Low power detection of wireless power devices

• US 9,853,478 B2
• Filed: 02/17/2011
• Issued: 12/26/2017
• Est. Priority Date: 07/28/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Kevin D, Low, Zhen Ning, Carobolante, Francesco
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Ortiz, Elim
• Application Number:
  US13/030,045
• Publication Number:
  US 20120025624A1
• Time in Patent Office: 2,504 Days
• Field of Search: 307104, 340 1034
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

Exemplary embodiments are directed to detection and validation of wirelessly chargeable devices positioned within a charging region of a wireless power transmitter. A device may include a wireless power transmitter configured detect a change in at least one parameter at the transmitter. The transmitter may further be configured to determine whether at least one valid chargeable device is positioned within a charging region of the transmitter upon detecting the change in the at least one parameter.

Claims

1. A device, comprising:

a wireless power transmitter comprising a controller, the wireless power transmitter being configured to operate in each of a first power state and a second separate power state, the transmitter transmitting at a lower power level in the first power state than in the second power state; and

a detector circuit configured to detect a change in at least one parameter at the wireless power transmitter,

wherein the controller is configured to attempt to establish wireless data communication with at least one valid chargeable device in response to the detector circuit detecting the change in the at least one parameter at the wireless power transmitter;

wherein the controller is further configured to determine whether the at least one valid chargeable device is positioned within a charging region of the wireless power transmitter based at least in part on whether the controller successfully established a wireless data communication link with the at least one valid chargeable device, and

wherein the transmitter is further configured to transition to the first power state in response to the controller determining that the charging region lacks any valid chargeable devices and transition to the second power state in response to the controller determining that the at least one valid chargeable device is positioned within the charging region of the wireless power transmitter.

2. The device of claim 1, the at least one parameter comprising at least one of a current level at the transmitter, a resonant frequency of the transmitter, or an amount of reactance at the transmitter.

3. The device of claim 1, the transmitter further configured to measure an amount of current at a power amplifier of the transmitter.

4. The device of claim 3, the transmitter further configured to reduce a power level of the transmitter prior to measuring the amount of current.

5. The device of claim 1, the transmitter further configured to compare a measured amount of current at an associated power amplifier to a baseline current to detect a change in a current level at the transmitter.

6. The device of claim 1, the controller being further configured to attempt to establish the wireless data communication link upon the detection circuit detecting the change in the at least one parameter.

7. The device of claim 1, the transmitter further configured to initiate a time delay if a current level at the transmitter is substantially equal to a baseline current.

8. The device of claim 7, the transmitter further configured to reduce a power level thereof prior to initiating the time delay.

9. The device of claim 1, the transmitter further configured to set a previously measured current level as a baseline current level if the at least one valid chargeable device is not positioned within the charging region of the transmitter.

10. The device of claim 1, the transmitter including a load sensing circuit configured to measure a current level at a power amplifier within transmit circuitry of the transmitter.

11. The device of claim 1, the at least one parameter comprising an impedance value at the transmitter.

12. A method, comprising:

detecting a change in at least one parameter at a wireless power transmitter;

attempting to establish wireless data communication with at least one valid chargeable device in response to detecting the change in the at least one parameter at the wireless power transmitter;

determining whether the at least one valid chargeable device is positioned within an associated charging region of the wireless power transmitter based at least in part on whether the controller successfully established a wireless data communication link with the at least one valid chargeable device;

operating the transmitter in one of at least a first power state or a second separate power state, the transmitter transmitting at a lower power level in the first power state than in the second power state; and

transitioning the transmitter to the first power state in response to determining that the charging region lacks any valid chargeable devices or transitioning the transmitter to the second power state in response to the controller determining that the at least one valid chargeable device is positioned within the charging region of the wireless power transmitter.

13. The method of claim 12, the detecting comprising detecting a change in at least one of a current level at the transmitter, a resonant frequency of the transmitter, or an amount of reactance at the transmitter.

14. The method of claim 13, the detecting the change in a current level comprising comparing a measured current level to a baseline current level.

15. The method of claim 14, further comprising setting the baseline current level as the measured current level if the at least one valid chargeable device is not positioned within the associated charging region.

16. The method of claim 12, further comprising measuring and storing a baseline current level within the wireless power transmitter.

17. The method of claim 12, further comprising initiating a time delay if a measured current level at the wireless power transmitter is substantially equal to a baseline current.

18. The method of claim 17, further comprising reducing a power level of the wireless power transmitter prior to initiating the time delay.

19. The method of claim 12, the attempting to establish the wireless data communication link with the at least one valid chargeable device being performed upon detecting a change in the current level.

20. The method of claim 12, the detecting comprising detecting a change in an impedance value at the transmitter.

21. A device, comprising:

means for detecting a change in at least one parameter at a wireless power transmitter;

means for attempting to establish a wireless data communication link with at least one valid chargeable device in response to the detection of the change in the at least one parameter;

means for determining whether the at least one valid chargeable device is positioned within an associated charging region of the wireless power transmitter based at least in part on whether the means for attempting to establish a wireless data communication link successfully established the wireless data communication link with the at least one valid chargeable device prior;

means for operating the transmitter in each of a first power state and a second separate power state, the transmitter transmitting at a lower power level in the first power state than in the second power state;

means for transitioning the transmitter to the first power state in response to determining that the charging region lacks any valid chargeable devices; and

means for transitioning the transmitter to the second state in response to determining that the at least one valid chargeable device is positioned within the charging region of the transmitter.

22. The device of claim 21, further comprising means for detecting a change in a current level at the wireless power transmitter.

23. The device of claim 22, the means for detecting a change in the current level comprising means for comparing a measured current level to a baseline current level.

24. The device of claim 21, the means for attempting to establish the wireless data communication link further comprising means for attempting to establish the wireless data communication link with the at least one valid chargeable device upon detecting a change in the current level.