JP6497483B2 - Current detection element and power supply device - Google Patents

Description

  The present invention relates to a current detection element that detects a high-frequency current flowing in a line, and a power supply apparatus including the current detection element.

  For example, a current transformer is known as an element for detecting a current flowing in a line. A current transformer is usually composed of a transformer wound around a toroidal core. Therefore, the size of parts is large. For this reason, the current transformer may not be suitable for a device that requires a reduction in size and height. Therefore, as an example of a small and thin transformer, for example, there is a laminated transformer described in Patent Document 1. The laminated transformer described in Patent Document 1 is a surface-mount electronic component in which a transformer is configured by laminating magnetic sheets on which conductor patterns are printed.

JP 2004-257964 A

  By using the laminated transformer described in Patent Document 1, the current detection element can be reduced in size. However, when a large current flows through a miniaturized current detection element, problems such as heat generation or damage or a decrease in detection accuracy occur due to resistance loss or magnetic saturation.

  Accordingly, an object of the present invention is to provide a current detection element that can detect a current even with a large current, and a power supply apparatus including the current detection element.

  The current detection element according to the present invention includes an insulator, a detected conductor formed inside the insulator, a detection conductor formed inside the insulator and magnetically coupled to the detected conductor, and the detected conductor. And a bypass conductor connected in parallel to the detection conductor.

  In this configuration, when a current flows through the detected conductor of the current detection element, the detected conductor and the detection conductor are magnetically coupled, and an induced current flows through the detection conductor. By detecting this induced current, the current flowing through the detected conductor can be detected. A bypass conductor is connected in parallel to the detected conductor. For this reason, a current flowing into the current detection element (hereinafter referred to as energization current) is divided into a detected conductor and a bypass conductor. In this case, the current flowing through the detected conductor and the bypass conductor is smaller than the energization current. Therefore, even if the energization current is a large current, a large current does not flow through the conductor to be detected, so that the resistance loss can be suppressed. Thereby, a current detection element capable of detecting a current even with a large current can be realized.

  Further, since the loss in the current detection element is small, even if a current detection element is provided in the middle of the line where current is desired to be detected, the influence on the line can be suppressed.

  The insulator includes a first insulator including a magnetic body, and a second insulator laminated on the first insulator and having a lower magnetic permeability than the magnetic body, and the detected conductor and the detection The conductor may be formed on the first insulator, and the bypass conductor may be formed on the second insulator.

  In this configuration, since the energized current is divided into the detected conductor and the bypass conductor, the concentration of magnetic flux in the vicinity of the detected conductor can be reduced, and the current transformation characteristics due to magnetic saturation of the magnetic material (current flowing through the detected conductor) The ratio of the current flowing through the detection conductor to the ratio) can be prevented.

  The current detection element may include an impedance element provided in the middle of the current path of the bypass conductor.

  In this configuration, the current flowing to the detected conductor can be adjusted. And it can avoid that an electric current does not flow into a to-be-detected conductor, an electric current flows only into a bypass conductor, and cannot perform an electric current detection.

  The inductance of the detected conductor may be lower than the inductance of the detecting conductor.

  With this configuration, it is possible to reduce the influence on the line connected to the detected conductor (the line on which the current detection element is inserted).

  The detected conductor may be formed in a straight line.

  In this configuration, the resistance component of the detected conductor can be suppressed.

  The detection conductor may be formed in a coil shape.

  In this configuration, the coupling between the detected conductor and the detection conductor can be strengthened. For this reason, the number of coil turns can be reduced, and the current detection element can be reduced in size.

  The insulator may include a third insulator having a magnetic permeability lower than that of the surrounding magnetic permeability, and the third insulator may be formed at least between the detected conductor and the detection conductor.

  In this configuration, since the magnetic flux generated from the detected conductor is less likely to pass between the detected conductor and the detection conductor, the coupling between the detected conductor and the detection conductor can be increased.

  The power supply device according to the present invention includes a power supply coupling unit coupled to a power reception coupling unit included in the power reception device by at least one of an electric field or a magnetic field, a power supply circuit that supplies AC power to the power supply coupling unit, and the power supply circuit. And a current detection element for detecting a current flowing in a power supply line connected to the power supply coupling unit, the current detection element comprising an insulator and a detected conductor formed inside the insulator. A detection conductor formed inside the insulator and magnetically coupled to the detected conductor, and a bypass conductor connected in parallel to the detected conductor, wherein the detected conductor is the power supply line It is characterized by constituting a part of

  In this configuration, when a current flowing through the power supply line flows through the detected conductor, the detected conductor and the detection conductor are magnetically coupled, and an induced current flows through the detection conductor. By detecting this induced current, the current flowing through the detected conductor can be detected. A bypass conductor is connected in parallel to the detected conductor. For this reason, the current flowing through the power supply line is divided into the detected conductor and the bypass conductor. In this case, the current flowing through the detected conductor is smaller than the current flowing through the power supply line. Therefore, even if the current flowing through the power supply line is a large current, a large current does not flow through the conductor to be detected, so that the resistance loss can be suppressed. Thereby, a current detection element capable of detecting a current even with a large current can be realized.

  In addition, since the loss of the current detection element is small, even if the current detection element is provided in the middle of the power supply line, the influence on the power supply line can be suppressed.

  The current detection element may include an impedance element provided in the middle of the bypass conductor.

  In this configuration, the current flowing to the detected conductor can be adjusted. And it can avoid that an electric current does not flow into a to-be-detected conductor, an electric current flows only into a bypass conductor, and cannot perform an electric current detection.

  The power supply device may include a resonance circuit including the power supply coupling unit and the impedance element, and the resonance circuit may resonate at a frequency of AC power supplied to the power supply coupling unit by the power supply circuit. .

  In this configuration, by making the impedance element a part of the resonance circuit, the current at the detection target frequency can be detected with high accuracy without being affected by the noise component. In addition, current detection by the current detection element can be performed without affecting supply efficiency.

  According to the present invention, even when a large current flows into the current detection element, the current is divided into the detected conductor and the bypass conductor. For this reason, the resistance loss of the detected conductor can be suppressed as compared with the case where a large current flows only in the detected conductor. That is, a current detection element that can detect a current even with a large current can be realized.

1A is a plan view of the current detection element, and FIG. 1B is a cross-sectional view taken along the line II of FIG. 1A. FIG. 2 is a bottom view of the current detection element. FIG. 3 is a circuit diagram of the current detection element. 4A, 4B, and 4C are cross-sectional views illustrating another example of the current detection element. FIGS. 5A and 5B are circuit diagrams of the current detection element according to the second embodiment. FIG. 6 is a circuit diagram of a power supply system according to the third embodiment. FIG. 7 is a circuit diagram of another example power supply system.

(Embodiment 1)
1A is a plan view of the current detection element 1, and FIG. 1B is a cross-sectional view taken along the line II of FIG. 1A. FIG. 2 is a bottom view of the current detection element 1. FIG. 3 is a circuit diagram of the current detection element 1.

  The current detection element 1 includes a stacked body 10. The laminated body 10 has a substantially rectangular parallelepiped shape. A plurality of mounting electrodes 14A, 14B, 14C, and 14D shown in FIG. 2 are formed on one main surface (hereinafter referred to as a mounting surface) of the multilayer body 10. The current detection element 1 is mounted on a circuit board by soldering a plurality of mounting electrodes 14A, 14B, 14C, and 14D to electrodes on the circuit board.

The laminated body 10 is formed by laminating a plurality of insulator layers and then sintering. The insulator layer includes an insulator layer made of only a magnetic material such as ferrite, an insulator layer made of a magnetic material and a nonmagnetic material, and an insulator layer made only of a nonmagnetic material. The magnetic body is a ferromagnetic body and has a relative permeability μ _r > 1. The nonmagnetic material has a lower magnetic permeability than the surrounding magnetic material, and the relative magnetic permeability μ _r = 1. A magnetic material having a low magnetic permeability (μ _r ≠ 1, but lower than the magnetic permeability of the magnetic material) may be used instead of a non-magnetic material.

  The laminated body 10 in which these insulator layers are laminated includes a high magnetic permeability portion 101 and low magnetic permeability portions 102A, 102B, and 103 having a lower magnetic permeability than the high magnetic permeability portion 101. The low magnetic permeability portions 102A and 102B are stacked on the high magnetic permeability portion 101 with the high magnetic permeability portion 101 interposed therebetween. The low magnetic permeability portion 103 is formed inside the high magnetic permeability portion 101.

  The high magnetic permeability portion 101 is an example of the “first insulator” according to the present invention. The low magnetic permeability portions 102A and 102B are examples of the “second insulator” according to the present invention. The low magnetic permeability portion 103 is an example of the “third insulator” according to the present invention.

  A linear current detection conductor 11 is formed in the low magnetic permeability portion 103 of the multilayer body 10. The current detection conductor 11 is an example of the “detected conductor” according to the present invention. By forming the current detection conductor 11 into a linear shape, the current detection conductor 11 can be easily formed. In addition, the current detection conductor 11 can be shortened and its inductance and resistance can be reduced as compared with the case where the current detection conductor 11 is bent and routed.

  End face vias 11 </ b> A and 11 </ b> B are formed on the side surface of the stacked body 10 along the stacking direction. The end face vias 11A and 11B are connected to mounting electrodes 14A and 14B formed on the mounting surface of the stacked body 10. Both ends in the longitudinal direction of the current detection conductor 11 are connected to end face vias 11A and 11B. That is, both ends of the current detection conductor 11 are connected to the mounting electrodes 14A and 14B via the end face vias 11A and 11B, respectively.

  It is also possible to form a via conductor inside the laminate 10 and connect the current detection conductor 11 to the mounting electrodes 14A and 14B via the via conductor.

  A bypass conductor 12 is formed in the low magnetic permeability portion 102B. The bypass conductor 12 is formed to face the current detection conductor 11. Both ends of the bypass conductor 12 in the longitudinal direction are connected to the end face vias 11A and 11B.

  That is, as shown in FIG. 3, the current detection conductor 11 and the bypass conductor 12 are connected in parallel between the mounting electrodes 14A and 14B. The inductor L1 shown in FIG. 3 is an inductance component of the current detection conductor 11. Also, Z1 in FIG. 3 is an equivalent impedance component (inductor, resistance, etc.) that the bypass conductor 12 has.

  A coil conductor 13 is formed in the high magnetic permeability portion 101 and the low magnetic permeability portion 103. The coil conductor 13 is an example embodiment that corresponds to the “detection conductor” according to the present invention. The coil conductor 13 is formed by winding a conductor pattern in a coil shape with the stacking direction of the multilayer body 10 as a winding axis. The coil conductor 13 is disposed adjacent to the current detection conductor 11 with a gap in a plan view shown in FIG.

  Specifically, the coil conductor 13 includes open loop conductors 131, 132, 133, 134, 135, and 136. Each of the open loop conductors 131 to 136 is formed on the main surface of a different insulator layer. A part of the open loop conductors 133 and 134 is formed on the main surface of the insulator layer constituting the low magnetic permeability portion 103. The open loop conductors 131 to 136 are connected by a via conductor (not shown).

  Note that the winding direction of the coil conductor 13 is not particularly limited. A plurality of coil conductors may be arranged along the direction in which the current detection conductor 11 extends. Furthermore, the winding axis direction of the coil conductor 13 is not limited to the stacking direction of the multilayer body 10.

  End face vias 13 </ b> A and 13 </ b> B along the stacking direction of the stacked body 10 are formed on the side surface of the stacked body 10. The end face vias 13A and 13B are connected to mounting electrodes 14C and 14D formed on the mounting surface of the laminate 10. Both ends of the coil conductor 13 are connected to the end face vias 13A and 13B. That is, both ends of the coil conductor 13 are connected to the mounting electrodes 14C and 14D via the end face vias 13A and 13B.

  Hereinafter, a current detection method in the current detection element 1 configured as described above will be described.

  The current detection element 1 is mounted on the circuit board so that the current detection conductor 11 and the bypass conductor 12 are arranged in the middle of the main line of the circuit board. Further, both ends of the coil conductor 13, that is, the mounting electrodes 14 </ b> C and 14 </ b> D are connected to a detection circuit for detecting a current flowing through the current detection conductor 11.

  When a current is input from the mounting electrode 14A (or mounting electrode 14B), the input current flows into the current detection conductor 11 and the bypass conductor 12 through the end face via 11A (or end face via 11B). Then, the input current is shunted to the current detection conductor 11 and the bypass conductor 12. At this time, since the bypass conductor 12 has an impedance component of Z1, no input current flows only through the bypass conductor 12.

  By dividing the input current, a current smaller than the input current flows through the current detection conductor 11 even if the input current is a large current. Thereby, the resistance loss of the current detection conductor 11 can be suppressed. Therefore, even if the current detection element 1 is provided in the middle of the main line of the circuit board, the influence on the main line can be suppressed.

  In order to suppress the influence on the main line, the current detection conductor 11 is preferably formed such that its inductance component (inductor L1 in FIG. 3) is smaller than the inductance of the coil conductor 13.

  When a current flows through the current detection conductor 11, a magnetic flux is generated from the current detection conductor 11. The magnetic flux interlinks with the coil opening of the coil conductor 13. Thereby, the current detection conductor 11 and the coil conductor 13 are magnetically coupled.

  Here, the bypass conductor 12 is formed in the low magnetic permeability portion 102B. The low magnetic permeability portion 102B is provided outside the high magnetic permeability portion 101. Therefore, even if a current flows through the bypass conductor 12, the magnetic field coupling between the coil conductor 13 and the bypass conductor 12 is suppressed.

  When an induced electromotive force is generated in the coil conductor 13, an induced current flows through the coil conductor 13 in accordance with the induced electromotive force. The current flowing through the current detection conductor 11 can be detected by detecting the induced electromotive force or the induced current by the detection circuit connected to the mounting electrodes 14C and 14D. The impedance components of the current detection conductor 11 and the bypass conductor 12 (impedance components of the inductors L1 and Z1 in FIG. 3) are known. For this reason, the current between the mounting electrodes 14A and 14B, that is, the current flowing through the main line of the circuit board can be detected from the detected current flowing through the current detection conductor 11.

  As described above, the current detection element 1 is configured so that the bypass conductor 12 is connected in parallel to the current detection conductor 11 through which the current to be detected flows. Current detection. Further, since the bypass conductor 12 is fixed to the current detection element 1, there is no occurrence of a characteristic shift due to a difference in configuration. Therefore, current detection can be performed with high accuracy.

  Further, by diverting the input current and reducing the current flowing through the current detection conductor 11, the concentration of the magnetic flux density of the high permeability portion 101 can be relaxed and the magnetic saturation of the high permeability portion 101 can be suppressed. it can. For this reason, the influence on the current transformation characteristics can be prevented, and the decrease in the current detection accuracy can be suppressed.

  Further, by forming the current detection conductor 11 in the low magnetic permeability portion 103, the inductance component or the magnetic loss of the current detection conductor 11 can be reduced. Furthermore, magnetic saturation of the magnetic body around the current detection conductor 11 can be prevented.

  Further, since the low magnetic permeability portion 103 is interposed between the current detection conductor 11 and the bypass conductor 12, a closed magnetic circuit is formed through which the magnetic field passes between the current detection conductor 11 and the coil conductor 13. Can be suppressed. As a result, the magnetic field coupling between the current detection conductor 11 and the coil conductor 13 can be strengthened, and current detection can be performed with high sensitivity. Further, by providing the low magnetic permeability portion 103 between the current detection conductor 11 and the coil conductor 13, the magnetic field coupling can be strengthened without reducing the distance between the current detection conductor 11 and the coil conductor 13. . That is, by separating the current detection conductor 11 and the coil conductor 13, the parasitic capacitance generated between the two conductors can be reduced.

  Furthermore, since only a part of the coil conductor 13 is formed in the low magnetic permeability portion 103, the inductance of the coil conductor 13 does not decrease significantly.

  Hereinafter, another example of the current detection element 1 will be described.

  4A, 4B, and 4C are cross-sectional views illustrating another example of the current detection element.

  4A is different from the current detection element 1 in the configuration of the stacked body 10A. The laminated body 10A is configured by sequentially laminating a low permeability portion 102B, a high permeability portion 101B, a low permeability portion 103A, a high permeability portion 101A, and a low permeability portion 102A. The high magnetic permeability portions 101A and 101B are insulator layers made only of a ferromagnetic material such as magnetic ferrite. The low magnetic permeability portions 102A and 102B and the low magnetic permeability portions 103A and 103B are insulator layers made of only a nonmagnetic material such as nonmagnetic ferrite.

  The current detection conductor 11 is formed on the main surface of the insulator layer constituting the low magnetic permeability portion 103A. The open loop conductors 133 and 134 of the coil conductor 13 are also formed on the main surface of the insulator layer constituting the low magnetic permeability portion 103A. Accordingly, a part of the current detection conductor 11 and the coil conductor 13 is formed in the low magnetic permeability portion 103A of the multilayer body 10A.

  In this configuration, each layer of the laminate 10A is formed of an insulator layer made of only a ferromagnetic material or an insulator layer made of only a non-magnetic material, so that the laminate 10A can be easily manufactured.

  The current detection element 1B shown in FIG. 4B is different from the current detection element 1 in the configuration of the bypass conductor 12A. The bypass conductor 12A is provided in the low magnetic permeability portion 102B. The bypass conductor 12 </ b> A has a size that overlaps both the coil conductor 13 and the current detection conductor 11 when viewed in plan in the winding axis direction of the coil conductor 13.

  Even in this configuration, the bypass conductor 12A is formed in the low magnetic permeability portion 102B provided outside the high magnetic permeability portion 101, so that magnetic field coupling with the coil conductor 13 is suppressed. Further, when the bypass conductor 12A overlaps the coil conductor 13 when viewed in plan in the winding axis direction of the coil conductor 13, the coil conductor 13 interlinks with the magnetic flux generated outside the current detection element 1. Functions as a magnetic shield to prevent

  A current detection element 1C shown in FIG. 4C is different from the current detection element 1 in that it includes two bypass conductors 12A and 12B. The bypass conductor 12A is provided in the low magnetic permeability portion 102B. The bypass conductor 12B is provided in the low magnetic permeability portion 102A.

  Although not shown, the bypass conductor 12 may be formed on the main surface of the high magnetic permeability portion 101 without providing the low magnetic permeability portions 102A and 102B in FIG. The bypass conductor 12 only needs to be formed at least outside the high magnetic permeability portion 101. Further, it is not necessary to provide the low permeability portion 103 in the laminate 10.

  Further, the bypass conductor 12 does not need to face the current detection conductor 11 and is preferably disposed at a position where magnetic coupling with the coil conductor 13 is unlikely to occur. By lowering the magnetic field coupling with the coil conductor 13, the influence of the bypass conductor 12 on the coil conductor can be suppressed.

  In this embodiment, the high permeability portion is a magnetic material (ferromagnetic material), and the low permeability portion is a non-magnetic material or a magnetic material having a lower permeability than that of the high permeability portion. For example, the low magnetic permeability portion may be made of a diamagnetic material (relative magnetic permeability μr <1), and the high magnetic permeability portion may be made of a magnetic material or a non-magnetic material. It is sufficient that at least the permeability of the low permeability portion is lower than the permeability of the surrounding high permeability portion.

(Embodiment 2)
The current detection element according to the second embodiment is different from the first embodiment in that an impedance element is provided in the middle of the bypass conductor.

  5A and 5B are circuit diagrams of the current detection elements 2A and 2B according to the present embodiment.

  In the current detection element 2 </ b> A shown in FIG. 5A, a resistor R <b> 1 is provided in the middle of the bypass conductor 12. The resistor R1 is an element mounted on the upper surface or inside of the stacked body 10 illustrated in FIG. By providing the resistor R1, the current flowing through the current detection conductor 11 can be adjusted. As a result, it is possible to avoid the possibility that the current flows only in the bypass conductor 12 and the current does not flow in the current detection conductor 11 and the current detection cannot be performed.

  In the current detection element 2 </ b> B shown in FIG. 5B, a capacitor C <b> 1 is provided in the middle of the bypass conductor 12. The capacitor C1 may be an element mounted on the top surface or inside of the multilayer body 10 shown in FIG. 1B, or may be constituted by an electrode formed in the multilayer body 10.

  When the capacitor C1 is provided, a parallel resonant circuit may be configured by the capacitor C1 and the inductance component (inductor L1) of the current detection conductor 11. In this case, by adjusting the resonance frequency of the parallel resonance circuit to a frequency other than the frequency of the current to be detected (for example, the third harmonic), the current detection element 2B allows a current having a frequency other than the frequency of the current to be detected. I can stop.

(Embodiment 3)
In this example, a power supply system including the current detection element 1 according to the first embodiment will be described.

  FIG. 6 is a circuit diagram of the power supply system 200 according to the third embodiment. The power supply system 200 includes a power feeding device 201 and a power receiving device 202. The power supply system 200 supplies power from the power supply apparatus 201 to the power reception apparatus 202 by a magnetic field coupling method.

  The power receiving device 202 includes a load circuit 213. The load circuit 213 includes a charging circuit and a secondary battery. Note that the secondary battery may be detachable from the power receiving apparatus 202. The power receiving apparatus 202 is, for example, a portable electronic device that includes the secondary battery. Examples of portable electronic devices include mobile phones, portable music players, notebook PCs, and digital cameras. The power feeding device 201 is a charging stand for charging the secondary battery of the power receiving device 202 placed thereon.

  The power supply apparatus 201 includes a DC power source Vin that outputs a DC voltage. The DC power source Vin is an AC adapter connected to a commercial power source. An inverter circuit 211 that converts a DC voltage into an AC voltage is connected to the DC power source Vin. The inverter circuit 211 outputs an alternating voltage. The AC voltage here means a voltage having an AC component, and includes a pulsating voltage containing a DC component. A resonance circuit including a capacitor C3 and a coil L2 is connected to the output side of the inverter circuit 211. The inverter circuit 211 is an example of the “power supply circuit” according to the present invention.

  In the resonance circuit illustrated in FIG. 6, both the power feeding apparatus 201 and the power receiving apparatus 202 constitute a series resonance circuit, but may be a parallel resonance circuit.

  Further, the current detection element 1 is provided between the inverter circuit 211 and the resonance circuit. The current detection conductor 11 and the bypass conductor 12 of the current detection element 1 are part of the power supply line 210 between the inverter circuit 211 and the resonance circuit. The coil conductor 13 of the current detection element 1 is connected to the capacitor C2 and the load R2.

  The capacitor C2 and the load R2 are the detection circuit described in the first embodiment. By detecting the voltage across the load R2, the induced current flowing through the coil conductor 13 can be detected. Then, the current flowing through the current detection conductor 11 and the bypass conductor 12 from the induced current, that is, the current flowing between the inverter circuit 211 and the resonance circuit (hereinafter referred to as a feeding current) can be detected.

  The power receiving apparatus 202 includes a capacitor C4 and a coil L3 that form a resonance circuit. The coils L <b> 2 and L <b> 3 are magnetically coupled to supply power from the power supply apparatus 201 to the power reception apparatus 202. The resonance circuit of the power receiving device 202 is set to the same resonance frequency as the resonance circuit of the power feeding device 201. By making the resonance frequencies of the resonance circuits of the power supply apparatus 201 and the power reception apparatus 202 the same, power can be supplied efficiently.

  The coil L2 is an example of the “feed coupling portion” according to the present invention. The coil L3 is an example of the “power receiving coupling portion” according to the present invention.

  A power reception circuit 212 is connected to the resonance circuit of the power reception device 202. The power receiving circuit 212 rectifies and smoothes the voltage induced in the coil L3. In addition, the power receiving circuit 212 converts the rectified and smoothed voltage into a stabilized predetermined voltage and supplies the voltage to the load circuit 213.

  In this power supply system 200, by detecting the power supply current of the power supply apparatus 201 and the input voltage V <b> 1 to the resonance circuit of the power supply apparatus 201, the impedance viewed from the inverter circuit 211 on the power reception apparatus 202 side can be detected. By detecting the impedance, for example, it can be determined whether or not the power receiving device 202 is placed on the power feeding device 201. When the power receiving apparatus 202 is mounted on the power feeding apparatus 201, the resonance circuit of the power feeding apparatus 201 and the power receiving apparatus 202 is coupled, and a frequency peak due to complex resonance appears. Then, by detecting the frequency characteristics of the impedance and detecting the presence or absence of a frequency peak, the presence or absence of the power receiving apparatus 202 can be determined.

  Even when only the power feeding current of the power feeding device 201 is detected using the current detection element 1, the presence or absence of the power receiving device 202 is detected or the state of the abnormality is detected based on the change in the magnitude or phase of the current. It can be performed.

  By using the current detection element 1 for detection of the feeding current, even when a large current is supplied to the coil L2, loss can be suppressed and current detection can be performed. Since the loss can be suppressed, even if the current detection element 1 is provided in the middle of the power supply line 210 between the inverter circuit 211 and the resonance circuit, the influence on the power supply line 210 can be suppressed.

  Further, since the bypass conductor 12 is fixed to the current detection element 1, there is no occurrence of a characteristic shift due to a difference in configuration. Therefore, the feeding current can be detected with high accuracy.

  Furthermore, it can suppress that a current detection precision falls by suppressing the magnetic saturation of the laminated body 10. FIG.

  As in the second embodiment, an impedance element may be provided in the middle of the bypass conductor 12.

  FIG. 7 is a circuit diagram of another example power supply system 200A.

  A power supply apparatus 201A of the power supply system 200A illustrated in FIG. 7 includes a current detection element 2B (see FIG. 5B) according to the second embodiment, instead of the current detection element 1 of FIG. The inductance component (inductor L1) of the capacitor C1 and the current detection conductor 11 constitutes a parallel resonance circuit having a resonance frequency other than the frequency of the current output from the inverter circuit 211 (for example, the third harmonic). Yes. Thereby, currents other than the frequency of the output current from the inverter circuit 211 (for example, third harmonic) can be blocked.

  When the capacitor C1 is provided, the capacitor C1 may be used as a part of a resonance circuit that constitutes a series resonance circuit including the coil L2. In this case, the influence on the supply efficiency when the current detection element 2B is provided can be suppressed.

  Note that the power supply system of the present embodiment supplies power from the power feeding device to the power receiving device by the magnetic field coupling method, but may supply power from the power feeding device to the power receiving device by the electric field coupling method. Good.

C1 Capacitor (impedance element)
C2, C3, C4 ... Capacitor L1 ... Inductor L2 ... Coil (feed coupling part)
L3 ... Coil (power receiving coupling part)
R1: Resistance (impedance element)
R2 ... Load V1 ... Input voltage Vin ... DC power supply Z1 ... Impedance components 1, 1A, 1B, 1C ... Current detection elements 2A, 2B ... Current detection elements 10, 10A ... Laminate 11 ... Current detection conductor (detected conductor)
11A, 11B ... end face vias 12, 12A, 12B ... bypass conductor 13 ... coil conductor (detection conductor)
13A, 13B ... end face vias 14A, 14B, 14C, 14D ... mounting electrodes 101, 101A, 101B ... high permeability part (first insulator)
102A, 102B ... Low permeability part (second insulator)
103, 103A, 103B ... Low permeability portion (third insulator)
131, 132, 133, 134, 135, 136 ... open loop conductors 200, 200A ... power supply system 201, 201A ... power feeding device 202 ... power receiving device 210 ... power supply line 211 ... inverter circuit (power supply circuit)
212 ... Power receiving circuit 213 ... Load circuit

Claims (10)

An insulator;
A conductor to be detected formed inside the insulator;
A detection conductor formed inside the insulator and magnetically coupled to the detected conductor;
A bypass conductor connected in parallel to the detected conductor;
With
The insulator includes a first insulator including a magnetic body, and a second insulator laminated on the first insulator and having a lower magnetic permeability than the magnetic body,
The detected conductor and the detection conductor are formed on the first insulator,
The bypass conductor is formed in the second insulator;
Current detection element. Comprising an impedance element provided in the middle current path before Symbol bypass conductor,
The current detection element according to claim 1 . Before SL insulator permeability has a third insulator is lower than the magnetic permeability of the first insulator,
The third insulator is:
At least formed between the detected conductor and the detection conductor,
The current detection element according to claim 1 . The inductance of the detected conductor is lower than the inductance of the detecting conductor,
The current detection element according to claim 1. The detected conductor is formed in a straight line,
The current detection element according to claim 1. The detection conductor is formed in a coil shape,
The current detection element according to claim 1. A power supply coupling unit coupled with at least one of an electric field or a magnetic field and a power reception coupling unit included in the power reception device;
A power supply circuit for supplying AC power to the power supply coupling unit;
A current detection element for detecting a current flowing in a power supply line connected to the power supply circuit and the power supply coupling unit;
With
The current detection element is
An insulator;
A conductor to be detected formed inside the insulator;
A detection conductor formed inside the insulator and magnetically coupled to the detected conductor;
A bypass conductor connected in parallel to the detected conductor;
Have
The detected conductor constitutes a part of the power supply line,
The insulator includes a first insulator including a magnetic body, and a second insulator laminated on the first insulator and having a lower magnetic permeability than the magnetic body,
The detected conductor and the detection conductor are formed on the first insulator,
The bypass conductor is formed in the second insulator;
Power supply device. Before SL insulator permeability has a third insulator is lower than the magnetic permeability of the first insulator,
The third insulator is:
At least formed between the detected conductor and the detection conductor,
The power feeding device according to claim 7 . Before Symbol current detection element,
Having an impedance element provided in the middle of the bypass conductor;
The power feeding device according to claim 7 . A resonant circuit including the feed coupling portion and the impedance element;
With
The resonant circuit resonates at a frequency of AC power that the power supply circuit supplies to the feed coupling unit.
The power feeding device according to claim 9.

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