POWER COUPLING DEVICE

• US 20160072297A1
• Filed: 09/08/2014
• Published: 03/10/2016
• Est. Priority Date: 09/08/2014
• Status: Active Grant

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: KRUGLICK, Ezekiel, FINE, Kevin S.
• Granted Patent: US 10,320,228 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

Systems and methods to wirelessly transmit power are provided. A coil assembly is provided. In some examples, the coil assembly is configured to generate a signal in response to an ambient field, and to magnetically couple with a device to deliver power to the device.

Claims

1. An apparatus for delivering a signal from a transmit coil to a device, the apparatus comprising:

a first coil that is configured to receive a transmit signal from the transmit coil such that a first signal is induced in the first coil;

a second coil connected with the first coil such that the first signal is present in the second coil, wherein the second coil is configured to couple with the device; and

a controller configured to adjust a resonant frequency of the first coil to match a drive frequency of the transmit coil.

2. The apparatus of claim 1, wherein the first coil and the second coil are formed from a loop of wire that includes at least one turn, wherein a portion of the loop of wire crosses itself at a location to form the first coil and the second coil, wherein the first coil is separated from the second coil at the location.

3. The apparatus of claim 1, wherein the first coil and the second coil are formed from a loop of wire that includes at least one turn, wherein a portion of the loop is brought close together without crossing at a location to form the first coil and the second coil.

4. The apparatus of claim 2, wherein an area of the second coil is smaller than an area of the first coil.

5. The apparatus of claim 3, wherein the loop of wire is flexible such that an area of the first coil changes in accordance with a change in a shape of the first coil.

6. The apparatus of claim 5, wherein the controller adjusts the resonant frequency in response to a change in the area of the first coil.

7. The apparatus of claim 6, wherein the controller comprises:

a rectifier that is connected to the loop of wire and that is configured to generate a voltage from a portion of the first signal that is correlated with the current in the loop of wire, wherein the voltage powers the controller;

an adjustable capacitance coupled with the receive coil; and

control logic that adjusts the adjustable capacitance to adjust the resonant frequency of the first coil such that the resonant frequency substantially matches the drive frequency, wherein the resonant frequency substantially matches the drive frequency when that the voltage is maximized.

8. The apparatus of claim 7, wherein the adjustable capacitance is adjustable in steps that are less than or equal to 0.1% of a total capacitance.

9. The apparatus of claim 8, wherein the adjustable capacitance includes a MOSFET switching network or a MEMs variable capacitor array.

10. The apparatus of claim 1, wherein the controller is configured to determine power delivered by the device via the second coil based on relative phases of a current and a voltage of the first signal in the first coil, wherein the controller outputs a status that indicates when the device is optimally placed relative to the second coil.

11. An apparatus configured to couple with a transmit coil to deliver a signal to a device, the apparatus comprising:

a host object;

a coil assembly that is attached to the host object, wherein the coil assembly is configured to couple with the transmit coil such that the coil assembly delivers a first signal to the device; and

a controller configured to change a resonant frequency of the coil assembly to match a drive frequency of the transmit coil.

12. The apparatus of claim 11, wherein the coil assembly is incorporated into a body of the host object.

13. The apparatus of claim 11, wherein the coil assembly includes a receive coil and a coupler coil, wherein the receive coil is configured to be responsive to a second signal generated by the transmit coil and wherein the coupler coil is configured to provide the first signal to the device in response to the second signal.

14. The apparatus of claim 13, wherein the coil comprises assembly includes at least one turn of a wire.

15. The apparatus of claim 14, wherein the coupler coil and the receive coil are formed from wire.

16. The apparatus of claim 15, wherein the wire is twisted at a location such that a first portion of the wire overlaps a second portion of the wire in order to form the receive coil apart from the coupler coil, wherein an area of the receive coil is larger than an area of the coupler coil.

17. The apparatus of claim 16, wherein the coupler coil is located inside an area of the receive coil or outside of the area of the receive coil.

18. The apparatus of claim 14, wherein a radius of the wire is about 1% of a radius of the coil.

19. The apparatus of claim 11, wherein the controller is coupled to the coil assembly and wherein the controller includes:

a rectifier;

control logic; and

an adjustable capacitance;

wherein the rectifier converts a portion of a current in the coil assembly that is generated in response to the second signal into a third signal,

wherein the control logic that adjusts the adjustable capacitance to maximize a value of the third signal, wherein the resonant frequency matches the drive frequency when the third signal is maximized.

20. The apparatus of claim 19, wherein the third signal is correlated with a current in the coil assembly and wherein the rectifier generates a power signal to power the control logic.

21. The apparatus of claim 19, wherein the adjustable capacitance is adjusted in accordance with changes in a shape of the coil.

22. The apparatus of claim 11, wherein the coil is flexible.

23. The apparatus of claim 19, wherein the controller includes at least one LED that indicates a state of the system.

24. The apparatus of claim 23, wherein the state of the system includes a first state where the at least one LED indicates that the coil assembly is responsive to the second signal generated by the transmit coil, a second state where the at least one LED indicates that the coil assembly is coupled to the device, and a third state where the at least one LED indicates that the coil assembly is not responsive to the second signal.

25. The apparatus of claim 13, wherein the first signal and the second signal include magnetic signals.

26. A method for wirelessly transferring energy to a device with an apparatus, the method comprising:

wirelessly receiving a first signal at a first coil;

converting a current that is generated in the first coil in response to the first signal into a detection signal; and

adjusting a reactance that is associated with the first coil based on the detection signal such that a resonant frequency of the first coil matches a drive frequency of the first signal.

27. The method of claim 26, wherein the reactance includes a capacitance, further comprising adjusting the capacitance in steps, wherein the resonant frequency matches the drive frequency when the detection signal is maximized.

28. The method of claim 26, further comprising providing a state of the apparatus, wherein the state indicates one or more of:

whether the first coil is coupled to the transmit coil; and

whether the device is properly positioned relative to a second coil, wherein the second coil is connected with the first coil and has an area that is smaller than an area of the first coil.

29. The method of claim 28, further comprising determining that the device is properly positioned relative to the second coil based on a phase relationship between a current and a voltage associated with the first coil.