Wireless power transfer

• US 9,444,270 B2
• Filed: 08/02/2012
• Issued: 09/13/2016
• Est. Priority Date: 08/02/2012
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Xing, Rongzhi, Stevens, Gregory Louis
• Primary Examiner(s): Wells, Kenneth B
• Assistant Examiner(s): Evans, James P
• Application Number:
  US13/565,429
• Publication Number:
  US 20140035379A1
• Time in Patent Office: 1,503 Days
• Field of Search: 301/104, 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence

Abstract

Systems and methods are disclosed that enable power regulation during wireless power transfer, such as during magnetic resonance (MR) charging of one or more devices from a power transfer device, by applying a cascading charging mechanism that includes identifying a priority order of charging of each of the one or more devices to allocate wirelessly transmitted power to the one or more devices.

Claims

1. A method performed by a wireless power transfer device, the method comprising:

applying a cascading charging mechanism to allocate wirelessly transmitted power to one or more wireless devices, wherein applying the cascading charging mechanism comprises, performing;

determining that a percentage of battery charge of each of the one or more wireless devices is at or below a threshold;

identifying a priority order of charging of each of the one or more wireless devices, wherein a first priority order of a first wireless device of the one or more wireless devices is based on a first percentage of battery charge of the first wireless device; and

repeating, according to the priority order, for each particular wireless device of the one or more wireless devices other than a lowest-priority wireless device;

determining an amount of remaining power available for wireless transfer; and

assigning to the particular wireless device a portion of the remaining power,

wherein the lowest-priority wireless device is assigned a remaining portion of available power.

2. The method of claim 1, further comprising:

receiving, wirelessly, from each particular wireless device of a plurality of wireless devices that includes the one or more wireless devices, an indication of a percentage of battery charge of the particular wireless device; and

determining whether the percentage of battery charge of the particular wireless device is at or below the threshold.

3. The method of claim 2, wherein the cascading charging mechanism is applied in response to determining that a first particular percentage of battery charge of a first particular wireless device of the plurality of wireless devices is at or below the threshold and that a second particular percentage of battery charge of a second particular wireless device of the plurality of wireless devices is at or below the threshold.

4. The method of claim 1, further comprising identifying an amount of total power available for wireless transfer to the one or more wireless devices.

5. The method of claim 4, wherein the remaining power available for wireless transfer to a particular wireless device is determined by subtracting power assigned to each higher-priority wireless device from the total power available for wireless transfer.

6. The method of claim 1, further comprising tuning a power transfer device transmitter to match a frequency of a particular wireless device of the one or more wireless devices to transmit power to the particular wireless device.

7. The method of claim 1, further comprising concurrently transmitting a first portion of power to a first particular wireless device of the one or more wireless devices and a second portion of power to a second particular wireless device of the one or more wireless devices, wherein the first portion of power assigned to the first particular wireless device is larger than the second portion of power assigned to the second particular wireless device.

8. The method of claim 1, further comprising transmitting power via magnetic resonance (MR).

9. The method of claim 1, wherein the portion of the remaining power corresponds to a particular percentage of the amount of the remaining power available for wireless transfer.

10. An apparatus comprising:

a power transfer device including;

a priority module configured to identify a priority order of charging of each of one or more wireless devices; and

a power allocation module configured to;

receive, from each device of a plurality of the wireless devices, an indication of a percentage of battery charge of the wireless device;

apply a cascading charging mechanism to allocate wirelessly transmitted power to the one or more wireless devices;

determine that the percentage of battery charge of at least one of the one or more wireless devices is at or below a threshold;

determine, for each particular wireless device of the one or more wireless devices other than a lowest-priority wireless device, an amount of remaining power available for wireless transfer;

assign to the particular wireless device a portion of the remaining power according to the priority order; and

assign a remaining portion of available power to the lowest-priority wireless device.

11. The apparatus of claim 10, wherein a first priority order of a first wireless device of the one or more wireless devices is based on a type of the first wireless device.

12. The apparatus of claim 11, wherein the cascading charging mechanism is applied in response to determining that a first particular percentage of battery charge of a first particular wireless device of the plurality of the wireless devices is at or below the threshold and that a second particular percentage of battery charge of a second particular wireless device of the plurality of the wireless devices is at or below the threshold.

13. The apparatus of claim 11, wherein the cascading charging mechanism is applied in response to determining that a first particular percentage of battery charge of a first particular wireless device of the plurality of the wireless devices is at or above the threshold and that a second particular percentage of battery charge of a second particular wireless device of the plurality of the wireless devices is at or above the threshold.

14. The apparatus of claim 10, wherein the power allocation module is further configured to identify an amount of total power available for wireless transfer to the one or more wireless devices.

15. The apparatus of claim 14, wherein the remaining power available for wireless transfer to a particular wireless device is determined by subtracting power assigned to each higher-priority wireless device from the total power available for wireless transfer.

16. The apparatus of claim 10, wherein the power allocation module is further configured to select each wireless device of the one or more wireless devices from the plurality of the wireless devices in response to determining that a first particular battery charge of the wireless device is at or below a threshold.

17. The apparatus of claim 10, wherein the power transfer device is configured to transmit power via magnetic resonance (MR).

18. The apparatus of claim 10, further comprising a transmitter configured to transmit power to the one or more wireless devices.

19. The apparatus of claim 18, wherein the power allocation module is further configured to tune the transmitter to match a frequency of a particular wireless device of the one or more wireless devices.

20. The apparatus of claim 10, wherein the portion of the remaining power corresponds to a particular percentage of the amount of the remaining power available for wireless transfer, wherein a first priority order of a first wireless device of the one or more wireless devices is based on a type of the first wireless device, and wherein the type of the first wireless device includes a medical device, a phone, an audio player, or a tablet device.