WO2011062097A1

WO2011062097A1 - Non-contact power-feed device

Info

Publication number: WO2011062097A1
Application number: PCT/JP2010/069992
Authority: WO
Inventors: 浩康北村; 恭平加田
Original assignee: パナソニック電工株式会社
Priority date: 2009-11-17
Filing date: 2010-11-10
Publication date: 2011-05-26
Also published as: TW201131926A; JP2011109810A

Abstract

Provided is a non-contact power-feed device that has: a primary coil (L1) that generates an alternating magnetic flux; and a secondary coil (L2) that receives, from the primary coil (L1), alternating power corresponding to the alternating magnetic flux, without contact, at a location that intersects the alternating magnetic flux generated by the primary coil (L1). The secondary coil (L2) is provided in a resonant circuit section (22A) that is configured so as to have a changeable circuit constant. A modulation control device (21) changes the circuit constant of the resonant circuit section (22A) on the basis of information to be conveyed by the primary coil (L1), thereby modulating the amplitude of the alternating power received by the secondary coil (L2). Based on the changes in the amplitude of the alternating power in the secondary coil (L2), a demodulation control device (11) demodulates the information conveyed by the primary coil (L1) from the changes in the amplitude of the alternating power generated by the primary coil (L1).

Description

Non-contact power feeding device

The present invention relates to a non-contact power feeding apparatus that performs electromagnetic transmission between devices in a non-contact manner using electromagnetic induction.

Such a contactless power supply device has been widely known in recent years as a device that can charge a secondary battery (battery) built in a portable device such as a mobile phone or a digital camera in a contactless manner. In such a non-contact power supply device, the portable device and the charger corresponding to the portable device are each provided with a coil for transferring power for charging, and the charger is provided by electromagnetic induction between the two coils. The AC power transmitted from the mobile device to the mobile device is converted into DC power by the mobile device, so that the secondary battery as the power source of the mobile device is charged. However, although the connection terminal for electrically connecting the charger and the portable device can be omitted by such non-contact charging, it is not easy to grasp the charging state of the secondary battery by the charger. Managing the amount of charge is also difficult.

Therefore, conventionally, a technique for adjusting the state of charge of the secondary battery on the mobile device side has been proposed, and an example thereof is described in Patent Document 1. That is, in the non-contact power supply device described in Patent Document 1, two taps with different numbers of windings are provided in the coil on the portable device side so that different electric power can be extracted from the taps. When a battery is charged, the power suitable for each charge can be taken out by selecting those taps according to the state of charge of the battery. As a result, the charge amount of the secondary battery can be adjusted on the portable device side, but the charger side continues to supply constant power to the coil regardless of such charge adjustment by the portable device. In addition, there is a problem that power is wasted.

For this reason, there has been proposed a technique that adjusts the power itself supplied to the portable device while grasping the charging state of the secondary battery on the charger side. It is described in Patent Document 2 and Patent Document 3. First, the non-contact power feeding device described in Patent Document 2 is connected in parallel to a power supply unit of a charger that controls oscillation of a primary coil, and a secondary coil that is supplied with power from the oscillated primary coil. And a load unit of a portable device having a secondary battery (storage battery). The secondary coil is connected in parallel with load control means for changing its output load. Then, this load control means changes the power supply characteristic for the secondary coil, that is, the power reception characteristic of the secondary coil, by switching between opening and shorting of the parallel circuit of the secondary coil according to the state of charge of the secondary battery. I have to. Further, the non-contact power supply device described in Patent Document 3 is for signal transmission that controls connection / disconnection of a resistor having a predetermined resistance value in parallel with an output of a secondary coil of a portable device that supplies power to a load. It has a load circuit. The output load is varied by connecting / disconnecting the resistor to change the power receiving characteristic of the secondary coil. In any of these cases, the change in the power reception characteristics of the secondary coil of the portable device according to the state of charge of the secondary battery is the output voltage of the primary coil of the charger that is electromagnetically coupled to the secondary coil. The power supplied to the primary coil by the charger can be controlled through the change in the output voltage of the primary coil.

Japanese Patent Laid-Open No. 11-89103 Japanese Patent No. 3247199 Japanese Patent Laid-Open No. 11-341711

In this way, the charger supplies unnecessary power to the corresponding portable device by adjusting the power supplied to the portable device based on the change of the power reception characteristic on the portable device side, that is, the information from the portable device side. This makes it possible to reduce the waste of electric power generated by this. However, if the output of the secondary coil is short-circuited for information transmission, or if the resistor is connected in parallel to the output of the secondary coil, the output power of the secondary coil is unnecessarily consumed and the same output Even in a load such as a secondary battery that receives power supply, inconveniences such as power supply being stopped or reduced are inevitable.

The present invention has been made in view of such circumstances, and its purpose is to share a circuit used for power supply when supplying power from a primary coil to a secondary coil in a contactless manner. Another object of the present invention is to provide a non-contact power feeding apparatus capable of transmitting information from a secondary coil to a primary coil with less power consumption.

The first aspect of the present invention is a non-contact power feeding device. The apparatus receives a primary coil that generates an alternating magnetic flux, and a secondary that receives the alternating power corresponding to the alternating magnetic flux from the primary coil in a non-contact manner at a position that intersects the alternating magnetic flux generated in the primary coil. A resonance circuit unit including a coil and configured to be able to change a circuit constant, and the secondary coil receives power by changing the circuit constant of the resonance circuit unit based on information to be transmitted to the primary coil. A modulation control device that modulates the amplitude of the alternating power, and a change in the amplitude of the alternating power generated in the primary coil in response to a change in the amplitude of the alternating power in the secondary coil. A demodulation control device for demodulating information.

According to such a configuration, the modulation control device changes the circuit constant of the resonance circuit unit based on information desired to transmit the amplitude of the alternating power voltage received by the secondary coil to the primary coil. Let The demodulation control device acquires predetermined information transmitted from the modulation control device based on the change in the voltage amplitude at the primary coil caused by the change in the voltage amplitude at the secondary coil. As a result, information from the modulation control device is transmitted to the demodulation control device. For example, a primary coil and a demodulation control device are provided in a first device such as a charger, and a secondary coil, a resonance circuit unit, and a modulation control device are provided in a second device such as a portable device including a secondary battery and a load. In such a case, the demodulation control device can suitably control the power transmitted to the secondary coil by controlling the drive of the primary coil according to the situation of the secondary battery or load connected to the modulation control device. become.

In addition, since the circuit constant of the resonant circuit unit including the secondary coil is changed, the DC power converted into a state suitable for supply to the load after receiving power at the secondary coil through adjustment such as rectification and smoothing is obtained. It is avoided that a large amount is consumed for information transmission. That is, when transmitting information from the secondary coil to the primary coil, the DC power to be supplied to the load such as the secondary battery is changed by changing the characteristics of the secondary coil due to the load fluctuation with respect to the DC power as in the past. Is suppressed from being consumed. As a result, there is a possibility that information transmission may adversely affect the supply of DC power to the load, for example, the risk of stopping the power supply to the load or significantly reducing the supply amount.

Furthermore, since the circuit constant of the resonance circuit unit including the secondary coil is changed, it becomes easy to adjust or change the power receiving characteristics applied to the secondary coil. This facilitates the design and adjustment of the power reception characteristics of the resonance circuit unit, and also improves the possibility of implementing and adopting the non-contact power feeding device having such a resonance circuit unit.

A second aspect of the present invention is a power receiving unit that receives power from a power transmission unit including a primary coil in a contactless manner. The power receiving unit includes a secondary coil that receives the alternating power corresponding to the alternating magnetic flux from the primary coil in a non-contact manner at a position that intersects the alternating magnetic flux generated in the primary coil, and the circuit constant can be changed. And modulation control for modulating the amplitude of the alternating power received by the secondary coil by changing the circuit constant of the resonant circuit unit based on information to be transmitted to the primary coil. Device. According to this structure, the electric power receiving part suitable for the non-contact electric power feeder of an above-mentioned 1st aspect can be provided.

1 is a circuit diagram schematically showing a circuit configuration of a first embodiment that embodies a contactless power feeding device according to the present invention. It is a graph which shows the voltage change of the alternating power of the electric power receiving part of the embodiment, Comprising: (a) shows the case where a power receiving characteristic is optimal, (b) shows the case where a power receiving characteristic is not optimal. FIG. 3 is a graph showing a state similar to FIG. 2 for a longer period than that of FIG. 2, where (a) shows a case where the power reception characteristics are optimum, and (b) shows a case where the power reception characteristics are not optimum. It is a graph which shows the reception state of the signal by the electric power transmission part of the embodiment, (a) is a graph which shows the voltage change of alternating power, (b) shows the signal demodulated based on the voltage change of (a). Figure. The circuit diagram which shows schematically the circuit structure of the electric power receiving part about 2nd Embodiment which actualized the non-contact electric power feeder which concerns on this invention. The circuit diagram which shows roughly the circuit structure of the electric power receiving part about 3rd Embodiment which actualized the non-contact electric power feeder which concerns on this invention. The circuit diagram which shows roughly the circuit structure of the electric power receiving part about 4th Embodiment which actualized the non-contact electric power feeder which concerns on this invention. The circuit diagram which shows roughly the circuit structure of the electric power receiving part about 5th Embodiment which actualized the non-contact electric power feeder which concerns on this invention. The circuit diagram which shows schematically the circuit structure of the electric power receiving part about 6th Embodiment which actualized the non-contact electric power feeder which concerns on this invention.

(First embodiment)
Hereinafter, a first embodiment embodying a non-contact power feeding device according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of an electric circuit of the contactless power supply device according to the first embodiment.

As shown in FIG. 1, the non-contact power supply apparatus is roughly divided into a power transmission unit 10 and a power reception unit 20. First, the power transmission unit 10 will be described.
The power transmission unit 10 includes a primary coil L1, and a resonance capacitor C4 is connected in parallel to the primary coil L1 to form a primary LC circuit. An LC circuit on the primary side, a parallel circuit of a diode D2 and a resistor R5, an N-channel MOS transistor FET1 as a switching element, and a resistor R7 are connected in series to form a series circuit. The DC power supply E is connected in parallel. Note that an RC circuit including a series connection of a resistor R6 and a capacitor C5 is connected in parallel to the resistor R7.

In addition, a capacitor C1 is connected in parallel to the DC power source E, and a series circuit including a starting resistor R1 and a capacitor C2 is also connected in parallel. The node N1 between the starting resistor R1 and the capacitor C2 is connected to the gate terminal of the MOS transistor FET1 through a series circuit including a feedback coil L3 that constitutes an oscillation transformer together with the primary coil L1 and a resistor R3. ing.

The power transmission unit 10 further includes a bias control transistor TR2 made of an NPN transistor, the collector terminal of which is connected to the gate terminal of the MOS transistor FET1, and the emitter terminal of which is connected to the negative terminal (ground) of the DC power supply E. ing. The base terminal of the bias control transistor TR2 is connected to a connection point N3 between the resistor R6 and the capacitor C5 constituting the RC circuit.

The power transmission unit 10 configured as described above is a self-excited voltage resonance type inverter circuit of one stone, that is, a so-called voltage resonance circuit. By the oscillation operation of this voltage resonance circuit, an alternating current having a constant frequency is generated from the primary coil L1. Magnetic flux is generated. This oscillation operation will be briefly described below.

When the power transmission unit 10 is supplied with a power supply voltage, for example, a voltage of 5 V, from the DC power supply E, a voltage is applied to the gate terminal of the MOS transistor FET1 via the starting resistor R1, the feedback coil L3, and the resistor R3. When the voltage applied to the gate terminal of the MOS transistor FET1 is increased to an ON voltage at which current flows between the drain and source of the MOS transistor FET1, the MOS transistor FET1 is turned on and current flows between the drain and source. Flows. As a result, a current flows through the primary coil L1, and a magnetic flux is generated. A voltage that maintains the ON voltage of the MOS transistor FET1 is generated in the feedback coil L3 that receives the magnetic flux, and the gate voltage of the MOS transistor FET1 is maintained at the ON voltage. Then, the ON state of the MOS transistor FET1 is maintained.

When a current flows between the drain and source when the MOS transistor FET1 is turned on, a voltage generated in the resistor R7 is applied to an RC circuit including the resistor R6 and the capacitor C5, and the RC circuit is charged with the charging of the capacitor C5. The voltage between terminals of the capacitor C5 is increased. Due to the increase in the voltage between the terminals, the voltage at the connection point N3 between the resistor R6 and the capacitor C5 of the RC circuit is increased, and the voltage at the base terminal of the bias control transistor TR2 connected to the connection point N3 is increased. Be raised. When the voltage at the base terminal of the bias control transistor TR2 rises and the current flows between the collector and the emitter, the current flows between the collector and the emitter, and the potential difference between the collector and the emitter is reduced. Decrease to approximately “0”. As a result, the voltage at the collector terminal of the bias control transistor TR2 is lowered to the level of the minus terminal (ground) of the DC power supply E, and the voltage at the gate terminal of the MOS transistor FET1 connected to the collector terminal also becomes the ground level. The MOS transistor FET1 is turned off so that no current flows between the drain and the source.

When the MOS transistor FET1 is turned off, the magnetic flux generated by the primary coil L1 decreases, so that the voltage direction of the feedback coil L3 changes to generate a voltage that maintains the off state, and the voltage is applied to the gate terminal. The MOS transistor FET1 is kept off. When the MOS transistor FET1 is turned off, the current flowing through the primary coil L1 flows into the resonance capacitor C4, and the LC circuit including the primary coil L1 and the resonance capacitor C4 resonates. Due to the resonance of the LC circuit, the voltage on the drain side of the MOS transistor FET1 increases and reaches a peak, and then decreases. At this time, the same voltage fluctuation as that of the primary coil L1 occurs between the terminals of the feedback coil L3. That is, at the first terminal of the feedback coil L3 coupled to the gate terminal of the MOS transistor FET1, the voltage drops to reach a peak and then rises. After a while, a voltage capable of turning on the MOS transistor FET1 is generated at the first terminal of the feedback coil L3, and the MOS transistor FET1 is turned on again. The MOS transistor FET1 is switched by repeating the ON and OFF of the MOS transistor FET1, and the primary coil L1 is oscillated by the switching. In the first embodiment, the frequency at which the MOS transistor FET1 is switched, that is, the frequency at which the primary coil L1 is oscillated is adjusted to be 100 kHz (kilohertz) to 200 kHz.

Further, the power transmission unit 10 is provided with a primary control device 11 as a demodulation control device. The primary-side control device 11 is mainly composed of a microcomputer having a central processing unit (CPU) and a storage device (nonvolatile memory ROM, volatile memory RAM, etc.), and various types stored in the storage device. Various controls such as oscillation control of the LC circuit of the power transmission unit 10 are executed based on the data and the program. In the first embodiment, the communication signal from the power receiving unit 20 is demodulated, the demodulated signal is analyzed, and the oscillation of the LC circuit is controlled based on the analysis result. . In addition, the nonvolatile memory ROM is necessary for a threshold value for comparison with the voltage at the connection point N2, a demodulation of a communication signal with the power receiving unit 20 described in detail later, and an analysis of the demodulated signal. Various parameters to be stored are stored in advance.

The primary side control device 11 is supplied with driving power from a DC power source E by a circuit (not shown), and is connected to the negative terminal of the DC power source E and is composed of a diode D1 and a resistor R2. Is connected to a connection point N2 between the LC circuit on the primary side and the parallel circuit of the diode D2 and the resistor R5. That is, the power at the connection point N2 is supplied to the primary side control device 11 after being half-wave rectified, and the primary side control device 11 is driven by the oscillation of the primary coil L1 through the connection point N2. The maximum voltage or the like can be acquired from the voltage waveform of the generated alternating power.

Further, similarly to the transistor TR2, the power transmission unit 10 is provided with a bias control transistor TR3 made of an NPN transistor, the collector terminal of which is connected to the gate terminal of the MOS transistor FET1, and the emitter terminal of the DC power supply E. Is connected to the negative terminal (ground). The bias control transistor TR3 has its base terminal connected to the primary side control device 11, and the control current supplied from the primary side control device 11 turns on and off the current flowing between the collector and the emitter. -It can be switched off so that no current flows between the emitters.

Next, the power receiving unit 20 will be described.
The power receiving unit 20 controls a resonance circuit unit 22A that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23A that converts alternating power (AC power) to DC power, and supply of DC power to a load. A supply control unit 24A and a battery BA as a load to which power is supplied from the supply control unit 24A are provided.

The resonance circuit unit 22A includes a secondary coil L2 that outputs an alternating power induced in the alternating magnetic field of the primary coil L1, a capacitor C6 (passive element) connected in parallel to the secondary coil L2, and a secondary coil. It has a series circuit consisting of a capacitor C8 (passive element) and a switch SW1 connected in parallel to the coil L2. Accordingly, the resonance circuit unit 22A is configured as a secondary resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 when the switch SW1 is opened, and when the switch SW1 is closed, The secondary side resonance circuit (LC circuit) is configured by parallel connection of the secondary coil L2, the capacitor C6, and the capacitor C8. For this reason, in the resonance circuit unit 22A, the circuit constant of the resonance circuit (LC circuit) is changed depending on the presence or absence of the capacitor C8, and the secondary coil L2 receives power from the primary coil L1 due to the change of the circuit constant. The amplitude of the alternating power is changed (modulated). That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed.

In the first embodiment, the value of the capacitor C6 is such that when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C6, the secondary coil L2 and the primary coil L1 The magnetic coupling property of is set to a value that can be obtained satisfactorily. On the other hand, when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2, the capacitor C6, and the capacitor C8, the value of the capacitor C8 is the magnetic value of the secondary coil L2 and the primary coil L1. The connectivity is set to a value that degrades compared to the resonance circuit composed of the secondary coil L2 and the capacitor C6.

That is, when the magnetic coupling between the secondary coil L2 and the primary coil L1 is good, the power receiving unit 20 can receive a large amount of power efficiently. At this time, the secondary coil L2 is 1 A large amount of power can be received from the secondary coil L1. That is, a large amount of DC power (current) can be supplied to the battery BA.

On the other hand, when the magnetic coupling between the secondary coil L2 and the primary coil L1 deteriorates, the power receiving unit 20 has a reduced efficiency of receiving power, and the secondary coil L2 can receive power from the primary coil L1. Electric power decreases. That is, the DC power (current) supplied to the battery BA also decreases. However, when the magnetic coupling between the secondary coil L2 and the primary coil L1 is deteriorated due to load fluctuation as in the conventional case, a resistor is connected in parallel to the battery BA or the DC power is short-circuited. As compared with, a decrease in the DC power supplied to the battery BA is suppressed.

By the way, in the configuration of the power receiving unit 20, when the power receiving characteristic of the secondary coil L2 changes, not only the amplitude of the power waveform of the alternating power received by the secondary coil L2 changes, but also the secondary coil L2 becomes magnetic. The amplitude of the power waveform of the alternating power of the primary coil L1 coupled to is also changed. That is, the amplitude of the power waveform (voltage waveform) of the alternating power generated in the primary coil L1 also changes in accordance with the change in the amplitude of the power waveform (voltage waveform) of the alternating power in the secondary coil L2. As a result, the amplitude (maximum voltage value) of the voltage waveform of the alternating power generated at the connection point N2 of the power transmission unit 10 changes. Specifically, the amplitude of the voltage waveform generated at the connection point N2 of the power transmission unit 10 is suppressed to a small value when the magnetic coupling between the primary coil L1 and the secondary coil L2 is good, and vice versa. It increases when the magnetic coupling between the primary coil L1 and the secondary coil L2 is degraded.

The power (voltage) generated between the terminals of the secondary coil L2 of the resonance circuit unit 22A is supplied to the rectification circuit unit 23A. The rectifier circuit unit 23A includes a rectifier diode D3 connected in series to the resonance circuit unit 22A and a smoothing capacitor C7 that smoothes the power rectified by the rectifier diode D3, and is input from the resonance circuit unit 22A. It is configured as a so-called half-wave rectifier circuit that converts alternating power (AC power) into DC power. The configuration of the rectifier circuit unit 23A is merely an example of a rectifier circuit that converts AC power into DC power, and is not limited to this configuration. A full-wave rectifier circuit using a diode bridge or other You may have the structure of a known rectifier circuit.

The supply control unit 24A turns on / off the P-channel MOS transistor FET3 that switches between supply and non-supply of the DC power rectified by the rectification circuit unit 23A to the battery BA and the MOS transistor FET3 according to the state of charge of the battery BA. And a secondary side control device 21 as a modulation control device to be switched. The drain terminal of the MOS transistor FET3 is connected to the positive side of the rectifier circuit unit 23A, the source terminal thereof is connected to the positive side of the battery BA, and the gate terminal thereof is connected to the secondary side control device 21.

The secondary-side control device 21 is mainly composed of a microcomputer having a central processing unit (CPU) and a storage device (nonvolatile memory ROM, volatile memory RAM, etc.), and various data stored in the memory. And based on a program, while determining the charge condition of battery BA of the electric power receiving part 20, various control, such as the charge amount control, is performed. In the present embodiment, a communication signal to the power transmission unit 10 is generated based on the state of charge of the battery BA, and the circuit constant of the resonance circuit is changed based on the generated communication signal to change the secondary coil L2. Control is also performed to modulate the alternating power that is received. The nonvolatile memory ROM also determines the state of charge of the battery BA, generates a threshold value required for charge amount control, generates a communication signal with the power transmission unit 10 described later, Various parameters required for modulation based on the parameters are stored in advance.

The secondary-side control device 21 is connected to the positive and negative electrodes of the battery BA, respectively, and receives power for driving from the battery BA. The secondary-side control device 21 receives the battery BA from the voltage across the terminals of the battery BA. It is possible to grasp the state of charge. Further, the secondary side control device 21 performs on / off control of the MOS transistor FET3 by changing the control voltage applied to the gate terminal of the MOS transistor FET3 in accordance with the state of charge of the battery BA. For example, when it is determined that it is preferable to charge the battery BA because the voltage between the terminals of the battery BA is lower than a preset threshold value for determining the state of charge, an on-voltage is applied to the gate terminal of the MOS transistor FET3. Then, the MOS transistor FET3 is turned on so that DC power is supplied from the rectifier circuit unit 23A to the battery BA. On the other hand, when it is determined that there is no need to charge the battery BA because the voltage between the terminals of the battery BA is higher than the threshold value for determining the charging state, a voltage lower than the ON voltage is applied to the gate terminal of the MOS transistor FET3 This is applied to turn off the MOS transistor FET3 so that the DC power from the rectifier circuit unit 23A is not supplied to the battery BA.

The secondary side control device 21 is connected to the switch SW1 of the resonance circuit unit 22A. The secondary side control device 21 controls the switching of the switch SW1 to connect / disconnect the capacitor C8 by the switch SW1. Switch the connection. That is, when the secondary side control device 21 controls opening and closing of the switch SW1, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22A is changed, and the alternating power received by the secondary coil L2 is changed. The amplitude of the alternating power transmitted by the primary coil L1 is changed by changing the amplitude of the first coil L1. Note that the switching control of the switch SW1 by the secondary-side control device 21 causes the oscillation period (for example, frequency 100) of the primary coil L1 so that interference with the resonance of the secondary-side resonance circuit (LC circuit) does not occur. The communication period is longer than, for example, 10 Hz (100 ms).

Next, information transmission by transmission of communication signals from the power receiving unit 20 to the power transmitting unit 10 will be described with reference to FIGS. 2A and 2B are graphs showing changes in the voltage amplitude generated in the alternating power according to the power reception characteristics of the power reception unit 20, where FIG. 2A shows a case where the power reception characteristics are good, and FIG. 2B shows that the power reception characteristics are degraded. It shows the case. FIG. 3 is a graph showing a longer time in the same state as FIG. 2, where (a) shows a case where the power reception characteristics are good, and (b) shows a case where the power reception characteristics are deteriorated. Show. 4 is a graph showing a signal reception state by the power transmission unit 10 in a longer time than FIG. 3, wherein (a) is a graph showing a voltage waveform of alternating power of the power transmission unit 10, and (b) is ( The signal calculated | required based on the amplitude of the voltage waveform of a) is shown.

First, communication signal modulation in the power receiving unit 20 will be described.
When the secondary control device 21 of the power receiving unit 20 normally receives power, the secondary coil L2 and the primary coil L1 are magnetically coupled so as to receive a large amount of power efficiently. The switch SW1 is opened in order to improve the resistance. At this time, as shown in FIG. 2A, the secondary coil L2 receives the alternating power having the maximum voltage of the voltage VL2. On the other hand, when it is desired to communicate information to the power transmission unit 10, the switch SW1 is connected to deteriorate the magnetic coupling between the secondary coil L2 and the primary coil L1 from a good state. At this time, as shown in FIG. 2 (b), the secondary coil L2 receives alternating power having a maximum voltage VH2 higher than the voltage VL2.

In the first embodiment, the secondary side control device 21 changes the power reception characteristics of the secondary coil L2 at a communication cycle longer than the oscillation cycle of the primary coil L1. That is, when the maximum voltage of the alternating power of the secondary coil L2 is set to the voltage VL2 for communication, the secondary-side control device 21 has one cycle for communication as shown in FIG. For example, during the period P1 from time t0 to time t1, the switch SW1 is opened. Further, when the maximum voltage of the alternating power of the secondary coil L2 is set to the voltage VH2 for communication, the secondary-side control device 21 becomes one cycle for communication as shown in FIG. For example, during the period P2 from time t1 to time t2, the switch SW1 is connected. In this way, by selectively changing the maximum voltage of the alternating power of the secondary coil L2 to either the voltage VL2 or the voltage VH2 for each communication cycle, the secondary-side control device 21 can transmit power. The alternating power of the secondary coil L2 can be modulated based on a binary communication signal generated based on a communication rule common between the unit 10 and the power receiving unit 20.

Next, reception of the communication signal generated by the power receiving unit 20 by the power transmitting unit 10 will be described. As shown in FIG. 4A, the amplitude of the alternating power voltage of the primary coil L <b> 1 of the power transmission unit 10 depends on the amplitude of the alternating power voltage modulated by the power receiving unit 20 in the communication cycle. The maximum value appears as the voltage VL1 or the voltage VH1. For example, when the power receiving unit 20 sets the maximum voltage of the alternating power to the voltage VL2 during the period P1 that is one cycle of the communication cycle, the maximum voltage of the alternating power of the primary coil L1 in the power transmitting unit 10 during the same period P1. Becomes the voltage VL1. Further, when the power receiving unit 20 sets the maximum voltage of the alternating power to the voltage VH2 during the period P2, which is one cycle of the communication cycle, the primary coil L1 of the power transmitting unit 10 alternates during the synchronization P2. The maximum power voltage becomes a voltage VH1 higher than the voltage VL1. Similarly, in each period P3, P4, P6 in which the power receiving unit 20 sets the maximum voltage of the alternating power to the voltage VL2, the maximum voltage of the alternating power of the primary coil L1 of the power transmitting unit 10 becomes the voltage VL1, respectively. In the period P5 in which the power reception unit 20 sets the maximum voltage of the alternating power to the voltage VH2, the maximum voltage of the alternating power of the primary coil L1 of the power transmission unit 10 becomes the voltage VH1.

And the power transmission part 10 acquires the maximum voltage of the alternating power of the primary coil L1 in the primary side control apparatus 11, and the signal demodulation which sets the acquired maximum voltage between the voltage VL1 and the voltage VH1 For example, the voltage VL1 is demodulated as the signal level L and the voltage VH1 as the signal level H as shown in FIG. A communication signal generated based on the communication rule by the power receiving unit 20 is received by the power receiving unit 20 through processing such as reading the demodulated signal at a communication cycle, and the content is transmitted to an internal circuit (not shown). Will be. For example, when the signal level L is expressed as “0” and the signal level H is expressed as “1”, the waveform shown in FIG. 4B is expressed as a signal “010010”. In addition, although there is no restriction | limiting in particular about the communication rule common between the electric power transmission part 10 and the electric power receiving part 20, For example, based on the known communication rule using a communication signal of 4 bits, 8 bits, and 16 bits. Can now communicate.

As described above, according to the contactless power supply device of the first embodiment, the effects listed below can be obtained.
(1) The secondary side control device 21 changes the amplitude of the voltage of the alternating power received by the secondary coil L2 in the resonance circuit unit 22A based on the information to be transmitted to the primary coil L1, and the amplitude of the voltage The primary-side control device 11 acquires information transmitted from the secondary-side control device 21 based on the voltage change of the primary coil L1 accompanying the change of. As a result, information from the secondary side control device 21 is transmitted to the primary side control device 11, for example, the primary side control device 11 is a secondary battery connected to the secondary side control device 21, It also becomes possible to suitably control the power transmitted to the secondary coil L2 by controlling the driving of the primary coil L1 according to the situation such as the load.

(2) Since the circuit constant of the resonance circuit unit 22A including the secondary coil L2 is changed, after receiving power at the secondary coil L2, the rectification circuit unit 23A performs adjustment such as rectification and smoothing. It is avoided that the DC power converted into a state suitable for supply to the load is consumed in large quantities for information transmission. That is, when transmitting information from the secondary coil L2 to the primary coil L1, as in the past, the characteristics of the secondary coil should be changed by changing the load with respect to the DC power to supply the load to the secondary battery or the like. The consumption of direct current power is suppressed. As a result, the possibility that information transmission may adversely affect the supply of direct-current power to the load, for example, the possibility of stopping the supply of power to the load such as the battery BA or greatly reducing the supply amount, is alleviated.

(3) Furthermore, since the circuit constant of the resonance circuit unit 22A including the secondary coil L2 is changed, it is easy to adjust or change the power reception characteristics applied to the secondary coil L2. This facilitates the design and adjustment of the power reception characteristics of the resonance circuit unit 22A, and improves the possibility of implementing and adopting a non-contact power feeding apparatus having such a resonance circuit unit 22A.

(4) Changing the circuit constant of the resonance circuit unit 22A based on the secondary coil L2 and the capacitor C6, that is, the amplitude of the alternating power received by the secondary coil L2, by connecting / disconnecting the capacitor C8 by the switch SW1. Will be able to. As a result, the change in the amplitude of the alternating power received by the secondary coil L2 can be easily performed by the few switches SW1.

(5) Since the amplitude of the alternating power received by the secondary coil L2 can be set by the combination of the capacitor C6 and the capacitor C8, the amplitude of the alternating power can be easily changed.

(Second Embodiment)
Next, a second embodiment in which the non-contact power feeding device according to the present invention is embodied will be described with reference to FIG. FIG. 5 is a diagram illustrating a circuit configuration of the power receiving unit 20 according to the non-contact power feeding device of the second embodiment.

In the second embodiment, the configuration of the resonance circuit unit 22B of the power receiving unit 20 is different from that of the first embodiment, but the other configurations are the same. Therefore, in the second embodiment, differences from the first embodiment will be mainly described, the same reference numerals are given to the same configurations as those in the first embodiment, and for the convenience of description, the detailed description will be given. Omitted.

As shown in FIG. 5, the power receiving unit 20 includes a resonant circuit unit 22B that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23B that converts alternating power (AC power) to DC power, A supply control unit 24B that controls supply to the load and a battery BA as a load to which power is supplied from the supply control unit 24B are provided. Note that the rectifier circuit unit 23B and the supply control unit 24B of the second embodiment have the same configurations as the rectifier circuit unit 23A and the supply control unit 24A of the first embodiment, respectively, and therefore detailed descriptions thereof are omitted. To do.

The resonance circuit unit 22B is a series composed of a secondary coil L2 that outputs an alternating power induced by an alternating magnetic field of the primary coil L1, and a capacitor C6 and a switch SW2 connected in parallel to the secondary coil L2. And a series circuit including a capacitor C8 and a switch SW1, which are connected in parallel to the secondary coil L2. Accordingly, the resonance circuit unit 22B is configured as a secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 when the switch SW1 is opened and the switch SW2 is closed. Further, when the switch SW1 is closed and the switch SW2 is opened, it is configured as a secondary side resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C8. As a result, the circuit constant of the resonance circuit (LC circuit) of the resonance circuit unit 22B is changed by the capacitor (capacitor C6 or capacitor C8) connected to the secondary coil L2. The amplitude of the alternating power received by the secondary coil L2 from the primary coil L1 is changed (modulated) by the change. That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed. Further, power (voltage) generated between the terminals of the secondary coil L2 of the resonance circuit unit 22B is supplied to the rectification circuit unit 23B.

In the second embodiment, the value of the capacitor C6 is such that when the secondary coil L2 and the capacitor C6 form a secondary resonance circuit (LC circuit), the secondary coil L2 and the primary coil L1 Is set to a value that provides good magnetic coupling. On the other hand, the value of the capacitor C8 is such that when the secondary resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C8, the magnetic coupling between the secondary coil L2 and the primary coil L1 is high. The value is set so as to deteriorate as compared with the resonance circuit composed of the secondary coil L2 and the capacitor C6.

The secondary-side control device 21 is connected to the switches SW1 and SW2 of the resonance circuit unit 22B. The switch SW1 and SW2 are individually controlled to be opened / closed, and the capacitor SW8 is connected / disconnected by the switch SW1. The connection / disconnection of the capacitor C6 by the switch SW2 is switched separately. That is, the secondary-side control device 21 controls the opening / closing of the switches SW1 and SW2, thereby changing the circuit constant of the secondary-side resonance circuit (LC circuit) of the resonance circuit unit 22B. The maximum voltage of the voltage waveform of the alternating power of L2 is changed to a different voltage VL2 or voltage VH2. Accordingly, the amplitude of the alternating power of the primary coil L1 is changed to, for example, the voltage VL1 or the voltage VH1. In the second embodiment, the switches SW1 and SW2 are controlled to be opened and closed so that at least one of the switches SW1 and SW2 is closed, whereby the circuit constant changes within a predetermined range. So that it is controlled.

Further, the switching control of the switch SW1 by the secondary side control device 21 is similar to the first embodiment in that the primary coil is not interfered with the resonance of the secondary side resonance circuit (LC circuit). The communication is performed in a cycle longer than the oscillation cycle of L1, for example, a communication cycle of 10 Hz (100 ms).

In this way, by selectively changing the maximum voltage of the alternating power of the secondary coil L2 to, for example, either the voltage VL2 or the voltage VH2 for each communication cycle, the secondary-side control device 21 can The alternating power of the secondary coil L2 can be modulated based on the binary communication signal generated based on the communication rule. Then, the power transmission unit 10 demodulates the communication signal by the primary side control device 11 from the modulated maximum voltage of the primary coil L1, and acquires the content of the communication signal generated by the power reception unit 20.

As described above, according to the second embodiment, the effects equivalent to or equivalent to the effects (1) to (5) of the first embodiment can be obtained, and the effects listed below. Can be obtained.

(6) The switches SW1 and SW2 are provided on the capacitor C8 and the capacitor C6 connected in parallel to the load, respectively. Accordingly, the circuit constant of the resonance circuit unit 22B, that is, the power reception characteristic of the secondary coil L2 can be changed based on the capacitor C8 or the capacitor C6.

(Third embodiment)
Next, a third embodiment embodying the non-contact power feeding device according to the present invention will be described with reference to FIG. FIG. 6 is a diagram illustrating a circuit configuration of the power receiving unit 20 according to the non-contact power feeding device of the third embodiment.

In the third embodiment, the configuration of the resonance circuit unit 22C of the power receiving unit 20 is different from that of the first embodiment, but the other configurations are the same. Therefore, in the third embodiment, differences from the first embodiment will be mainly described. The same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description will be given for convenience of description. Omitted.

As shown in FIG. 6, the power receiving unit 20 includes a resonant circuit unit 22C that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23C that converts alternating power (AC power) into DC power, and DC power A supply control unit 24C that controls supply to the load and a battery BA as a load to which power is supplied from the supply control unit 24C are provided. Note that the rectifier circuit unit 23C and the supply control unit 24C of the third embodiment have the same configurations as the rectifier circuit unit 23A and the supply control unit 24A of the first embodiment, respectively, and therefore detailed description thereof is omitted. To do.

The resonance circuit unit 22C includes a secondary coil L2 that outputs an alternating power induced in the alternating magnetic field of the primary coil L1, and the secondary coil L2 includes a series circuit including a capacitor C6 and a switch SW2. A parallel circuit composed of a series circuit composed of a capacitor C8 and a switch SW1 is connected in series. Thus, the resonance circuit unit 22C is configured as a secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 when the switch SW1 is opened and the switch SW2 is closed. Further, when the switch SW1 is closed and the switch SW2 is opened, it is configured as a secondary side resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C8. For this reason, the circuit constant of the resonance circuit (LC circuit) of the resonance circuit unit 22C is changed by the capacitor (capacitor C6 or capacitor C8) connected to the secondary coil L2. The amplitude of the alternating power received by the secondary coil L2 from the primary coil L1 is changed (modulated) by the change. That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed. Further, power (voltage) generated between the terminals of the LC circuit on the secondary side of the resonance circuit unit 22C is supplied to the rectification circuit unit 23C.

In the third embodiment, when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C6, the value of the capacitor C6 is determined by the secondary coil L2 and the primary coil L1. Is set to a value that provides good magnetic coupling. On the other hand, the value of the capacitor C8 is such that when the secondary resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C8, the magnetic coupling between the secondary coil L2 and the primary coil L1 is high. The value is set so as to deteriorate as compared with the resonance circuit composed of the secondary coil L2 and the capacitor C6.

The secondary-side control device 21 is connected to the switches SW1 and SW2 of the resonance circuit unit 22C, and controls the switching of each switch SW1 and SW2 to connect / disconnect the capacitor C8 by the switch SW1. The connection / disconnection of the capacitor C6 by the switch SW2 is switched separately. That is, the secondary-side control device 21 controls opening / closing of the switches SW1 and SW2, thereby changing the circuit constant of the secondary-side resonance circuit (LC circuit) of the resonance circuit unit 22C, thereby the secondary coil. The maximum voltage of the voltage waveform of the alternating power of L2 is changed to a different voltage VL2 or voltage VH2. Accordingly, the amplitude of the alternating power of the primary coil L1 is changed to, for example, the voltage VL1 or the voltage VH1. In the third embodiment, the switches SW1 and SW2 are controlled to be closed so that at least one of the switches SW1 and SW2 is closed, whereby the circuit constant changes within a predetermined range. So that it is controlled.

As described above, according to the third embodiment, the effects equivalent to or equivalent to the effects (1) to (5) of the first embodiment can be obtained, and the effects listed below. Can be obtained.

(7) The switches SW1 and SW2 are provided on the capacitor C8 and the capacitor C6 connected in series with the load, respectively. This also makes it possible to change the circuit constant of the resonance circuit unit 22C, that is, the power reception characteristic of the secondary coil L2, based on the capacitor C8 or the capacitor C6.

(Fourth embodiment)
Next, a fourth embodiment embodying the non-contact power feeding device according to the present invention will be described with reference to FIG. FIG. 7 is a diagram illustrating a circuit configuration of the power receiving unit 20 according to the contactless power supply device of the fourth embodiment.

In the fourth embodiment, the configuration of the resonance circuit unit 22D of the power receiving unit 20 is different from that of the first embodiment, but the other configurations are the same. Therefore, in the fourth embodiment, differences from the first embodiment will be mainly described. The same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description will be given for convenience of description. Omitted.

As shown in FIG. 7, the power receiving unit 20 includes a resonant circuit unit 22D that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23D that converts alternating power (AC power) into DC power, and DC power A supply control unit 24D for controlling supply to the load and a battery BA as a load to which power is supplied from the supply control unit 24D are provided. Note that the rectifier circuit unit 23D and the supply control unit 24D of the fourth embodiment have the same configurations as the rectifier circuit unit 23A and the supply control unit 24A of the first embodiment, respectively, and thus detailed description thereof is omitted. To do.

The resonance circuit unit 22D includes a secondary coil L2 that outputs an alternating power induced in the alternating magnetic field of the primary coil L1, a capacitor C6 that is connected in series to the secondary coil L2, a secondary coil L2, and a capacitor C6. And a series circuit composed of a capacitor C8 and a switch SW1 connected in parallel to the series circuit constituted by Accordingly, the resonance circuit unit 22D is configured as a secondary-side resonance circuit (LC circuit) including a series connection of the secondary coil L2 and the capacitor C6 when the switch SW1 is opened. Further, when the switch SW1 is closed, it is configured as a secondary side resonance circuit (LC circuit) including a series circuit including the secondary coil L2 and the capacitor C6 and a capacitor C8 connected in parallel to the series circuit. Is done. For this reason, in the resonance circuit unit 22D, the circuit constant of the resonance circuit (LC circuit) is changed depending on the presence or absence of the capacitor C8, and the secondary coil L2 receives power from the primary coil L1 due to the change of the circuit constant. The amplitude of the alternating power is changed (modulated). That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed. The rectifier circuit unit 23D is supplied with electric power (voltage) generated between terminals connected in series between the secondary coil L2 and the capacitor C6.

In the fourth embodiment, the value of the capacitor C6 is such that when the secondary coil L2 and the capacitor C6 form a secondary resonance circuit (LC circuit), the secondary coil L2 and the primary coil L1 Is set to a value that provides good magnetic coupling. On the other hand, when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2, the capacitor C6, and the capacitor C8, the value of the capacitor C8 is the magnetic value of the secondary coil L2 and the primary coil L1. The connectivity is set to a value that degrades compared to the resonance circuit composed of the secondary coil L2 and the capacitor C6.

The secondary side control device 21 is connected to the switch SW1 of the resonance circuit unit 22D, and controls the switch SW1 to switch the connection / disconnection of the capacitor C8 by the switch SW1. That is, when the secondary side control device 21 controls opening and closing of the switch SW1, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22D is changed, whereby the alternating coil of the secondary coil L2 is changed. The maximum voltage of the voltage waveform of power is changed to a different voltage VL2 or voltage VH2. Accordingly, the amplitude of the alternating power of the primary coil L1 is changed to, for example, the voltage VL1 or the voltage VH1.

As described above, according to the fourth embodiment, effects similar to or equivalent to the effects (1) to (5) of the first embodiment can be obtained, and the effects listed below are obtained. Can be obtained.

(8) The circuit constant of the resonance circuit unit 22D based on the secondary coil L2 and the capacitor C6, that is, the amplitude of the alternating power received by the secondary coil L2, is changed by connecting / disconnecting the capacitor C8 by the switch SW1. Can do. As a result, it is possible to easily change the amplitude of the alternating power received by the secondary coil L2 with a small number of switches.

(Fifth embodiment)
Next, a fifth embodiment of the non-contact power feeding device according to the present invention will be described with reference to FIG. FIG. 8 is a diagram illustrating a circuit configuration of the power receiving unit 20 according to the contactless power supply device of the fifth embodiment.

In the fifth embodiment, the configuration of the resonance circuit unit 22E of the power receiving unit 20 is different from that of the first embodiment, but the other configurations are the same. Therefore, in the fifth embodiment, differences from the first embodiment will be mainly described. The same components as those in the first embodiment will be denoted by the same reference numerals, and detailed description will be given for convenience of description. Omitted.

As shown in FIG. 8, the power receiving unit 20 includes a resonant circuit unit 22E that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23E that converts alternating power (AC power) into DC power, A supply control unit 24E that controls supply to a load and a battery BA as a load to which electric power is supplied from the supply control unit 24E are provided. Note that the rectifier circuit unit 23E and the supply control unit 24E of the fifth embodiment have the same configurations as the rectifier circuit unit 23A and the supply control unit 24A of the first embodiment, respectively, and thus detailed description thereof is omitted. To do.

The resonance circuit unit 22E includes a secondary coil L2 that outputs an alternating power induced in the alternating magnetic field of the primary coil L1, and a coil L4 as an inductor and a switch SW3 that are connected in series to the secondary coil L2. And a capacitor C6 connected in parallel to a series circuit constituted by the parallel circuit and the secondary coil L2. Thereby, when the switch SW3 is opened, the resonance circuit unit 22E has a secondary side resonance circuit including a series circuit of the secondary coil L2 and the coil L4 and a capacitor C6 connected in parallel to the series circuit. (LC circuit). Further, when the switch SW3 is closed, it is configured as a secondary resonance circuit (LC circuit) composed of a parallel circuit of the secondary coil L2 and the capacitor C6. For this reason, in the resonance circuit unit 22E, the circuit constant of the resonance circuit (LC circuit) is changed depending on the presence or absence of the coil L4, and the secondary coil L2 receives power from the primary coil L1 due to the change of the circuit constant. The amplitude of the alternating power is changed (modulated). That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed. Further, power (voltage) generated between the terminals of the capacitor C6 of the resonance circuit unit 22E is supplied to the rectification circuit unit 23E.

In the fifth embodiment, the value of the capacitor C6 is such that when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C6, the secondary coil L2 and the primary coil L1 Is set to a value that provides good magnetic coupling. On the other hand, the value of the coil L4 is such that when a secondary side resonance circuit (LC circuit) is formed by a series circuit of the secondary coil L2 and the coil L4 and a capacitor C6 connected in parallel to the series circuit, The magnetic coupling between the secondary coil L2 and the primary coil L1 is set to a value that deteriorates as compared with the resonance circuit including the secondary coil L2 and the capacitor C6.

The secondary-side control device 21 is connected to the switch SW3 of the resonance circuit unit 22E, and controls the switching of the switch SW3 to switch the connection / disconnection of the coil L4 by the switch SW3. That is, when the secondary side control device 21 controls opening / closing of the switch SW3, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22E is changed, and thereby the secondary coil L2 is alternated. The maximum voltage of the voltage waveform of power is changed to a different voltage VL2 or voltage VH2. Accordingly, the amplitude of the alternating power of the primary coil L1 is changed to, for example, the voltage VL1 or the voltage VH1.

The switching control of the switch SW3 by the secondary side control device 21 is similar to the first embodiment in that the primary coil is not interfered with the resonance of the secondary side resonance circuit (LC circuit). The communication is performed in a cycle longer than the oscillation cycle of L1, for example, a communication cycle of 10 Hz (100 ms).

As described above, according to the fifth embodiment, effects equivalent to or equivalent to the effects (1) to (4) of the first embodiment can be obtained, and the effects listed below. Can be obtained.

(9) The circuit constant of the resonance circuit unit 22E based on the secondary coil L2 and the capacitor C6, that is, the amplitude of the alternating power received by the secondary coil L2, is represented by the coil L4 by the switch SW3 connected in series to the secondary coil L2. It can be changed by connecting / disconnecting. As a result, the change in the amplitude of the alternating power received by the secondary coil L2 can be easily performed with a small number of switches SW3.

(10) Since the amplitude of the alternating power received by the secondary coil L2 can be set by the combination of the capacitor C6 and the coil L4, the degree of freedom of setting for changing the amplitude of the alternating power is increased.

(Sixth embodiment)
Next, a sixth embodiment of the non-contact power feeding device according to the present invention will be described with reference to FIG. FIG. 9 is a diagram illustrating a circuit configuration of the power receiving unit 20 according to the contactless power supply device of the sixth embodiment.

In the sixth embodiment, the configuration of the resonance circuit unit 22F of the power receiving unit 20 is different from that of the first embodiment, but the other configurations are the same. Therefore, in the sixth embodiment, differences from the first embodiment will be mainly described, the same components as those in the first embodiment will be denoted by the same reference numerals, and the detailed description will be given for convenience of description. Omitted.

As shown in FIG. 9, the power receiving unit 20 includes a resonant circuit unit 22F that receives alternating power from the power transmitting unit 10, a rectifier circuit unit 23F that converts alternating power (AC power) to DC power, and DC power A supply control unit 24F that controls supply to the load and a battery BA as a load to which power is supplied from the supply control unit 24F are provided. Note that the rectifier circuit unit 23F and the supply control unit 24F of the sixth embodiment have the same configurations as the rectifier circuit unit 23A and the supply control unit 24A of the first embodiment, respectively, and thus detailed description thereof is omitted. To do.

The resonant circuit unit 22F includes a secondary coil L2 that outputs an alternating power induced in the alternating magnetic field of the primary coil L1, a resistor R8 as a resistance element, and a switch SW4 that are connected in series to the secondary coil L2. And a capacitor C6 connected in parallel to a series circuit of the parallel circuit and the secondary coil L2. Thus, when the switch SW4 is opened, the resonance circuit unit 22F has a secondary resonance circuit including a series circuit of the secondary coil L2 and the resistor R8 and a capacitor C6 connected in parallel to the series circuit. (RLC circuit). Further, when the switch SW4 is closed, it is configured as a secondary resonance circuit (LC circuit) composed of a parallel circuit of the secondary coil L2 and the capacitor C6. For this reason, in the resonance circuit unit 22F, the circuit constant of the resonance circuit (RLC circuit or LC circuit) is changed depending on the presence or absence of the resistor R8, and the secondary coil L2 is changed to the primary coil by the change of the circuit constant. The amplitude of the alternating power received from L1 is changed (modulated). That is, by changing the circuit constant of the resonance circuit, the power reception characteristic of the secondary coil L2 that receives the power supplied from the primary coil L1 is changed. Further, power (voltage) generated between the terminals of the capacitor C6 of the resonance circuit unit 22F is supplied to the rectification circuit unit 23F.

In the sixth embodiment, when the secondary side resonance circuit (LC circuit) is formed by the secondary coil L2 and the capacitor C6, the value of the capacitor C6 is determined by the secondary coil L2 and the primary coil L1. Is set to a value that provides good magnetic coupling. On the other hand, the value of the resistor R8 is such that when a secondary resonance circuit (RLC circuit) is formed by a series circuit of the secondary coil L2 and the resistor R8 and a capacitor C6 connected in parallel to the series circuit, The magnetic coupling between the secondary coil L2 and the primary coil L1 is set to a value that deteriorates as compared with the resonance circuit including the secondary coil L2 and the capacitor C6.

The secondary-side control device 21 is connected to the switch SW4 of the resonance circuit unit 22F, and controls the switching of the switch SW4 to switch connection / disconnection of the resistor R8 by the switch SW4. That is, the secondary-side control device 21 controls opening / closing of the switch SW4, whereby the circuit constant of the secondary-side resonance circuit of the resonance circuit unit 22F is changed, whereby the voltage waveform of the alternating power of the secondary coil L2 is changed. Is changed to a different voltage VL2 or VH2. Accordingly, the amplitude of the alternating power of the primary coil L1 changes to, for example, the voltage VL1 or the voltage VH1.

Further, the switching control of the switch SW4 by the secondary-side control device 21 is similar to the first embodiment, so that interference with the resonance of the secondary-side resonance circuit (RLC circuit and LC circuit) does not occur. The communication is performed at a cycle longer than the oscillation cycle of the primary coil L1, for example, a communication cycle of 10 Hz (100 ms).

In this way, by selectively changing the maximum voltage of the alternating power of the secondary coil L2 to, for example, either the voltage VL2 or the voltage VH2 for each communication cycle, the secondary-side control device 21 can The alternating power of the secondary coil can be modulated based on the binary communication signal generated based on the communication rule. Then, the power transmission unit 10 demodulates the communication signal by the primary side control device 11 from the modulated maximum voltage of the primary coil L1, and acquires the content of the communication signal generated by the power reception unit 20.

As described above, according to the sixth embodiment, effects equivalent to or equivalent to the effects (1) to (4) of the first embodiment can be obtained, and the effects listed below. Can be obtained.

(11) The circuit constant of the resonance circuit unit 22F based on the secondary coil L2 and the capacitor C6, that is, the amplitude of the alternating power received by the secondary coil L2, is a resistance R8 by a switch SW4 connected in series to the secondary coil L2. It can be changed by connecting / disconnecting. As a result, it is possible to easily change the amplitude of the alternating power received by the secondary coil L2 with a small number of switches SW4.

(12) Since the amplitude of the alternating power received by the secondary coil L2 can be set by the combination of the capacitor C6 and the resistor R8, the degree of freedom of setting for changing the amplitude of the alternating power is increased.

In addition, each said embodiment can also be changed as follows, for example.
In each of the above embodiments, the case where the power transmission unit 10 demodulates the communication signal from the power reception unit 20 based on the maximum voltage of the alternating power of the primary coil L1 is illustrated. However, the present invention is not limited to this, and the power transmission unit 10 may detect a change that occurs in the amplitude of the alternating power of the primary coil L1 according to a change in the amplitude of the received power in the secondary coil L2 by another method. For example, the power transmission unit 10 may detect a change in the amplitude based on the average voltage of the alternating power in the primary coil L1. In this method, the communication signal from the power receiving unit 20 can be demodulated regardless of the alternating power modulation method. Thereby, the freedom degree of the structure of the electric power transmission part 10 comes to be raised.

In each of the embodiments described above, the case where the circuit constants of the resonance circuit units 22A to 22F are changed by the capacitor C6, the capacitor C8, or the like is illustrated. However, the present invention is not limited to this, and any passive element can be used for the resonance circuit unit as long as the circuit constant of the resonance circuit unit can be changed. For example, the coil L4 in FIG. 8 or the resistor R8 in FIG. 9 may be changed to a capacitor. Alternatively, one of the two capacitors of the resonance circuit unit may be changed to a resistance element or a coil (inductor). Alternatively, one of the two capacitors of the resonant capacitor may be a resistance element and the other may be an inductor such as a coil. Alternatively, the two capacitors of the resonance circuit unit may both be a resistance element or a coil (inductor).

For example, when two passive elements are coils, the circuit configuration of the resonance circuit unit can be simplified because the passive elements are composed only of inductance. In addition, when the two passive elements are resistance elements, the passive elements are composed only of the resistance elements, so that the circuit configuration of the resonance circuit unit can be simplified.

In each of the above embodiments, the resonance circuit units 22A to 22F change their circuit constants by the secondary coil L2 and one or two other passive elements (capacitor C6, capacitor C8, coil L4, resistor R8, etc.). The case was illustrated. However, the present invention is not limited to this, and the circuit constant of the resonance circuit unit may be changed in cooperation with three or more passive elements in addition to the secondary coil L2.

In each of the above embodiments, the case where DC power is charged to the battery BA has been illustrated. However, the present invention is not limited to this, and the DC power may be consumed as it is. Thereby, the applicability of such a non-contact electric power feeder is improved.

In each of the above embodiments, the case where the power receiving unit 20 is used for a portable device or the like is illustrated. However, the present invention is not limited to this, and the power receiving unit 20 may be used for a mobile body such as an electric vehicle in which non-contact power supply is desired. Thereby, the freedom degree of application of such a non-contact electric power feeder is raised.

Claims

A non-contact power feeding device,
A primary coil that generates alternating magnetic flux;
A resonance that includes a secondary coil that receives the alternating power corresponding to the alternating magnetic flux from the primary coil in a non-contact manner at a position that intersects with the alternating magnetic flux generated in the primary coil, and is configured so that the circuit constant can be changed. A circuit section;
A modulation control device that modulates the amplitude of the alternating power received by the secondary coil by changing the circuit constant of the resonant circuit unit based on information to be transmitted to the primary coil;
A non-contact control device for demodulating information transmitted to the primary coil from a change in the amplitude of the alternating power generated in the primary coil in response to a change in the amplitude of the alternating power in the secondary coil Power supply device.
The resonant circuit unit includes a parallel circuit composed of a first passive element and a second passive element and connected in parallel to the secondary coil,
The parallel circuit includes a switch connected in series to at least one of the first passive element and the second passive element to open and close the parallel circuit,
The non-contact power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through switching control of the switch.
The resonant circuit unit includes a parallel circuit composed of a first passive element and a second passive element and connected in series to the secondary coil,
The parallel circuit includes a switch connected in series to at least one of the first passive element and the second passive element to open and close the parallel circuit,
The non-contact power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through switching control of the switch.
The resonance circuit unit is connected in parallel to the first series circuit including the secondary coil and the first passive element, and is connected in parallel to the first series circuit, and includes a second passive element and a switch. A series circuit of
The non-contact power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through switching control of the switch.
The resonant circuit unit includes a first passive element and a switch, a parallel circuit connected in series to the secondary coil, and a second circuit connected in parallel to a series circuit of the parallel circuit and the secondary coil. Including passive elements,
The non-contact power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through switching control of the switch.
The contactless power supply device according to any one of claims 2 to 5, wherein each of the first passive element and the second passive element includes a capacitor.
6. The non-contact power feeding device according to claim 2, wherein one of the first passive element and the second passive element is a capacitor and the other is an inductor.
The contactless power feeding device according to any one of claims 2 to 5, wherein one of the first passive element and the second passive element is a capacitor and the other is a resistance element.
The contactless power feeding device according to any one of claims 2 to 5, wherein each of the first passive element and the second passive element includes an inductor.
The contactless power feeding device according to any one of claims 2 to 5, wherein each of the first passive element and the second passive element includes a resistive element.
The rectifier circuit unit further includes a rectifier circuit unit that is connected to the output of the oscillator circuit unit and converts alternating power received by the secondary coil into DC power, and the modulation control device transmits the oscillating circuit unit to the rectifier circuit unit. The non-contact electric power feeder of Claim 1 which modulates the amplitude of the alternating power to be performed.
A power receiving unit that receives power in a non-contact manner from a power transmission unit including a primary coil,
A resonance that includes a secondary coil that receives the alternating power corresponding to the alternating magnetic flux from the primary coil in a non-contact manner at a position that intersects with the alternating magnetic flux generated in the primary coil, and is configured so that the circuit constant can be changed. A circuit section;
A modulation control device that modulates the amplitude of the alternating power received by the secondary coil by changing the circuit constant of the resonant circuit unit based on information to be transmitted to the primary coil;
A power receiving unit comprising: