JP2013047660A - Current detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce decrease in current detection sensitivity while suppressing influences of unnecessary external magnetic field and external electric field.SOLUTION: A current detector 10 includes a coil 12 that is formed in an annular shape and detects current flowing through a conductor that penetrates the coil, and a shield part 13 covering the coil 12. Part of the shield part 13 covering the inner part of the coil 12 is provided with a slit 13a annularly extending along the coil 12 and communicating the coil 12 with the outside.

Description

  The present invention relates to a current detector that has a coil formed in an annular shape and detects a current flowing through a conductor penetrating the inside of the coil.

2. Description of the Related Art Conventionally, a current detector that has a coil formed in an annular shape, for example, a laminated type Rogowski coil and detects a current flowing through a conductor passing through the inside of the coil is known. In this type of current detector, for example, as disclosed in Patent Document 1, it is considered that the coil is covered with a shield portion made of a nonmagnetic material in order to suppress the influence of an unnecessary external magnetic field.
However, if the coil is covered with the shield part, the magnetic field from the conductor from which the current is to be detected is also shielded, and the current detection sensitivity is lowered.

JP 2009-85620 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a current detector capable of suppressing a decrease in current detection sensitivity while suppressing the influence of an unnecessary external magnetic field or external electric field. There is.

According to the first aspect of the present invention, the shield portion that covers the coil formed in an annular shape has a slit that extends annularly along the coil and communicates the coil and the outside in a portion that covers the inner portion of the coil. doing. Therefore, the magnetic field from the conductor penetrating the inside of the coil acts on the coil through the slit. As a result, it is possible to suppress the influence of unnecessary external magnetic field and external electric field by the shield part in the part other than the inner part of the coil, and the inner part of the coil shields the magnetic field from the current detection target conductor. Since it acts on the coil without any problem, it is possible to suppress a decrease in current detection sensitivity.
In this case, as in the invention described in claim 2, the shield portion may be provided inside a laminated substrate in which a plurality of insulating substrates are laminated. According to this configuration, the insulating substrate further exists outside the shield portion. Thereby, the current detection process can be performed in a more insulated state, and the current detection accuracy can be improved.

In addition, as a formation aspect of the shield part and a formation aspect of the slit, for example, as in the invention described in claim 3, at least a side part of the shield part is a plurality of pieces extending in the thickness direction of the current detector inside the multilayer substrate. It is possible to form through-hole pins by arranging them continuously in the circumferential direction, that is, by arranging them continuously. Further, as in the invention described in claim 4, the slit facing the inside of the coil can be formed by providing one or more unconnected layers on the side of the shield part composed of the plurality of through-hole pins. Is possible.
Further, as in the invention described in claim 5, the surface of the shield portion having the slit is covered with the inner peripheral surface of the opening formed in the laminated substrate so as to penetrate the conductor which is the current detection target. It is good to do. According to this configuration, a portion of the coil that faces the slit, that is, a portion that is not covered by the shield portion, is covered by a part of the insulating substrate that constitutes the multilayer substrate, thereby insulating the portion. Can be ensured, and current detection accuracy can be improved.

In addition, as in the invention described in claim 6, it is preferable that the slit is formed in a range where the coil exists in the thickness direction of the current detector. As in the invention described in claim 7, it is preferable that the slit has an opening width equal to or smaller than the thickness of the coil in the thickness direction of the current detector.
Further, as in the invention described in claim 8, the coil is a coil having a winding portion spirally wound in the circumferential direction and a return line portion extending in the circumferential direction in the winding portion, so-called logo. A ski coil can be used.

The perspective view which shows 1st Embodiment of this invention and shows the external appearance of a current detector Longitudinal sectional view showing the internal configuration of the current detector The perspective view which shows the structure of a coil The figure which shows the relationship between the frequency of the electric current which flows through an electric current detection object, and the passage characteristic of the magnetic field generated from an electric current detection object FIG. 2 equivalent diagram showing a comparative example The longitudinal cross-sectional view which shows the modification of 1st Embodiment and shows a part of electric current detector The top view (a) and longitudinal cross-sectional view (b) which show the modification of 1st Embodiment, and expand and show the part which covers the inner part of a coil among shield parts. FIG. 2 equivalent view according to the second embodiment of the present invention. (A) is a top view which shows an outer side part and an inner side part among shield parts, (b) is a longitudinal cross-sectional view of a shield part The figure for demonstrating the manufacturing method of an electric current detector The figure which shows the relationship between the frequency of the electric current which flows through a feed part, and the detection sensitivity of a current detector

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the current detector 10 has a substantially rectangular plate shape as a whole, and has an opening 10 a penetrating the current detector 10 at the center thereof. In this case, the opening 10a is formed in a circular shape. A conductor (not shown) which is a current detection target is inserted into the opening 10a, and the current detector 10 is configured to detect a current flowing through the conductor in this state.

Next, the internal configuration of the current detector 10 will be described with reference to FIGS. As shown in FIG. 2, the current detector 10 includes a substrate 11, a current detection coil 12, and a shield part 13.
The substrate 11 has a configuration in which a plurality of, in this case, four insulating substrates 11a to 11d are stacked in the thickness direction of the current detector 10, in other words, in the axial direction of the current detector 10. That is, the substrate 11 is a laminated substrate in which a plurality of insulating substrates 11a to 11d are laminated. The substrate 11 has an opening 11e corresponding to the opening 10a at the center.
The coil 12 is provided on the substrate 11 which is the laminated substrate, and as shown in FIG. 3, the coil 12 includes a plurality of coil forming pieces 12a, a plurality of through-hole pins 12b, and a return wire portion 12c. Yes.

  The coil forming pieces 12a are each formed in an elongated plate shape. These coil forming pieces 12a are formed in any two layers among the plurality of insulating substrates 11a to 11d constituting the substrate 11, and in this case, the outer surface of the insulating substrate 11b constituting the intermediate layer And it is arrange | positioned at the outer surface of the insulating board | substrate 11c, respectively. In this case, the outer surface of the insulating substrate 11b is the upper surface in FIG. 2, and the outer surface of the insulating substrate 11c is the lower surface in FIG. The plurality of coil forming pieces 12a are arranged in an annular shape around the opening 11e, and are arranged in a state of being directed radially. The through-hole pins 12b are respectively inserted into a plurality of through-holes formed in the insulating substrates 11b and 11c constituting two arbitrary layers of the substrate 11, in this case, the intermediate two layers, and arranged as described above. The plurality of coil forming pieces 12a are electrically connected. The coil forming piece 12 a and the through-hole pin 12 b configured as described above form a winding portion 12 d that is spirally wound in the circumferential direction of the current detector 10.

The return line portion 12c is formed in an elongated plate shape, one end portion thereof is electrically connected to one end portion of the winding portion 12d through the through-hole pin 12b, and the other end portion is configured as described above. The winding portion 12d extends in an annular shape in the circumferential direction. In this case, the return line portion 12c includes an inner surface of the insulating substrate 11b constituting the middle two layers of the plurality of insulating substrates 11a to 11d constituting the substrate 11, and an inner surface of the insulating substrate 11c. It is arranged between. In this case, the inner surface of the insulating substrate 11b is the lower surface in FIG. 2, and the inner surface of the insulating substrate 11c is the upper surface in FIG. The other end portion of the winding portion 12d and the other end portion of the return line portion 12c are electrically connected to an external signal processing circuit (not shown). This signal processing circuit executes signal processing of the current detected by the coil 12 and specifies the current flowing through the conductor that is the current detection target.
As described above, the substrate is a laminated substrate having the winding part 12d spirally wound in the circumferential direction of the current detector 10 and the return line part 12c extending in the circumferential direction in the winding part 12d. 11 is configured as a so-called laminated Rogowski coil.

The shield part 13 is made of a nonmagnetic material, and covers the substrate 11 and the coil 12 configured as described above, and constitutes an outer shell of the current detector 10. The shield part 13 mainly has a function of shielding an external magnetic field and an external electric field, that is, a magnetic field and an electric field generated from an element other than a conductor that is a current detection target penetrating the opening 10a of the current detector 10. And this shield part 13 has a slit 13a in the part which covers the inner side part of the board | substrate 11, in other words, the inner side part which is an inner peripheral part of the coil 12, and the part corresponding to said opening part 10a. The slit 13a extends in an annular shape along the coil 12, and communicates the coil 12 with the outside, that is, the space in the opening 10a.
The slit 13a is formed in the thickness direction of the current detector 10 within a range where the coil 12 exists, in other words, within a range where the insulating substrate 11b and the insulating substrate 11c sandwiched between the coils 12 exist. ing. Further, the slit 13a has an opening width in the thickness direction of the current detector 10 that is equal to or less than the thickness of the coil 12, in other words, equal to or less than the sum of the thicknesses of the insulating substrate 11b and the insulating substrate 11c sandwiched between the coils 12. have.

  According to the current detector 10 according to the present embodiment described above, a magnetic field generated from a conductor that is a current detection target inserted through the opening 10a, that is, a conductor that penetrates the inside of the coil 12, is supplied to the current detector. The coil 12 acts on the coil 12 through a slit 13a that communicates the outside and the inside of 10. Thereby, in the part other than the inner part of the coil 12, the influence of the unnecessary external magnetic field and the external electric field can be suppressed by the shield part 13, and the magnetic field from the conductor which is a current detection target is shielded in the inner part of the coil 12. Since it acts on the coil 12 without being reduced, it is possible to suppress a decrease in current detection sensitivity.

  FIG. 4 shows the relationship between the frequency of the current flowing through the conductor that is the current detection target and the detection sensitivity of the magnetic field generated from the conductor. The detection sensitivity of the magnetic field generated from the conductor is the magnitude of the induced electromotive force generated when the magnetic field generated from the conductor passes through the slit 13a and acts on the coil 12, that is, the current that the current detector 10 flows through the conductor. The sensitivity to detect is shown. As shown in FIG. 4, the detection sensitivity of the magnetic field generated from the conductor is such that when the slit 13a is provided in the shield part 13 indicated by the symbol a, the slit 13a is not provided in the shield part 13 indicated by the symbol b. Bigger than. Therefore, by providing the slit 13a in the portion of the shield portion 13 that covers the inner portion of the coil 12, it can be confirmed that the magnetic field detection sensitivity of the coil 12 is increased regardless of the frequency of the current flowing through the conductor.

  For example, as shown in FIG. 5, the slit 13 a is outside the range where the coil 12 exists in the thickness direction of the current detector 10, in other words, the insulating substrate 11 b and the insulating substrate 11 c sandwiched between the coils 12. In the configuration formed outside the existing range, it has been confirmed by experiments of the inventor that the magnetic field detection sensitivity of the coil 12 is significantly reduced. Therefore, as described above, the slit 13a is preferably formed in a range where the coil 12 exists in the thickness direction of the current detector 10. Thereby, it can avoid that the detection sensitivity of the magnetic field by the coil 12 falls remarkably.

  Moreover, as described above, the slit 13 a preferably has an opening width equal to or smaller than the thickness of the coil 12 in the thickness direction of the current detector 10. Thereby, the shielding effect of the external magnetic field and the external electric field by the shield part 13 can be sufficiently ensured. It has been confirmed by experiments of the inventors that the opening width of the slit 13a can be suppressed if the opening width of the slit 12 is at least 50 μm or more regardless of the thickness of the coil 12. If the type of current detection coil, current detection performance, shape, configuration, size, etc. are different, even if the opening width of the slit 13a is 50 μm or less, a decrease in magnetic field detection sensitivity due to the coil can be suppressed. There may be cases.

  In this embodiment, the following modifications and expansions are possible. That is, the slit 13a is basically formed in a portion covering the inner portion of the coil 12 in the shield portion 13 and extends annularly along the coil 12 so that the outside and inside of the current detector 10, that is, the coil 12 and the outside are connected. Various configurations can be adopted as long as the configurations communicate with each other. For example, as shown to Fig.6 (a), the recessed part 13b may be provided in the part which covers the inner side part of the coil 12 among the shield parts 13, and it is good also considering a part of the said recessed part 13b as a slit 13a in this case. In this case, a part of the insulating substrate 11b existing in the recess 13b is fixed to the upper insulating substrate 11a via the slit 13a.

  Moreover, as shown in FIG.6 (b), the step part 13c is provided in the part which covers the inner side part of the coil 12 among the shield parts 13, and it is good also considering a part of the said step part 13c, in this case, one surface as the slit 13a. . In this case, a part of the insulating substrate 11c existing in the step portion 13c is fixed to the insulating substrate 11b above the slit 13a, and the insulating substrate 11d existing in the step portion 13c is fixed. A part is fixed to the insulating substrate 11c on the upper part. Further, as shown in FIG. 6C, a shield piece 13 d extending downward and a shield piece 13 e extending upward are formed on the portion of the shield 13 that covers the inner side of the coil 12. You may make it provide the part which mutually opposes in a direction, ie, the overlapping part.

  Further, as shown in FIG. 7, the shield portion 13 is formed by continuously arranging a plurality of through-hole pins 13f for forming a shield surface extending in the thickness direction of the current detector 10 in the circumferential direction. One slit 13a may be formed by providing one unconnected layer 13g on the shield surface composed of the plurality of through-hole pins 13f. In this case, the unconnected layer 13g is a layer formed by dividing the through-hole pin 13f in the axial direction of the current detector 10, that is, in the thickness direction, and each part of the divided through-hole pin 13f is mutually connected. It is a layer that is not connected. Note that a plurality of slits 13a may be formed by providing a plurality of unconnected layers 13g, that is, one or more layers. Moreover, you may form the part which covers the inner part of the coil 12 among the shield parts 13 by arrange | positioning continuously in the circumferential direction, without overlapping the several through-hole pin 13f.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. Only the differences from the first embodiment will be described below. As shown in FIG. 8, the current detector 20 has an opening 20 a penetrating the current detector 20 in the axial direction at the center, and a current detection coil 22 and a magnetic field inside the substrate portion 21. And a shielding part 23 for shielding. In this case, the opening 20a is configured by an opening 21a provided at the center of the substrate 21 so as to penetrate the substrate 21 in the axial direction. That is, the opening 21 a of the substrate portion 21 constitutes the opening 20 a of the current detector 20.

The substrate portion 21 has a configuration in which a plurality of, in this case, 12 insulating substrates 21A to 21L are stacked in the thickness direction of the current detector 20, in other words, in the axial direction of the current detector 20. That is, this board | substrate part 21 is a laminated substrate which laminated | stacked several insulating board | substrates 21A-21L. The current detector 20 includes a coil 22 and a shield part 23 inside the substrate part 21. Therefore, the current detector 20 has a configuration in which the outer periphery is formed by the substrate portion 21, and the insulating substrate which is a part of the substrate portion 21 is exposed on the surface of the current detector 20.
The coil 22 is provided inside the substrate portion 21 which is the laminated substrate, and a winding portion 22d including a plurality of coil forming pieces 22a and a plurality of through-hole pins 22b, and the inside of the winding portion 22d in the circumferential direction. And a return line portion 22c extending in an annular shape. That is, the coil 22 is also configured as a so-called laminated Rogowski coil.

  The shield part 23 is made of a non-magnetic material, and covers the coil 22 configured as described above inside the substrate part 21. And this shield part 23 bears the function which mainly shields the external magnetic field and external electric field, ie, the magnetic field and electric field which generate | occur | produce from elements other than the conductor which is the electric current detection object which penetrated the opening part 20a of the current detector 20. FIG. And this shield part 23 has the slit 23a in the part which covers the inner peripheral part of the coil 22. FIG. The slit 23a extends in an annular shape along the circumferential direction of the coil 22, and opens between the coil 22 and the opening 20a. That is, the shield part 23 is configured to cover almost the entire coil 22 except for a part of the inner peripheral part of the coil 22, that is, a part facing the opening 20a.

  The slit 23a is formed in the thickness direction of the current detector 20 within a range where the coil 22 exists, in other words, within a range where the insulating substrates 21E to 21H sandwiched between the coils 22 exist. The slit 23 a has an opening width in the thickness direction of the current detector 20 that is equal to or less than the thickness of the coil 22, in other words, equal to or less than the sum of the thicknesses of the insulating substrates 21 </ b> E to 21 </ b> H sandwiched between the coils 22. ing.

  As shown in FIG. 9, the outer side portion (outer side surface portion) and the inner side portion (inner side surface portion) of the shield portion 23 are a plurality of through-hole pins extending in the thickness direction of the current detector 20 inside the substrate portion 21. It is formed by arranging 23f continuously in the circumferential direction. On the inner side of the shield part 23, one slit 23a is formed by providing one unconnected layer 23g on the inner side of the shield part 23 composed of the plurality of through-hole pins 23f. In this case, the unconnected layer 23g is a layer formed by dividing the through-hole pin 23f in the axial direction of the current detector 20, that is, the thickness direction, and each part of the divided through-hole pin 23f is mutually connected. It is a layer that is not connected. Note that a plurality of slits 23a may be formed on the side of the shield part 23 by providing a plurality of unconnected layers 23g, that is, one or more layers. Moreover, you may form the part which covers the inner side part of the coil 12 among the shield parts 23 by arrange | positioning continuously in the circumferential direction, without overlapping the several through-hole pin 23f.

  Moreover, the surface which has the slit 23a among the shield parts 23 is covered with the part which comprises the internal peripheral surface of the opening part 21a among the board | substrate parts 21 which consist of a several insulating board | substrate. That is, the shield part 23 that covers the coil 22 is not exposed to the opening 20a of the current detector 20 through which the conductor that is the current detection target penetrates (the part that includes the opening 21a of the substrate part 21), and is not exposed to the outside. It is covered with an insulating substrate without opening.

Next, a method of manufacturing the current detector 20 in which the shield part 23 is provided inside the substrate part 21 as described above will be described with reference to FIG. In this case, the current detector 20 is manufactured by using a manufacturing technique in which a plurality of flexible resin insulating substrates are stacked and the stacked substrates are formed by hot pressing them in a lump.
That is, the insulating substrate a shown in FIG. 10 (a) uses, for example, a resin film made of a thermoplastic resin as a base material. In this case, the thermoplastic resin becomes soft at, for example, around 200 ° C., and has a property of maintaining hardness when the temperature is lowered from a high temperature. And the metal foil b which consists of nonmagnetic materials, such as copper, for example is affixed on the single side | surface of the insulating board | substrate a which consists of such a thermoplastic resin.

  Next, the process proceeds to the steps of FIGS. 10B and 10C, respectively. In the step of FIG. 10B, the metal foil b is etched to form a pattern c that constitutes the upper surface or the lower surface of the shield part 23. Moreover, the protective film d is affixed on the surface in which the pattern c is not formed among the insulating substrates a. On the other hand, in the step of FIG. 10C, the metal foil b is peeled from the insulating substrate a. Moreover, the protective film d is affixed on the surface in which the pattern c is not formed among the insulating substrates a.

Next, the process proceeds to the steps of FIG. 10 (d) and FIG. 10 (e), respectively. In the step of FIG. 10D, a laser beam is irradiated from the protective film d side to form a bottomed through hole e having the pattern c as a bottom surface. At this time, the hole of the pattern c is prevented from opening by adjusting the laser intensity, irradiation time, and the like. Also in the process of FIG. 10E, a through hole e is formed by irradiating a laser from the protective film d side.
Next, the process proceeds to the steps of FIG. 10 (f) and FIG. 10 (g), respectively. In the steps of FIG. 10F and FIG. 10G, the metal paste f made of a nonmagnetic material such as copper is filled in the through hole e. The metal paste f can be filled by screen printing using a metal mask, for example.

Next, the process proceeds to the steps of FIG. 10 (h) and FIG. 10 (i), respectively. In these steps of FIG. 10H and FIG. 10I, the protective film d is peeled from the insulating substrate a. In the following steps, for convenience of explanation, the insulating substrate generated by the steps (b), (d), (f), and (h), that is, the insulating substrate a having the pattern c is referred to as the insulating substrate a1. The insulating substrate generated by the steps (c), (e), (g), and (i), that is, the insulating substrate a having no pattern c is referred to as an insulating substrate a2.
Next, the process proceeds to the step of FIG. In this step, a plurality of insulating substrates a2 are stacked between the two insulating substrates a1. Further, both insulating substrates a1 sandwiching a plurality of insulating substrates a2 are further sandwiched by two insulating substrates a3. The insulating substrate a3 is obtained by peeling the metal foil b from the insulating substrate a with the metal foil b shown in the step of FIG. 10A, and has neither the pattern c nor the metal paste f. It is.

Next, the process proceeds to the process of FIG. In this step, the laminated insulating substrates a1, a2, and a3 are pressed by hot pressing. This hot pressing is performed, for example, at 200 to 350 ° C. under the condition of 0.1 to 10.0 MPa. As a result, the insulating substrates a1, a2, and a3 are pressed in a softened state and fused to each other, thereby forming the substrate portion 21 having the shield portion 23 therein.
In the completed state of the substrate portion 21, the pattern c is integrated with the metal paste f to form the shield portion 23 inside the substrate portion 21. In this case, the pattern c forms the upper and lower surfaces of the shield part 23, and the plurality of metal pastes f form the through-hole pins 23f.

  Next, the result of the simulation performed by the inventor for the current detector 20 configured as described above will be described with reference to FIG. In FIG. 11, the symbol a indicates the detection sensitivity of the current detector 20 with respect to the internal magnetic field generated from the power supply unit when a power supply unit (not shown) as a conductor is inserted into the opening 20 a of the current detector 20. ing. Reference sign b indicates the detection sensitivity of the current detector 20 with respect to an internal electric field generated from the power supply section when a power supply section (not shown), which is a conductor, is inserted into the opening 20a of the current detector 20. Reference numeral c denotes a conductor (not shown), which is a conductor, arranged horizontally with a predetermined distance (for example, about 0.5 mm) from the current detector 20, in other words, the power feeder is connected to the current detector 20. In the case where the current detector 20 is arranged so as to be orthogonal to the axial direction, the detection sensitivity of the current detector 20 with respect to the external electric field generated from the power supply unit is shown. In addition, the symbol d indicates that a power supply unit (not shown) that is a conductor is arranged vertically with a predetermined distance (for example, about 0.5 mm) from the current detector 20, in other words, the power supply unit is connected to the current detector 20. When it arrange | positions so that it may be parallel to the axial direction of this, the detection sensitivity of the current detector 20 with respect to the external electric field generated from the said electric power feeding part is shown. In this case, the power feeding unit used had an internal impedance of about 50Ω.

As is clear from the simulation results shown in FIG. 11, the detection sensitivity for the internal electric field (see symbol b) or the detection sensitivity for the external electric field (see symbols c and d) of the current detector 20 is as follows. a) and significantly lower. That is, it is confirmed that the current detector 20 configured as described above is not easily influenced by the internal electric field or the external electric field, and reacts with high accuracy to the internal magnetic field generated from the conductor inserted through the opening 20a. It was done.
According to the embodiment described above, since the shield portion 23 is provided inside the substrate portion 21, the insulating substrate is further present outside the shield portion 23. It is possible to sufficiently ensure the insulation between the circuit and the shield part 23 and the coil 22 covered by the shield part 23. Thereby, the current detection process can be performed in a more insulated state, and the current detection accuracy can be improved.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist thereof. For example, the present invention can be modified or expanded as follows.
The coils 12 and 22 are not limited to so-called Rogowski coils, and various coils can be adopted. For example, a current transformer may be used. In short, any coil may be used as long as it is formed in an annular shape and detects a current flowing through a conductor penetrating the inside. The coils 12 and 22 are not limited to an annular shape, and may be formed in an elliptical shape, a rectangular shape, or a polygonal shape, for example. Further, the openings 10a and 20a are not limited to a circular shape, and may be formed in an elliptical shape, a rectangular shape, or a polygonal shape, for example.

The insulating substrates constituting the substrates 11 and 21 are not limited to four or twelve. In short, it is preferable that the substrates 11 and 21 are formed of a laminated substrate in which a plurality of substrates are laminated.
In addition, a plurality of slits 13 a and 23 a may be provided in portions of the shield portions 13 and 23 that cover the inner portions of the coils 12 and 22.
Further, the opening widths of the slits 13a and 23a can be appropriately changed and set according to the type of the current detection coil, the current detection performance, the shape, the configuration, the size, and the like.
You may implement combining each embodiment mentioned above.

  In the drawings, 10 and 20 are current detectors, 11 and 21 are substrates (laminated substrates), 12 and 22 are coils, 12c and 22c are return wire portions, 12d and 22d are winding portions, 13 and 23 are shield portions, Reference numerals 13a and 23a denote slits, reference numerals 13f and 23f denote through-hole pins, and reference numerals 13g and 23g denote unconnected layers.

Claims (8)

A coil that is formed in an annular shape and detects a current flowing through a conductor penetrating the inside;
A shield that covers the coil;
A current detector comprising:
The shield part is a current detector having a slit that extends in an annular shape along the coil and communicates the coil and the outside at a portion that covers the inner part of the coil.   The current detector according to claim 1, wherein the shield part is provided inside a laminated substrate in which a plurality of insulating substrates are laminated.   The current detector according to claim 2, wherein the side portion of the shield portion is formed by continuously arranging a plurality of through-hole pins extending in the thickness direction in the laminated substrate in the circumferential direction.   The current detector according to claim 3, wherein the slit is formed by providing one or more unconnected layers on a side portion of the shield portion including a plurality of the through-hole pins. The laminated substrate has an opening for penetrating the conductor,
5. The current detector according to claim 2, wherein a surface of the shield portion having the slit is covered with an inner peripheral surface of the opening.   The current detector according to any one of claims 1 to 5, wherein the slit is formed in a range where the coil exists in a thickness direction of the current detector.   The current detector according to any one of claims 1 to 6, wherein the slit has an opening width equal to or smaller than a thickness of the coil in a thickness direction of the current detector. The coil is
A winding portion spirally wound in the circumferential direction;
A return line portion extending in the circumferential direction in the winding portion;
The current detector according to claim 1, comprising:

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