JP2011109810A - Noncontact power supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noncontact power supply device by which information is transmitted from a mobile device or the like to a charger or the like with smaller electric power consumption while sharing a circuit used for power supply even when electric power is supplied from the charger or the like to the mobile device or the like in a noncontact manner. <P>SOLUTION: The noncontact power supply device receives an alternating electric power supplied to a primary coil L1 by a secondary coil L2 which intersects the alternating magnetic flux generated from a primary coil L1 receiving the alternating electric power, and converts the received alternating electric power to DC power to be supplied to a battery BA. The noncontact power supply device is equipped with: a resonance circuit 22A which includes the secondary coil L2 and is constituted so that the circuit constant is changeable; a secondary-side control device 21 in which the circuit constant of the resonance circuit 22A is changed based on information to be transmitted to the primary coil L1 to modulate the amplitude of the alternating electric power to be received by the secondary coil L2; and a primary-side control device 11 which demodulates the information to be transmitted to the primary coil L1 from changes in the amplitude of the alternating electric power generated on the primary coil L1 in accordance with changes in the amplitude of the alternating electric power at the secondary coil L2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a non-contact power feeding device that uses electromagnetic induction to perform power transmission between devices in a non-contact manner.

  In recent years, such a non-contact power supply device has been widely known as a device capable of charging a secondary battery (battery) built in a portable device such as a mobile phone or a digital camera in a non-contact manner. Such a portable device and a charger corresponding to the portable device are each provided with a coil for transmitting and receiving power for charging, and is transmitted from the charger to the portable device by electromagnetic induction between the two coils. The AC power is converted into DC power by the portable device, so that the secondary battery as the power source of the portable 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 includes a power supply unit such as a charger that controls oscillation of the primary coil, and a secondary coil that supplies power from the oscillated primary coil as a supply unit. A load unit such as a portable device having a secondary battery (storage battery) connected in parallel with the battery is configured. The secondary coil is connected in parallel with load control means for changing its output load. And this load control means changes the power supply characteristic as the secondary coil, that is, the power receiving characteristic, by switching the open and short of the parallel circuit of the secondary coil according to the state of charge of the secondary battery. . In addition, the non-contact power feeding device described in Patent Document 3 is for signal transmission that controls connection / opening of a resistor having a predetermined resistance value in parallel with the output of a secondary coil such as a portable device that supplies power to a load. It has a load circuit. The output load is varied by connecting / opening the resistor to change the power reception characteristics as the secondary coil. That is, in any of these cases, the change in the power reception characteristics of the secondary coil of the portable device or the like according to the charging state of the secondary battery is changed to the primary of the charger or the like electromagnetically coupled to the secondary coil. The change of the output voltage of the coil is caused, and the power supplied from the charger or the like to the primary coil can be controlled through the change of 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, it is unnecessary for the corresponding portable device by adjusting the power supplied to the portable device based on the change of the power reception characteristics on the portable device side, that is, the information from the portable device side. It is possible to reduce waste of power generated by supplying a large amount of power. 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 even when supplying power from a charger or the like to a portable device or the like in a contactless manner. On the other hand, it is an object of the present invention to provide a non-contact power supply apparatus that can transmit information from a portable device or the like to a charger or the like with less power consumption.

  In order to solve the above problems, the invention according to claim 1 is directed to the alternating power supplied to the primary coil by causing the alternating magnetic flux generated from the primary coil supplied with the alternating power to cross the secondary coil. Is a non-contact power supply device that receives the alternating power received through the secondary coil, converts the received alternating power into DC power, and supplies it to a load, including the secondary coil that receives the alternating power, and a circuit. The resonance circuit unit configured to change the constant, and the amplitude of the alternating power received by the secondary coil by changing the circuit constant of the resonance circuit unit based on information to be transmitted to the primary coil. A modulation control device for modulating, and a demodulation control device for demodulating information to be 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 And summarized in that comprises and.

  According to such a configuration, the modulation control device changes the amplitude of the voltage of the alternating power received by the secondary coil in the resonance circuit unit based on the information to be transmitted to the primary coil, and changes in the amplitude of the voltage The demodulation control device acquires predetermined information transmitted from the modulation control device on the basis of the voltage change of the primary coil accompanying the. As a result, information from the modulation control device is transmitted to the demodulation control device. For example, the demodulation control device drives the primary coil according to the situation of the secondary battery or the load connected to the modulation control device. Thus, it is possible to suitably control the power transmitted to the secondary coil.

  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 is adjusted through rectification and smoothing, etc. Therefore, it will be avoided that a large amount is consumed. 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. Consumption is suppressed. 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 reception characteristics applied to the secondary coil. This facilitates the design and adjustment of the power reception characteristics of the resonant circuit unit, and improves the possibility of implementing and adopting a non-contact power supply apparatus having such a resonant circuit unit.

  According to a second aspect of the present invention, the resonant circuit unit includes a switch that opens and closes a circuit, and a parallel circuit including a first passive element and a second passive element is connected in parallel to the secondary coil. It is connected in series to at least one of the first passive element and the second passive element, and the modulation control device changes a circuit constant of the resonance circuit unit through switching control of the switch. To do.

  According to such a configuration, the circuit constant of the resonance circuit unit based on the secondary coil and the passive element that does not have a switch, that is, the amplitude of the alternating power received by the secondary coil, is determined by the passive element having the switch. It can be changed by connection / release. As a result, the amplitude of the alternating power received by the secondary coil can be easily changed with a small number of switches.

  When both the first passive element and the second passive element are provided with switches, the modulation control device selectively opens only one of the different switches. By controlling, the circuit constant of the resonance circuit unit, that is, the power reception characteristic of the secondary coil can be changed based on the first passive element and the second passive element.

  According to a third aspect of the present invention, the resonant circuit unit includes a switch that opens and closes a circuit, and a parallel circuit including a first passive element and a second passive element is connected in series to the secondary coil. The modulation control device is connected in series to at least one of the first passive element and the second passive element, and the modulation control device changes a circuit constant of the resonance circuit through switching control of the switch. .

  According to such a configuration, the circuit constant of the resonance circuit unit based on the secondary coil and the passive element that does not have a switch, that is, the amplitude of the alternating power received by the secondary coil, is determined by the passive element having the switch. It can be changed by connection / release. As a result, the amplitude of the alternating power received by the secondary coil can be easily changed with a small number of switches.

  When both the first passive element and the second passive element are provided with switches, the modulation control device selectively opens only one of the different switches. By controlling, the circuit constant of the resonance circuit unit, that is, the power reception characteristic of the secondary coil can be changed based on the first passive element and the second passive element.

  According to a fourth aspect of the present invention, in the resonance circuit unit, a series circuit including a second passive element and a switch for opening and closing the circuit is added to the series circuit including the secondary coil and the first passive element. In summary, the modulation control device is configured to change a circuit constant of the resonance circuit unit through switching control of the switch.

  According to such a configuration, the circuit constant of the resonance circuit unit based on the secondary coil and the passive element that does not have a switch, that is, the amplitude of the alternating power received by the secondary coil, is determined by the passive element having the switch. It can be changed by connection / release. As a result, the amplitude of the alternating power received by the secondary coil can be easily changed with a small number of switches.

  According to a fifth aspect of the present invention, in the resonance circuit unit, a serial circuit including a first passive element and a parallel circuit including a switch that opens and closes the circuit is connected in series to the secondary coil. Two passive elements are connected in parallel, and the modulation control device changes the circuit constant of the resonance circuit unit through switching control of the switch.

  According to such a configuration, the circuit constant of the resonance circuit unit based on the secondary coil and the passive element having no switch, that is, the amplitude of the alternating power received by the secondary coil is connected in series to the secondary coil. It can be changed by connecting / disconnecting the passive element by the switch. As a result, the amplitude of the alternating power received by the secondary coil can be easily changed with a small number of switches.

The gist of the invention described in claim 6 is that each of the first passive element and the second passive element comprises a capacitor.
According to such a configuration, since the amplitude of the alternating power received by the secondary coil can be set by the combination of the capacitors, the amplitude of the alternating power can be easily changed.

The gist of the invention described in claim 7 is that one of the first passive element and the second passive element is a capacitor and the other is an inductor.
According to such a configuration, since the amplitude of the alternating power received by the secondary coil can be set by the combination of the capacitor and the inductor, the degree of freedom of setting for changing the amplitude of the alternating power is increased.

The gist of the invention described in claim 8 is that one of the first passive element and the second passive element is a capacitor and the other is a resistance element.
According to such a configuration, since the amplitude of the alternating power received by the secondary coil can be set by the combination of the capacitor and the resistor, the degree of freedom of setting for changing the amplitude of the alternating power is increased.

The gist of the invention described in claim 9 is that both the first passive element and the second passive element are inductors.
According to such a configuration, since the passive element is composed only of the inductance, the circuit configuration of the resonance circuit unit can be simplified.

The gist of the invention described in claim 10 is that each of the first passive element and the second passive element is composed of a resistance element.
According to such a configuration, since the passive element is composed of only the resistive element, the circuit configuration of the resonance circuit unit can be simplified.

  According to the present invention, even when power is supplied from a charger or the like to a portable device or the like in a contactless manner, the circuit used for the power supply is shared, and the portable device or the like can be connected to the charger or the like with less power. Therefore, it is possible to provide a non-contact power feeding device capable of transmitting the information.

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 showing a specific configuration of an electric circuit of the non-contact power feeding device of the present embodiment.

As shown in FIG. 1, the non-contact power feeding apparatus is roughly composed of 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. The LC circuit on the primary side forms a direct circuit in which 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. The power supply E is connected in parallel. Note that an RC circuit constituted by a resistor R6 and a capacitor C5 connected in series 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, the 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 to generate a magnetic flux, and a voltage for maintaining the ON voltage of the MOS transistor FET1 is generated in the feedback coil L3 receiving the magnetic flux.
The gate voltage of the OS transistor FET1 is maintained at the on voltage, and 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, the voltage generated in the resistor R7 is applied to the RC circuit including the resistor R6 and the capacitor C5, and the RC circuit is charged with the capacitor C5. The voltage between the terminals of the capacitor C5 is increased with charging. 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. In the resonance of the LC circuit, the voltage on the drain side of the MOS transistor FET1 rises to reach a peak, and then falls. 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, the voltage drops and reaches a peak at the terminal of the feedback coil L3 on the gate terminal side of the MOS transistor FET1, Then rise. After a while, a voltage capable of turning on the MOS transistor FET1 is generated at the 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 present 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.

  The power transmission unit 10 is provided with a primary side control device 11. 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 data stored in the memory. And based on the program, various controls such as oscillation control of the LC circuit of the power transmission unit 10 are executed. In the present 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. In other words, the power at the connection point N2 is half-wave rectified and input to the primary side control device 11, and the primary side control device 11 receives 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 that is connected in parallel to the secondary coil L2, and a parallel connection to the secondary coil L2. And a series circuit composed of a capacitor C8 and a switch SW1. Thereby, the resonance circuit unit 22A is configured as a secondary resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C6 when the switch SW1 is opened, and when the switch SW1 is connected, 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 is changed from the primary coil L1 by the change of the circuit constant. The amplitude of the alternating power to be received is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit.

  In the present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, the secondary side resonance circuit (LC circuit) composed of the secondary coil L2, the capacitor C6 and the capacitor C8 has a value of the capacitor C8 such that the magnetic coupling between the secondary coil L2 and the primary coil 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.

  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. Power is reduced. 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, the change in the power reception characteristics of the secondary coil L2 not only changes the amplitude of the power waveform of the alternating power received by the secondary coil L2, but also the primary coil L1 magnetically coupled to the secondary coil L2. The amplitude of the power waveform of the alternating power 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 is known that it increases when the magnetic coupling between the primary coil L1 and the secondary coil L2 is degraded.

  Electric 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 for switching. 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. This is applied to turn on the MOS transistor FET3 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 control device 21 is connected to the switch SW1 of the resonance circuit unit 22A. The secondary control device 21 controls the switch SW1 to open / close the circuit by the switch SW1. Switch. 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. ˜200 kHz), for example, a communication cycle of 10 Hz (100 ms).

  Next, information transmission by transmission of a communication signal 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 voltage amplitude generated in the alternating power according to the power reception characteristics of the power reception unit. FIG. 2A shows a case where the power reception characteristics are good, and FIG. 2B shows that the power reception characteristics deteriorate. 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. FIG. 4 is a graph showing a signal reception state by the power transmission unit in a longer time than FIG. 3, wherein (a) is a graph showing a voltage waveform of alternating power of the power transmission unit, and (b) is (a). The signal calculated | required based on the amplitude of a voltage waveform 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 present 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 of the communication cycle as shown in FIG. For example, the switch SW1 is connected during a period P2 from time t1 to time t2. 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 by the power transmission unit 10 of the communication signal generated by the power reception unit 20 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 which 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 synchronization 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 P1. 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 voltage 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 contents thereof are transmitted. . 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 this 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 control device 11 acquires information transmitted from the secondary control device 21 based on the voltage change of the primary coil L1 accompanying the change. 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) Further, since the circuit constant of the resonance circuit unit 22A including the secondary coil L2 is changed, it is suitable for supply to the load after rectification and smoothing by the rectification circuit unit 23A after receiving power. It is avoided that the DC power converted into the state is consumed in large quantities for information transmission. That is, when information is transmitted from the secondary coil L2 to the primary coil L1, as in the conventional case, the DC to be supplied to a load such as a secondary battery by changing the characteristics of the secondary coil due to load fluctuations with respect to DC power. It is suppressed that power is consumed. 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 / opening the capacitor C8 having 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 according to the contactless power feeding device of the present embodiment.

  In this embodiment, the configuration of the resonance circuit unit of the power receiving unit is different from that of the first embodiment, but the other configurations are the same. Therefore, in the present 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 the detailed description will be omitted for convenience of description. .

  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 present 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 will be omitted.

  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 resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 when the switch SW1 is opened and the switch SW2 is connected. The Further, when the switch SW1 is connected 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 resonance circuit unit 22B is changed by the capacitor (capacitor C6 or capacitor C8) to which the circuit constant of the resonance circuit (LC circuit) is connected, and the secondary coil is changed by the change of the circuit constant. The amplitude of the alternating power that L2 receives from the primary coil L1 is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit. 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 present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, the secondary side resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C8 has a value of the capacitor C8 that is higher than the magnetic coupling between the secondary coil L2 and the primary coil. It is set to a value that deteriorates compared to a resonance circuit composed of the secondary coil L2 and the capacitor C6.

Further, the secondary side control device 21 is connected to each switch SW1, SW2 of the resonance circuit section 22B, and the secondary side control device 21 controls the opening / closing of each switch SW1, SW2 separately. The circuit opening / connection by the switch SW1 and the circuit opening / connection by the switch SW2 are switched separately. That is, when the secondary side control device 21 controls opening / closing of the switches SW1 and SW2, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22B is changed, and the secondary coil L2 is alternated. The maximum voltage of the power voltage waveform is changed to a voltage VL2 or a voltage VH2, which are different voltages. Accordingly, the amplitude of the alternating power of the primary coil L1 is
For example, the voltage is changed to the voltage VL1 or the voltage VH1. In the present 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 connected, so that the circuit constant changes within a predetermined range. You are in control.

  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 can be modulated based on the binary communication signal generated based on the communication rule. And the power transmission part 10 demodulates a communication signal from the maximum voltage of the primary coil L1 modulated by the primary side control apparatus 11, and acquires the content of the communication signal produced | generated by the power receiving part 20. FIG.

  As described above, according to the present 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. Be able to.

  (6) The switches SW1 and SW2 are provided on both the capacitor C8 and the capacitor C6 connected in parallel to the load. 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 a power receiving unit according to the non-contact power feeding device of the present embodiment.

  In this embodiment, the configuration of the resonance circuit unit of the power receiving unit is different from that of the first embodiment, but the other configurations are the same. Therefore, in the present 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 the detailed description will be omitted for convenience of description. .

  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 present 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 will be omitted.

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. Accordingly, the resonance circuit unit 22C 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 the switch SW2 is connected. The Further, when the switch SW1 is connected and the switch SW2 is opened, the secondary coil L2 and the capacitor C8 are used.
It is configured as a secondary resonance circuit (LC circuit). For this reason, the resonance circuit unit 22C is changed by the capacitor (capacitor C6 or capacitor C8) to which the circuit constant of the resonance circuit (LC circuit) is connected, and the secondary coil is changed by the change of the circuit constant. The amplitude of the alternating power that L2 receives from the primary coil L1 is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit. 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 present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, the secondary side resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C8 has a value of the capacitor C8 that is higher than the magnetic coupling between the secondary coil L2 and the primary coil. It is set to a value that deteriorates compared to a resonance circuit composed of the secondary coil L2 and the capacitor C6.

  Further, the secondary side control device 21 is connected to each of the switches SW1 and SW2 of the resonance circuit unit 22C, and the secondary side control device 21 controls the opening and closing of the switches SW1 and SW2 separately. The circuit opening / connection by the switch SW1 and the circuit opening / connection by the switch SW2 are switched separately. That is, when the secondary side control device 21 controls opening / closing of each switch SW1, SW2, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22C is changed, and the secondary coil L2 is alternated. The maximum voltage of the power voltage waveform is changed to a voltage VL2 or a voltage VH2, which are different voltages. 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 present 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 connected, so that the circuit constant changes within a predetermined range. You are in control.

  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 can be modulated based on the binary communication signal generated based on the communication rule. And the power transmission part 10 demodulates a communication signal from the maximum voltage of the primary coil L1 modulated by the primary side control apparatus 11, and acquires the content of the communication signal produced | generated by the power receiving part 20. FIG.

  As described above, according to the present 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. Be able to.

  (7) The switches SW1 and SW2 are provided on both the capacitor C8 and the capacitor C6 connected in series with the load. 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 a power receiving unit according to the contactless power feeding device of the present embodiment.

  In this embodiment, the configuration of the resonance circuit unit of the power receiving unit is different from that of the first embodiment, but the other configurations are the same. Therefore, in the present 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 the detailed description will be omitted for convenience of description. .

  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 present 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 will be omitted.

  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 switch C1 and a capacitor C8 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 connected, it is configured as a secondary resonance circuit (LC circuit) including a capacitor C8 connected in parallel to a series circuit including the secondary coil L2 and the capacitor C6. For this reason, in the resonance circuit unit 22C, 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 is changed from the primary coil L1 by the change of the circuit constant. The amplitude of the alternating power received is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit. 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 present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, the secondary side resonance circuit (LC circuit) composed of the secondary coil L2 and the capacitor C8 has a value of the capacitor C8 that is higher than the magnetic coupling between the secondary coil L2 and the primary coil. It is set to a value that deteriorates compared to a resonance circuit composed of the secondary coil L2 and the capacitor C6.

  Further, the secondary side control device 21 is connected to the switch SW1 of the resonance circuit unit 22D, and the secondary side control device 21 controls the switching of the switch SW1 to open / close the circuit by the switch SW1. Is switched. That is, when the secondary side control device 21 controls the switching of the switch SW1, the circuit constant of the secondary side resonance circuit (LC circuit) of the resonance circuit unit 22D is changed, and the voltage of the alternating power of the secondary coil L2 is changed. The maximum voltage of the waveform is changed to a voltage VL2 or a voltage VH2, which are different voltages. Accordingly, the amplitude of the alternating power of the primary coil L1 is changed to, for example, the voltage VL1 or the voltage VH1.

  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 can be modulated based on the binary communication signal generated based on the communication rule. And the power transmission part 10 demodulates a communication signal from the maximum voltage of the primary coil L1 modulated by the primary side control apparatus 11, and acquires the content of the communication signal produced | generated by the power receiving part 20. FIG.

  As described above, according to the present 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. Be able to.

  (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 / opening the capacitor C8 having the switch SW1. Will be able to. As a result, the amplitude of the alternating power received by the secondary coil can be easily changed 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 a power receiving unit according to the contactless power feeding device of the present embodiment.

  In this embodiment, the configuration of the resonance circuit unit of the power receiving unit is different from that of the first embodiment, but the other configurations are the same. Therefore, in the present 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 the detailed description will be omitted for convenience of description. .

  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 present 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 will be omitted.

  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 connected, it is configured as a secondary resonance circuit (LC circuit) composed of a parallel circuit composed of the secondary coil L2 and the capacitor C6. For this reason, in the resonance circuit unit 22C, 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 is changed from the primary coil L1 by the change of the circuit constant. The amplitude of the alternating power received is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit. 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 present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, a secondary side resonance circuit (LC circuit) comprising a series circuit of the secondary coil L2 and coil L4 and a capacitor C6 connected in parallel to the series circuit has a value of the coil L4 of the secondary circuit. The magnetic coupling between the coil L2 and the primary coil is set to a value that deteriorates compared to the resonance circuit composed of the secondary coil L2 and the capacitor C6.

  Further, the secondary side control device 21 is connected to the switch SW3 of the resonance circuit unit 22E, and the secondary side control device 21 controls the switching of the switch SW3 to open / close the circuit by the switch SW3. Is switched. That is, when the secondary side control device 21 controls opening and 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 the voltage of the alternating power of the secondary coil L2 is changed. The maximum voltage of the waveform is changed to the voltage VL2 or the voltage VH2, which are different voltages. 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).

  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. And the power transmission part 10 demodulates a communication signal from the maximum voltage of the primary coil L1 modulated by the primary side control apparatus 11, and acquires the content of the communication signal produced | generated by the power receiving part 20. FIG.

  As described above, according to the present embodiment, the 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. Be able to.

  (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, it is possible to easily change the amplitude of the alternating power received by the secondary coil L2 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 a power receiving unit according to the non-contact power feeding device of the present embodiment.

  In this embodiment, the configuration of the resonance circuit unit of the power receiving unit is different from that of the first embodiment, but the other configurations are the same. Therefore, in the present 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 the detailed description will be omitted for convenience of description. .

  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 present 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 will be omitted.

  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 constituted by 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 connected, it is configured as a secondary resonance circuit (LC circuit) composed of a parallel circuit composed of the secondary coil L2 and the capacitor C6. For this reason, the circuit constant of the resonant circuit (RLC circuit or LC circuit) of the resonant circuit unit 22C is changed depending on the presence or absence of the resistor R8, and the secondary coil L2 is changed to the primary by the change of the circuit constant. The amplitude of the alternating power received from the coil L1 is changed (modulated). That is, the power reception characteristic of the secondary coil L2 of the power supplied from the primary coil L1 is changed by changing the circuit constant of the resonance circuit. 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 present embodiment, the secondary-side resonance circuit (LC circuit) including the secondary coil L2 and the capacitor C6 has a value of the capacitor C6 that is magnetic between the secondary coil L2 and the primary coil L1. The value is set so that the connectivity is good. On the other hand, a secondary side resonance circuit (RLC circuit) comprising a series circuit of the secondary coil L2 and the resistor R8 and a capacitor C6 connected in parallel to the series circuit has a value of the resistor R8 of the secondary circuit. The magnetic coupling between the coil L2 and the primary coil is set to a value that deteriorates compared to the resonance circuit composed of the secondary coil L2 and the capacitor C6.

  Further, the secondary side control device 21 is connected to the switch SW4 of the resonance circuit unit 22F, and the secondary side control device 21 controls the switching of the switch SW4 to open / close the circuit by the switch SW4. Is switched. That is, when the secondary-side control device 21 controls opening / closing of the switch SW4, the circuit constant of the secondary-side resonance circuit of the resonance circuit unit 22F is changed, and the maximum voltage of the voltage waveform of the alternating power of the secondary coil L2 is changed. Are changed to different voltages VL2 or VH2, respectively, and the amplitude of the alternating power of the primary coil L1 is changed 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. And the power transmission part 10 demodulates a communication signal from the maximum voltage of the primary coil L1 modulated by the primary side control apparatus 11, and acquires the content of the communication signal produced | generated by the power receiving part 20. FIG.

  As described above, according to the present embodiment, the 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. Be able to.

  (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.

In addition, each said embodiment can also be implemented in the following aspects, for example.
(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 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 may be, for example, an alternating primary coil as long as it is based on a change that occurs in the alternating power amplitude of the primary coil based on a change in the amplitude of the received power of the secondary coil. The communication signal from the power receiving unit may be demodulated regardless of the alternating power processing method, based on the average voltage of the power. Thereby, the freedom degree of a structure of an electric power transmission part comes to be raised.

  In each of the above embodiments, 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 if the circuit constant of the resonant circuit unit can be changed, the resonant circuit unit can be either a resistive element or an inductor for the capacitor of the resonant circuit unit, or when there are two capacitors. May be a resistance element and the other may be an inductor such as a coil, or both may be a resistance or a coil.

  For example, when two passive elements are coils, the passive element is composed only of an inductance, so that the circuit configuration of the resonance circuit unit can be simplified. 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 if the circuit constant of the resonant circuit unit can be changed, the resonant circuit unit can change the circuit constant in cooperation with three or more passive elements in addition to the secondary coil L2. You may make it do.

  In each of the above embodiments, the case where DC power is charged in the battery BA is 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 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.

  DESCRIPTION OF SYMBOLS 10 ... Electric power transmission part, 11 ... Primary side control apparatus as a demodulation control apparatus, 20 ... Electric power receiving part, 21 ... Secondary side control apparatus as a modulation control apparatus, 22A-22F ... Resonance circuit part, 23A-23F ... Rectifier circuit unit, 24A to 24F ... supply control unit, E ... DC power supply, BA ... battery, C1, C2, C4, C5 ... capacitor, C6, C8 ... capacitor as first or second passive element, C7 ... smoothing Capacitor, D1, D2 ... Diode, D3 ... Rectifier diode, L1 ... Primary coil, L2 ... Secondary coil, L3 ... Feedback coil, L4 ... Coil as first or second passive element, R1 ... Starting resistance, R2 ˜R7... Resistor, R8... Resistor as first or second passive element, SW1 to SW4... Switch, TR2, TR3... Bias control transistor, FET1, FET3. Register.

Claims (10)

By alternating the alternating magnetic flux generated from the primary coil supplied with the alternating power to the secondary coil, the alternating power supplied to the primary coil is received via the secondary coil, and the received alternating power is A non-contact power supply device that converts to DC power and supplies the load to a load,
A resonance circuit unit including the secondary coil for receiving the alternating power and configured to change a circuit constant;
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 demodulation control device for demodulating information to be 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. A non-contact power feeding device. In the resonance circuit unit, a parallel circuit including a first passive element and a second passive element is connected in parallel to the secondary coil, and a switch for opening and closing the circuit includes the first passive element and the first passive element. Connected in series to at least one of the two passive elements,
The contactless power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through opening / closing control of the switch. In the resonance circuit unit, a parallel circuit including a first passive element and a second passive element is connected in series to the secondary coil, and a switch that opens and closes the circuit includes the first passive element and the first passive element. Connected in series to at least one of the two passive elements,
The contactless power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit through switching control of the switch. The resonance circuit unit is formed by connecting a series circuit including a second passive element and a switch for opening and closing the circuit in parallel to a series circuit including the secondary coil and the first passive element,
The contactless power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through opening / closing control of the switch. The resonant circuit unit includes a parallel circuit including a first passive element and a switch that opens and closes the circuit connected in series to the secondary coil, and a second passive element connected in parallel. Become
The contactless power feeding device according to claim 1, wherein the modulation control device changes a circuit constant of the resonance circuit unit through opening / closing control of the switch. 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 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 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 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 resistance element.