Wireless power utilization in a local computing environment

• US 10,199,873 B2
• Filed: 09/28/2016
• Issued: 02/05/2019
• Est. Priority Date: 11/17/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Culbert, Michael F., Bilbrey, Brett C., Simon, David I., Arnold, Peter M.
• Primary Examiner(s): Bae, Ji H
• Application Number:
  US15/279,367
• Publication Number:
  US 20170018972A1
• Time in Patent Office: 860 Days
• Field of Search: 713300, 307104, 455 411, 320108
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Various embodiments of a wirelessly powered local computing environment are described. The wireless powered local computing environment includes at least a near field magnetic resonance (NFMR) power supply arranged to wirelessly provide power to any of a number of suitably configured devices. In the described embodiments, the devices arranged to receive power wirelessly from the NFMR power supply must be located in a region known as the near field that extends no further than a distance D of a few times a characteristic size of the NFMR power supply transmission device. Typically, the distance D can be on the order of 1 meter or so.

Claims

1. A method of wirelessly distributing power, comprising:

at a wireless power supply, establishing a first power transmission channel with a first accessory device and transmitting power to the first accessory device over the first power transmission channel;

at the wireless power supply, sensing first and second characteristic load factors that are respectively associated with at least the first accessory device and a second accessory device;

at the first accessory device, establishing a second power transmission channel with the second accessory device in response to at least one of the first and second characteristic load factors changing in a manner that indicates that the second accessory device is not able to receive adequate power directly from the wireless power supply; and

at the first accessory device, transmitting power to the second accessory device over the second power transmission channel.

2. The method of claim 1, wherein the power transmitted by the first accessory device to the second accessory device over the second power transmission channel includes at least a portion of the power transmitted by the wireless power supply to the first accessory device over the first power transmission channel.

3. The method of claim 1, further comprising:

at a resonant circuit in the first accessory device, tuning to at least one of a plurality of power transmission frequency bands supported by the wireless power supply.

4. The method of claim 1, further comprising:

at the wireless power supply, establishing a third power transmission channel with the second accessory device;

establishing a communication channel between the first and second accessory devices.

5. The method of claim 4, wherein the establishing the communication channel comprises:

selectively tuning and detuning the first and second accessory devices on the second power transmission channel according to an encoding pattern.

6. The method of claim 1, further comprising:

at the wireless power supply, establishing a third power transmission channel with the second accessory device;

at wireless power supply, receiving an indication that a power transfer efficiency metric for at least one of the first and second accessory devices has fallen below a usable threshold.

7. The method of claim 6, further comprising:

in response to receiving the indication, adjusting a resonance frequency associated with at least one of the first and second power transmission channels until the power transfer efficiency metric has risen to at least the usable threshold.

8. The method of claim 6, wherein the indication that the power transfer efficiency metric has fallen below the usable threshold is for the first accessory device, the method further comprising:

in response to receiving the indication, directing the second accessory device to detune from the third power transmission channel.

9. The method of claim 6, further comprising:

in response to receiving the indication, altering at least one of the phase, frequency, and amplitude of a power transmission signal associated with one of the first and third power transmission channels.

10. The method of claim 1, further comprising:

at the first accessory device, selectively tuning and detuning a resonant circuit to a resonance frequency associated with the first power transmission channel according to a communications protocol.

11. The method of claim 10, further comprising:

at the wireless power supply, detecting changes in the first characteristic load factor caused by the selective tuning and detuning of the resonant circuit in the first accessory device to receive communications from the first accessory device.

12. The method of claim 10, wherein the selective tuning and detuning of the resonant circuit to the resonance frequency associated with the first power transmission channel comprises:

encoding information at the first accessory device according to the communications protocol; and

performing the selective tuning and detuning of the resonant circuit based on the encoding of the information.

13. The method of claim 12, wherein the information comprises at least one of a device identifier, a synchronization flag, a charge state, and a power requirement indication.

14. A system for wirelessly distributing power, comprising:

a wireless power supply;

a first accessory device that is coupled to the the wireless power supply over a first power transmission channel and that has power receiving circuitry configured to receive power from the wireless power supply over the first power transmission channel; and

a second accessory device that is coupled to the first accessory device over a second power transmission channel, and that has power receiving circuitry configured to receive power over the second power transmission channel in response to a change in a load state associated with at least one of the first and second accessory devices that indicates that the second accessory device is unable to receive adequate power from the wireless power supply.

15. The system defined in claim 14, wherein the power received at the power receiving circuitry in the second accessory device from the first accessory device is at least partly comprised of power received by the first accessory device from the wireless power supply.

16. The system defined in claim 14, wherein the first accessory device has a characteristic load state associated with being tuned to the first power transmission channel and selectively tunes and detunes to the first power transmission channel, wherein the wireless power supply detects the changes in the characteristic load state of the first accessory device, and wherein the changes in the characteristic load state communicate encoded information from the first accessory device to the wireless power supply.

17. A computing device, comprising:

a processor;

a wireless power supply; and

memory storing instructions that when executed by the processor, cause the wireless power supply to perform the steps of;

establishing a first power transmission channel with a first accessory device and transmitting power to the first accessory device over the first power transmission channel;

sensing first and second characteristic load factors that are respectively associated with at least the first and second accessory devices;

directing the first accessory device to establish a second power transmission channel with the second accessory device in response to detecting a change in at least one of the first and second characteristic load factors that indicates that the second accessory device is unable to receive adequate power directly from the wireless power supply; and

directing the first accessory device to wirelessly transmit power to the second accessory device over the second power transmission channel.

18. The computing device of claim 17, wherein the steps further comprise:

receiving communications from the first accessory device based on changes in the first characteristic load factor sensed at the wireless power supply.

19. The computing device of claim 18, wherein receiving the communications from the first accessory device comprises:

interpreting changes to the first characteristic load factor in accordance with a predetermined communications protocol.