Contactless power supply device

• US 9,270,124 B2
• Filed: 06/25/2012
• Issued: 02/23/2016
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kamata, Koichiro
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US13/531,636
• Publication Number:
  US 20130002036A1
• Time in Patent Office: 1,338 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A contactless power supply device capable of appropriately supplying power to a plurality of power supplied devices at the same time without contact is provided. A contactless power supply device capable of supplying power without contact even when the positional flexibility of a plurality of power supplied devices is increased is provided. The contactless power supply device determines a power supply condition that power can be most appropriately supplied to a plurality of power supplied devices that need power supply in a short time. The contactless power supply device can appropriately supply power to a plurality of power supplied devices at the same time without contact by controlling the resonant capacitance of a power transmission coil in an optimized power supply condition. The positional flexibility of the plurality of power supplied devices with respect to the contactless power supply device can be increased.

Claims

1. A contactless power supply device comprising:

a plurality of high frequency power sources;

an excitation coil configured to be supplied with alternating current from a one of the plurality of high frequency power sources;

a resonance coil electromagnetically inductively coupled with the excitation coil;

a variable capacitor electrically connected to the resonance coil; and

a control circuit electrically connected to the variable capacitor,

wherein the control circuit is configured to select the one of the plurality high frequency power sources for changing oscillation frequency, and

wherein the variable capacitor is configured to make resonant capacitance of the resonance coil variable.

2. The contactless power supply device according to claim 1, wherein the variable capacitor is a variable condenser.

3. The contactless power supply device according to claim 1, wherein the variable capacitor is a variable capacitance diode.

4. The contactless power supply device according to claim 1, wherein the control circuit is configured to store a sum of power supplied from the resonance coil to a plurality of power supplied devices.

5. The contactless power supply device according to claim 4, the contactless power supply device further comprising a detection circuit electrically connected to the control circuit,

wherein the detection circuit is configured to determine the resonant capacitance and the oscillation frequency on the basis of the sum of the power.

6. The contactless power supply device according to claim 4, wherein the plurality of power supplied devices have different specific resonance frequencies.

7. The contactless power supply device according to claim 4, wherein a period during which power is supplied to the plurality of power supplied devices at the same time is provided when power is supplied to the plurality of power supplied devices by resonance coupling at the determined resonance frequency of the resonance coil.

8. A contactless power supply device comprising:

a plurality of high frequency power sources;

an excitation coil configured to be supplied with alternating current from a one of the plurality of high frequency power sources;

a resonance coil electromagnetically inductively coupled with the excitation coil;

a variable capacitor electrically connected to the resonance coil; and

a control circuit including a digital/analog converter and a microprocessor,

wherein the digital/analog converter is electrically connected to the microprocessor,

wherein the digital/analog converter is electrically connected to the variable capacitor and the plurality of high frequency power sources,

wherein the control circuit is configured to select the one of the plurality of high frequency power sources for changing oscillation frequency, and

wherein the variable capacitor is configured to make resonant capacitance of the resonance coil variable.

9. The contactless power supply device according to claim 8, wherein the variable capacitor is a variable condenser.

10. The contactless power supply device according to claim 8, wherein the variable capacitor is a variable capacitance diode.

11. The contactless power supply device according to claim 8, wherein the control circuit is configured to store a sum of power supplied from the resonance coil to a plurality of power supplied devices.

12. The contactless power supply device according to claim 11, the contactless power supply device further comprising a detection circuit electrically connected to the control circuit,

wherein the detection circuit is configured to determine the resonant capacitance and the oscillation frequency on the basis of the sum of the power.

13. The contactless power supply device according to claim 12,

wherein the detection circuit comprises a transceiver electrically connected to an antenna, and

wherein the transceiver is electrically connected to the microprocessor.

14. The contactless power supply device according to claim 11, wherein the plurality of power supplied devices have different specific resonance frequencies.

15. The contactless power supply device according to claim 11, wherein a period during which power is supplied to the plurality of power supplied devices at the same time is provided when power is supplied to the plurality of power supplied devices by resonance coupling at the determined resonance frequency of the resonance coil.

16. A contactless power supply method for a contactless power supply device comprising:

a plurality of high frequency power sources;

an excitation coil;

a resonance coil electromagnetically inductively coupled with the excitation coil; and

a variable capacitor electrically connected to the resonance coil,

the method comprising the steps of;

supplying alternating current having oscillation frequency of a one selected from the plurality of high frequency power sources to the excitation coil;

transmitting the alternating current to the resonance coil; and

transmitting power to a plurality of power supplied devices when oscillation frequency of the resonance coil corresponds to oscillation frequency of the plurality of power supplied devices,

wherein the power is supplied to the plurality of power supplied devices at the same time.

17. The contactless power supply method according to claim 16, the contactless power supply method further comprising the step of detecting the plurality of power supplied devices before the supplying step.

18. The contactless power supply method according to claim 16, the contactless power supply method further comprising the steps of:

changing the oscillation frequency by selecting the plurality of the high frequency power sources; and

varying the resonant capacitance of the resonance coil by the variable capacitor.

19. The contactless power supply method according to claim 16, the contactless power supply method further comprising the steps of:

storing a sum of power supplied from the resonance coil to the plurality of power supplied devices, and

determining the oscillation frequency of the resonance coil and any one of the plurality of the high frequency power sources on the basis of the sum of the power.

20. The contactless power supply method according to claim 16, wherein the plurality of power supplied devices have different specific resonance frequencies.

21. The contactless power supply method according to claim 16, wherein the variable capacitor is a variable condenser.

22. The contactless power supply method according to claim 16, wherein the variable capacitor is a variable capacitance diode.