Wireless power receiver

Abstract

A wireless power reception device (10) comprises: a first power-receiving AC circuit including a power-receiving resonance circuit (21) and a rectification circuit (31); a first power-receiving DC circuit including a smoothing circuit (41) and a load circuit (50); a second power-receiving AC circuit including a rectification circuit (32); a second power-receiving DC circuit including a smoothing circuit (42); and a connection line (700) that electrically connects the first power-receiving DC circuit and an electronic control circuit (60). The electronic control circuit (60) is provided with a ground terminal (PG). The connection line (700) electrically connects a DC reference potential (PDCL) of the first power-receiving DC circuit and the ground terminal (PG) through an impedance circuit (70). The impedance circuit (70) is stabilized by the DC potential of the ground terminal (PG) being the same potential as the DC reference potential (PDCL) of the first power-receiving DC circuit, and an impedance value is set so as to suppress a first AC current flowing from the power-receiving DC circuit to the connection line (700).

Description

Technical Field

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[0001] The present invention relates to a wireless power receiving device that performs wireless power reception and wireless communication.

Background Art

[0002] Patent Document 1 describes a circuit device including an RFID and a wireless power receiving circuit. In the circuit device of Patent Document 1, it is described that there is a current flowing from the wireless power receiving circuit to the RFID when the ground potential of the wireless power receiving circuit and the reference potential are connected to the RFID.

[0003] The circuit device of Patent Document 1 has a symmetric circuit configuration of the wireless power receiving circuit in order to suppress the current flowing from the wireless power receiving circuit to the RFID.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a method such as the circuit device of Patent Document 1, the design freedom of the wireless power receiving circuit is reduced, and it may be difficult to configure a wireless power receiving circuit having desired power receiving characteristics.

[0006] Further, based on Patent Document 1, for example, when the wireless power receiving circuit has an asymmetric circuit configuration, the current flowing from the wireless power receiving circuit to the communication circuit including the RFID cannot be suppressed. Therefore, the noise current generated in the wireless power receiving circuit leaks into the communication circuit.

[0007] <00Furthermore, if the wireless power receiving circuit and the communication circuit are not connected, the DC reference potential of the wireless power receiving circuit and the ground potential of the communication circuit will not match, causing the ground potential of RFID and other devices to become unstable.

[0008] Therefore, the object of the present invention is to provide a wireless power receiving device that can stabilize the ground potential of the communication circuit and suppress the leakage of noise current generated in the wireless power receiving circuit into the communication circuit. [Means for solving the problem]

[0009] The wireless power receiving device of this invention comprises a power receiving resonant circuit including a power receiving coil and a power receiving resonant capacitor; a power receiving circuit electrically connected to the power receiving resonant circuit; a load circuit electrically connected to the power receiving circuit and driven by the output power from the power receiving circuit; and an electronic control circuit that performs predetermined electrical signal processing. The power receiving circuit comprises a first rectifier circuit that rectifies a first alternating current flowing through the power receiving resonant circuit; and a first smoothing circuit electrically connected to the first rectifier circuit and smoothing the rectified voltage. The electronic control circuit is electrically connected to a second rectifier circuit that rectifies a second alternating current flowing through the power receiving coil or a second power receiving coil provided separately from the power receiving coil; and a second smoothing circuit electrically connected to the second rectifier circuit and smoothing the voltage.

[0010] The wireless power receiving device includes a first AC power receiving circuit including a power receiving resonant circuit and a first rectifier circuit, a first DC power receiving circuit including a smoothing circuit and a load circuit, a second AC power receiving circuit including a second rectifier circuit, a second DC power receiving circuit including a second smoothing circuit, and a connection line that electrically connects the first DC power receiving circuit and an electronic control circuit.

[0011] The electronic control circuit is provided with a ground terminal. The connecting line electrically connects the ground terminal to the DC reference potential of the first DC receiving circuit through an impedance circuit. The impedance value of the impedance circuit is set so that the DC potential of the ground terminal is stabilized to be the same potential as the DC reference potential of the first DC receiving circuit, and so as to suppress the flow of the first AC current or the second AC current from the DC receiving circuit to the connecting line.

[0012] In this configuration, even when the first DC receiving circuit and the electronic control circuit are connected, the impedance circuit ensures that the ground terminal of the electronic control circuit and the DC reference potential of the first DC receiving circuit are at the same potential, and that the flow of the first AC current or the second AC current through the electronic control circuit is suppressed. [Effects of the Invention]

[0013] According to this invention, the ground potential of the communication circuit can be stabilized, and the leakage of noise current generated in the wireless power receiving circuit into the communication circuit can be suppressed. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to the first embodiment of the present invention. [Figure 2] Figures 2(A) and 2(B) show an example of the circuit configuration of an impedance circuit according to the first embodiment of the present invention. [Figure 3] Figure 3(A) is an equivalent circuit diagram of the portion of the wireless power receiving device that includes an impedance circuit in DC, and Figure 3(B) is an equivalent circuit diagram of the portion of the wireless power receiving device that includes an impedance circuit in noise current at a predetermined frequency. [Figure 4] Figure 4 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to a second embodiment of the present invention. [Figure 5] Figure 5 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to a third embodiment of the present invention. [Figure 6] Figure 6 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to the fourth embodiment of the present invention. [Figure 7] Figure 7 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to the fifth embodiment of the present invention.

Mode for Carrying Out the Invention

[0015] [First Embodiment] The wireless power receiving device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a wireless power supply system including the wireless power receiving device according to the first embodiment of the present invention.

[0016] As shown in FIG. 1, the wireless power supply system 1 includes a wireless power receiving device 10 and a wireless power transmitting device 80. The wireless power receiving device 10 includes a power receiving resonance circuit 21, a communication resonance circuit 22, a rectifier circuit 31, a rectifier circuit 32, a smoothing circuit 41, a smoothing circuit 42, a load circuit 50, an electronic control circuit 60, and an impedance circuit 70.

[0017] (Power Receiving Circuit of Wireless Power Receiving Device 10) The power receiving resonance circuit 21 includes a power receiving coil 201, a power receiving resonance capacitor 202, and a power receiving resonance capacitor 203. The power receiving coil 201 is a loop coil having a predetermined inductance. The power receiving resonance capacitor 202 is connected in parallel with the power receiving coil 201. One terminal of the power receiving resonance capacitor 20 is electrically connected to a node where one terminal of the power receiving coil 201 and one terminal of the power receiving resonance capacitor 202 are connected. The resonance frequency of the power receiving resonance circuit 21 is set to be substantially the same as the frequency of the alternating magnetic field coupled by the power receiving coil 201, that is, the resonance frequency of the power transmitting resonance circuit 81 (described later), and further, the switching frequency of the power transmitting circuit 82 (described later).

[0018] The rectifier circuit 31 includes a plurality of diodes D311 - D314. The anode of the diode D311 and the cathode of the diode D312 are electrically connected. The anode of the diode D313 and the cathode of the diode D314 are electrically connected. The cathode of the diode D311 and the cathode of the diode D313 are electrically connected. The anode of the diode D312 and the anode of the diode D314 are electrically connected.

[0019] The node between the anode of diode D311 and the cathode of diode D312 is electrically connected to the other terminal of the power receiving resonant capacitor 203. The node between the anode of diode D313 and the cathode of diode D314 is connected to the node where the other terminal of the power receiving coil 201 and the other terminal of the power receiving resonant capacitor 202 in the power receiving resonant circuit 21 are connected.

[0020] The node between the cathode of diode D311 and the cathode of diode D313 is electrically connected to the Hi-side power supply line 45H. The node between the anode of diode D312 and the anode of diode D314 is electrically connected to the Low-side power supply line 45L.

[0021] The smoothing circuit 41 includes a smoothing capacitor 411. The smoothing capacitor 411 is electrically connected between the Hi-side power supply line 45H and the Low-side power supply line 45L.

[0022] The Hi-side terminal of the load circuit 50 is electrically connected to the Hi-side power supply line 45H. The Low-side terminal of the load circuit 50 is electrically connected to the Low-side power supply line 45L.

[0023] (Communication circuit of the wireless power receiving device 10) The communication resonant circuit 22 includes the power receiving coil 201, the power receiving resonant capacitor 202, and the communication resonant capacitor 204. The power receiving coil 201 and the power receiving resonant capacitor 202 are common to the power receiving resonant circuit 21. The power receiving resonant capacitor 202 is connected in parallel with the power receiving coil 201. One terminal of the communication resonant capacitor 204 is electrically connected to the node where one terminal of the power receiving coil 201 and one terminal of the power receiving resonant capacitor 202 are connected. The resonant frequency of the communication resonant circuit 22 is substantially the same as the resonant frequency of the power receiving resonant circuit.

[0024] The rectifier circuit 32 includes multiple diodes D321-D324. The anode of diode D321 and the cathode of diode D322 are electrically connected. The anode of diode D323 and the cathode of diode D324 are electrically connected. The cathode of diode D321 and the cathode of diode D323 are electrically connected. The anode of diode D322 and the anode of diode D324 are electrically connected.

[0025] The anode of diode D321 and the cathode of diode D322 are electrically connected to the other terminal of the communication resonant capacitor 204. The anode of diode D323 and the cathode of diode D324 are electrically connected to the node where the other terminal of the receiving coil 201 in the communication resonant circuit 22 is connected to the other terminal of the receiving resonant capacitor 202.

[0026] The cathode of diode D321 and the cathode of diode D323 are electrically connected to the Hi-side power supply line 46H. The anode of diode D322 and the anode of diode D324 are electrically connected to the Low-side power supply line 46L.

[0027] The smoothing circuit 42 includes a smoothing capacitor 421. The smoothing capacitor 421 is electrically connected between the Hi-side power supply line 46H and the Low-side power supply line 46L.

[0028] The Hi-side terminal of the electronic control circuit 60 is electrically connected to the Hi-side power supply line 46H. The Low-side terminal of the load circuit 50 is electrically connected to the Low-side power supply line 46L.

[0029] (Connection point between the power receiving circuit and the communication circuit) The low-side power supply line 45L of the power receiving circuit and the low-side power supply line 46L of the communication circuit are electrically connected via a connecting line 700. An impedance circuit 70 is connected in series to the connecting line 700.

[0030] (Wireless power transmission device 80) The wireless power transmission device 80 includes a power transmission resonant circuit 81 and a power transmission circuit 82. The power transmission resonant circuit 81 includes a power transmission coil 801 consisting of a loop coil and a power transmission resonant capacitor 802. The power transmission coil 801 and the power transmission resonant capacitor 802 are connected in series. The power transmission resonant circuit 81 is electrically connected to the power transmission circuit 82. A DC power supply 89 is electrically connected to the power transmission circuit 82.

[0031] (Outline of wireless power transfer and wireless communication) The wireless power receiving device 10 is positioned relative to the wireless power transmitting device 80 such that the power receiving coil 201 is electromagnetically coupled to the power transmitting coil 801.

[0032] The power transmission circuit 82 of the wireless power transmission device 80 is driven by DC power from a DC power supply 89. The power transmission circuit 82 includes a power conversion circuit having a switching element. The power transmission circuit 82 converts the DC current into an AC current based on the switching frequency by controlling the conduction and opening of the switching element of the power conversion circuit, and supplies it to the power transmission resonant circuit 81.

[0033] The resonant frequency (transmission resonant frequency) of the power transmission resonant circuit 81 is set to be approximately the same as the switching frequency. The power transmission coil 801 of the power transmission resonant circuit 81 is excited by an alternating current at the power transmission resonant frequency, generating an alternating magnetic field.

[0034] The receiving coil 201 of the wireless power receiving device 10 is coupled to the alternating magnetic field generated by the transmitting coil 801, and the power receiving resonant circuit 21 and the communication resonant circuit 22 output a power receiving current.

[0035] At this time, by setting the switching frequency of the power transmission circuit 82, the power transmission resonant frequency of the power transmission resonant circuit 81, and the power receiving resonant frequency of the power receiving resonant circuit 21 to predetermined values, the wireless power transmission device 80 and the wireless power receiving device 10 can achieve wireless power transfer by DC resonance. By achieving wireless power transfer by DC resonance, the wireless power transmission device 80 can supply power to the wireless power receiving device 10 with low loss and high efficiency.

[0036] The rectifier circuit 31 rectifies the AC power current output from the power receiving resonant circuit 21 into DC power. The smoothing circuit 41 smooths the DC output voltage of the rectifier circuit 31. The smoothed DC voltage is supplied to the load circuit 50. The rectifier circuit 31 is the first rectifier circuit, and the smoothing circuit 41 is the first smoothing circuit. The circuit including the power receiving resonant circuit 21 and the rectifier circuit 31 is the first AC power receiving circuit, and the circuit including the smoothing circuit 41 and the load circuit 50 is the first DC power receiving circuit.

[0037] The load circuit 50 is driven by the supplied DC power and performs predetermined processing. The load circuit 50 also includes a circuit (for example, a fingerprint authentication circuit) that provides a predetermined instruction signal to the electronic control circuit 60. This circuit is driven by the supplied DC power, performs predetermined control, and provides an instruction signal to the electronic control circuit 60.

[0038] The rectifier circuit 32 rectifies the AC power receiving current output from the communication resonant circuit 22 into DC power. The smoothing circuit 42 smooths the DC output voltage of the rectifier circuit 32. The smoothed DC voltage is supplied to the electronic control circuit 60. The rectifier circuit 32 is the second rectifier circuit, and the smoothing circuit 42 is the second smoothing circuit. The circuit including the rectifier circuit 32 is the second AC power receiving circuit, and the circuit including the smoothing circuit 42 is the second DC power receiving circuit.

[0039] The electronic control circuit 60 is driven by supplied DC power and performs predetermined processing. The electronic control circuit 60 includes, for example, a semiconductor IC such as an RFID. The electronic control circuit 60 changes its impedance based on an instruction signal from a circuit that provides a predetermined instruction signal to the load circuit 50.

[0040] By changing the impedance of the electronic control circuit 60, the amplitude of the alternating magnetic field coupled to the receiving coil 201 fluctuates. As the amplitude of the alternating magnetic field fluctuates, the amplitude of the transmission current flowing through the transmission resonant circuit 81 fluctuates. The transmission circuit 82 detects that the amplitude of the transmission current in the transmission resonant circuit 81 has fluctuated, thereby enabling wireless communication with the electronic control circuit 60.

[0041] In this way, the wireless power supply system 1 can supply power from the wireless power transmission device 80 to the wireless power receiving device 10 while simultaneously achieving wireless communication between the wireless power transmission device 80 and the wireless power receiving device 10. In this case, the wireless power transmission device 80 and the wireless power receiving device 10 achieve wireless power supply by DC resonance, so power can be supplied to the wireless power receiving device 10 with low loss.

[0042] Furthermore, the frequency of the alternating magnetic field (resonant frequency) in this case is preferably in the 13.56 MHz band or the 6.78 MHz band. This allows the wireless power transfer system 1 to achieve wireless power transfer and wireless communication using the ISM band.

[0043] (Impedance circuit 70) Figures 2(A) and 2(B) show an example of the circuit configuration of an impedance circuit according to the first embodiment of the present invention.

[0044] (In the case of a parallel resonant circuit) The impedance circuit 70LC shown in Figure 2(A) comprises an inductor 71 and a capacitor 72. The inductor 71 and the capacitor 72 are connected in parallel. The resonant frequency of the parallel circuit of the inductor 71 and the capacitor 72 is set to the predetermined frequency described above.

[0045] The impedance circuit 70LC is an LC parallel resonant circuit, so it has low impedance in DC and high impedance at a predetermined frequency and in the frequency band near that predetermined frequency, which is determined by the inductance of the inductor 71 and the capacitance of the capacitor 72.

[0046] Therefore, by providing the impedance circuit 70LC, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are DC-conducted. As a result, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same DC potential. Consequently, communication between the load circuit 50 and the electronic control circuit 60 is stable, and for example, the electronic control circuit 60 can stably receive instruction signals from the load circuit 50, suppressing malfunctions.

[0047] More specifically, in communication between the load circuit 50 and the electronic control circuit 60, a digital circuit transmits High and Low digital signals. This High and Low transition in the digital signal requires alternating current to flow between the ground of the load circuit 50 and the electronic control circuit 60. In the above configuration, the resonant frequency of the LC parallel resonant circuit is not matched to the frequency of the digital signal, but rather to the frequency of the alternating magnetic field noise current and the switching noise of the rectifier diode. This allows the alternating current for the High and Low transitions of the digital signal to flow while suppressing the noise current (alternating current) of the receiving AC circuit. In other words, digital signal communication is possible even with an impedance element. To put it another way, the impedance circuit 70LC does not suppress all alternating current, but rather suppresses the noise current of the receiving AC circuit.

[0048] Furthermore, by providing the impedance circuit 70LC, the AC noise current of a predetermined frequency flowing from the low-side power supply line 45L of the power receiving circuit to the low-side power supply line 46L of the communication circuit is reduced. Therefore, the wireless power receiving device 10 can suppress the leakage of AC noise current of a predetermined frequency to the electronic control circuit 60. As a result, the noise current input to the electronic control circuit 60 is suppressed, and communication between the load circuit 50 and the electronic control circuit 60 is stabilized. Malfunctions, damage, etc., of the electronic control circuit 60 can be suppressed.

[0049] Furthermore, by making the resonant frequency of the impedance circuit 70LC overlap with the frequency of the alternating magnetic field, the leakage of noise current due to the alternating magnetic field into the electronic control circuit 60 can be significantly suppressed. As a result, noise current caused by the alternating magnetic field input to the electronic control circuit 60 is suppressed, communication between the load circuit 50 and the electronic control circuit 60 is stabilized, and malfunctions, damage, etc., of the electronic control circuit 60 can be suppressed.

[0050] (In the case of ferrite beads) The impedance circuit 70F shown in Figure 2(B) is equipped with a ferrite bead 73. The ferrite bead 73 has low impedance in DC, and its impedance increases as the frequency increases, becoming high impedance at high frequencies. Because the impedance circuit 70F is equipped with a ferrite bead 73, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are DC-conducted. As a result, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same DC potential. Therefore, communication between the load circuit 50 and the electronic control circuit 60 is stable, and for example, the electronic control circuit 60 can stably receive instruction signals from the load circuit 50 and suppress malfunctions.

[0051] Furthermore, by providing the impedance circuit 70F, the AC noise current at a predetermined frequency and above that flows from the low-side power supply line 45L of the power receiving circuit to the low-side power supply line 46L of the communication circuit is reduced. Therefore, the wireless power receiving device 10 can suppress the leakage of AC noise current to the electronic control circuit 60. As a result, the noise current input to the electronic control circuit 60 is suppressed, communication between the load circuit 50 and the electronic control circuit 60 is stabilized, and malfunctions, damage, etc., of the electronic control circuit 60 can be suppressed.

[0052] Thus, by using the impedance circuit 70 (70LC, 70F), the same circuit configuration as in Figure 3(A) can be realized for DC current, and the same circuit configuration as in Figure 3(B) can be realized for noise current.

[0053] Figure 3(A) is an equivalent circuit diagram of the portion of the wireless power receiving device that includes an impedance circuit in DC, and Figure 3(B) is an equivalent circuit diagram of the portion of the wireless power receiving device that includes an impedance circuit in noise current at a predetermined frequency.

[0054] As shown in Figure 3(A), in the DC circuit, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are conductive. As a result, the DC reference potential PDCL of the DC receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same potential in DC.

[0055] As shown in Figure 3(B), at a noise current of a predetermined frequency, the Low-side power supply line 45L of the power receiving circuit and the Low-side power supply line 46L of the communication circuit are equivalently open. This suppresses the leakage of noise current from the power receiving circuit to the electronic control circuit 60.

[0056] As a result, AC noise current (first AC signal) does not flow (is suppressed) from the DC receiving circuit of the power receiving circuit to the electronic control circuit of the communication circuit, preventing malfunctions in the electronic control circuit and enabling predetermined electrical signal processing. Furthermore, it is possible to suppress the flow of AC current (second AC signal) from the electronic control circuit to the DC receiving circuit. Therefore, it is possible to prevent large currents resulting from this from flowing into the electronic control circuit and damaging it, and to suppress the generation of localized heat. In this way, by suppressing the leakage of noise current, performing stable electrical signal processing, and suppressing the generation of localized heat, a compact, high-performance wireless power receiving device 10 with excellent electromagnetic noise characteristics can be realized.

[0057] In particular, in the wireless power receiving device 10, the current of the power receiving circuit output through the power receiving resonant circuit 21 is greater than the current of the communication circuit output through the communication resonant circuit 22. Therefore, the noise current of the power receiving circuit is greater than the noise current of the communication circuit. As a result, the adverse effects (potential malfunctions and damage) of the noise current of the power receiving circuit on the electronic control circuit 60 become greater. However, by having the above configuration, leakage of the noise current of the power receiving circuit to the electronic control circuit 60 is suppressed, so malfunctions and damage to the electronic control circuit 60 are effectively suppressed.

[0058] Furthermore, in the wireless power receiving device 10, a portion of the circuits of the power receiving resonant circuit 21 and the communication resonant circuit 22 are common. The wireless power receiving device 10 forms a closed loop with the common portion of the power receiving resonant circuit 21 and the communication resonant circuit 22, the rectifier circuit 31, smoothing circuit 41, and connection line 700 of the power receiving circuit, and the electronic control circuit 60, smoothing circuit 42, and rectifier circuit 32 of the communication circuit. As a result, noise current from the power receiving circuit side can easily flow into the communication circuit side through the connection line 700. However, by providing the impedance circuit 70, noise current from the power receiving circuit side is less likely to flow into the communication circuit side. Therefore, the wireless power receiving device 10 can suppress the noise current input to the electronic control circuit 60, thereby preventing malfunctions, damage, etc., to the electronic control circuit 60.

[0059] The impedance circuit 70LC and the impedance circuit 70F may be used selectively, or both may be used. When using the impedance circuit 70LC and the impedance circuit 70F selectively, using the impedance circuit 70LC can suppress the generation of heat due to noise current. On the other hand, using the impedance circuit 70F can suppress the reflection of noise current to the power supply circuit side.

[0060] Furthermore, the impedance circuit 70 only needs to have an impedance value set such that the DC potential of the ground terminal PG of the electronic control circuit 60 is approximately the same as the DC reference potential PDCL of the receiving DC circuit, and that AC current (noise current) is suppressed from flowing from the receiving DC circuit to the connection line 700. Therefore, the impedance circuit 70 may be, for example, a resistive element. In this case, the resistance value of the resistive element should be set such that the DC potential of the ground terminal PG of the electronic control circuit 60 and the DC reference potential PDCL of the receiving DC circuit are within a potential difference sufficient to stably transmit signals between the load circuit 50 and the electronic control circuit 60.

[0061] [Second Embodiment] A wireless power receiving device according to a second embodiment of the present invention will be described with reference to the figures. Figure 4 is a diagram showing an example of the configuration of a wireless power supply system including a wireless power receiving device according to a second embodiment of the present invention.

[0062] As shown in Figure 4, the wireless power receiving device 10A according to the second embodiment differs from the wireless power receiving device 10 according to the first embodiment in the connection position of the impedance circuit 70. The other configurations of the wireless power receiving device 10A are the same as those of the wireless power receiving device 10, and the description of the similar parts will be omitted.

[0063] The impedance circuit 70 is connected between the node of the smoothing circuit 41 (smoothing capacitor 411) and the negative terminal of the load circuit 50 in the low-side power supply line 45L of the power receiving circuit.

[0064] This configuration is effective when the impedance of the load circuit 50 is high, in other words, when the load on the load circuit 50 is light, that is, when the current consumption of the load circuit 50 is small.

[0065] With this configuration, the wireless power receiving device 10A can achieve the same effects as the wireless power receiving device 10.

[0066] [Third Embodiment] A wireless power receiving device according to a third embodiment of the present invention will be described with reference to the figures. Figure 5 is a diagram showing an example of the configuration of a wireless power supply system including a wireless power receiving device according to the third embodiment of the present invention.

[0067] As shown in Figure 5, the wireless power receiving device 10B according to the third embodiment differs from the wireless power receiving device 10 according to the first embodiment in the connection position of the connection line 700 on the power receiving circuit side. The other configurations of the wireless power receiving device 10B are the same as those of the wireless power receiving device 10, and the description of the similar parts will be omitted.

[0068] In the wireless power receiving device 10B, one end of the connection line 700 is connected to the Hi-side power supply line 45H.

[0069] In this configuration, the DC reference potential PDCH on the Hi side of the DC receiving circuit of the power receiving circuit is connected to the DC potential of the ground terminal PG of the electronic control circuit 60 through the connection line 700 and the impedance circuit 70.

[0070] With this configuration, the wireless power receiving device 10B can achieve the same effects as the wireless power receiving device 10.

[0071] [Fourth Embodiment] A wireless power receiving device according to a fourth embodiment of the present invention will be described with reference to the figures. Figure 6 is a diagram showing an example of the configuration of a wireless power supply system including a wireless power receiving device according to a fourth embodiment of the present invention.

[0072] As shown in Figure 6, the wireless power receiving device 10C according to the fourth embodiment differs from the wireless power receiving device 10 according to the first embodiment in the connection position of the connection line 700 on the power receiving circuit side. The other configurations of the wireless power receiving device 10C are the same as those of the wireless power receiving device 10, and the description of the similar parts will be omitted.

[0073] In the wireless power receiving device 10C, one end of the connection line 700 is connected to a DC reference potential PDCL 50, which is based on the negative terminal of the load circuit 50 in the low-side power supply line 45L. In other words, a resistive component 79 may be connected in series between the node between the low-side power supply line 45L and the connection line 700, and between the node between the low-side power supply line 45L and the smoothing circuit 41 (smoothing capacitor 411). The resistive component 79 is, for example, the parasitic impedance component of the low-side power supply line 45L.

[0074] With this configuration, the wireless power receiving device 10C can achieve the same effects as the wireless power receiving device 10. Furthermore, the wireless power receiving device 10C is not affected by the potential difference generated by the resistive component 79 in the DC reference potential between the load circuit 50 and the electronic control circuit 60. Therefore, even in the presence of the resistive component 79, communication between the load circuit 50 and the electronic control circuit 60 remains stable.

[0075] [Fifth Embodiment] A wireless power receiving device according to a fifth embodiment of the present invention will be described with reference to the figures. Figure 7 shows an example of the configuration of a wireless power supply system including a wireless power receiving device according to a fifth embodiment of the present invention.

[0076] As shown in Figure 7, the wireless power receiving device 10D according to the fifth embodiment differs from the wireless power receiving device 10 according to the first embodiment in that it separately includes a power receiving resonant circuit 21D and a communication resonant circuit 22D. The other components of the wireless power receiving device 10D are the same as those of the wireless power receiving device 10, and the description of the similar parts will be omitted.

[0077] The wireless power receiving device 10D comprises a power receiving resonant circuit 21D and a communication resonant circuit 22D. The power receiving resonant circuit 21D comprises a power receiving coil 201W, a power receiving resonant capacitor 202, and a power receiving resonant capacitor 203. The configuration of the power receiving resonant circuit 21D is the same as that of the power receiving resonant circuit 21, and therefore its description is omitted.

[0078] The communication resonant circuit 22D comprises a communication antenna 201RF and a resonant capacitor 205. The communication antenna 201RF is, for example, a loop coil. The resonant capacitor 205 is connected in parallel to the communication antenna 201RF. The resonant frequency of the communication resonant circuit 22D is set to be approximately the same as the frequency of the alternating magnetic field.

[0079] The node between one terminal of the communication antenna 201RF and one terminal of the resonant capacitor 205 is connected to the node between the anode of diode D321 and the cathode of diode D322 in the rectifier circuit 32.

[0080] The node between the other terminal of the communication antenna 201RF and the other terminal of the resonant capacitor 205 is connected to the node between the anode of diode D323 and the cathode of diode D324 in the rectifier circuit 32.

[0081] Thus, even with the receiving coil 201W and communication antenna 201RF in separate configurations, the wireless power receiving device 10D can achieve the same effects as the wireless power receiving device 10. Furthermore, in this configuration, a closed loop like that of the wireless power receiving device 10, which realizes power reception and communication with a single coil, is not formed. Therefore, the noise current leaking from the power receiving circuit to the electronic control circuit 60 is smaller than in the case of a closed loop. As a result, the impedance of the impedance circuit 70 can be set to a smaller value, and for example, the impedance circuit 70 can be miniaturized.

[0082] Furthermore, the configurations of each of the above embodiments can be combined as appropriate, and effects can be achieved depending on the combination.

[0083] <1> A resonant receiving circuit including a receiving coil and a resonant receiving capacitor, A power receiving circuit electrically connected to the aforementioned power receiving resonant circuit, A load circuit is electrically connected to the aforementioned power receiving circuit and driven by the output power from the aforementioned power receiving circuit, An electronic control circuit that performs predetermined electrical signal processing, Equipped with, The aforementioned power receiving circuit is A first rectifier circuit that rectifies the first alternating current flowing through the aforementioned power receiving resonant circuit, A first smoothing circuit is electrically connected to the first rectifier circuit and smooths the rectified voltage, Equipped with, The aforementioned electronic control circuit is A second rectifier circuit for rectifying a second alternating current flowing through the aforementioned power receiving coil or a second power receiving coil provided separately from the aforementioned power receiving coil, A second smoothing circuit is electrically connected to the second rectifier circuit and smooths the rectified voltage, It is electrically connected to, A first AC receiving circuit including the resonant receiving circuit and the first rectifier circuit, A first DC receiving circuit including the smoothing circuit and the load circuit, A second AC receiving circuit including the second rectifier circuit, A second DC receiving circuit including the second smoothing circuit, A connection line for electrically connecting the first DC receiving circuit and the electronic control circuit, Equipped with, The aforementioned electronic control circuit is equipped with a ground terminal, The aforementioned connection line electrically connects the DC reference potential of the first DC receiving circuit and the ground terminal through an impedance circuit. A wireless power receiving device in which the impedance circuit is configured such that the DC potential of the ground terminal is stabilized to be the same as the DC reference potential of the first power receiving DC circuit, and the impedance value is set to suppress the flow of the first AC current or the second AC current from the power receiving DC circuit to the connection line.

[0084] <2> The DC reference potential is the potential of the negative electrode of the first smoothing circuit. <1> A wireless power receiving device.

[0085] <3> The DC reference potential is the potential of the positive electrode of the first smoothing circuit. <1> A wireless power receiving device.

[0086] <4> The DC reference potential is the potential of the negative electrode of the load circuit. <1> A wireless power receiving device.

[0087] <5> The aforementioned impedance circuit is constructed using a parallel resonant circuit consisting of a capacitor and an inductor. <1> ~ <4> One of the following wireless power receiving devices.

[0088] <6> The impedance circuit is constructed using ferrite beads. <1> ~ <4> One of the following wireless power receiving devices.

[0089] <7> The impedance circuit is constructed using resistors. <1> ~ <4> One of the following wireless power receiving devices.

[0090] <8> The aforementioned electronic control circuit includes a wireless communication IC, The aforementioned wireless communication IC is electrically connected to a receiving coil and performs wireless communication using the receiving coil. <1> ~ <7> One of the following wireless power receiving devices.

[0091] <9> The aforementioned electronic control circuit includes a wireless communication IC, The wireless communication IC is connected to a communication antenna different from the receiving coil, and wireless communication is performed using the communication antenna. <1> ~ <7> One of the following wireless power receiving devices.

[0092] <10> The power receiving circuit receives power from a magnetic field with a frequency of 13.56 MHz or 6.78 MHz. <1> ~ <9> One of the following wireless power receiving devices. [Explanation of Symbols]

[0093] 1: Wireless power supply system 10, 10A, 10B, 10C, 10D: Wireless power receiving devices 21, 21D: Resonant power receiving circuit 22, 22D: Communication resonant circuit 31, 32: Rectifier circuit 41, 42: Smoothing circuit 45H: Hi-side power supply line 45L: Low-side power supply line 46H: Hi-side power supply line 46L: Low-side power supply line 50: Load circuit 60: Electronic control circuits 70, 70F, 70LC: Impedance circuits 71: Inductor 72: Capacitor 73: Ferrite beads 79: Resistance component 80: Wireless power transmission device 81: Power transmission resonant circuit 82: Power transmission circuit 89:DC power supply 201: Power receiving coil 201RF: Communication antenna 201W: Power receiving coil 202, 203: Resonant capacitors 204: Communication resonant capacitor 205: Resonant Capacitor 411: Smoothing Capacitor 421: Smoothing Capacitor 700: Connection line 801: Power transmission coil 802: Power transmission resonant capacitor D311, D312, D313, D314, D321, D322, D323, D324: Diodes PDCH, PDCL, PDCL50: DC reference potential PG: Ground terminal

Claims

1. A resonant receiving circuit including a receiving coil and a resonant receiving capacitor, A power receiving circuit electrically connected to the aforementioned power receiving resonant circuit, A load circuit is electrically connected to the aforementioned power receiving circuit and driven by the output power from the aforementioned power receiving circuit, An electronic control circuit that performs predetermined electrical signal processing, Equipped with, The aforementioned power receiving circuit is A first rectifier circuit that rectifies the first alternating current flowing through the power receiving resonant circuit, A first smoothing circuit is electrically connected to the first rectifier circuit and smooths the rectified voltage, Equipped with, The aforementioned electronic control circuit is A second rectifier circuit for rectifying a second alternating current flowing through the aforementioned power receiving coil or a second power receiving coil provided separately from the aforementioned power receiving coil, A second smoothing circuit is electrically connected to the second rectifier circuit and smooths the rectified voltage, It is electrically connected to, A first AC receiving circuit including the resonant receiving circuit and the first rectifier circuit, A first DC receiving circuit including the first smoothing circuit and the load circuit, A second AC receiving circuit including the second rectifier circuit, A second DC receiving circuit including the second smoothing circuit, A connection line for electrically connecting the first DC receiving circuit and the electronic control circuit, Equipped with, The aforementioned electronic control circuit is equipped with a ground terminal, The aforementioned connection line electrically connects the DC reference potential of the first DC receiving circuit and the ground terminal through an impedance circuit. Wireless power receiving device.

2. The impedance circuit is configured such that the DC potential of the ground terminal is stabilized to be the same as the DC reference potential of the first DC receiving circuit, and the impedance value is set such that the first AC current does not flow from the first DC receiving circuit to the connection line, or the second AC current does not flow from the second DC receiving circuit to the connection line. The wireless power receiving device according to claim 1.

3. The DC reference potential is the potential of the negative electrode of the first smoothing circuit. A wireless power receiving device according to claim 1 or claim 2.

4. The DC reference potential is the potential of the positive electrode of the first smoothing circuit. A wireless power receiving device according to claim 1 or claim 2.

5. The DC reference potential is the potential of the negative electrode of the load circuit. A wireless power receiving device according to claim 1 or claim 2.

6. The aforementioned impedance circuit is constructed using a parallel resonant circuit consisting of a capacitor and an inductor. A wireless power receiving device according to claim 1 or claim 2.

7. The impedance circuit is constructed using ferrite beads. A wireless power receiving device according to claim 1 or claim 2.

8. The impedance circuit is constructed using resistors. A wireless power receiving device according to claim 1 or claim 2.

9. The aforementioned electronic control circuit includes a wireless communication IC, The aforementioned wireless communication IC is electrically connected to a receiving coil and performs wireless communication using the receiving coil. A wireless power receiving device according to claim 1 or claim 2.

10. The aforementioned electronic control circuit includes a wireless communication IC, The wireless communication IC is connected to a communication antenna different from the receiving coil, and wireless communication is performed using the communication antenna. A wireless power receiving device according to claim 1 or claim 2.

11. The power receiving circuit receives power using a magnetic field with a frequency of 13.56 MHz or 6.78 MHz. A wireless power receiving device according to claim 1 or claim 2.

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