Wireless power transfer method and circuit

• US 9,787,140 B2
• Filed: 11/19/2014
• Issued: 10/10/2017
• Est. Priority Date: 11/19/2014
• Status: Active Grant

• Current Assignee: TE Connectivity Corporation (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: TE Connectivity Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Hassan-Ali, Mudhafar, Larson, Jason
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): YESHAW, ESAYAS G
• Application Number:
  US14/548,088
• Publication Number:
  US 20160141881A1
• Time in Patent Office: 1,056 Days
• CPC Class Codes: H02J 50/10 using inductive coupling

Abstract

A power circuit for wirelessly communicating power to a receiving device includes one or more switches for coupling respective ends of different coils of a group of coils together to facilitate selectively connecting the coils in a series configuration, parallel configuration, or combination thereof. The circuit includes a controller configured to control a conduction state of each of the one or more switches, and power terminals in electrical communication with the coils through which a power signal flows.

Claims

1. A power circuit for wirelessly communicating power to a receiving device comprising:

one or more switches for coupling respective ends of different coils of a plurality of coils together to facilitate selectively connecting the plurality of coils such that in a first switch configuration the plurality of coils are in a series configuration, in a second switch configuration the plurality of coils are in a parallel configuration, and in a third switch configuration some of the plurality of coils are in a series configuration and other coils of the plurality are in a parallel configuration;

a controller configured to control a conduction state of each of the one or more switches; and

first and second power terminals in electrical communication with the plurality of coils through which a power signal flows.

2. The power transmission circuit of claim 1, wherein the plurality of coils overlap one another and are substantially centered with one another to thereby concentrate a magnetic field in a first direction towards the receiving device.

3. The power transmission circuit of claim 2, wherein each coil corresponds to a single loop of conductive material that is disposed on a different layer of a printed circuit board.

4. The power transmission circuit of claim 1, wherein the controller is configured to determine an amount of power delivered to the receiving device.

5. The power transmission circuit of claim 4, wherein the controller determines the amount of power delivered based on a phase difference between a voltage and current phase of the power signal.

6. The power transmission circuit of claim 4, wherein the controller determines the amount of power delivered to the receiving device based on a signal received from the receiving device indicative of an amount of power received at the receiving device.

7. The power transmission circuit of claim 4, wherein when the power delivered is below a threshold, the controller is configured to control the conduction state of the plurality of switches to maximize power delivery.

8. The power transmission circuit of claim 7, wherein the controller is configured to control the conduction state of the plurality of switches to connect the plurality of coils into a series configuration to maximize power delivery.

9. The power transmission circuit of claim 4, wherein when the power delivered is at or above a threshold, the controller is configured to control the conduction state of the plurality of switches to maximize a power efficiency of the power transmission circuit.

10. The power transmission circuit of claim 9, wherein the controller is configured to control the conduction state of the plurality of switches to connect at least some of the plurality of coils into a parallel configuration to maximize power efficiency.

11. The power transmission circuit of claim 1, wherein a shape of the plurality of coils defines two or more lobed regions in which a magnetic field generated by the plurality of coils is concentrated.

21. A system that includes a charging station and a device to be charged in the charging station, wherein at least one of the charging station and the device to be charged comprises the circuit of claim 1.

12. A method for wirelessly communicating power to a receiving device, the method comprising:

coupling respective ends of different coils of a plurality of coils together in one of a series configuration, parallel configuration, or combination thereof to form a first configuration;

determining an amount of power delivered to the receiving device;

coupling the respective ends of different coils of the plurality of coils together in one of a series configuration, parallel configuration, or combination thereof to form a combination different than the first configuration based on the determined amount of power.

13. The method for wirelessly communicating power of claim 12, wherein the plurality of coils overlap one another and are substantially centered with one another to thereby concentrate a magnetic field in a first direction towards the receiving device.

14. The method for wirelessly communicating power of claim 13, wherein each coil corresponds to a single loop of conductive material that is disposed on a different layer of a printed circuit board.

15. The method for wirelessly communicating power of claim 12, further comprising determining the amount of power delivered based on a phase difference between a voltage and current phase of the power signal.

16. The method for wirelessly communicating power of claim 12, further comprising determining the amount of power delivered to the receiving device based on a signal received from the receiving device indicative of an amount of power received at the receiving device.

17. The method for wirelessly communicating power of claim 12, wherein when the power delivered is determined to be below a threshold, the method further comprising coupling respective ends of different coils of the plurality of coils together to form a configuration that maximizes power delivery.

18. The method for wirelessly communicating power of claim 17, wherein the respective ends of the plurality of coils are coupled together to form a series configuration to maximize power delivery.

19. The method for wirelessly communicating power of claim 12, wherein when the power delivered is determined to be at or above a threshold, the method further comprising coupling respective ends of different coils of the plurality of coils together to form a configuration that maximizes power efficiency.

20. The method for wirelessly communicating power of claim 18, wherein the respective ends of the plurality of coils are coupled together so that at least some of the plurality of coils are coupled together in a parallel configuration to maximize power efficiency.