WIRELESS POWER TRANSFER USING A FIELD ALTERING CIRCUIT

• US 20160352147A1
• Filed: 03/21/2016
• Published: 12/01/2016
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William Henry III, Kallal, Edward Kenneth, Wheeland, Cody Burton, Jeong, Seong Heon
• Granted Patent: US 10,224,753 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A wireless power transmitter includes a power transmit coil configured to generate a magnetic field for wirelessly coupling charging power to one or more receiver devices, the magnetic field having a magnetic field distribution over an area defining a charging region, a circuit configured to alter the magnetic field generated by the power transmit coil to alter the magnetic field distribution, and a controller operably coupled to the circuit, the controller configured to control the circuit to alter the magnetic field distribution responsive to a detected characteristic of the one or more receiver devices.

Claims

1. A wireless power transmitter, comprising:

a power transmit coil configured to generate a magnetic field for wirelessly coupling charging power to one or more receiver devices, the magnetic field having a magnetic field distribution over an area defining a charging region;

a circuit configured to alter the magnetic field generated by the power transmit coil to alter the magnetic field distribution; and

;

a controller operably coupled to the circuit, the controller configured to control the circuit to alter the magnetic field distribution responsive to a detected characteristic of the one or more receiver devices.

2. The wireless power transmitter of claim 1, wherein the controller is configured to control the circuit to selectively amplify the magnetic field to alter the magnetic field distribution within at least a portion of the charging area responsive to the detected characteristic such that the magnetic field distribution is less uniform than the magnetic field distribution when the circuit is not activated.

3. The wireless power transmitter of claim 2, wherein the circuit is configured to operate as a resonant circuit.

4. The wireless power transmitter of claim 1, wherein the controller is configured to control the circuit to selectively attenuate the magnetic field to alter the magnetic field distribution within at least a portion of the charging area responsive to the detected characteristic such that the magnetic field distribution is more uniform than the magnetic field distribution when the circuit is not activated.

5. The wireless power transmitter of claim 4, wherein the circuit is configured to operate as a short circuit.

6. The wireless power transmitter of claim 1, wherein the magnetic field distribution is substantially constant over the charging region and wherein the controller is configured to control the circuit to one of selectively amplify the magnetic field and selectively attenuate the magnetic field to alter the magnetic field distribution responsive to the detected characteristic.

7. The wireless power transmitter of claim 1, wherein the power transmit coil comprises a plurality of coil segments and the circuit is located adjacent one of the plurality of coil segments of the power transmit coil.

8. The wireless power transmitter of claim 1, wherein the power transmit coil comprises a plurality of coil segments and the circuit is connected to one of the plurality of coil segments of the power transmit coil.

9. The wireless power transmitter of claim 1, wherein the power transmit coil comprises a plurality of antenna coil segments having a first antenna coil segment and a second antenna coil segment arranged at a periphery of the power transmit coil and a third antenna coil segment arranged at a center of the power transmit coil and the circuit is connected to the third antenna coil segment.

10. The wireless power transmitter of claim 9, wherein the circuit connected to the third antenna coil segment is configured to selectively amplify the magnetic field toward the center of the power transmit coil.

11. The wireless power transmitter of claim 9, wherein the circuit connected to the third antenna coil segment is configured to selectively attenuate the magnetic field toward the center of the power transmit coil.

12. A device for generating a magnetic field having a magnetic field distribution over an area defining a charging region for wirelessly charging or powering one or more receiver devices, comprising:

means for detecting a characteristic of one or more receiver devices indicative of an amount or efficiency of wirelessly coupling charging power via the magnetic field generated by the device; and

means for altering the magnetic field to alter the magnetic field distribution within the charging region in response to the detecting means.

13. The device of claim 12, wherein the means for altering the magnetic field further comprises means for selectively amplifying the magnetic field within at least a portion of the charging area such that the magnetic field distribution is less uniform than the magnetic field distribution when the means for altering the magnetic field is not activated.

14. The device of claim 13, further comprising means for operating a resonant circuit in a vicinity of the magnetic field.

15. The device of claim 12, wherein the means for altering the magnetic field further comprises means for selectively attenuating the magnetic field within at least a portion of the charging area such that the magnetic field distribution is more uniform than the magnetic field distribution when the means for altering the magnetic field is not activated.

16. The device of claim 15, further comprising means for operating a short circuit in a vicinity of the magnetic field.

17. A method of operating a wireless power transmitter apparatus configured to generate a magnetic field having a magnetic field distribution over an area defining a charging region for wirelessly charging or powering one or more receiver devices, the method comprising:

detecting a characteristic of one or more receiver devices indicative of an amount or efficiency of wirelessly coupling charging power via the magnetic field generated by the wireless power transmitter apparatus; and

altering the magnetic field to alter the magnetic field distribution within the charging region in response to detecting the characteristic.

18. The method of claim 17, wherein the method further comprises selectively amplifying the magnetic field within at least a portion of the charging area responsive to the characteristic of the one or more receiver devices such that the magnetic field distribution is less uniform than the magnetic field distribution when the magnetic field is not altered.

19. The method of claim 18, wherein altering the magnetic field further comprises operating a resonant circuit in a vicinity of the magnetic field.

20. The method of claim 17, wherein the method further comprises selectively attenuating the magnetic field within at least a portion of the charging area responsive to the characteristic of the one or more receiver devices such that the magnetic field distribution is more uniform than the magnetic field distribution when the magnetic field is not altered.

21. The method of claim 20, wherein altering the magnetic field further comprises operating a short circuit in a vicinity of the magnetic field.

22. The method of claim 17, wherein the method further comprises one of selectively amplifying the magnetic field and selectively attenuating the magnetic field within at least a portion of the charging area responsive to the characteristic of the one or more receiver devices such that the magnetic field distribution is different than the magnetic field distribution when the magnetic field is not altered.

23. The method of claim 17, wherein altering the magnetic field to alter the magnetic field distribution comprises altering the magnetic field corresponding to a first magnetic field distribution or altering the magnetic field corresponding to a second magnetic field distribution, different from the first magnetic field distribution.

24. The method of claim 23, wherein the first magnetic field distribution corresponds to a substantially uniform field distribution over the charging region.

25. The method of claim 24, wherein the second magnetic field distribution comprises a distribution where a central portion of the charging area has a magnetic field with a magnitude higher than an outer portion outside the central portion.

26. The method of claim 17, wherein detecting the characteristic comprises receiving a message from the one or more receiver devices.

27. The method of claim 17, wherein the characteristic to be detected comprises at least one of a number of the one or more receiver devices present in the charging region at a given point in time, or an amount of power being received by the one or more receiver devices, or an amount of coupling between the transmitter apparatus and the one or more receiver devices, or a power requirement of the one or more receiver devices, or an amount of metal within the one or more receiver devices, or a size of the one or more receiver devices, or any combination thereof.

28. An apparatus for wireless power transfer, comprising:

a housing having a surface configured for direct or indirect placement of one or more receiver devices, the surface defining a charging region for wirelessly charging the one or more receiver devices;

a power transmit coil configured to generate a magnetic field within the charging region for wirelessly coupling charging power to the one or more receiver devices, the magnetic field having a magnetic field distribution within the charging region; and

a circuit configured to alter the magnetic field generated by the power transmit coil to alter the magnetic field distribution within the charging region.

29. The apparatus of claim 28, wherein the circuit comprises a field altering coil and is at least partially enclosed by the power transmit coil.

30. The apparatus of claim 29, wherein the circuit is configured to selectively alter the magnetic field distribution between two different field distributions.

31. The apparatus of claim 30, wherein a first field distribution of the two different field distributions is substantially uniform over the charging region, and wherein a second field distribution of the two different field distributions is substantially non-uniform over the charging region.

32. The apparatus of claim 31, wherein the second, substantially non-uniform, field distribution has a peak in a center portion of the charging region.