Wireless power supply system and power transmission device of the wireless power supply system

Abstract

A wireless power supply system (1) comprises a power transmission device (20) and a power reception device (30). The power transmission device (20) comprises a power transmission circuit (21) and a power transmission coil (29). The power reception device (30) comprises a power reception circuit (31) and a power reception coil (39). The power reception device (30) is placed with respect to the power transmission device (20) such that the power reception coil (39) is electromagnetically coupled to the power transmission coil (29). The power transmission circuit (21) and the power reception circuit (31) set a signal insertion period (Ts) in which an interrupt signal for power transmission authentication is locally inserted in the repetition cycle (Tc), with the majority of the repetition cycle (Tc) of power transmission and reception being occupied by a power dedicated period (Tp) in which the interrupt signal for power transmission authentication is not used.

Description

[Technical field]

[0001] The present invention relates to a wireless power supply system that authenticates a power transmission device and a power receiving device, and to a power transmission device and a power receiving device used in the wireless power supply system. [Background technology]

[0002] Patent Document 1 describes an electronic device that wirelessly receives power from a power supply device. In the configuration described in Patent Document 1, the power supply device transmits an authentication request command to the electronic device. In response to the authentication request command, the electronic device transmits an authentication response signal to the power supply device through a modulation / demodulation circuit.

[0003] Patent Document 2 describes a wireless power receiving device that receives power from a wireless power transmitting device and transmits it to a load circuit. The wireless power receiving device described in Patent Document 2 sets a predetermined threshold value for rectified DC power, and controls the transmission of power to the load circuit based on this threshold value. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6278687 specification Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configurations described in Patent Documents 1 and 2, if the power transmitting device intentionally falsifies the information and transmits power at a specific frequency, the power receiving circuit may operate and erroneously supply power to the load circuit. Such erroneous power supply to the load circuit may cause unnecessary operation of the load circuit, and may lead to adverse effects on the body or unauthorized acquisition of vital signs, for example, if the load circuit measures the body or performs a specific process.

[0006] Furthermore, if the coil receiving power is also used for authentication, this may result in a decrease in power receiving efficiency.

[0007] Therefore, an object of the present invention is to provide a wireless power supply system that can realize secure authentication and suppress a decrease in power receiving efficiency. [Means for solving the problem]

[0008] The wireless power supply system of the present invention includes a power transmitting device and a power receiving device. The power transmitting device includes a power transmitting circuit that generates both AC power to be transmitted and a power transmission signal from a DC voltage, and a power transmitting coil that wirelessly transmits the AC power and transmits the power transmission signal. The power receiving device includes a power receiving coil that is electromagnetically coupled to the power transmitting coil, and a power receiving circuit that rectifies the AC power received by the power receiving coil and converts it to a DC voltage.

[0009] The power transmitting circuit includes a power transmitting side control circuit that generates an interrupt signal for power transmission authentication, and a power transmitting side switching circuit that adjusts the output of the power transmitting signal to the power transmitting coil in response to the interrupt signal.

[0010] The power receiving circuit is equipped with a power receiving side control circuit that determines an interrupt signal for power transmission authentication corresponding to the power transmitting device from the power transmission signal, performs power transmission authentication of the power transmitting device using the interrupt signal for power transmission authentication, and starts supplying power to the load circuit or charging the secondary battery after performing the authentication.

[0011] The power transmitting side control circuit and the power receiving side control circuit mainly set a power-only period during the power transmission and reception period in which an interrupt signal for power transmission authentication is not used, and set a signal insertion period in which an interrupt signal for power transmission authentication is locally inserted into the power transmission and reception period.

[0012] In this configuration, a power-only period not used for authentication is set within the time during which power is transmitted, and the power-only period is set to be significantly longer than the signal insertion period used for authentication. Then, in the authentication, authentication of the power transmitting device becomes possible. Effect of the Invention

[0013] According to this invention, it is possible to provide a wireless power supply system that realizes secure authentication by authenticating a power transmission device using an interrupt signal for power transmission authentication, and at the same time, suppresses a decrease in power receiving efficiency by setting a signal insertion period in which an interrupt signal is inserted mainly locally during a power-only period in a power transmission and reception period. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a functional block diagram showing a schematic configuration of a wireless power supply system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a functional block diagram of the power transmitting device according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a functional block diagram of the power receiving device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a device code used for authentication. [Diagram 5] Fig. 5(A) is a diagram showing an example of a power transmission voltage transition when the device code is authenticated, Fig. 5(B) is a diagram showing an enlarged signal insertion period of Fig. 5(A), Fig. 5(D) is a diagram showing an example of a power reception voltage transition when the device code is authenticated, and Fig. 5(C) is a diagram showing an enlarged signal insertion period of Fig. 5(D). [Figure 6] FIG. 6(A) is an enlarged view of the interrupt signal period in FIG. 5(B), and FIG. 6(B) is an enlarged view of the interrupt signal period in FIG. 5(D). [Figure 7] FIG. 7 is a further enlarged view of the signal waveform during the interrupt signal period in FIG. 6(A). [Figure 8] Fig. 8(A) is a diagram showing an example of a power transmission voltage transition when the device code is not authenticated, Fig. 8(B) is a diagram showing an enlarged signal insertion period of Fig. 8(A), Fig. 8(D) is a diagram showing an example of a power reception voltage transition when the device code is not authenticated, and Fig. 8(C) is a diagram showing an enlarged signal insertion period of Fig. 8(D). [Figure 9]FIG. 9(A) is an enlarged view of the interrupt signal period in FIG. 8(B), and FIG. 9(B) is an enlarged view of the interrupt signal period in FIG. 8(D). [Figure 10] FIG. 10 is a graph showing an example of the relationship between the length of the power receiving period and the received power. [Figure 11] FIG. 11 is a flow chart showing a first mode of authentication. [Figure 12] FIG. 12 is a flowchart of power transmission control for transmitting the power transmitting device code shown in FIG. [Figure 13] FIG. 13 is a flowchart of the detection of the power transmitting device code shown in FIG. [Figure 14] FIG. 14 is a flow chart showing a second mode of authentication. [Figure 15] FIG. 15 is a flowchart of the process in the power transmitting device in the third mode of authentication. [Figure 16] FIG. 16 is a flowchart of processing in the power receiving device in the third mode of authentication. [Figure 17] FIG. 17 is a flowchart of the process in the power transmitting device in the fourth mode of authentication. [Figure 18] FIG. 18 is a flowchart of processing in the power receiving device in the fourth mode of authentication. [Figure 19] FIG. 19 is a diagram illustrating an example of an operation code. [Figure 20] FIG. 20 is a flow chart for controlling the operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A wireless power supply system according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a functional block diagram showing a schematic configuration of the wireless power supply system according to an embodiment of the present invention. Fig. 2 is a functional block diagram of a power transmission device according to an embodiment of the present invention. Fig. 3 is a functional block diagram of a power receiving device according to an embodiment of the present invention.

[0016] (Configuration of wireless power supply system 1) 1, the wireless power supply system 1 includes a power transmitting device 20 and a power receiving device 30. A DC power supply 901 is connected to the power transmitting device 20. A load circuit 99 is connected to the power receiving device 30.

[0017] When the power receiving device 30 and the load 99 circuit are used for bioinformation sensing, the load circuit 99 is a sensing circuit, a wireless communication circuit, or the like. The sensing circuit senses various types of bioinformation (temperature, etc.) of a living body. The wireless communication circuit communicates the acquired bioinformation. The load circuit 99 may be a secondary battery for charging.

[0018] (Configuration of power transmission device 20) 1 and 2, the power transmitting device 20 includes a power transmitting circuit 21, a voltage conversion circuit 22, and a power transmitting coil 29. The power transmitting circuit 21 includes a filter 211, a power transmitting side control circuit 212, a regulator 213, an EMI filter 214, a resonance adjustment circuit 215, a detector 216, a switching element QH, and a switching element QL. The power transmitting side control circuit 212 includes an MPU 212M and a driver IC 212D.

[0019] An input terminal of the voltage conversion circuit 22 is connected to a DC power supply 901. An output terminal of the voltage conversion circuit 22 is connected to an input terminal of a filter 211.

[0020] The high potential side output terminal of the filter 211 is connected to the drain of the switching element QH, and the low potential side output terminal of the filter 211 is connected to the source of the switching element QL.

[0021] The source of the switching element QH and the drain of the switching element QL are connected together. The switching element QH and the switching element QL together form a power transmitting side switching circuit.

[0022] The MPU 212M is connected to a driver IC 212D. The driver IC 212D is connected to the gate of the switching element QH and the gate of the switching element QL.

[0023] The detector 216 is connected between the high potential side output terminal of the filter 211 and the drain of the switching element QH. The regulator 213 is connected to a high potential side line that connects the high potential side output terminal of the filter 211 and the drain of the switching element QH, and is also connected to the MPU 212M of the power transmitting side control circuit 212.

[0024] An input terminal of the EMI filter 214 is connected to the node between the source of the switching element QH and the drain of the switching element QL, the source of the switching element QL, and the low potential side output terminal of the filter 211.

[0025] An output terminal of the EMI filter 214 is connected to an input terminal of the resonance adjustment circuit 215. An output terminal of the resonance adjustment circuit 215 is connected to the power transmitting coil 29.

[0026] (Basic Operation of Power Transmission Device 20 During Power Transmission) The voltage conversion circuit 22 is a so-called DC-DC converter, which converts the DC voltage from the DC power supply 901 into a predetermined voltage and outputs the voltage to the filter 211. The filter 211 performs filtering (for example, noise suppression) on the DC voltage (DC current) from the voltage conversion circuit 22.

[0027] The DC voltage (DC current) after filtering in the filter 211 is supplied to a switching circuit made up of a switching element QH and a switching element QL.

[0028] Furthermore, the DC voltage filtered by the filter 211 is supplied to the regulator 213. The regulator 213 generates a power supply voltage for the MPU 212M from the input DC voltage and supplies it to the MPU 212M.

[0029] The MPU 212M generates a control signal for controlling the switching of the switching element QH and the switching element QL. The control signal has as its base signal a square-wave clock signal with a predetermined clock frequency (for example, 6.78 MHz or 13.56 MHz in the ISM band) that specifies the start and end of power transmission. Although details will be described later, the control signal is a signal obtained by performing an interrupt process for power transmission authentication on this clock signal. The signal during the period in which the interrupt process is performed in the control signal corresponds to the "interrupt signal for power transmission authentication" of the present invention.

[0030] The MPU 212M outputs a control signal to the driver IC 212D.

[0031] The driver IC 212D generates a Hi-side switching control signal for the switching element QH and a Low-side switching control signal for the switching element QL based on the control signal. The Hi-side switching control signal and the Low-side switching control signal are signals whose voltages are inverted from each other. That is, when the Hi-side switching control signal is at a high potential, the Low-side switching control signal is at a low potential, and when the Hi-side switching control signal is at a low potential, the Low-side switching control signal is at a high potential.

[0032] The driver IC 212D supplies a Hi-side switching control signal to the switching element QH and a Low-side switching control signal to the switching element QL. At this time, the driver IC 212D synchronizes the Hi-side switching control signal and the Low-side switching control signal and supplies them to the switching elements QH and QL.

[0033] The switching element QH is on / off controlled in response to a Hi-side switching control signal, and the switching element QL is on / off controlled in response to a Low-side switching control signal.

[0034] As a result, an AC signal in which high potential and low potential are alternately repeated according to the frequency of the clock signal is output from the switching circuit to the EMI filter 214. Note that, as will be described in detail later, at this time, during the period of the interrupt process for power transmission authentication, the AC signal undergoes a waveform change according to this interrupt process.

[0035] This AC signal is filtered by the EMI filter 214 and input to the resonance adjustment circuit 215.

[0036] The resonance adjustment circuit 215 includes at least one capacitor, and configures a power transmitting resonant circuit together with the power transmitting coil 29. The resonant frequency of the power transmitting resonant circuit is set to be the same as the frequency of the clock signal.

[0037] The power transmitting coil 29 generates an alternating magnetic field in response to an AC signal.

[0038] (Configuration of power receiving device 30) 1 and 3, the power receiving device 30 includes a power receiving circuit 31 and a power receiving coil 39. The power receiving circuit 31 includes a resonance adjustment circuit 311, a rectifying and smoothing circuit 312, a regulator 313, an MPU 314, a trigger generation circuit 315, a modulation control circuit 316, and a voltage control circuit 317. The MPU 314, the trigger generation circuit 315, and the modulation control circuit 316 configure a "power receiving side control circuit" of the present invention.

[0039] An input terminal of the resonance adjustment circuit 311 is connected to the power receiving coil 39. An output terminal of the resonance adjustment circuit 311 is connected to an input terminal of the rectification smoothing circuit 312. An output terminal of the rectification smoothing circuit 312 is connected to an input terminal of a voltage control circuit 317. An output terminal of the voltage control circuit 317 is an output terminal of the power receiving device 30, and is connected to the load circuit 99.

[0040] The regulator 313 is connected to the rectifying and smoothing circuit 312 and is also connected to the MPU 314. The MPU 314 is connected to a modulation control circuit 316 and is also connected to a voltage control circuit 317.

[0041] (Basic Operation of Power Receiving Device 30 During Power Reception) The resonance adjustment circuit 311 includes at least one capacitor, and configures a power receiving resonant circuit together with the power receiving coil 39. The resonant frequency of the power receiving resonant circuit is set to the same frequency as the alternating magnetic field, that is, the resonant frequency of the power transmitting resonant circuit.

[0042] When the power receiving coil 39 is arranged so as to be electromagnetically coupled to the power transmitting coil 29, the power receiving coil 39 is coupled to an alternating magnetic field and generates an alternating current. In this case, as described above, the resonant frequency of the power receiving resonant circuit and the resonant frequency of the power transmitting resonant circuit are set to be the same, so that the alternating current can be generated from the alternating magnetic field with low loss.

[0043] The resonance adjustment circuit 311 outputs this AC current to the rectification smoothing circuit 312 .

[0044] The rectifying and smoothing circuit 312 is configured by, for example, a full-wave rectifying circuit using a rectifying element and a smoothing circuit using an inductor. The rectifying and smoothing circuit 312 converts the AC current input from the resonance adjustment circuit 311 into a DC voltage. The rectifying and smoothing circuit 312 outputs the DC voltage to the voltage control circuit 317.

[0045] The voltage control circuit 317 is a so-called DC-DC converter or the like, and converts the DC voltage input from the rectifying and smoothing circuit 312 into a DC output voltage according to the load circuit 99. The voltage control circuit 317 supplies the DC output voltage (DC output current) to the load circuit 99.

[0046] The DC voltage output from the rectifying and smoothing circuit 312 is supplied to a regulator 313. The regulator 313 generates a power supply voltage for an MPU 314 from the input DC voltage, and supplies the power supply voltage to the MPU 314.

[0047] The MPU 314 controls the driving of the voltage control circuit 317. For example, the MPU 314 observes the output voltage of the rectifying and smoothing circuit 312, and controls the driving and stopping of the voltage control circuit 317 according to the observation result. The MPU 314 also controls the driving and stopping of the voltage control circuit 317 according to a power supply instruction from the power transmitting device 20 to the load circuit 99, which will be described later.

[0048] (A brief description of the configuration and operation used for authentication) (Authentication of power transmitting device 20 by power receiving device 30) The MPU 212M of the power transmitting device 20 generates an interrupt signal (interrupt signal for power transmission authentication) reflecting the power transmitting device code of the power transmitting device 20, and provides it to the driver IC 212D. The driver IC 212D controls the on / off of the switching elements QH and QL in response to the interrupt signal.

[0049] As a result, a signal obtained by shaping the waveform of the AC signal for power transmission described above using the interrupt signal for power transmission authentication is supplied to the power transmission coil 29.

[0050] By electromagnetically coupling the power transmitting coil 29 and the power receiving coil 39, the AC current output from the resonance adjustment circuit 311 of the power receiving device 30 has the same waveform as the AC signal for power transmission, and the waveform is kept shaped by the interrupt signal for power transmission authentication. As a result, the power transmitting device code of the power transmitting device 20 is transmitted from the power transmitting device 20 to the power receiving device 30 as the interrupt signal for power transmission authentication using the AC signal for power transmission and reception.

[0051] The trigger generation circuit 315 of the power receiving device 30 is connected to the resonance adjustment circuit 311 and is realized by, for example, a resistive voltage divider circuit. The trigger generation circuit 315 converts the AC current flowing through the resonance adjustment circuit 311 into a voltage signal and outputs it to the MPU 314 as an interrupt detection signal.

[0052] The MPU 314 determines whether the interrupt signal for power transmission authentication is a power transmission authentication interrupt signal from the interrupt detection signal. The MPU 314 demodulates the power transmission device code from the power transmission authentication interrupt signal and performs authentication of the power transmission device 20.

[0053] If the authentication is successful, the MPU 314 performs drive start control on the voltage control circuit 317. For example, the MPU 314 outputs an enable signal to the voltage control circuit 317. As a result, power is supplied to the load circuit 99. If the authentication is unsuccessful, the MPU 314 does not perform drive start control on the voltage control circuit 317, or performs drive stop control on the voltage control circuit 317. For example, the MPU 314 stops outputting an enable signal to the voltage control circuit 317. As a result, power is not supplied to the load circuit 99.

[0054] In this manner, the wireless power supply system 1 can authenticate the power transmitting device 20 by the power receiving device 30. This allows the wireless power supply system 1 to realize a secure system.

[0055] (Authentication of power receiving device 30 by power transmitting device 20) The MPU 314 generates a powered device code and provides it to the modulation control circuit 316 .

[0056] The modulation control circuit 316 adjusts the impedance of the resonance adjustment circuit 311 according to the power receiving device code. When the impedance of the resonance adjustment circuit 311 changes, the coupling state between the power receiving coil 39 and the power transmitting coil 29 changes, and the load modulation level changes.

[0057] A change in the load modulation level changes the current value of the DC current flowing through the power transmission circuit 21. As a result, the power receiving device code from the power receiving device 30 is transmitted from the power receiving device 30 to the power transmitting device 20 using an AC signal for power transmission and reception.

[0058] The detector 216 converts this DC current into a voltage to generate a signal for detecting the power receiving device code, and outputs it to the MPU 212M.

[0059] The MPU 212M demodulates the power receiving device code from the power receiving device code detection signal and determines whether authentication is OK or NG.

[0060] If the authentication is successful, the MPU 212M performs power transmission control (power transmission continuation control) on the switching circuit via the driver IC 212D. This allows power to be continuously supplied from the power transmitting device 20 to the power receiving device 30. If the authentication is unsuccessful, the MPU 314 performs power transmission stop control on the switching circuit via the driver IC 212D. This prevents power from being supplied from the power transmitting device 20 to the power receiving device 30.

[0061] In this manner, the wireless power supply system 1 can authenticate the power receiving device 30 by the power transmitting device 20. This allows the wireless power supply system 1 to realize a secure system.

[0062] Furthermore, by having the power receiving device 30 authenticate the power transmitting device 20 and the power receiving device 30 authenticate each other, the wireless power supply system 1 can achieve a more secure system.

[0063] (More specific explanation of authentication of power transmitting device 20 by power receiving device 30) Fig. 4 is a diagram showing an example of a device code used for authentication. Fig. 5(A) is a diagram showing an example of a power transmission voltage transition when the device code is authenticated, and Fig. 5(B) is a diagram showing an enlarged signal insertion period of Fig. 5(A). Fig. 5(D) is a diagram showing an example of a power reception voltage transition when the device code is authenticated, and Fig. 5(C) is a diagram showing an enlarged signal insertion period of Fig. 5(D).

[0064] Fig. 6(A) is an enlarged view of the interrupt signal period in Fig. 5(B), and Fig. 6(B) is an enlarged view of the interrupt signal period in Fig. 5(C). Fig. 7 is a further enlarged view of the signal waveform during the interrupt signal period in Fig. 6(A).

[0065] Fig. 8(A) is a diagram showing an example of a power transmission voltage transition when the device code is not authenticated, Fig. 8(B) is a diagram showing an enlarged signal insertion period of Fig. 8(A), Fig. 8(D) is a diagram showing an example of a power reception voltage transition when the device code is not authenticated, and Fig. 8(C) is a diagram showing an enlarged signal insertion period of Fig. 8(D).

[0066] FIG. 9(A) is an enlarged view of the interrupt signal period in FIG. 8(B), and FIG. 9(B) is an enlarged view of the interrupt signal period in FIG. 8(D).

[0067] For example, the power transmission device code is made up of 4 bits as shown in Fig. 4. The power transmission device code is made up of a start bit "1", a 2-bit device ID, and an end bit "1".

[0068] In the following, an example will be described in which authentication is successful when the device ID is "11" and authentication is unsuccessful when the device ID is "10".

[0069] As shown in Figs. 5(A), 5(D), 8(A) and 8(D), the power transmitting device 20 and the power receiving device 30 set a repetition period Tc, and repeat the exchange of signals between the transmitting device and the receiving device at this repetition period Tc.

[0070] 5(A) and 8(A), the power transmitting device 20 sets a signal insertion period Ts and a power-only period Tp for the repetition period Tc. The power transmitting device 20 sets the signal insertion period Ts and the power-only period Tp in this order from the start of the repetition period Tc within the repetition period Tc. The signal insertion period Ts is set to about 10% or less of the repetition period Tc.

[0071] As shown in Fig. 5(B) and Fig. 8(B), the power transmitting device 20 sets a power transmitting side interrupt signal period Tt and a data receiving period Tdsr for the signal insertion period Ts. The power transmitting device 20 sets the power transmitting side interrupt signal period Tt and the data receiving period Tdsr in this order from the start of the signal insertion period Ts within the signal insertion period Ts. The power transmitting side interrupt signal period Tt is set to about 20% of the signal insertion period Ts.

[0072] The power transmitting device 20 sets a preliminary power supply period Tpre and an actual insertion period TD for the power transmitting side interrupt signal period Tt. The power transmitting device 20 sets the preliminary power supply period Tpre and the actual insertion period TD in this order from the start of the power transmitting side interrupt signal period Tt within the power transmitting side interrupt signal period Tt. The preliminary power supply period Tpre is set to a time length sufficient to supply power that enables authentication processing to the power receiving device 30. The actual insertion period TD is set to a time length sufficient to insert the power transmitting device code (4-bit data in the above case).

[0073] As shown in Fig. 5(D) and Fig. 8(D), the power receiving device 30 sets a signal insertion period Ts and a power-only period Tp for the repetition period Tc. The power receiving device 30 sets the signal insertion period Ts and the power-only period Tp in this order from the start of the repetition period Tc within the repetition period Tc. The signal insertion period Ts is set to approximately 10% or less of the repetition period Tc. That is, the signal insertion period Ts and the power-only period Tp are set to have the same configuration and the same time length for the repetition period Tc in the power receiving device 30 and the power transmitting device 20.

[0074] The first time of the repetition period Tc of the power receiving device 30 is synchronized with the first time of the repetition period Tc of the power transmitting device 20. This synchronization can be achieved, for example, by detecting the time when the power receiving device 30 first receives power supply. Also, this synchronization can be achieved by referring to the detection time of the interrupt signal.

[0075] 5(C) and 8(C), the power receiving device 30 sets a power receiving side interrupt signal period Tr and a data transmission period Tdst for the signal insertion period Ts. The power receiving device 30 sets the power receiving side interrupt signal period Tr and the data transmission period Tdst in this order from the start of the signal insertion period Ts within the signal insertion period Ts.

[0076] The power receiving side interrupt signal period Tr is set to about 40% of the signal insertion period Ts. In other words, the power receiving side interrupt signal period Tr is set to be longer than the power transmitting side interrupt signal period Tt. This allows the power receiving device 30 to more reliably receive the interrupt signal, i.e., the device code.

[0077] With each period set in this manner, the power transmitting device 20 first performs power transmission control so as to continue supplying power to the power receiving device 30 from the beginning of the repetition period Tc through the signal insertion period Ts. More specifically, the power transmitting device 20 performs interrupt signal control so as to continuously output a rectangular wave having a clock period TCL according to the above-mentioned clock frequency, as shown in FIG.

[0078] Furthermore, during a power transmission side interrupt signal period Tt in the signal insertion period Ts, the power transmitting device 20 generates an interrupt signal according to the power transmitting device code and performs on / off control (switching control) of a switching circuit.

[0079] More specifically, the MPU 212M of the power transmitting device 20 does not perform interrupt processing by an interrupt signal during the preliminary power supply period Tpre, and maintains a high potential for power supply. This allows power to be supplied to the power receiving device 30 for authentication.

[0080] Then, when the actual insertion period TD begins, the MPU 212M of the power transmitting device 20 generates an interrupt signal to set the power transmitting device code to a low potential at a bit of "1" and to a high potential at a bit of "0" (to maintain a high potential for power supply), and provides the interrupt signal to the driver IC 212D. At this time, as shown in Figures 6(A) and 7, the MPU 212M sets an individual bit period Tit with a time length obtained by dividing the power transmitting side interrupt signal period Tt by the number of bits of the device code. The MPU 212M assigns each bit of the device code to each individual bit period Tit.

[0081] Then, the MPU 212M forms the waveform of a bit "1" by maintaining a low potential for a time length Tb shorter than the individual bit period Tit. That is, in the bit "1", a low potential period with a time length Tb first exists within the individual bit period Tit, followed by a high potential period.

[0082] 7, this time length Tb is set longer than the clock cycle TCL, and is preferably at least two cycles of the clock cycle TCL, which makes it possible to more reliably distinguish between a waveform representing a bit "1" due to the low potential time during the time length Tb and a square wave due to the clock cycle TCL.

[0083] On the other hand, as shown in the third bit of FIG. 9B, the MPU 212M forms a waveform of a bit "0" by maintaining a high potential for power supply during the individual bit period Tit.

[0084] As a result, for example, if the device code is "1111", a waveform will be obtained in which low potential periods and high potential periods alternate and are repeated four times in this order from the start of the actual insertion period TD, as shown in Figures 5(B), 6(A), and 7.

[0085] On the other hand, if the device code is "1101", as shown in Figures 8(B) and 9(A), from the start of the actual insertion period TD, low potential periods and high potential periods are repeated alternately in this order three times, and the waveform has a period between the second low potential period and the third low potential period that is longer than the individual bit period Tit.

[0086] This allows the power transmitting device 20 to transmit the power transmitting side device code to the power receiving device 30 by utilizing the change in the amplitude of the power transmission voltage.

[0087] The power receiving device 30 detects the reception of power from the power transmitting device 20, and detects the first time of the repetition period Tc. Then, the power receiving device 30 continues to receive power supply from the power transmitting device 20 from the beginning of the repetition period Tc through a signal insertion period Ts.

[0088] During a power receiving side interrupt signal period Tr of a signal insertion period Ts, the power receiving device 30 first receives power supply and activates the MPU 314. More specifically, the power receiving device 30 receives power supply for a period corresponding to a preliminary power supply period Tpre of the power transmitting device 20. The MPU 314 is activated by this power.

[0089] The trigger generating circuit 315 of the power receiving device 30 converts the received AC current into a voltage signal during the power receiving side interrupt signal period Tr of the signal insertion period Ts to generate an interrupt detection signal. The MPU 314 detects an amplitude change of the interrupt detection signal.

[0090] As shown in Fig. 6(B) and Fig. 9(B), the MPU 314 detects the time when the amplitude of the interruption detection signal first becomes low, and sets the time as the detection reference time t0 of the interruption signal. The MPU 314 sets a plurality of individual bit periods Tir based on the detection reference time t0. The number of the plurality of individual bit periods Tir is set to be the same as the number of bits of the device code. The plurality of individual bit periods Tir is set to have the same time length as the individual bit period Tit of the power transmitting device 20.

[0091] The MPU 314 detects a change in the amplitude of the interruption detection signal for each individual bit period Tir. When the MPU 314 detects an individual bit period Tir that includes a low potential period, it detects it as a bit "1", and when the MPU 314 detects an individual bit period Tir that does not include a low potential period, it detects it as a bit "0".

[0092] For example, as shown in Fig. 6(B), if a low potential period is detected in each of four consecutive individual bit periods Tir from the detection reference time t0, it will be detected as a bit string of "1111." On the other hand, as shown in Fig. 9(B), if a low potential period is detected in each of two consecutive individual bit periods Tir from the detection reference time t0, no low potential period is detected in one individual bit period Tir, and a low potential period is detected in the next individual bit period Tir, it will be detected as a bit string of "1101."

[0093] The MPU 314 demodulates the device ID from the detected bit string. For example, if the bit string is "1111", the MPU 314 demodulates it as the device ID, excluding the start bit "1" and the end bit "1". Also, if the bit string is "1101", the MPU 314 demodulates it as the device ID, excluding the start bit "1" and the end bit "1".

[0094] Through such processing, the MPU 314 of the power receiving device 30 can identify the device ID of the power transmitting device 20 by using the amplitude of the received voltage.

[0095] The MPU 314 authenticates the power transmitting device 20 using the identified device ID. More specifically, the MPU 314 stores in advance in a memory or the like device IDs that have been authenticated. If the identified device ID is an authenticated device ID, the MPU 314 determines that the authentication has been successful (OK). On the other hand, if the identified device ID is not one of the authenticated device IDs, the MPU 314 determines that the authentication has been unsuccessful (NG).

[0096] In this way, in the wireless power supply system 1, the power receiving device 30 can authenticate the power transmitting device 20. In this case, since the wireless power supply system 1 performs authentication using the amplitude of the voltage transmitted and received, it is not necessary to provide a circuit configuration for authentication separately from that for power transmission and reception. This allows the wireless power supply system 1 to realize a secure system with a simple configuration.

[0097] In the above-described configuration and processing, the signal insertion period Ts used for authentication is 10% or less of the repetition cycle Tc, and the power-only period Tp, i.e., the period during which no interrupt for authentication is performed, is 90% or more of the repetition cycle Tc. As a result, the wireless power supply system 1 mainly supplies power and performs authentication interrupt processing in a localized period. Therefore, the wireless power supply system 1 can suppress a decrease in power receiving efficiency due to authentication. In other words, the wireless power supply system 1 can realize a system that is secure and has high power receiving efficiency.

[0098] Furthermore, even during the signal insertion period Ts, the high potential for power supply is maintained except for some low potential periods of the individual bit periods Tit and Tir representing the bit “1.” This allows the wireless power supply system 1 to further suppress a decrease in power receiving efficiency caused by authentication.

[0099] Fig. 10 is a graph showing an example of the relationship between the length of the power receiving period and the received power. In Fig. 10, the horizontal axis shows the ratio of the power receiving period (power-only period Tp) in the repetition cycle, and the vertical axis shows the normalized value of the received power. The vertical axis shows a value of 1 when the power receiving period is 100%.

[0100] As shown in Fig. 10, the received power decreases as the power receiving period (power-only period Tp) becomes shorter. In other words, the received power increases as the power receiving period (power-only period Tp) becomes longer. By setting the power receiving period (power-only period Tp) to 90% or more, the received power can be made 0.9 or more when the power receiving period (power-only period Tp) in which authentication is not performed is 100%. Therefore, by setting the power receiving period (power-only period Tp) to 90% or more, the decrease in the received power can be suppressed to the extent of an installation error of the power receiving coil 39 relative to the power transmitting coil 29, and a system with better power receiving efficiency can be realized.

[0101] The power receiving period can be set to less than 90%. However, by setting the power receiving period to at least 70% or more, the decrease in power receiving efficiency can be suppressed to a practical level.

[0102] Depending on the authentication result by the MPU 314, the power receiving device 30 and the power transmitting device 20 perform the following process.

[0103] (A) Power supply control to the load circuit 99 in the power receiving device 30 If the authentication is successful, the MPU 314 controls the voltage control circuit 317 to supply power to the load circuit 99. On the other hand, if the authentication is unsuccessful, the MPU 314 controls the voltage control circuit 317 to stop the power supply to the load circuit 99.

[0104] (B) Return of authentication result to power transmitting device 20 and power transmitting operation of power transmitting device 20 The MPU 314 generates an authentication code according to the authentication result and provides the authentication code to the modulation control circuit 316.

[0105] The modulation control circuit 316 adjusts the impedance of the resonance adjustment circuit 311 in response to the authentication code.

[0106] As in the authentication of the power receiving device 30 described above, a change in the impedance of the resonance adjustment circuit 311 changes the coupling state between the power receiving coil 39 and the power transmitting coil 29, and the load modulation level changes.

[0107] In the power transmitting device 20, a change in the load modulation level changes the current value of the DC current flowing through the power transmitting circuit 21. As a result, the authentication code from the power receiving device 30 is transmitted from the power receiving device 30 to the power transmitting device 20 using an AC signal for power transmission and reception.

[0108] The detector 216 converts this DC current into a voltage to generate an authentication code detection signal, and outputs it to the MPU 212M.

[0109] The MPU 212M demodulates the authentication code from the authentication code detection signal and determines whether authentication is OK or NG. If the MPU 212M determines authentication is OK, it continues the power transmission operation. As a result, as shown in Figures 5(A) and 5(D), power is continuously supplied from the power transmitting device 20 to the power receiving device 30 during the power-only period Tp. On the other hand, if the MPU 212M determines authentication is NG, it stops power transmission. As a result, as shown in Figures 8(A) and 8(D), power is not supplied from the power transmitting device 20 to the power receiving device 30 during the power-only period Tp.

[0110] This allows the power transmitting device 20 to transmit power to the power receiving device 30 to which it should transmit power, and more reliably suppresses power transmission to the power receiving device 30 to which it should not transmit power. As a result, the power receiving device 30 can receive power from the power transmitting device 20 to which it should receive power, and can prevent power reception from the power transmitting device 20 to which it should not receive power.

[0111] Such a transmission process of the authentication code from the power receiving device 30 to the power transmitting device 20 is performed in the data transmission period Tdst and the data reception period Tdsr in the signal insertion period Ts, as shown in Fig. 5(C), Fig. 5(B) and Fig. 8(C) and Fig. 8(B). That is, the transmission process of the authentication code is also performed at a time different from the power-only period Tp. As described above, the signal insertion period Ts is significantly shorter than the power-only period Tp, and therefore the signal insertion period in which the interrupt signal is inserted mainly and locally in the power-only period in the power transmission and reception period is set, so that the wireless power supply system 1 can also suppress a decrease in power receiving efficiency due to the transmission and reception of the authentication code. Furthermore, the period in which the authentication code is actually transmitted and received is a part of the signal insertion period Ts. Therefore, the wireless power supply system 1 can further suppress a decrease in power receiving efficiency due to the transmission and reception of the authentication code.

[0112] (Explanation of various aspects of authentication) In the above description, authentication between the power transmitting device 20 and the power receiving device 30 has been described using specific configurations of the power transmitting device 20 and the power receiving device 30. In the following, in order to make the control flow easier to understand, authentication between the power transmitting device 20 and the power receiving device 30 will be described using a flowchart.

[0113] (First aspect) In the first mode, the power receiving device 30 authenticates the power transmitting device 20 and returns the authentication result to the power transmitting device 20.

[0114] Fig. 11 is a flowchart showing a first mode of authentication. Fig. 12 is a flowchart of power transmission control for transmitting a power transmission device code shown in Fig. 11. Fig. 13 is a flowchart of detection of the power transmission device code shown in Fig. 11.

[0115] As shown in FIG. 11, when the power transmitting device 20 starts transmitting power (S11), the power transmitting device 20 performs a power transmitting operation for transmitting a power transmitting device code (S12).

[0116] In the power transmission operation for the power transmission device code transmission, the power transmission device 20 continues only the power transmission for power supply until the control start timing for the code transmission (the start timing of the actual insertion period TD) arrives (S121: NO). When the control start timing for the code transmission arrives (S121: YES), the power transmission device 20 starts clocking for the code transmission (S122).

[0117] The power transmitting device 20 refers to the measured time and controls the amplitude of the power transmitting voltage for each individual bit period Tit so as to realize the power transmitting device code (S123). The power transmitting device 20 repeats this amplitude control until the code transmission period (actual insertion period TD) ends (S124: NO). When the code transmission period (actual insertion period TD) ends (S124: YES), the power transmitting device 20 ends the power transmitting operation for transmitting the power transmitting device code (S125). Then, the power transmitting device 20 continues the power transmitting operation for transmitting only power (S13). Note that the continuation of the power transmitting operation performed in step S13 is limited to the signal insertion period Ts (see FIG. 8(A)), and the operations of steps S12 and S13 are repeated until an authentication code described below is obtained.

[0118] When the power receiving device 30 starts receiving power (S21), the power receiving device 30 detects the power transmitting device code (S22).

[0119] In detecting the power transmitting device code, the power receiving device 30 continues to detect an authentication trigger (the phenomenon in which the amplitude of the above-mentioned interruption detection signal initially becomes low) until it detects an authentication trigger (S221: NO), and when it detects the authentication trigger (S221: YES), it starts authentication timing (S222).

[0120] The power receiving device 30 refers to the measured time, detects the amplitude change of the interruption detection signal based on the received voltage for each individual bit period Tir, and detects the bit (S223). The power receiving device 30 repeats this bit detection until the bit detection period ends (S224: NO). The bit detection period is set to a time length obtained by multiplying the number of bits of the power transmitting device code stored in advance by the individual bit period Tir, for example.

[0121] When the bit detection period ends (S224: YES), the power receiving device 30 demodulates the power transmitting device code (S225).

[0122] The power receiving device 30 uses the power transmission device code to authenticate the power transmission device 20. If the power transmission device 20 is authenticated (S23: OK), the power receiving device 30 performs impedance control for the authentication OK code (S24). Then, the power receiving device 30 continues receiving power (S25) and supplies power to the load circuit 99 (S26).

[0123] If the authentication of the power transmitting device 20 is NG (S23: NG), the power receiving device 30 performs impedance control for an authentication NG code (S27).

[0124] The power transmitting device 20 detects a change in the transmission current caused by the impedance control of the power receiving device 30, and detects the authentication code (S14). Note that the power transmitting device 20 continues transmitting power (S13) until it detects the authentication code (S14: NO).

[0125] If the received code is an authentication OK code (S15: YES), the power transmitting device 20 continues transmitting power (S16). If the received code is an authentication NG code (S15: NO), the power transmitting device 20 stops transmitting power (S17).

[0126] (Second aspect) In the second mode, the power receiving device 30 authenticates the power transmitting device 20, but does not return the authentication result to the power transmitting device 20. Note that the power transmission control for transmitting the power transmitting device code in the power transmitting device 20 and the detection of the power transmitting device code in the power receiving device 30 are the same as in the first mode, and therefore the description will be omitted.

[0127] FIG. 14 is a flow chart showing a second mode of authentication.

[0128] 14, when the power transmitting device 20 starts power transmission (S11), it performs a power transmitting operation for transmitting a power transmitting device code (S12). Then, the power transmitting device 20 continues the power transmitting operation only for transmitting power (S13).

[0129] When the power receiving device 30 starts receiving power (S21), the power receiving device 30 detects the power transmitting device code (S22).

[0130] The power receiving device 30 authenticates the power transmitting device 20 using the power transmitting device code. If the power transmitting device 20 is authenticated (S23: OK), the power receiving device 30 performs impedance control for the authentication OK code (S24). Then, the power receiving device 30 continues receiving power (S25) and supplies power to the load circuit 99 (S26).

[0131] The power transmitting device 20 detects a change in the transmission current caused by the impedance control of the power receiving device 30, and detects the authentication code (S14). If the power transmitting device 20 cannot detect the authentication code (S14: NO), it continues transmitting power (S13) until a predetermined time has elapsed (S18: NO).

[0132] When the power transmitting device 20 detects the authentication code (authentication OK code) (S14: YES), the power transmitting device 20 continues power transmission (S16).

[0133] If the power transmitting device 20 cannot detect the authentication code (S14: NO) and a predetermined time has elapsed (S18: YES), the power transmitting device 20 stops transmitting power (S17).

[0134] (Third aspect) In the third aspect, the power receiving device 30 and the power transmitting device 20 authenticate each other. In the third aspect, the power receiving device 30 authenticates the power transmitting device 20 after the power transmitting device 20 authenticates the power receiving device 30. Note that the third aspect differs from the first aspect in that authentication of the power receiving device is added, but the subsequent processing is the same. Therefore, a description of the same parts will be omitted.

[0135] Fig. 15 is a flowchart of a process in the power transmitting device in the third authentication mode. Fig. 16 is a flowchart of a process in the power receiving device in the third authentication mode.

[0136] 16, when the power receiving device 30 starts receiving power (S21), it performs impedance control for the power receiving device cord (S41). That is, the power receiving device 30 performs impedance control of the power receiving resonant circuit using the power receiving device cord.

[0137] 15, the power transmitting device 20 detects a change in amplitude of the transmitted current and demodulates the power receiving device code (S31). The power transmitting device 20 authenticates the power receiving device 30 using the power receiving device code.

[0138] If the power receiving device 30 has been authenticated (S32: OK), the power transmitting device 20 performs the process for authenticating the power transmitting device 20 in the same manner as in the first embodiment described above.

[0139] If the power receiving device 30 is not authenticated (S32: NG), the power transmitting device 20 stops power transmission (S17).

[0140] (Fourth aspect) In the fourth aspect, the power receiving device 30 and the power transmitting device 20 authenticate each other. In the fourth aspect, the power receiving device 30 authenticates the power transmitting device 20, and then the power transmitting device 20 authenticates the power receiving device 30. As in the third aspect, the fourth aspect differs from the first aspect in that authentication of the power receiving device is added, and the subsequent processing is the same. Therefore, a description of the same parts will be omitted.

[0141] Fig. 17 is a flowchart of a process in the power transmitting device in the fourth authentication mode. Fig. 18 is a flowchart of a process in the power receiving device in the fourth authentication mode.

[0142] As shown in FIG. 18, if the power transmission device 20 is authenticated OK (S23: OK), the power receiving device 30 performs impedance control for the authentication OK code (S24), and performs impedance control for the power receiving device code (S41).

[0143] 17, when the power transmitting device 20 detects a change in amplitude of the transmitting current and detects an authentication OK code from the power receiving device 30 for the power transmitting device 20 itself (S15: YES), the power transmitting device 20 demodulates the power receiving device code (S31). The power transmitting device 20 authenticates the power receiving device 30 using the power receiving device code.

[0144] If the power receiving device 30 is authenticated (S32: OK), the power transmitting device 20 measures the power transmission (S16). If the power receiving device 30 is authenticated (S32: NG), the power transmitting device 20 stops the power transmission (S17).

[0145] (How the operation code is transmitted and received) In the above description, the device code or the authentication code is transmitted by changing the amplitude of the voltage for power transmission. However, the operation code can also be transmitted by changing the amplitude of the voltage for power transmission. The operation code is a code that specifies an operation command signal for the operation transition of the power receiving device 30.

[0146] Fig. 19 is a diagram showing an example of an operation code. As shown in Fig. 19, the operation code is made up of 4 bits. The operation code is made up of a start bit "1", a 2-bit operation ID, and an end bit "1".

[0147] The operation ID is associated with an operation (such as power supply control) performed by the power receiving device 30, and is stored in the power transmitting device 20 and the power receiving device 30.

[0148] FIG. 20 is a flow chart for controlling the operation.

[0149] As shown in FIG. 20, when the power transmitting device 20 starts transmitting power (S51), the power transmitting device 20 performs authentication processing in any of the above-mentioned modes (S52).

[0150] If the authentication is successful, the power transmitting device 20 performs a power transmitting operation for transmitting an operation code (S53) and continues power transmission (S54). Note that the power transmitting operation for transmitting an operation code is a control in which the power transmitting device code in the power transmitting operation for transmitting the power transmitting device code described above is replaced with the operation code.

[0151] The power transmitting device 20 repeats the power transmitting operation for transmitting the operation code every time it performs operational control on the power receiving device 30.

[0152] When the power receiving device 30 starts receiving power (S61), the power receiving device 30 performs authentication processing in any of the above-mentioned modes (S62).

[0153] The power receiving device 30 detects the operation code (S63), demodulates the operation code (S64), and continues receiving power (S65). Note that the detection and demodulation of the operation code are the same processes as the detection and demodulation of the power transmitting device code described above.

[0154] The power receiving device 30 generates an operation command signal for operation transition according to the operation code, and executes control using the operation command signal (S66). This causes a transition in the operation of the power receiving device 30. Every time the power receiving device 30 detects and demodulates an operation code from the power transmitting device 20, the power receiving device 30 executes control according to the demodulated operation code.

[0155] In this way, in the wireless power supply system 1, not only authentication but also operation control can be realized using the voltage for power transmission. Then, like the case of authentication, the transmission of the operation code is also performed in the signal insertion period Ts different from the power-only period Tp. Therefore, the wireless power supply system 1 can suppress a decrease in power receiving efficiency while controlling the operation of the power receiving device 30 wirelessly.

[0156] In the above description, the power receiving device 30 uses the voltage control circuit 317 to supply power to the load circuit 99. However, the power supply to the load circuit 99 may be a regulator circuit. [Explanation of symbols]

[0157] 1: Wireless power supply system 20: Power transmission equipment 21: Power transmission circuit 22: Voltage conversion circuit 29: Transmitting coil 30: Power receiving device 31: Receiving circuit 39: Receiving coil 99:Load circuit 211: Filter 212: Power transmission side control circuit 212M: MPU 212D: Driver IC 213: Regulator 214: EMI filters 215: Resonance adjustment circuit 216: Detector 311: Resonance adjustment circuit 312: Rectifier smoothing circuit 313: Regulator 314: MPU 315: Trigger generation circuit 316: Modulation control circuit 317: Voltage control circuit 901: DC power supply QH: Switching element QL: Switching element

Claims

1. A power transmitting device including: a power transmitting circuit that generates both AC power to be transmitted and a power transmitting signal from a DC voltage; and a power transmitting coil that transmits the AC power wirelessly and transmits the power transmitting signal wirelessly; a power receiving device including a power receiving coil that is electromagnetically coupled to the power transmitting coil, and a power receiving circuit that rectifies AC power received together with the power receiving coil and converts it into a DC voltage; A wireless power supply system comprising: The power transmission circuit includes: a power transmission side control circuit that generates an interrupt signal for power transmission authentication; a power transmitting side switching circuit that adjusts an output of the power transmitting signal to the power transmitting coil in response to the interrupt signal; Equipped with The power transmitting side control circuit includes: A square wave clock signal having a predetermined clock frequency is used as a base signal to transmit power; A low voltage period and a high voltage period are set to a period longer than the cycle of the base signal to generate an interrupt signal for the power transmission authentication; The power receiving circuit includes: a power receiving side control circuit that determines an interrupt signal for power transmission authentication corresponding to the power transmitting device from the power transmission signal, performs power transmission authentication for the power transmitting device using the interrupt signal for power transmission authentication, and starts supplying power to a load circuit or charging a secondary battery after the power transmission authentication is performed; the power transmitting side control circuit and the power receiving side control circuit mainly set a power dedicated period during a power transmission / reception period in which the interrupt signal for the power transmission authentication is not used, and set a signal insertion period during which the interrupt signal for the power transmission authentication is locally inserted into the power transmission / reception period. Wireless power supply system.

2. A period of 90% or more of the power transmission / reception period is set as the power-only period, A period other than the power-only period in the power transmission / reception period is set as the signal insertion period. The wireless power supply system according to claim 1 .

3. the signal insertion period of the power transmission authentication interrupt signal is preset in the power transmitting side control circuit and the power receiving side control circuit, The power receiving side control circuit includes: Detecting the start of the signal insertion period; performing the power transmission authentication using amplitude information of the power reception signal at a predetermined time interval based on the start time of the signal insertion period; The wireless power supply system according to claim 1 .

4. The power receiving side control circuit includes: A change in impedance determined by the power receiving coil and the power receiving circuit is controlled for power receiving authentication of the power receiving device; The power transmitting side control circuit includes: performing power reception authentication of the power receiving device based on a change in current in the power transmitting circuit caused by a change in impedance on the power receiving device side; generating an interrupt signal for the power transmission authentication after authenticating the power receiving device for power reception; The wireless power supply system according to claim 1 .

5. The power transmitting side control circuit includes: Controlling a change in a switching operation determined by the power transmitting coil and the power transmitting circuit for power transmission authentication of the power transmitting device; The power receiving side control circuit includes: performing power transmission authentication of the power transmitting device based on a change in current in the power receiving circuit caused by a change in a switching operation of the power transmitting device; generating an impedance change for power reception authentication after performing power transmission authentication on the power transmitting device; The wireless power supply system according to claim 1 .

6. The power transmitting side control circuit includes: generating an operation command signal for an operation transition of the power receiving side during the signal insertion period; The power receiving side control circuit includes: When the operation command signal is detected, the operation of the power receiving device is transitioned. The wireless power supply system according to claim 1 .

7. The power transmitting side control circuit includes: setting a signal insertion period of the operation command signal a plurality of times with a time interval therebetween; generating the operation command signal for each of a plurality of signal insertion periods; The power receiving side control circuit includes: transitioning the operation of the power receiving device every time the operation command signal is detected; The wireless power supply system according to claim 6 .

8. The power receiving circuit includes: a voltage conversion circuit or a power receiving regulator circuit for supplying power to the load circuit or the secondary battery; The power receiving side control circuit includes: Depending on the result of the power reception authentication, output control of an enable signal to the voltage conversion circuit or control of the power reception side regulator circuit is performed. The wireless power supply system according to claim 1 .

9. The load circuit includes a sensing circuit or a wireless communication circuit. The wireless power supply system according to claim 1 .

10. The power transmission side control circuit comprises: In the signal insertion period, a preliminary power supply period in which power capable of realizing an authentication process is supplied to the power receiving device beforehand and an actual insertion period in which a code of the power transmitting device is inserted are set, The signal insertion period is set in the order of the first time of the signal insertion period, the pre-power supply period, and the actual insertion period. The wireless power supply system according to claim 1 .

11. The power transmitting control circuit and the power receiving control circuit have the same repetition period of the power transmitting and receiving period, a signal insertion period set in the power receiving side control circuit is longer than a signal insertion period set in the power transmitting side control circuit; The wireless power supply system according to claim 1 .

12. A power transmission circuit that generates both AC power to be transmitted and a power transmission signal from a DC voltage; a power transmission coil that wirelessly transmits the AC power; A power transmission device of a wireless power supply system comprising: The power transmission circuit includes: a power transmission side control circuit that generates an interrupt signal for power transmission authentication; a power transmitting side switching circuit that adjusts an output of the power transmitting signal to the power transmitting coil in response to the interrupt signal; Equipped with The power transmitting side control circuit includes: A square wave clock signal having a predetermined clock frequency is used as a base signal to transmit power; A low voltage period and a high voltage period are set to a period longer than the cycle of the base signal to generate an interrupt signal for the power transmission authentication; a power-only period during a power transmission / reception period in which the interrupt signal for power transmission authentication is not used is mainly set, and a signal insertion period during which the interrupt signal for power transmission authentication is locally inserted into the power transmission / reception period is set. A power transmission device for a wireless power supply system.

13. The power transmitting side control circuit includes: After performing power reception authentication of a power receiving device including a power receiving coil with which the power transmitting coil is electromagnetically coupled, an interrupt signal for the power transmission authentication is output. The power transmitting device of the wireless power supply system according to claim 12.

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