Wireless power reception device

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

Wireless Power Receiver

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

[0002] Patent Document 1 describes a circuit device including an RFID and a wireless power receiving circuit. It describes that in the circuit device of Patent Document 1, when the ground potential and reference potential of the wireless power receiving circuit and the RFID are connected, a current flows from the wireless power receiving circuit to the RFID.

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

[0004] U.S. Pat. No. 10,348,130

[0005] However, with a method such as the circuit device of Patent Document 1, the degree of freedom in designing 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] Furthermore, according to Patent Document 1, for example, if the wireless power receiving circuit has an asymmetric circuit configuration, it is not possible to suppress the current flowing from the wireless power receiving circuit to the communication circuit including the RFID, and as a result, noise current generated in the wireless power receiving circuit leaks into the communication circuit.

[0007] Furthermore, if the wireless power receiving circuit and the communication circuit are not connected, the DC reference potential of the wireless power receiving circuit will not match the ground potential of the communication circuit, making the ground potential of the RFID and the like unstable.

[0008] Therefore, an object of the present invention is to provide a wireless power receiving device that can stabilize the ground potential of a communication circuit and prevent noise current generated in the wireless power receiving circuit from leaking to the communication circuit.

[0009] The wireless power receiver of the present invention includes 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 output power from the power receiving circuit, and an electronic control circuit that performs predetermined electrical signal processing. The power receiving circuit includes a first rectifier circuit that rectifies a first AC 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 AC 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 comprises a first power receiving AC circuit including a power receiving resonant circuit and a first rectifier circuit, a first power receiving DC circuit including a smoothing circuit and a load circuit, a second power receiving AC circuit including a second rectifier circuit, a second power receiving DC circuit including a second smoothing circuit, and a connection line electrically connecting the first power receiving DC circuit and an electronic control circuit.

[0011] The electronic control circuit includes a ground terminal, and the connection line electrically connects the ground terminal to a DC reference potential of the first power receiving DC circuit through an impedance circuit, and the impedance circuit has an impedance value set so that the DC potential of the ground terminal becomes equal to and stabilizes the DC reference potential of the first power receiving DC circuit and prevents the first AC current or the second AC current from flowing from the power receiving DC circuit to the connection line.

[0012] In this configuration, even when the first receiving DC 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 receiving DC circuit are at the same potential, and prevents the first AC current or the second AC current from flowing through the electronic control circuit.

[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 to the communication circuit can be suppressed.

[0014] FIG. 1 is a diagram showing an example of the configuration of a wireless power supply system including a wireless power receiving device according to a first embodiment of the present invention. FIGS. 2A and 2B are diagrams showing an example of the circuit configuration of an impedance circuit according to the first embodiment of the present invention. FIG. 3A is a DC equivalent circuit diagram of a portion of a wireless power receiving device including an impedance circuit, and FIG. 3B is an equivalent circuit diagram of a portion of a wireless power receiving device including an impedance circuit, in terms of a noise current at a predetermined frequency. FIG. 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. FIG. 5 is a diagram showing 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. FIG. 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. FIG. 7 is a diagram showing 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.

[0015] [First Embodiment] A wireless power receiving device according to a 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 a wireless power receiving device according to the first embodiment of the present invention.

[0016] 1 , the wireless power supply system 1 includes a wireless power receiver 10 and a wireless power transmitter 80. The wireless power receiver 10 includes a power receiver resonant circuit 21, a communication resonant 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 receiver 10) The power receiving resonant circuit 21 includes a power receiving coil 201, a power receiving resonant capacitor 202, and a power receiving resonant capacitor 203. The power receiving coil 201 is a loop coil having a predetermined inductance. The power receiving resonant capacitor 202 is connected in parallel to the power receiving coil 201. One terminal of the power receiving resonant capacitor 203 is electrically connected to a 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 power receiving resonant circuit 21 is set to be approximately the same as the frequency of the alternating magnetic field coupled to the power receiving coil 201, in other words, the resonant frequency of the power transmitting resonant circuit 81 (described later) and further the switching frequency (described later) of the power transmitting circuit 82.

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

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

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

[0022] The high-side terminal of the load circuit 50 is electrically connected to the high-side power supply line 45H, and the low-side terminal of the load circuit 50 is electrically connected to the low-side power supply line 45L.

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

[0024] The rectifier circuit 32 includes a plurality of diodes D321-D324. The anode of the diode D321 is electrically connected to the cathode of the diode D322. The anode of the diode D323 is electrically connected to the cathode of the diode D324. The cathode of the diode D321 is electrically connected to the cathode of the diode D323. The anode of the diode D322 is electrically connected to the anode of the diode D324.

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

[0026] The node between the cathode of the diode D321 and the cathode of the diode D323 is electrically connected to the high-side power supply line 46H. The node between the anode of the diode D322 and the anode of the diode D324 is 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 high-side power supply line 46H and the low-side power supply line 46L.

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

[0029] (Connection Between Power Receiving Circuit and 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 connection line 700. An impedance circuit 70 is connected to the connection line 700 in series.

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

[0031] (Outline of Wireless Power Supply and Wireless Communication) The wireless power receiver 10 is disposed relative to the wireless power transmitter 80 so that the power receiver coil 201 is electromagnetically coupled to the power transmitter coil 801 .

[0032] The power transmitting circuit 82 of the wireless power transmitting device 80 is driven by DC power from a DC power supply 89. The power transmitting circuit 82 includes a power conversion circuit having a switching element. The power transmitting circuit 82 controls the conduction and opening of the switching element of the power conversion circuit to convert DC current into AC current based on a switching frequency and provides the AC current to the power transmitting resonant circuit 81.

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

[0034] The power receiving coil 201 of the wireless power receiving device 10 is coupled to the alternating magnetic field generated by the power 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 transmitting circuit 82, the power transmitting resonant frequency of the power transmitting resonant circuit 81, and the power receiving resonant frequency of the power receiving resonant circuit 21 to predetermined values, the wireless power transmitting device 80 and the wireless power receiving device 10 can realize wireless power feeding by DC resonance. By realizing wireless power feeding by DC resonance, the wireless power transmitting device 80 can feed power to the wireless power receiving device 10 with low loss and high efficiency.

[0036] The rectifier circuit 31 rectifies the AC receiving current output from the power receiving resonant circuit 21 to DC. The smoothing circuit 41 smoothes 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 a first rectifier circuit, and the smoothing circuit 41 is a first smoothing circuit. A circuit including the power receiving resonant circuit 21 and the rectifier circuit 31 is a first power receiving AC circuit, and a circuit including the smoothing circuit 41 and the load circuit 50 is a first power receiving DC circuit.

[0037] The load circuit 50 is driven by the supplied DC power and executes a predetermined process. The load circuit 50 includes a circuit (e.g., 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 a predetermined control, and provides an instruction signal to the electronic control circuit 60.

[0038] The rectifier circuit 32 rectifies the AC receiving current output from the communication resonant circuit 22 to DC. The smoothing circuit 42 smoothes 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 a second rectifier circuit, and the smoothing circuit 42 is a second smoothing circuit. A circuit including the rectifier circuit 32 is a second receiving AC circuit, and a circuit including the smoothing circuit 42 is a second receiving DC circuit.

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

[0040] Changing the impedance of the electronic control circuit 60 varies the amplitude of the alternating magnetic field coupled to the power receiving coil 201. The variation in the amplitude of the alternating magnetic field varies the amplitude of the power transmission current flowing through the power transmission resonance circuit 81. The power transmission circuit 82 realizes wireless communication with the electronic control circuit 60 by detecting the variation in the amplitude of the power transmission current of the power transmission resonance circuit 81.

[0041] In this way, the wireless power supply system 1 can realize wireless communication between the wireless power transmitter 80 and the wireless power receiver 10 while supplying power from the wireless power transmitter 80 to the wireless power receiver 10. At this time, wireless power supply is realized between the wireless power transmitter 80 and the wireless power receiver 10 by DC resonance, so that power can be supplied to the wireless power receiver 10 with low loss.

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

[0043] (Impedance Circuit 70) FIGS. 2A and 2B are diagrams showing an example of the circuit configuration of an impedance circuit according to the first embodiment of the present invention.

[0044] 2A includes 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, and therefore has low impedance in direct current, and high impedance at a predetermined frequency determined by the inductance of the inductor 71 and the capacitance of the capacitor 72 and in a frequency band around the predetermined frequency.

[0046] Therefore, by providing the impedance circuit 70LC, the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are electrically connected in a DC manner. As a result, the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same DC potential. This stabilizes communication between the load circuit 50 and the electronic control circuit 60, allowing the electronic control circuit 60 to stably receive instruction signals from the load circuit 50, for example, and suppresses malfunctions.

[0047] More specifically, communication between the load circuit 50 and the electronic control circuit 60 involves transmitting high and low digital signals via a digital circuit. The high-to-low transitions of this digital signal require an AC current to flow between the grounds of the load circuit 50 and the electronic control circuit 60. In the above-described configuration, the resonant frequency of the LC parallel resonant circuit is not adjusted to the frequency of the digital signal, but rather to the frequency of the noise current of the alternating magnetic field and the switching noise of the rectifier diode. This allows the AC current of the high and low transitions of the digital signal to flow while suppressing the noise current (AC current) in the power receiving AC circuit. In other words, communication using digital signals is possible even with the inclusion of an impedance element. In other words, the impedance circuit 70LC does not suppress all AC current, but rather suppresses the noise current in the power receiving AC circuit.

[0048] Furthermore, by providing the impedance circuit 70LC, the AC noise current of a predetermined frequency 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 prevent AC noise current of a predetermined frequency from leaking to the electronic control circuit 60. This reduces the noise current input to the electronic control circuit 60, stabilizing communication between the load circuit 50 and the electronic control circuit 60. This can prevent malfunction, damage, etc. of the electronic control circuit 60.

[0049] Furthermore, by overlapping the resonant frequency of the impedance circuit 70LC with the frequency of the alternating magnetic field, it is possible to significantly prevent noise currents due to the alternating magnetic field from leaking into the electronic control circuit 60. This suppresses the noise currents caused by the alternating magnetic field input to the electronic control circuit 60, stabilizes communication between the load circuit 50 and the electronic control circuit 60, and prevents malfunction, damage, etc. of the electronic control circuit 60.

[0050] (In the Case of Ferrite Beads) The impedance circuit 70F shown in FIG. 2B includes a ferrite bead 73. The ferrite bead 73 has low impedance in DC, and its impedance increases as the frequency increases, resulting in high impedance at high frequencies. By including the ferrite bead 73 in the impedance circuit 70F, the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are electrically connected in DC. This ensures that the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same DC potential. This stabilizes communication between the load circuit 50 and the electronic control circuit 60, allowing the electronic control circuit 60 to stably receive instruction signals from the load circuit 50 and suppress malfunctions.

[0051] Furthermore, by providing the impedance circuit 70F, AC noise current at a predetermined frequency and above that 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 prevent AC noise current from leaking to the electronic control circuit 60. This reduces the noise current input to the electronic control circuit 60, stabilizes communication between the load circuit 50 and the electronic control circuit 60, and prevents malfunction, damage, etc. of the electronic control circuit 60.

[0052] In this way, by using the impedance circuit 70 (70LC, 70F), a circuit configuration similar to that shown in FIG. 3A can be realized for DC, and a circuit configuration similar to that shown in FIG. 3B can be realized for noise current.

[0053] FIG. 3A is a DC equivalent circuit diagram of a portion of a wireless power receiving device including an impedance circuit, and FIG. 3B is an equivalent circuit diagram of a noise current of a predetermined frequency of a portion of a wireless power receiving device including an impedance circuit.

[0054] 3A, in the case of DC, the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 of the communication circuit are electrically connected. As a result, the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and the ground terminal PG of the electronic control circuit 60 are at the same DC potential.

[0055] 3B, when a noise current of a predetermined frequency is present, the equivalent circuit between the low-side power supply line 45L of the power receiving circuit and the low-side power supply line 46L of the communication circuit is open, thereby preventing the noise current from the power receiving circuit from leaking to the electronic control circuit 60.

[0056] This prevents (suppresses) AC noise current (first AC signal) from flowing from the power receiving DC circuit of the power receiving circuit to the electronic control circuit of the communication circuit, preventing malfunction in the electronic control circuit and enabling predetermined electrical signal processing. Furthermore, it is possible to suppress AC current (second AC signal) from flowing from the electronic control circuit to the power receiving DC circuit. This prevents large currents from flowing into the electronic control circuit, which could cause damage to the electronic control circuit, and suppresses localized heat generation. This suppresses noise current leakage, performs stable electrical signal processing, and suppresses localized heat generation, resulting in a compact, high-performance wireless power receiving device 10 with excellent electromagnetic noise characteristics.

[0057] In particular, in the wireless power receiver 10, the current of the power receiving circuit output through the power receiving resonant circuit 21 is larger than the current of the communication circuit output through the communication resonant circuit 22. Therefore, the noise current of the power receiving circuit is larger than the noise current of the communication circuit. This increases the adverse effect (possibility of malfunction or damage) that the noise current of the power receiving circuit has on the electronic control circuit 60. However, by providing the above-described configuration, the noise current of the power receiving circuit is prevented from leaking to the electronic control circuit 60, thereby effectively preventing malfunction or damage to the electronic control circuit 60.

[0058] Furthermore, in the wireless power receiver 10, the power receiver resonant circuit 21 and the communication resonant circuit 22 share a portion of their circuits, and the wireless power receiver 10 forms a closed loop consisting of the common portion between the power receiver resonant circuit 21 and the communication resonant circuit 22, the rectifier circuit 31 of the power receiver circuit, the smoothing circuit 41, the connection line 700, and the electronic control circuit 60 of the communication circuit, the smoothing circuit 42, and the rectifier circuit 32. This makes it easy for noise current from the power receiver circuit to flow into the communication circuit through the connection line 700. However, the inclusion of the impedance circuit 70 makes it difficult for noise current from the power receiver circuit to flow into the communication circuit. Therefore, the wireless power receiver 10 can suppress noise current input to the electronic control circuit 60 and prevent malfunction, damage, etc. of 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 the impedance circuit 70LC and the impedance circuit 70F are used selectively, the use of the impedance circuit 70LC can suppress heat generation due to noise current. On the other hand, the use of the impedance circuit 70F can suppress reflection of the noise current toward the power feed circuit.

[0060] Furthermore, the impedance circuit 70 only needs to have an impedance value set so that the DC potential of the ground terminal PG of the electronic control circuit 60 is substantially the same as the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit and so that AC current (noise current) is prevented from flowing from the power receiving DC circuit of the power receiving 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 only needs to be set so that the DC potential of the ground terminal PG of the electronic control circuit 60 and the DC reference potential PDCL of the power receiving DC circuit of the power receiving circuit fall within a potential difference that allows stable signal transmission 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 drawings. Fig. 4 is a diagram showing an example of the configuration of a wireless power supply system including a wireless power receiving device according to the second embodiment of the present invention.

[0062] 4, the wireless power receiver 10A according to the second embodiment differs from the wireless power receiver 10 according to the first embodiment in the connection position of the impedance circuit 70. Other configurations of the wireless power receiver 10A are similar to those of the wireless power receiver 10, and a description of 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 electrode 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 of 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 drawings. Fig. 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] 5, the wireless power receiver 10B according to the third embodiment differs from the wireless power receiver 10 according to the first embodiment in the connection position on the power receiving circuit side of the connection line 700. The other configuration of the wireless power receiver 10B is the same as that of the wireless power receiver 10, and a description of 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 power receiving DC 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 drawings. Fig. 6 is a diagram showing 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.

[0072] 6 , a wireless power receiver 10C according to the fourth embodiment differs from the wireless power receiver 10 according to the first embodiment in the connection position on the power receiving circuit side of the connection line 700. Other configurations of the wireless power receiver 10C are similar to those of the wireless power receiver 10, and a description of similar parts will be omitted.

[0073] In the wireless power receiver 10C, one end of the connection line 700 is connected to a DC reference potential PDCL50 based on the negative electrode of the load circuit 50 in the low-side power supply line 45L. In other words, a resistance component 79 may be connected in series between a node between the low-side power supply line 45L and the connection line 700 and a node between the low-side power supply line 45L and the smoothing circuit 41 (smoothing capacitor 411). The resistance component 79 is, for example, a parasitic impedance component of the low-side power supply line 45L.

[0074] With this configuration, the wireless power receiver 10C can achieve the same effects as the wireless power receiver 10. Furthermore, the wireless power receiver 10C is not affected by the potential difference generated by the resistance component 79 in the DC reference potential between the load circuit 50 and the electronic control circuit 60. Therefore, even when the resistance component 79 is present, communication between the load circuit 50 and the electronic control circuit 60 is 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 drawings. Fig. 7 is a diagram showing 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.

[0076] 7 , a wireless power receiver 10D according to the fifth embodiment differs from the wireless power receiver 10 according to the first embodiment in that it separately includes a power receiver resonant circuit 21D and a communication resonant circuit 22D. Other configurations of the wireless power receiver 10D are the same as those of the wireless power receiver 10, and a description of similar parts will be omitted.

[0077] The wireless power receiver 10D includes a power receiver resonant circuit 21D and a communication resonant circuit 22D. The power receiver resonant circuit 21D includes a power receiver coil 201W, a power receiver resonant capacitor 202, and a power receiver resonant capacitor 203. The configuration of the power receiver resonant circuit 21D is similar to that of the power receiver resonant circuit 21, and therefore a description thereof will be omitted.

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

[0079] A node between one terminal of the communication antenna 201RF and one terminal of the resonance capacitor 205 is connected to a node between the anode of the diode D321 and the cathode of the 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 resonance capacitor 205 is connected to the node between the anode of the diode D323 and the cathode of the diode D324 in the rectifier circuit 32.

[0081] In this way, in a configuration in which the power receiving coil 201W and the communication antenna 201RF are separate, 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 is not formed as in the wireless power receiving device 10, which achieves power reception and communication with a single coil. Therefore, the noise current leaking from the power receiving circuit to the electronic control circuit 60 is smaller than when a closed loop is formed. This allows the impedance of the impedance circuit 70 to be set small, and the impedance circuit 70 can be made smaller, for example.

[0082] The configurations of the above-described embodiments can be combined as appropriate, and effects according to the combination can be achieved.

[0083] <1> 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 output power from the power receiving circuit; and an electronic control circuit performing predetermined electrical signal processing, wherein the power receiving circuit comprises: a first rectifier circuit that rectifies a first AC current flowing in the power receiving resonant circuit; and a first smoothing circuit electrically connected to the first rectifier circuit and smoothing the rectified voltage, and the electronic control circuit comprises: a second rectifier circuit that rectifies a second AC current flowing in 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 rectified voltage, a first power receiving AC circuit including the power receiving resonant circuit and the first rectifier circuit; and a first power receiving DC circuit including the smoothing circuit and the load circuit, a second power receiving AC circuit including the second rectifier circuit; a second power receiving DC circuit including the second smoothing circuit; and a connection line electrically connecting the first power receiving DC circuit and the electronic control circuit, wherein the electronic control circuit has a ground terminal, and the connection line electrically connects a DC reference potential of the first power receiving DC circuit to the ground terminal through an impedance circuit, and the impedance circuit has an impedance value set so that the DC potential of the ground terminal is stabilized at the same potential as the DC reference potential of the first power receiving DC circuit, and the first AC current or the second AC current is prevented from flowing from the power receiving DC circuit to the connection line.

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

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

[0086] <4> The wireless power receiving device according to <1>, wherein the DC reference potential is a potential of a negative electrode of the load circuit.

[0087] <5> The wireless power receiving device according to any one of <1> to <4>, wherein the impedance circuit is configured using a parallel resonant circuit made up of a capacitor and an inductor.

[0088] <6> The wireless power receiving device according to any one of <1> to <4>, wherein the impedance circuit is configured using ferrite beads.

[0089] <7> The wireless power receiving device according to any one of <1> to <4>, wherein the impedance circuit is configured using a resistor.

[0090] <8> The wireless power receiving device according to any one of <1> to <7>, wherein the electronic control circuit includes a wireless communication IC, and the wireless communication IC is electrically connected to a receiving coil and performs wireless communication using the receiving coil.

[0091] <9> The wireless power receiving device according to any one of <1> to <7>, wherein the electronic control circuit includes a wireless communication IC, and the wireless communication IC is connected to a communication antenna different from the power receiving coil, and performs wireless communication using the communication antenna.

[0092] <10> The wireless power receiving device according to any one of <1> to <9>, wherein the power receiving circuit receives power using a magnetic field with a frequency in the 13.56 MHz band or the 6.78 MHz band.

[0093] 1: Wireless power supply system 10, 10A, 10B, 10C, 10D: Wireless power receiver 21, 21D: Power receiver resonant 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 circuit 70, 70F, 70LC: Impedance circuit 71: Inductor 72: Capacitor 73: Ferrite bead 79: Resistance component 80: Wireless power transmitter 81: Power transmitter resonant circuit 82: Power transmitter circuit 89: DC power supply 201: Power receiver coil 201RF: Communication antenna 201W: Power receiver coil 202, 203: Power receiver resonant capacitor 204: Communication resonant capacitor 205: Resonant capacitor 411: Smoothing capacitor 421: Smoothing capacitor 700: Connection line 801: Power transmitting coil 802: Power transmitting resonance capacitor D311, D312, D313, D314, D321, D322, D323, D324: Diodes PDCH, PDCL, PDCL50: DC reference potential PG: Ground terminal

Claims

1. A power receiving resonance circuit including a power receiving coil and a power receiving resonance capacitor; A power receiving circuit electrically connected to the power receiving resonance circuit; A load circuit electrically connected to the power receiving circuit and driven by the output power from the power receiving circuit; An electronic control circuit that performs predetermined electrical signal processing; Comprising; The power receiving circuit is; A first rectifying circuit that rectifies a first alternating current flowing through the power receiving resonance circuit; A first smoothing circuit electrically connected to the first rectifying circuit and smoothing the rectified voltage; Comprising; The electronic control circuit is; A second rectifying 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; A second smoothing circuit electrically connected to the second rectifying circuit and smoothing the rectified voltage; Electrically connected to; A first power receiving AC circuit including the power receiving resonance circuit and the first rectifying circuit; A first power receiving DC circuit including the first smoothing circuit and the load circuit; A second power receiving AC circuit including the second rectifying circuit; A second power receiving DC circuit including the second smoothing circuit; A connection line that electrically connects the first power receiving DC circuit and the electronic control circuit; Comprising; The electronic control circuit includes a ground terminal; The connection line electrically connects the DC reference potential of the first power receiving DC circuit and the ground terminal through an impedance circuit; A wireless power receiving device.

2. The impedance value of the impedance circuit is set such that the DC potential of the ground terminal is stabilized at the same potential as the DC reference potential of the first power receiving DC circuit, and the flow of the first alternating current from the first power receiving DC circuit to the connection line is suppressed, or the flow of the second alternating current from the second power receiving DC circuit to the connection line is suppressed. 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. The 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. The 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. The wireless power receiving device according to Claim 1 or Claim 2.

6. The impedance circuit is configured using a parallel resonance circuit of a capacitor and an inductor. The wireless power receiving device according to Claim 1 or Claim 2.

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

8. The impedance circuit is configured using a resistor. The wireless power receiving device according to claim 1 or claim 2.

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

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

11. The power receiving circuit receives power by a magnetic field having a frequency in the 13.56 MHz band or the 6.78 MHz band. The wireless power receiving device according to claim 1 or claim 2.