Wireless energy transfer with feedback control for lighting applications

• US 8,552,592 B2
• Filed: 02/02/2010
• Issued: 10/08/2013
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Schatz, David A., Lou, Herbert T., Kesler, Morris P., Hall, Katherine L., Kulikowski, Konrad J., Giler, Eric R., Fiorello, Ron
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/698,523
• Publication Number:
  US 20100201203A1
• Time in Patent Office: 1,344 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

Described herein are improved configurations for a wireless lighting power transfer method including providing a source having a source resonator that includes a high-Q source magnetic resonator coupled to a power source, providing a device having a device resonator that includes a high-Q device magnetic resonator, distal from the source resonator, the device including a light emitting part electrically coupled to the device resonator, providing a signaling capability between the source and the device, signaling a state of the device to the source using the signaling capability, and energizing the source to generate an oscillating magnetic field according to the state of the device.

Claims

1. A wireless lighting power transfer method comprising:

providing a source having a source resonator that includes a high-Q source magnetic resonator coupled to a power source;

providing a device having a device resonator that includes a high-Q device magnetic resonator, distal from the source resonator, the device including a light emitting part electrically coupled to the device resonator;

providing a signaling capability between the source and the device;

signaling a state of the device to the source using the signaling capability; and

energizing the source to generate an oscillating magnetic field according to the state of the device.

2. The method of claim 1, wherein the device further comprises energy storage wherein the energy storage is rechargeable by electrical energy from the device resonator.

3. The method of claim 1, wherein the source can be energized at two or more power levels.

4. The method of claim 3, wherein the source is energized at a low power level when the light emitting part is off.

5. The method of claim 3, wherein the source is not energized when the light emitting part is off.

6. The method of claim 2, wherein the source is energized to recharge the energy storage.

7. The method of claim 6, wherein the device signals the source to provide power using the signaling capability when the electrical energy in the energy storage is low.

8. The method of claim 1, wherein the source resonator and the device resonator are separated by a supporting structure.

9. A wireless lighting system comprising:

a source having at least one high-Q source magnetic resonator coupled to a power source and generating an oscillating magnetic field;

a device having at least one high-Q device magnetic resonator, distal from the source magnetic resonator, having a light emitting part electrically coupled to the device magnetic resonator; and

a signaling capability between the source and the device;

wherein power is transferred wirelessly from the source resonator to the device resonator via the oscillating magnetic field and the light emitting part is energized by the electrical energy captured by the device magnetic resonator.

10. The system of claim 9, wherein the device further comprises an energy storage unit wherein the energy storage unit is rechargable by electrical energy from the device magnetic resonator.

11. The system of claim 10, wherein the device signals the source using the signaling capability when electrical energy in the energy storage unit is low.

12. The system of claim 9, wherein the source resonator and the device resonator are separated by a supporting structure.

13. The system of claim 12, wherein the supporting structure is a wall of a building.

14. The system of claim 12, wherein the supporting structure is a ceiling of a building.

15. The system of claim 12, wherein the supporting structure is a part of a vehicle.

16. The system of claim 9 wherein the source resonator and the device resonator are separated by at least five centimeters.

17. The system of claim 9, wherein the device further comprises a means for detecting and indicating proximity to the source resonator.

18. The system of claim 9, wherein the device further comprises a motion sensor.

19. The system of claim 9, where at least one of the high-Q source magnetic resonator and the high-Q device magnetic resonator has a quality factor Q greater than one hundred.

20. A system comprising:

an outdoor lighting fixture sealed in a weatherproof enclosure that houses a light emitter to illuminate an area, a high-Q device magnetic resonator electrically coupled to the light emitter, and a transmitter to wirelessly communicate a signal; and

a source spaced apart from the outdoor lighting fixture, the source including a power source, a high-Q source magnetic resonator wirelessly coupled through an oscillating magnetic field to the high-Q device magnetic resonator to transfer power from the power source to the light emitter, and a receiver to receive the signal and conditionally activate the power source to deliver power to the outdoor lighting fixture according to a state of the outdoor lighting fixture.

21. The system of claim 20, wherein the transmitter communicates the signal by varying an impedance of the device.

22. A lighting fixture comprising:

an illumination device including a battery;

a magnetic resonator to wirelessly receive power for the illumination device through an oscillating magnetic field;

a receiver to wirelessly receive a control signal for operation of the illumination device;

a transmitter to wirelessly transmit a feedback signal characterizing a state of the illumination device; and

a weatherproof housing enclosing the illumination device, the magnetic resonator, the receiver, and the transmitter for outdoor use.

23. The fixture of claim 22, wherein the transmitter communicates the feedback signal by varying at least one electrical parameter of the magnetic resonator.

24. The fixture of claim 23, wherein the at least one electrical parameter includes an inductance.

25. The fixture of claim 23, wherein the at least one electrical parameter includes a capacitance.

26. The fixture of claim 23, wherein the at least one electrical parameter includes a resonant frequency.