Radio power supply device

Abstract

To enable radio transmission while nipping a strong magnetic body.SOLUTION: A radio power supply device comprises: a first member and a second member that are oppositely provided across a strong magnetic plate-like member; and a power supply part that supplies power to a first coil having the first member. The first member and the second member are provided across the plate-like member. The first member includes a first core to which the first coil is provided, and the second member includes a second coil and a second core to which the second coil is provided. The first core includes: a first end member; and a first coupling part to which the first coil is provided. The second core includes: a second end member; and a second coupling part to which the second coil is provided. A first end as a tip end of the first end member and a second end as a tip end of the second end member are opposite at a position separated from a plurality of positions across the plate-like member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wireless power supply device. [Background technology]

[0002] Patent Document 1 discloses a filter system for wireless power transmission. In this filter system, a wireless power receiver is associated with a filter body, and the wireless power receiver includes a feedback channel circuit. The feedback channel circuit includes a receiving antenna, a control circuit in electrical communication with the wireless power receiver, and a feedback channel circuit in communication with the control circuit, and is configured to transmit through a channel separated from the receiving antenna.

[0003] Also, Non-Patent Document 1 discloses that power is supplied to a sensor inside a metal wall using a circuit system of the SS type or SP type. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-512778 [Non-Patent Document 1] Mai Otsuka, Takehiro Imura, Hiroshi Fujimoto, and Yoichi Hori, "Basic Study on Circuit Configuration for Improving Efficiency of Wireless Power Transmission Through Metal Walls," IEICE Technical Report, January 2017, Vol. 116, No. 398, pp. 33-38 Summary of the Invention [Problem to be solved by the invention]

[0005] The invention described in Patent Document 1 uses high-frequency electromagnetic waves such as 14 MHz. However, when the receiving side or transmitting side of high-frequency electromagnetic waves is covered with a conductive material, the electromagnetic waves are attenuated, making it impossible to communicate or supply power.

[0006] Prior art document 1 discloses a wireless power supply technology that transmits power even when a metal wall is present between the coils by passing an AC current with a frequency of 100 KHz or the like through the coils and using magnetic resonance coupling between two coils placed through a metal wall. However, in the conventional technologies including Prior art document 1 in particular, it is difficult to supply power wirelessly across a ferromagnetic body (including materials such as iron-based metals with high magnetic permeability).

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a wireless power supply device capable of performing wireless transmission via a ferromagnetic material. [Means for solving the problem]

[0008] In order to solve the above problem, the wireless power supply device of the present invention is, for example, a wireless power supply device including a first member and a second member arranged opposite each other with a plate-shaped member made of a ferromagnetic material therebetween, and a power supply unit that supplies power to a first coil of the first member, wherein the first member and the second member are arranged opposite each other with the plate-shaped member in between, the first member has a first core in which the first coil is arranged, the second member has a second coil and a second core in which the second coil is arranged, the first core has a first end member and a first connecting portion in which the first coil is arranged, the second core has a second end member and a second connecting portion in which the second coil is arranged, and a first end which is a tip of the first end member and a second end which is a tip of the second end member face each other at multiple separated positions across the plate-shaped member.

[0009] According to the wireless power supply device of the present invention, a first member having a first coil and a first core and a second member having a second coil and a second core are provided facing each other with a ferromagnetic plate-like member sandwiched between them. A first end, which is a tip of a first end member of the first core, and a second end, which is a tip of a second end member, face each other at a plurality of separated positions with the plate-like member sandwiched between them. This allows wireless transmission to be performed with the ferromagnetic member sandwiched between them.

[0010] The first core and the second core may be formed into a U-shape, a V-shape, or a U-shape by a rod-like or band-like member, the first end member has a third end member and a fourth end member arranged at a distance from each other, the first connecting portion connects the third end member and the fourth end member, the second end member has a fifth end member and a sixth end member arranged at a distance from each other, the second connecting portion connects the fourth end member and the fifth end member, the third end which is the tip of the third end member faces the fifth end which is the tip of the fifth end member across the plate-like member, and the fourth end which is the tip of the fourth end member faces the sixth end which is the tip of the sixth end member across the plate-like member. This allows the magnetic poles of the second core to be separated from each other, and wireless transmission across the plate-like member to be performed efficiently.

[0011] The first end and the plate-like member may be in contact with each other, and the second end and the plate-like member may be in contact with each other, thereby reducing magnetic resistance at the first end and the second end and enabling efficient wireless transmission.

[0012] The power supply unit may change the magnetic flux generated by the first coil at a frequency of 60 kHz or less, thereby making it possible to reduce the power that can be wirelessly transferred to at least 1 / 1000 of the original power.

[0013] The power supply unit may modulate an alternating current flowing through the first coil, thereby enabling wireless communication from the first member to the second member.

[0014] The wireless communication device may further include an adjustment unit that changes the impedance of a circuit including the second coil, and an acquisition unit that acquires the change in impedance of the circuit by the adjustment unit by measuring the current flowing through the first coil. This enables wireless communication from the second member to the first member. Effect of the Invention

[0015] According to the present invention, wireless transmission can be performed by sandwiching a ferromagnetic material. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an outline of a wireless power supply device 1. FIG. [Diagram 2] 2 is a diagram showing a simplified model of the wireless power supply device 1. The positional relationship between the members in Fig. 2 is obtained by tilting Fig. 1 by 90° to the right. [Diagram 3] 2 is a block diagram showing an outline of the electrical configuration of the wireless power supply device 1. FIG. [Figure 4] 11 is a graph showing the relationship between the frequency of magnetic flux and loss when power is transmitted wirelessly. [Diagram 5] 13(A) to 13(C) are diagrams showing examples of the shape of a core according to a modified example. [Figure 6] FIG. 1 is a diagram illustrating a conventional example. [Figure 7] FIG. 1 is a diagram illustrating a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The wireless power supply device of the present invention performs wireless transmission by sandwiching a plate-shaped member made of ferromagnetic material. A ferromagnetic material is a material that has the property of being strongly magnetized by an externally applied magnetic field and retaining the magnetization even when the magnetic field is removed (ferromagnetic material). Examples of ferromagnetic materials include iron, nickel, cobalt, and alloys containing these materials (carbon steel, alloy steel, cast iron, etc.) or oxides (ferrite, etc.). The wireless transmission of the present invention is a concept that includes wireless power supply and communication. In general, ferromagnetic materials have a high relative magnetic permeability.

[0018] <First embodiment> 1 is a diagram showing an outline of a wireless power supply device 1. The wireless power supply device 1 mainly has a first member 10 and a second member 20. The first member 10 and the second member 20 are electromagnets, and are provided with a plate-like member 100 made of a ferromagnetic material sandwiched between them. For example, the first member 10 is provided outside a case, and the second member 20 is provided inside the case. The first member 10 is the primary side (the side that sends power), and the second member 20 is the secondary side (the side that receives power).

[0019] The first member 10 mainly has a core 11 and a coil 12 provided in the core 11. The second member 20 mainly has a core 21 and a coil 22 provided in the core 21. The core 11 and the core 21 have approximately the same shape.

[0020] Core 11 has end members 11a and 11b (corresponding to a first end member of the present invention) that are spaced apart from each other, and a connecting portion 11c (corresponding to a first connecting portion of the present invention) that connects end member 11a and end member 11b. Coil 12 is provided on connecting portion 11c.

[0021] Similar to core 11, core 21 has end members 21a and 21b (corresponding to the second end member of the present invention) disposed apart from each other, and a connecting portion 21c (corresponding to the second connecting portion of the present invention) connecting end member 21a and end member 21b. Coil 22 is provided on connecting portion 21c.

[0022] In this embodiment, the cores 11 and 21 are formed of rod-shaped or strip-shaped members. In this embodiment, the cores 11 and 21 are U-shaped, but the cores 11 and 21 may be U-shaped or V-shaped (described in detail later). The end member 11a corresponds to the third end member of the present invention, and the end member 11b corresponds to the fourth end member of the present invention. The end member 21a corresponds to the fifth end member of the present invention, and the end member 21b corresponds to the sixth end member of the present invention.

[0023] The areas of the tips 11d and 21d are substantially the same, and the areas of the tips 11e and 21e are substantially the same. The tip 11d (corresponding to the third end of the present invention) of the end member 11a faces the tip 21d (corresponding to the fifth end of the present invention) of the end member 21a across the plate-like member 100. The tip 11e (corresponding to the fourth end of the present invention) of the end member 11b faces the tip 21e (corresponding to the sixth end of the present invention) of the end member 21a across the plate-like member 100.

[0024] In this way, the tips 11d, 11e of core 11 and the tips 21d, 21e of core 21 face each other at multiple separated positions across the plate-shaped member 100, generating a pair of strong magnetic fields, thereby enabling wireless transmission with the magnetic material sandwiched between them.

[0025] In order to perform wireless transmission, it is required that the magnetic flux path is in close contact with the plate-shaped member 100. If there is a gap d between the tips 11d, 21d, 11e, 21e and the plate-shaped member 100, the magnetic resistance increases, and the efficiency of wireless transmission decreases. Therefore, it is desirable that the tips 11d, 21d, 11e, 21e abut the plate-shaped member 100. However, it is difficult to completely eliminate the gap d between the tips 11d, 21d, 11e, 21e and the plate-shaped member 100 (the gap d between the tips 11d, 21d, 11e, 21e and the plate-shaped member 100=0). Therefore, in the present invention, abutment is a concept that includes a case where two members (here, the tips 11d, 21d, 11e, 21e and the plate-shaped member 100) are in contact with each other and a case where they are adjacent to each other with a small distance (about 1 to 2 mm) between them.

[0026] In order to bring the tips 11d, 21d, 11e, and 21e into contact with the plate-shaped member 100, it is preferable that the tips 11d, 21d, 11e, and 21e be flat when the surface of the plate-shaped member 100 is flat, as shown in Fig. 1. In addition, for example, when the plate-shaped member 100 is curved, it is preferable that the tips 11d, 21d, 11e, and 21e be curved along the plate-shaped member 100.

[0027] Furthermore, in order to perform wireless transmission, it is necessary to reduce as much as possible the magnetic flux passing through the inside of the plate-shaped member 100. Specifically, by making the magnetic resistance of the plate-shaped member 100 at least α times the magnetic resistance of the magnetic circuit (including the coil 22) on the receiving side (second member 20), it is possible to make the leakage of magnetic flux to the plate-shaped member 100 1 / α or less of the magnetic flux flowing through the coil 22. This will be explained in detail below.

[0028] When the plate-shaped member 100 is a ferromagnetic material, it is difficult to perform wireless transmission even using magnetic resonance coupling. The author came up with the idea that the reason is that most of the magnetic flux generated by the coil 12 on the transmitting side passes only through the inside of the ferromagnetic material and returns to the transmitting side again, and performed an analysis using a magnetic circuit model. First, in a situation where the cores 11 and 21 shown in FIG. 1 face each other through the plate-shaped member 100, it is desirable that the gap d is zero. Therefore, the gap d is simplified to zero. Furthermore, if the plate-shaped member 100 and the cores 11 and 21 are made of the same material for simplification, FIG. 1 can be expressed by a greatly simplified model as shown in FIG. 2 (three-legged iron core magnetic circuit). In FIG. 2, the positional relationship between the members in FIG. 1 is tilted 90 degrees to the right.

[0029] 2, the magnetic flux generated by coil 104 in left leg 101 is distributed to center leg 103 and right leg 102. The distribution ratio at this time is the inverse ratio of the magnetic resistance (= length L / (magnetic permeability μ×cross-sectional area S)) of center leg 103 and right leg 102. The magnetic resistance can be expressed by the following formula (1). [Number 1] Magnetic reluctance = length L / (magnetic permeability μ × cross-sectional area S) (1)

[0030] For example, when (magnetic resistance of center leg 103):(magnetic resistance of right leg 102)=10:1, (magnetic flux of center leg 103):(magnetic flux of right leg 102)=1:10.

[0031] Therefore, to optimize power transmission through the plate-shaped component 100, it is desirable to reduce the magnetic flux leaking into the central leg 103 and increase the magnetic flux flowing through the right leg 102. To achieve this, the magnetic resistance of the central leg 103 is increased and the magnetic resistance of the right leg 102 is decreased.

[0032] Since the magnetic resistance is expressed by the above formula (1), it is better for the center leg 103 to have a small cross-sectional area or a long length. Also, it is better for the right leg 102 to be short in length and large in cross-sectional area. In other words, it is better for the center leg 103 to be thinner, for the poles of the coils 104, 105 to be farther apart, and for the end faces of the cocoils 104, 105 to be thicker.

[0033] 1, right leg 102 in Fig. 2 corresponds to gap d between tip 21d and plate-like member 100, the length of core 21, and gap d between tip 21e and plate-like member 100 in Fig. 1. Effective ways to reduce the magnetic resistance in this portion are (1) increasing the cross-sectional area and shortening the length of core 21, (2) increasing the distance D between tip 11d and tip 11e and the distance D between tip 21d and tip 21e, and (3) reducing gap d.

[0034] Regarding (1) above, in order to increase the area of ​​tips 21d, 21e and shorten core 21, it is preferable to use a rod-shaped or band-shaped member, and in particular to curve or bend a rod-shaped member to form U-shaped core 21. Regarding (2) above, by separating the magnetic poles (distance D), it is possible to increase the magnetic resistance of the portion corresponding to central leg 103 in Fig. 2. Also, regarding (3) above, the medium inside gap d is air, etc., which has a smaller relative permeability and a larger magnetic resistance compared to iron, so it is preferable to make gap d as small as possible, or set it to 0.

[0035] Furthermore, in order to reduce the magnetic resistance in the portion corresponding to the right leg 102 (gap d between the tip 21d and the plate-like member 100, the length of the core 21, and the length of the gap d for two of the cores), it is desirable to insert a core 21 (iron core, etc.) in the second member 20 to increase the magnetic permeability. The first member 10 and the second member 20 use U-shaped cores 11, 21. Magnetic poles are concentrated in the cores 11, 21. Also, the use of the core 21 reduces the magnetic resistance in the portion corresponding to the right leg 102 in FIG. 2.

[0036] Thus, considering the overall picture, the U-shaped core 21 can increase the magnetic resistance of the plate-like member 100 and reduce the magnetic resistance of the part corresponding to the right leg 102 in Figure 2, thereby improving the efficiency of wireless transmission.

[0037] 3 is a block diagram showing an outline of the electrical configuration of the wireless power supply device 1. The wireless power supply device 1 mainly includes a first circuit 55 on the power transmission side included in the first member 10, and a second circuit 56 on the power reception side included in the second member 20. The first circuit 55 mainly includes a power supply unit 55a and an acquisition unit 55b. The second circuit 56 mainly includes a reception unit 56a and an adjustment unit 56b.

[0038] First, power supply by the wireless power supply device 1 will be described. The power supply unit 55a supplies power to the coil 12. When power is supplied by the power supply unit 55a and a current flows through the coil 12, a magnetic field is generated between the core 11 and the core 21, and an induced current is generated in the coil 22 due to a change in this magnetic field. The receiver 56a supplies the power generated by the induced current flowing through the coil 22 to a battery (not shown). Thus, wireless power supply is performed.

[0039] Here, the frequency of the magnetic flux generated by coil 12 will be described. Because eddy current loss is proportional to the square of the frequency (see Non-Patent Document 1), it is preferable to set the frequency as low as possible. In particular, in order to make the power that can be transmitted wirelessly at least 1 / 1000 of the original power (attenuation of -30 dB or less), it is preferable to set the frequency of the magnetic flux generated by coil 12 to 60 kHz or less.

[0040] Fig. 4 is a graph showing the relationship between the frequency of the magnetic flux and the loss (attenuation) when transmitting power wirelessly. The graph in Fig. 4 shows the results obtained using a plate-like member 100 having a thickness of about 0.5 mm. To limit the loss to 30 dB, the frequency of the magnetic flux generated by the coil 12 should be set to 60 kHz or less.

[0041] In addition, the upper limit of the frequency can be increased by decreasing the thickness of the plate-like member 100, and the upper limit of the frequency can be decreased by increasing the thickness of the plate-like member 100. However, since a plate-like member 100 of approximately 0.5 mm is the practical limit of its thinness, it can be said that the upper limit of the frequency of the magnetic flux generated by the coil 12 is 60 kHz.

[0042] 3, a description will be given of wireless communication (data communication) by the wireless power supply device 1. The wireless communication includes wireless communication from the first circuit 55 to the second circuit 56 and wireless communication from the second circuit 56 to the first circuit 55.

[0043] First, a description will be given of wireless communication from the first circuit 55 to the second circuit 56. The power supply unit 55a modulates the current flowing through the coil 12 as necessary. The power supply unit 55a may include a rectifier circuit, a modulation circuit, and the like.

[0044] For example, the power supply unit 55a can perform amplitude modulation, frequency modulation, and phase modulation of an AC current that is a sine wave. The power supply unit 55a can also rectify the sine wave and modulate it into a pulse wave. The modulation into a pulse wave can be OnOff modulation in which the voltage is 0 when Off, or OnOff modulation with offset in which the voltage is not 0 when Off, etc. For example, when the amplitude of the sine wave of the AC current is 2V, the power supply unit 55a switches between an amplitude of 0V and an amplitude of 2V at a time width longer than the period of the sine wave. For example, when the amplitude of the sine wave of the AC current is 2V, the power supply unit 55a switches between an amplitude of 1V and an amplitude of 2V at a time width longer than the period of the sine wave.

[0045] The receiver 56a detects the waveform of the signal that the power supply unit 55a has sent to the coil 12 based on the induced current generated in the coil 22. The receiver 56a also holds the relationship between the waveform that the power supply unit 55a has sent to the coil 12 and the data, and acquires the data transmitted from the first circuit 55 to the second circuit 56 based on this relationship. For example, the receiver 56a may include a demodulation circuit.

[0046] Next, wireless communication from the second circuit 56 to the first circuit 55 will be described. The adjustment unit 56b changes the impedance of a circuit including the coil 22. This makes it possible to wirelessly transmit information from the second circuit 56 to the first circuit 55. The adjustment unit 56b may include an impedance converter.

[0047] The acquiring unit 55b measures the current flowing through the coil 12. When the impedance of the coil 22 is changed by the adjusting unit 56b, the current flowing through the coil 12 changes. The acquiring unit 55b acquires the change in the impedance of the coil 22 by measuring the current flowing through the coil 12. The acquiring unit 55b holds the relationship between the change in impedance of the coil 22 and data, and acquires data transmitted from the second circuit 56 to the first circuit 55 based on this relationship.

[0048] According to this embodiment, the tips 11d, 11e of the core 11 and the tips 21d, 21e of the core 21 face each other at multiple separated positions across the plate-shaped member 100, so that wireless transmission can be performed using the wireless power supply device 1 by sandwiching the plate-shaped member 100 made of a ferromagnetic material.

[0049] Furthermore, according to this embodiment, by using cores 11, 21 formed into a U-shape using rod-like or band-like members and arranging coils 12, 22 at connecting portions 11c, 21c, the magnetic poles (tips 11d, 21d and tips 11e, 21e) are separated from each other, and wireless transmission can be efficiently performed across the plate-like member 100.

[0050] For example, in the case of a rod-shaped core as shown in Fig. 6, the magnetic pole on the outside of the core is far from the plate-shaped member 100, and the magnetic lines must pass through the air, resulting in a large magnetic resistance and making it impossible to perform wireless transmission beyond the plate-shaped member made of ferromagnetic material. In the case of a planar coil as shown in Fig. 7 (see Prior Art Document 1), the cross-sectional area when the magnetic lines pass through the ferromagnetic material is the circumference x thickness, so the magnetic resistance of the plate-shaped member made of ferromagnetic material is small, resulting in poor wireless transmission efficiency. In addition, the planar coil as shown in Fig. 5 does not include an iron core, so the magnetic resistance on the secondary side is large, which also leads to poor wireless transmission efficiency.

[0051] In contrast, in the wireless power supply device 1 having the U-shaped cores 11, 21, the magnetic poles are concentrated, so that the cross-sectional area when the magnetic flux leaks through the plate-shaped member 100 can be reduced, and the magnetic resistance of the plate-shaped member 100 can be increased. Also, by separating the magnetic poles (distance D), the magnetic resistance of the plate-shaped member 100 can be increased. Also, since the core 21 is included in the structure, the magnetic resistance on the secondary side is small. Therefore, the U-shaped cores 11, 21 can increase the magnetic resistance of the plate-shaped member 100 and reduce the magnetic resistance on the secondary side, thereby enabling efficient wireless transmission.

[0052] Furthermore, according to this embodiment, by bringing the tips 11d, 21d, 11e, and 21e into contact with the plate-like member 100, the magnetic resistance can be reduced, and wireless transmission can be performed efficiently.

[0053] Furthermore, according to this embodiment, by changing the magnetic flux generated by coil 12 at a frequency of 60 kHz or less, the power that can be wirelessly transmitted can be reduced to 1 / 1000 or more of the original power.

[0054] Furthermore, according to this embodiment, wireless communication can be performed from the first circuit 55 to the second circuit 56 by modulating the current that the power supply unit 55a supplies to the coil 12.

[0055] Moreover, according to the present embodiment, the adjustment unit 56b changes the impedance of the circuit including the coil 22, so that wireless communication can be performed from the second circuit 56 to the first circuit 55.

[0056] In this embodiment, the core 11 and the core 21 have substantially the same shape, but the shapes of the cores 11 and 21 may be different. For example, the height of the core 11 may be greater than the height of the core 21. By increasing the height of the core 11, the number of turns of the coil 12 can be increased or the size can be increased. Alternatively, the thickness of the core 21 may be greater than that of the core 11. By making the core 21 thicker, the area of ​​the tips 21d and 21e becomes greater than that of the tips 11d and 11e, and the magnetic flux that has expanded in area when entering the plate-like member 100 from the tips 11d and 11e can be efficiently passed through the core 21.

[0057] In the present embodiment, the cores 11 and 21 are U-shaped, but the shape of the cores 11 and 21 is not limited to this. Figs. 5(A) to 5(C) are diagrams showing an example of the shape of the core according to a modified example (illustration of the coil is omitted in Fig. 5). Fig. 5(A) shows the first member 10A and the second member 20A having V-shaped cores 11A and 21A, Fig. 5(B) shows the first member 10B and the second member 20B having U-shaped cores 11B and 21B, and Fig. 5(C) shows the first member 10C and the second member 20C having cylindrical cores 11C and 21C. In any case, the cores face each other at a plurality of separate positions across the plate-shaped member 100, so that wireless transmission can be performed across the plate-shaped member 100. However, in order to perform efficient wireless transmission, it is desirable to use a U-shape (see FIG. 1), a U-shape (see FIG. 5(B)), or a V-shape (see FIG. 5(A)) in which the magnetic poles are spaced apart.

[0058] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes within the scope of the gist of the present invention are also included. For example, the above example has been described in detail to clearly explain the present invention, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of the embodiment with the configuration of another embodiment, and it is also possible to add, delete, or replace other configurations to the configuration of the embodiment.

[0059] In addition, "approximately" is a concept that includes not only the case of being strictly identical, but also an error or deformation that does not lose the identity. For example, "cylindrical shape" is not limited to the case of being strictly cylindrical, but is a concept that includes, for example, a case that can be regarded as being identical to a cylindrical shape. In addition, for example, when expressing orthogonal, parallel, coincident, etc., it includes not only strictly orthogonal, parallel, coincident, etc., but also approximately parallel, approximately orthogonal, approximately coincident, etc.

[0060] In addition, "vicinity" means including a certain range (which can be determined arbitrarily) near a reference position. For example, in the case of "near an end," it is a concept indicating a certain range of an area near the end, which may or may not include the end. [Explanation of symbols]

[0061] 1: Wireless power supply device 10, 10A, 10B, 10C: First member 20, 20A, 20B, 20C: second member 11, 11A, 11B, 11C, 21, 21A, 21B, 21C: Core 11a, 11b, 21a, 21b: End members 11c, 21c: Connection part 11d, 11e, 21d, 21e: Tip 12, 22: Coil 55: 1st circuit 55a: Power supply section 55b: Acquisition part 56: 2nd circuit 56a: Receiving section 56b: Adjustment section 60: Sensor 100: Plate-shaped member 101:Left leg 102:Right leg 103: Central leg 104, 105: Coil

Claims

1. a first member and a second member disposed opposite each other with a ferromagnetic plate-shaped member interposed therebetween; a power supply unit that supplies power to a first coil included in the first member; A wireless power supply device comprising: the first member and the second member are provided with the plate-like member sandwiched therebetween, the first member has a first core on which the first coil is provided, the second member has a second coil and a second core on which the second coil is provided, the first core has a first end member and a first connecting portion provided with the first coil, the second core has a second end member and a second connecting portion to which the second coil is provided, A wireless power supply device characterized in that a first end, which is the tip of the first end member, and a second end, which is the tip of the second end member, face each other at multiple separated positions across the plate-shaped member.

2. The first core and the second core are formed into a U-shape, a V-shape, or a U-shape using rod-shaped or strip-shaped members, the first end member has a third end member and a fourth end member spaced apart; the first connecting portion connects the third end member and the fourth end member, the second end member has a fifth end member and a sixth end member disposed at a distance from each other; the second connecting portion connects the fourth end member and the fifth end member, a third end, which is a tip end of the third end member, faces a fifth end, which is a tip end of the fifth end member, across the plate-like member; The wireless power supply device according to claim 1 , wherein a fourth end, which is a tip end of the fourth end member, faces a sixth end, which is a tip end of the sixth end member, across the plate-like member.

3. 3. The wireless power supply device according to claim 1, wherein the first end and the plate-like member are in contact with each other, and the second end and the plate-like member are in contact with each other.

4. 3. The wireless power supply device according to claim 1, wherein the power supply unit changes the magnetic flux generated by the first coil at a frequency of 60 kHz or less.

5. 3. The wireless power supply device according to claim 1, wherein the power supply unit modulates the current flowing through the first coil.

6. an adjustment unit that changes the impedance of a circuit including the second coil; an acquisition unit that acquires information indicating that the impedance of the circuit has been changed by the adjustment unit by measuring a current flowing through the first coil; 3. The wireless power supply device according to claim 1, further comprising:

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