10 shown in FIG. The current sensor unit 4 includes a plurality (three in this example) of current detection elements 22 </ b> A to 22 </ b> C that are spaced apart from each other and arranged at equal intervals on the outer periphery of the electric wire 10. The current detection elements 22A to 22C are, for example, Hall elements, and detect the current based on the magnetic flux generated around the current due to the current flowing through the conducting wires 11A to 11C. The current detection elements 22A to 22C are respectively fixed to one end surfaces of magnetic bodies 21A to 21C such as ferrite cores for guiding the generated magnetic flux to the current detection elements 22A to 22C. The magnetic bodies 21 </ b> A to 21 </ b> C have an arcuate outer shape corresponding to the curvature of the outer circumference circle of the electric wire 10. As shown in FIG. 3, a gap 23A is provided between the current detection element 22A and the other end face of the magnetic body 21B, and a gap 23B is provided between the current detection element 22B and the other end face of the magnetic body 21C. A gap 23C is provided between the current detection element 22C and the other end surface of the magnetic body 21A.

  FIG. 4 is a diagram illustrating a specific example of a structure for attaching the current sensor unit 4 to the electric wire 10. The springs 25 </ b> A and 25 </ b> B are fixed to the inner surface of the upper housing 2, and the spring 25 </ b> C is fixed to the inner surface of the lower housing 3. Each one side surface of the upper housing 2 and the lower housing 3 is rotatably connected by a hinge 26. The user opens the upper housing 2 and arranges the electric wire 10 and the current sensor unit 4 at predetermined locations on the lower housing 3. Next, after closing the upper casing 2, the other side surfaces of the upper casing 2 and the lower casing 3 are fixed by the stopper 27. Thereby, magnetic body 21A-21C is pressed toward the electric wire 10 by the urging | biasing force of spring 25A-25C, As a result, magnetic body 21A-21C and the electric wire 10 contact | adhere. By adopting such an attachment structure, the current sensor unit 4 can be appropriately attached to various electric wires 10 having different diameters.

  FIG. 5 is a diagram showing magnetic flux generated through the current detection elements 22A and 22B when a current flows through the conducting wires 11A and 11B. In this example, a current flows from the front of the paper to the back in the lead wire 11A, and a current flows from the back of the paper to the front in the lead wire 11B. According to the well-known Biosavart's law, the magnitude of the magnetic flux generated around the conductor due to the current flowing in the conductor decreases as the distance from the conductor increases. In the example shown in FIG. 5, the distance between the current detection element 22A and the conductor 11A is smaller than the distance between the current detection element 22A and the conductor 11B. Therefore, the magnitude of the magnetic flux (arrow Y1) generated through the current detection element 22A due to the current flowing through the conductive wire 11A is generated through the current detection element 22A due to the current flowing through the conductive wire 11B. It becomes larger than the magnitude of the magnetic flux (arrow Y2). Therefore, an electromotive force corresponding to the remaining magnetic flux in the direction of the arrow Y1 after the two magnetic fluxes cancel each other appears in the current detection element 22A. Further, the distance between the current detection element 22B and the conductor 11A is larger than the distance between the current detection element 22B and the conductor 11B. Therefore, the magnitude of the magnetic flux (arrow Y3) generated through the current detection element 22B due to the current flowing through the conductive wire 11A is generated through the current detection element 22B due to the current flowing through the conductive wire 11B. It becomes smaller than the magnitude of the magnetic flux (arrow Y4). Therefore, an electromotive force corresponding to the remaining magnetic flux in the direction of the arrow Y4 after the two magnetic fluxes cancel each other appears in the current detection element 22B.

  Theoretically, when the current detection element is arranged on the straight line X1 passing through the center point of the conductive wires 11A and 11B, the difference in the distance between the current detection element and the conductive wires 11A and 11B becomes the largest and orthogonal to the straight line X1. When the current detection element is arranged on the straight line X2, the difference in the distance between the current detection element and the conductors 11A and 11B is the smallest. Therefore, the current detection element arranged near the straight line X1 has a larger output value, and the current detection element arranged near the straight line X2 has a smaller output value. In the example shown in FIG. 5, since the current detection element 22A is disposed closest to the straight line X1, the output value of the current detection element 22A is the largest. Further, since the current detection element 22C is disposed near the straight line X2, the output value of the current detection element 22C becomes small.

  FIG. 6 is a block diagram showing a first example of current measuring means 50 formed on the circuit board 5 shown in FIG. The current measuring means 50 includes amplifier circuits 31A to 31C and a signal processing device 34 such as a microcomputer. The signal processing device 34 includes AD converters 32 </ b> A to 32 </ b> C and a data processing unit 33. The outputs of the current detection elements 22A to 22C are connected to the amplifier circuits 31A to 31C, respectively, and the outputs of the amplifier circuits 31A to 31C are connected to the AD converters 32A to 32C, respectively. The output is connected to the data processing unit 33. The output values from the current detection elements 22A to 22C are first amplified by the amplifier circuits 31A to 31C, respectively, then converted into digital data by the AD converters 32A to 32C, and input to the data processing unit 33. The data processing unit 33 selects the maximum output value from the output values from the current detection elements 22A to 22C, and measures the current flowing through the electric wire 10 based on the maximum output value. For example, a predetermined threshold value for distinguishing between a state where current is flowing through the electric wire 10 and a state where current is not flowing is set in advance and stored in the data processing unit 33, and the maximum output value is the threshold value. When it is above, it determines with the electric current flowing into the electric wire 10, and when the maximum output value is less than a threshold value, it determines with the electric current not flowing into the electric wire 10. FIG. The result of the determination is displayed on the display unit 6 and transmitted from the communication unit 7 to an external terminal such as a personal computer or a display device. Alternatively, the current value flowing through the electric wire 10 is calculated by converting the maximum output value into the current value, and the calculated current value is displayed on the display unit 6 and transmitted from the communication unit 7 to the external terminal. To do.

  FIG. 7 is a block diagram showing a second example of the current measuring means 50 formed on the circuit board 5 shown in FIG. The current measuring means 50 includes a switching circuit 35 such as an analog multiplexer, an amplifier circuit 31, and a signal processing device 34. The signal processing device 34 includes an AD converter 32 and a data processing unit 33. Each output of the current detection elements 22A to 22C is connected to the switching circuit 35. The output of the switching circuit 35 is connected to the amplifier circuit 31, and the output of the amplifier circuit 31 is connected to the AD converter 32. The output of the converter 32 is connected to the data processing unit 33. Each output value from the current detection elements 22 </ b> A to 22 </ b> C is input to the switching circuit 35. The switching circuit 35 sequentially switches and outputs the output values from the current detection elements 22A to 22C based on a control signal periodically input from the data processing unit 33. The output values sequentially output from the switching circuit 35 are first amplified by the amplifier circuit 31, then converted into digital data by the AD converter 32, and sequentially input to the data processing unit 33. The data processing unit 33 selects the maximum output value among the output values from the current detection elements 22A to 22C, and measures the current flowing through the electric wire 10 based on the maximum output value as described above.

<First Modification>
FIG. 8 is a cross-sectional view showing a state where an additional current sensor unit 8 is attached around the electric wire 10 shown in FIG. Similarly to the current sensor unit 4 shown in FIG. 3, the current sensor unit 8 includes a plurality (three in this example) of current detection elements 22 </ b> D to 22 that are spaced apart from each other and arranged on the outer periphery of the electric wire 10 at equal intervals. 22F. The current detection elements 22D to 22F are respectively fixed to one end surfaces of the magnetic bodies 21D to 21F for guiding the generated magnetic flux to the current detection elements 22D to 22F. The magnetic bodies 21 </ b> D to 21 </ b> F have an arcuate outer shape corresponding to the curvature of the outer circumference circle of the electric wire 10. As shown in FIG. 8, a gap 23D is provided between the current detection element 22D and the other end face of the magnetic body 21E, and a gap 23E is provided between the current detection element 22E and the other end face of the magnetic body 21F. A gap 23F is provided between the current detection element 22F and the other end surface of the magnetic body 21D.

  FIG. 9 is a diagram illustrating a state in which a plurality of current sensor units 4 and 8 are attached around the electric wire 10. As shown in FIG. 9, the current sensor unit 8 is disposed close to the current sensor unit 4. 3 and FIG. 8, the arrangement positions of the current detection elements 22D to 22F in the current sensor unit 8 and the arrangement positions of the current detection elements 22A to 22C in the current sensor unit 4 are mutually clear. There is a positional relationship to interpolate. Specifically, the current detection element 22D is arranged at an intermediate position between the current detection element 22A and the current detection element 22B (that is, a position shifted by 60 degrees with respect to each arrangement position of the current detection elements 22A and 22B). The detection element 22E is arranged at an intermediate position between the current detection element 22B and the current detection element 22C (that is, a position shifted by 60 degrees with respect to each arrangement position of the current detection elements 22B and 22C), and the current detection element 22F is a current detection element. It is arranged at an intermediate position between the element 22C and the current detection element 22A (that is, a position shifted by 60 degrees with respect to the arrangement positions of the current detection elements 22C and 22A).

<Second Modification>
10 to 12 are cross-sectional views showing modifications of the structure of the electric wire and the current sensor unit, respectively. In the said embodiment, although the electric wire 10 included the three conducting wires 11A-11C and the current sensor unit 4 each had the three current detection elements 22A-22C and the magnetic bodies 21A-21C, the conducting wire was described. May be two or more, and the number of current detecting elements and magnetic bodies may be two or more (preferably three or more).

  In the example shown in FIG. 10, the electric wire 10 includes two conducting wires 11A and 11B, and the current sensor unit 4 includes three current detection elements 22A to 22C and magnetic bodies 21A to 21C, respectively.

  In the example shown in FIG. 11, the electric wire 10 includes three conducting wires 11A to 11C, and the current sensor unit 4 includes four current detecting elements 22A to 22D and magnetic bodies 21A to 21D, respectively.

  In the example shown in FIG. 12, the electric wire 10 includes two conducting wires 11A and 11B, and the current sensor unit 4 includes four current detection elements 22A to 22D and magnetic bodies 21A to 21D, respectively.

  Moreover, the cross-sectional shape of the electric wire 10 is not limited to a circle, and may be an arbitrary shape such as a flat shape, a square shape, or an oval shape.

<Summary>
As described above, according to the current measurement device 1 according to the present embodiment, the plurality of current detection elements 22 </ b> A to 22 </ b> C are arranged separately on the outer periphery of the arbitrary cross section of the electric wire 10. The magnetic flux at the arrangement position of the current detection elements 22A to 22C decreases as the distance between the current detection elements 22A to 22C and the conductors 11A and 11B increases. Therefore, even if the direction of the magnetic flux generated around the conducting wire 11A and the direction of the magnetic flux generated around the conducting wire 11B are opposite to each other, the distance between the conducting wires 11A and 11B is arranged at a large position. A relatively large output value is obtained from the current detection elements 22A and 22B. Therefore, based on the output value of the current detection element 22A having the maximum output value among the plurality of current detection elements 22A to 22C, the current flowing through the electric wire 10 can be measured by the current measurement means 50. Moreover, according to the current measuring apparatus 1 according to the present embodiment, the object to be measured is not limited to a flat parallel cord including two conducting wires, and may be an arbitrary one such as a round electric wire or an electric wire containing three or more conducting wires. Current measurement can be performed on the electric wire of the type.

  Further, according to the current measuring apparatus 1 according to the present embodiment, the plurality of magnetic bodies 21A to 21C are arranged corresponding to each of the plurality of current detection elements 22A to 22C, and the adjacent magnetic bodies 21A to 21C are arranged. Predetermined gaps 23A to 23C are provided between them. By providing gaps 23A to 23C between adjacent magnetic bodies 21A to 21C and leaking a part of the magnetic flux generated around the conducting wire 10 from the gaps 23A to 23C to the outside, The total magnetic flux in the opposite direction can be intentionally different. As a result, it is possible to avoid a situation in which the opposite magnetic fluxes completely cancel each other.

  Moreover, according to the current measurement device 1 according to the present embodiment, the current sensor unit 4 includes at least three current detection elements 22A to 22C. By arranging at least three current detection elements 22A to 22C, the situation in which the opposite magnetic fluxes completely cancel each other does not occur in all the current detection elements 22A to 22C. Is possible.

  Moreover, according to the current measurement device 1 according to the present embodiment, the current sensor unit 4 includes three current detection elements 22A to 22C arranged at equal intervals. Therefore, compared to the case where four or more current detection elements are used (for example, FIGS. 11 and 12), the manufacturing cost can be reduced and the magnetic flux leaking from the gap can be minimized, so that the current measurement accuracy can be reduced. Can be improved.

  Moreover, according to the current measuring apparatus 1 according to the first modification, the plurality of current sensor units 4 and 8 including the plurality of current detection elements 22A to 22C and 22D to 22F shift the arrangement positions of the current detection elements. Arranged. Therefore, the possibility that any current detection element is arranged at a position where the difference in distance from the conductive wires 11A and 11B is larger is increased. Therefore, since the possibility that a larger maximum output value can be obtained increases, the current measurement accuracy can be improved.

  Further, according to the current measuring means 50 shown in FIG. 6, the output values of the current detection elements 22A to 22C are amplified by connecting the amplification circuits 31A to 31C to the outputs of the current detection elements 22A to 22C. The signals are amplified by the circuits 31 </ b> A to 31 </ b> C and input to the signal processing device 34. Therefore, each output value of the plurality of current detection elements 22A to 22C can be input to the signal processing device 34 in real time.

  Further, according to the current measuring means 50 shown in FIG. 7, the outputs of the current detection elements 22 </ b> A to 22 </ b> C are connected to the switching circuit 35, and the output of the switching circuit 35 is connected to the amplifier circuit 31. Therefore, the number of amplifier circuits can be reduced compared with the case where the amplifier circuits 31A to 31C are connected to the outputs of the current detection elements 22A to 22C, respectively (FIG. 6), so that the cost can be reduced. .

  Moreover, according to the current measurement device 1 according to the present embodiment, the electric wire 10 that is a measurement target has a circular cross-sectional shape. As described above, the current measuring apparatus 1 according to the present invention can perform current measurement on not only a flat cable but also a round cable or the like by using the plurality of current detection elements 22A to 22C. .

DESCRIPTION OF SYMBOLS 1 Current measuring device 4,8 Current sensor unit 10 Electric wire 11A-11C Conductor 21A-21F Magnetic body 22A-22F Current detection element 23A-23F Gap 31, 31A-31C Amplifying circuit 34 Signal processing device

Claims (8)

A current measuring device for measuring a current flowing in an electric wire containing a plurality of conductive wires,
A plurality of current detecting elements that are arranged on the outer periphery of the arbitrary cross section of the electric wire and detect the current based on the magnetic flux generated due to the current flowing through the conducting wire;
Based on the output value of one current detection element having the maximum output value among the plurality of current detection elements, measuring means for measuring the current flowing through the wire;
A current measuring device. A plurality of magnetic bodies arranged corresponding to each of the plurality of current detection elements and guiding the generated magnetic flux to each of the current detection elements;
The current measuring apparatus according to claim 1, wherein a predetermined gap is provided between the adjacent magnetic bodies.   The current measurement device according to claim 1, wherein the plurality of current detection elements include at least three current detection elements.   The current measurement device according to claim 3, wherein the plurality of current detection elements include three current detection elements arranged at equal intervals.   5. The current measuring device according to claim 1, wherein a plurality of units including the plurality of current detection elements are arranged by shifting an arrangement position of the current detection elements. The measuring means includes
A plurality of amplifier circuits connected to outputs of the plurality of current detection elements;
A signal processing device connected to the outputs of the plurality of amplifier circuits;
The current measuring device according to claim 1, comprising: The measuring means includes
A switching circuit connected to the outputs of the plurality of current detection elements, and sequentially switching and outputting the output values from the plurality of current detection elements;
An amplifier circuit connected to the output of the switching circuit;
A signal processing device connected to the output of the amplifier circuit;
The current measuring device according to claim 1, comprising: The current measuring device according to claim 1, wherein the electric wire has a circular cross-sectional shape.

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