Method and apparatus for charging a self powered USB device at different charge rates according to the charge level of a rechargeable element on the device

• US 6,665,801 B1
• Filed: 01/27/2000
• Issued: 12/16/2003
• Est. Priority Date: 01/27/2000
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Weiss, Martin M.
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): YANCHUS III, PAUL B
• Application Number:
  US09/492,468
• Time in Patent Office: 1,419 Days
• Field of Search: 320/116, 320/125, 320/135, 320/136, 320/149, 320/159, 320/164, 709/202, 429/300, 713/300, 713/310, 713/320, 713/340
• 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: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3253 Power saving in bus
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A Universal Serial Bus (USB) remote hub or function device is provided that includes a large energy well (e.g. rechargeable device such as a battery or large capacitor) for providing the required power to peripherals when the peripheral device requires more power than the USB allows. The large energy well or rechargeable device shall charge using current drawn from the USB bus and terminate charge by the controller or discrete circuitry provided on the remote hub or function. The rechargeable device shall draw current from the USB at a maximum of 100 ma during power up and may enter a high power bus powered mode, so that it can draw the maximum 500 ma of current provided by the USB. The rechargeable device will turn off or draw a sleep current of less than 500 pa when the USB is placed in a suspend state. The device may optionally be configured to provide remote wake up functionality to provided support to the USB power management to allow recharging to resume.

Claims

1. A remote function device coupleable to a host computer through a Universal Serial Bus port, comprising;

a function controller coupleable to the host computer;

a mode and status system coupled to the function controller; and

a rechargeable device coupled to the mode and status system and a peripheral device, the rechargeable device adapted to drive the peripheral device, wherein the rechargeable device draws current from the Universal Serial Bus to charge the rechargeable device to a predetermined level for driving the peripheral device, the predetermined charge level exceeding a charge level that can be provided by the Universal Serial Bus directly.

2. The device of claim 1, wherein the rechageable device draws current at a low charge rate during power up and then is reconfigured to draw current at a high charge rate after power up.

3. The device of claim 1, wherein the rechargeable device draws current at a high charge rate until the rechargeable device reaches a predetermined charge level for the high rate wherein the rechargeable device draws current at a low charge rate.

4. The device of claim 3, wherein the rechargeable device stops charging at the low charge rate upon reaching a predetermined charge level for the low charge rate.

5. The device of claim 4, wherein the current drawn by the rechargeable device at the high charge rate is greater than 100 milliamps and less than 500 milliamps.

6. The device of claim 1, wherein the mode and status system is discrete system that operates to monitor the charge level of the rechargeable device and operates to alternate the charging mode of the rechargeable device in response to different charge levels of the rechargeable device.

7. The device of claim 1, wherein the mode and status system includes a status system that monitors the charge level of the rechargeable device and provides this information to the function controller and a mode system which is controlled by the function controller and operates to charge the charging mode of the rechargeable device.

8. The device of claim 1, wherein the device is configured with remote wake up capabilities.

9. The device of claim 8, wherein the device wakes up from a suspended state and sends a remote wake up signal to the host computer when the high powered peripheral device draws current from the rechargeable device.

10. The device of claim 1, wherein the rechargeable device is a battery.

11. A remote hub device coupleable to a host computer through a Universal Serial Bus port, comprising;

a hub controller coupleable to the host computer;

a mode and status system coupled to the hub controller; and

a rechargeable device coupled to the mode and status system and adapted to provide current to at least four power ports, each port limiting the current, wherein the rechargeable device draws current from the Universal Serial Bus to charge the rechargeable device to a predetermined level for providing the current to the at least four power ports.

12. The device of claim 11, wherein the rechargeable device draws current at a low charge rate during power up and then is reconfigured to draw current at a high charge rate after power up.

13. The device of claim 11, wherein the rechargeable device draws current at a high charge rate until the rechargeable device reaches a predetermined charge level for the high charge rate wherein the rechargeable device draws current at a low charge rate.

14. The device of claim 13, wherein the rechargeable device stops charging at the low charge rate upon reaching a predetermined charge level for the low charge rate.

15. The device of claim 14, wherein the current drawn by the rechargeable device at the high charge rate is greater than 100 milliamps and less than 500 milliamps.

16. The device of claim 11, wherein the mode and status system is a discrete system that operates to monitor the charge level of the rechargeable device and operates to alternate the charging mode of the rechargeable device in response to different charge levels of the rechargeable device.

17. The device of claim 11, wherein the mode and status system includes a status system that monitors the charge level of the rechargeable device and provides this information to the hub controller and a mode system which is controlled by the hub controller and operates to change the charging mode of the rechargeable device.

18. The device of claim 11, wherein the device is configured with remote wake up capabilities.

19. The device of claim 18, wherein the device wakes up from a suspended state and sends a remote wake up signal to the host computer when the high powered peripheral device draws current from the rechargeable device.

20. The device of claim 11, wherein the rechargeable device is a battery.

21. A method of charging a rechargeable device on a Universal Serial Bus device coupled to a host computer comprising the steps of;

initializing the Universal Serial Bus device in a low charge rate;

configuring the Universal Serial Bus device to operate in a high power bus powered mode; and

charging the rechargeable device at a high charge rate until the rechargeable device reaches a predetermined charge level for the high charge rate; and

charging the device at a low charge rate until the rechargeable device reaches a predetermined charge level for the low charge rate.

22. The method of claim 21, further including the step of monitoring the rechargeable device after the step of charging the device at a low charge rate to determined if the rechargeable device falls below a predetermined charge level for driving a high powered peripheral device.

23. The method of claim 22, further including the step of charging the rechargeable device at a high charge rate until the rechargeable device reaches a predetermined charge level for the high charge rate, if the rechargeable device falls below the predetermined charge level for driving the high pow peripheral device.

24. The method of claim 21, further including the step of monitoring the Universal Serial Bus for lack of activity and charging the rechargeable device at a trickle charge rate upon detection of no activity on the Universal Serial Bus for a predetermined amount of time.

25. The method of claim 24, further including the step of configuring the Universal Serial Bus device as a remote wake up device and configuring the device to operate in a high trickle charge mode for charging the rechargeable device at a high trickle charge rate upon detection of no activity on the Universal Serial Bus for a predetermined amount of time.

26. The method of claim 25, further including the step of monitoring a high powered peripheral device driven by the rechargeable device to determine if the high powered peripheral device is running, and waking up the Universal Serial Bus device upon detection that the high powered peripheral device is running.

27. The method of claim 21, further including the step of monitoring a high powered peripheral device driven by the rechargeable device to determine if the high powered device is running and putting the rechargeable device in the high powered peripheral device running mode if the high powered peripheral device is running.

28. The method of claim 27, further including the step of monitoring the charge level of the rechargeable device to determine if the charge level is low for driving the high powered peripheral device and sending a warning signal to the host computer if the charge level is low for driving the high powered peripheral device.

29. A remote Universal Serial Bus device coupleable to a host computer through a Universal Serial Bus port, comprising,

means for powering a high powered peripheral device, the means for powering the high powered peripheral device being rechargeable and connected to the high powered peripheral device;

means for monitoring the charge level of the means for powering the high powered peripheral device;

means for changing the charge level of the means for powering the high powered peripheral device; and

means for controlling the configuration of the Universal Serial Bus device which communicates this to the remote host computer wherein the means for controlling the configuration of the Universal Serial Bus device configures the Universal Serial Bus device as a high power bus powered device after power up.

30. The device of claim 29, wherein the means for monitoring determines when the means for powering the high powered peripheral device reaches a predetermined charge level for a high charge rate wherein the means for changing the charge level of the means for powering the high powered peripheral device changes the charge level of the means for powering to a low charge rate.

31. A remote function device coupleable to a host computer through a Universal Serial Bus port, comprising;

a function controller coupleable to the host computer;

a mode and status system coupled to the function controller; and

a rechargeable device coupled to the mode and status system and adapted to drive a high powered function device wherein the rechargeable device draws more than 100 ma and less than 500 ma of current from the Universal Serial Bus to charge the rechargeable device to a predetermined charge level for a high charge rate, then the rechargeable device draws less than 100 ma until the rechargeable device reaches a predetermined charge level for a low charge rate wherein the rechargeable device stops charging at the low charge rate upon reaching the predetermined charge level for the low charge rate.

32. The device of claim 31, wherein the mode and status system operates to monitor the charge level of the rechargeable device and operates to alternate the charging mode of the rechargeable device in response to different charge levels of the rechargeable device.

33. The device of claim 31, wherein the mode and status system monitors the charge level of the rechargeable device and provides this information to the function controller.

34. The device of claim 31, wherein the device is configured with remote wake up capabilities.

35. The device of claim 34, wherein the device wakes up from a suspended state and sends a remote wake up signal to the host computer when the high powered peripheral device draws current from the rechargeable device.

36. The device of claim 31, wherein the rechargeable device is a battery.