System and method for facilitating avoidance of wireless charging cross connection

• US 9,660,478 B2
• Filed: 09/17/2013
• Issued: 05/23/2017
• Est. Priority Date: 12/12/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William H., Kallal, Edward
• Primary Examiner(s): Tat, Binh
• Application Number:
  US14/029,689
• Publication Number:
  US 20140159653A1
• Time in Patent Office: 1,344 Days
• Field of Search: 320107-115
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A system and method for charging a chargeable device is provided. The system can include a wireless charger including a wireless power antenna and a wireless power transmitter coupled to the wireless power antenna and configured to generate a wireless charging field in at least one charging region. The wireless charging field includes a plurality of power signals. The wireless charger further includes a communication antenna and a transceiver coupled to the communication antenna and configured to communicate with the chargeable device via the communication antenna. The wireless charger further includes a controller configured to facilitate avoidance of cross connection of the chargeable device with the wireless charger and at least one other wireless charger in which the chargeable device receives power from the wireless power transmitter of the wireless charger while communicating with at least one other wireless charger. The system can include a chargeable device including a controller configured to generate a load pulse configured to be received by the wireless charger.

Claims

1. A wireless charger for charging a chargeable device, the wireless charger comprising:

a wireless power transmitter configured to generate a wireless charging field in at least one charging region;

a transceiver configured to communicate with the chargeable device; and

a controller configured to detect an impedance change at the wireless power transmitter due to the chargeable device and to use the detected impedance change to facilitate avoidance of cross connection of the chargeable device in which the chargeable device receives power from the wireless power transmitter while communicating with at least one other wireless charger or in which the chargeable device receives power from the at least one other wireless charger while communicating with the transceiver.

2. The wireless charger of claim 1, wherein the controller is further configured to generate a plurality of power signals by modulating the wireless charging field by an amplitude that is sufficiently low so as to not affect power transmission but sufficiently high to be detected by the chargeable device.

3. The wireless charger of claim 2, wherein the controller is configured to modulate the wireless charging field in a pattern that is unique to the wireless charger.

4. The wireless charger of claim 1, wherein the controller is configured to accept out-of-band communication signals from the chargeable device during a predetermined period of time after the controller detects the impedance change at the wireless power transmitter being greater than a predetermined amount.

5. The wireless charger of claim 1, wherein the controller is configured to not accept out-of-band communication signals for a period of time if the controller does not detect an impedance change at the wireless power transmitter being greater than a predetermined amount.

6. The wireless charger of claim 1, wherein the controller is further configured to detect whether a load pulse from the chargeable device and an advertisement from the chargeable device are concurrent with one another.

7. The wireless charger of claim 6, wherein the load pulse comprises an AC side impedance modulation.

8. The wireless charger of claim 6, wherein the load pulse comprises a DC side impedance modulation.

9. The wireless charger of claim 6, wherein, upon detecting a load pulse but not an advertisement from the chargeable device, the controller is further configured to extend a beacon mode time period.

10. The wireless charger of claim 6, wherein the load pulse comprises a single pulse of impedance modulation.

11. The wireless charger of claim 6, wherein the load pulse comprises a train of pulses or a tone burst of impedance modulation.

12. The wireless charger of claim 1, wherein the controller is further configured to communicate with the at least one other wireless charger.

13. The wireless charger of claim 12, wherein the wireless power transmitter transfers power to the chargeable device if the transceiver has a larger received signal strength indication (RSSI) than does the at least one other wireless charger.

14. The wireless charger of claim 1, wherein the at least one charging region comprises a plurality of charging regions.

15. The wireless charger of claim 1, wherein the controller is configured to establish a communication link with the chargeable device if the transceiver has received an out-of-band communication signal having a received signal strength indication (RSSI) larger than a predetermined threshold and the controller detects the impedance change within a predetermined period of time of the out-of-band communication signal.

16. The wireless charger of claim 1, wherein the controller is configured to establish a communication link with the chargeable device if the transceiver has received an out-of-band communication signal having a received signal strength indication (RSSI) larger than a predetermined first threshold and the controller detects that the impedance change is larger than a predetermined second threshold and within a predetermined period of time of the out-of-band communication signal.