Power transfer between devices

• US 8,898,485 B2
• Filed: 07/15/2009
• Issued: 11/25/2014
• Est. Priority Date: 07/15/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Scott, James W., Hodges, Stephen E.
• Primary Examiner(s): Yanchus, III, Paul
• Assistant Examiner(s): Chang, Eric
• Application Number:
  US12/503,605
• Publication Number:
  US 20110016333A1
• Time in Patent Office: 1,959 Days
• Field of Search: 713/300
• US Class Current: 713/300
• 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 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

Power transfer between devices such as laptop computers, mobile phones, personal digital assistants, media players and other devices is described. In an embodiment power transfer is achieved either from a power source at a device or to a power source at that device using a bidirectional power transfer connector. In some embodiments a power management module at the device uses context, models or other information to control factors such as the power transfer direction, duration and amount. In examples, user preferences are taken into account. In an example, the bi-directional power transfer connector is provided as a USB connection or a wireless power transfer connection.

Claims

1. A device comprising:

a processor;

a memory coupled to the processor;

a power source;

a user interface arranged to;

display an availability of other devices having respective power sources from which power can be accessed;

display a current power status of the device; and

display user selectable power transfer preferences that enable a user to define power transfer preferences between the device and the other devices;

at least one bi-directional power transfer connector arranged to enable the device to be connected to another device having a power source;

a power bus linking the power source and the power transfer connector and arranged to enable bi-directional power transfer relative to the power source; and

a power management module connected to the power bus and arranged to control the bi-directional power transfer, the power management module being configured to determine whether to provide a first level of power or a second level of power to a second device, the first level of power being sufficient to power operation of the second device, the second level of power being sufficient to power operation of the second device and charging of a battery of the second device, the determination being based at least in part on whether the battery of the second device is to be charged.

2. A device as claimed in claim 1 wherein the power management module is arranged to control at least one of the:

amount, direction, duration, and type of the power transfer.

3. A device as claimed in claim 1 which further comprises a power transfer protocol engine arranged to enable communication with other devices enabled with the same protocol.

4. A device as claimed in claim 3 wherein the power transfer protocol engine is arranged to enable negotiation with other devices about any of:

amount, direction, duration, type of power transfer between those devices.

5. A device as claimed in claim 3 wherein the power transfer protocol engine is arranged to implement security measures.

6. A device as claimed in claim 3 wherein the processor is arranged to automatically detect the presence of at least one other device having a power source and wherein the power transfer protocol engine is arranged to negotiate potential power transfer with that detected device.

7. A device as claimed in claim 6 wherein the processor is arranged to provide a user interface and wherein the processor is arranged to generate a request at the user interface to request that a user establish a power transfer connection with the detected device on the basis of the negotiation.

8. A device as claimed in claim 1 wherein the power management module is arranged to use at least one of:

power transfer context information;

the user defined preferences;

thresholds;

metrics;

rules;

type of connected device;

battery state.

9. A device as claimed in claim 1 wherein the power management module is arranged to form a model of the other device and to use that model to control the bi-directional power transfer.

10. A device as claimed in claim 1 wherein the power bus and at least one power transfer connector are arranged to be operable when the device is powered down.

11. A device as claimed in claim 1 wherein the power bus, power management module and at least one power transfer connector are arranged to be operable when the device is powered down.

12. A device as claimed in claim 1 wherein the power source is rechargeable and wherein the power management module is arranged to allow charging of the power source up to a target which is less than 100% and to allow transfer of power from the power source up to a maximum of all the power.

13. A device as claimed in claim 1 which further comprises at least one switch arranged to enable or disable the power transfer connector.

14. A device as claimed in claim 1 wherein the power management module uses metrics including determining whether the device is to provide power to at least one of the other devices based at least in part on a determination by the device of whether the device has surplus power to reach an expected next recharge opportunity for the device based on an expected power usage of the device until the expected next recharge opportunity.

15. A portable device comprising:

a processor;

a memory coupled to the processor;

a power source;

a user interface arranged to enable a user to provide user power transfer preferences between the first device and a second device having a power source from which power can be accessed;

at least one bi-directional power transfer connector arranged to enable the first device to be connected to the second device having the power source;

a power bus linking the power source and the power transfer connector and arranged to enable bi-directional power transfer relative to the power source both when the first device is powered on and when the first device is powered down; and

a power management module connected to the power bus and arranged to control the bi-directional power transfer, the power management module being configured to determine whether to provide a first level of power or a second level of power to the first device, the first level of power being sufficient to power operation of the first device, the second level of power being sufficient to power operation of the first device and charging of a battery of the first device, the determination being based at least in part on whether the battery of the first device is to be charged.

16. A portable device as claimed in claim 15 wherein the power management module is arranged to take the user power transfer preferences into account.

17. A portable device as claimed in claim 15 which further comprises at least one switch arranged to enable or disable the power transfer connector.

18. A method at a device having a power source comprising:

using a processor to detect the presence of at least one other device having a power source;

using the processor to assess whether power transfer negotiation with the detected device is possible;

using the processor to display, on a user interface of the device, power transfer preferences, the displayed power transfer preferences being selectable by a user and defining power transfer preferences between the device and the detected device;

using a power management module to make a decision about bi-directional power transfer between the devices on the basis of the user selected power transfer preferences, the decision including a determination of whether to provide a first level of power or a second level of power to a second device, the first level of power being sufficient to power operation of the second device, the second level of power being sufficient to power operation of the second device and charging of a battery of the second device, the determination being based at least in part on whether the battery of the second device is to be charged;

establishing a connection between the detected device and a bi-directional power transfer connector at the device; and

using a power transfer bus to carry out power transfer between the devices.

19. A method as claimed in claim 18 wherein the step of establishing a connection comprises using the processor to generate a request at the user interface of the device, the request being for the user to form a physical connection between the devices.

20. A method as claimed in claim 18 which further comprises using a power transfer protocol engine to carry out power transfer negotiation with the detected device.