Bus-powered computer peripheral with supplement battery power to overcome bus-power limit

• US 6,357,011 B2
• Filed: 07/15/1998
• Issued: 03/12/2002
• Est. Priority Date: 07/15/1998
• Status: Expired due to Term

• Current Assignee: Gateway Incorporated (Acer, Inc.)
• Original Assignee: Gateway Incorporated (Acer, Inc.)
• Inventors: Gilbert, Timothy G.
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Jean, Frantz B.
• Application Number:
  US09/115,843
• Publication Number:
  US 20010003205A1
• Time in Patent Office: 1,336 Days
• Field of Search: 713/300, 713/310, 713/320, 709/238, 702/122, 326/34, 400/88
• 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

Abstract

A computer system typically includes a central computer and several peripherals, such as a mouse and a printer, which communicate with the computer via a communications channel known as a serial bus. The serial bus may also supply a limited amount of power to some peripherals. Unfortunately, the power limit compels high-power peripherals to include independent power supplies, an arrangement which increase their complexity and cost. Accordingly, one embodiment of the present invention provides a bus-powered peripheral that includes a controller, a rechargeable battery, and a voltage regulator or recharge circuit. The recharge circuit monitors data on a serial bus, recharges the battery during inactive periods, and allows the battery to supplement bus power during active periods, thereby overcoming the power limit of the serial bus.

Claims

1. A system comprising:

a computer;

a bus having at least a pair of data lines for communicating data and at least a pair of power lines for supplying power according to a predetermined power limit; and

a peripheral coupled to the computer via the bus to receive data and power, the peripheral including;

a rechargeable battery;

a communications port having two power terminals for coupling to the pair of power lines and having two data terminals for coupling to the pair of data lines;

a voltage regulator coupled to the power terminals and the rechargeable battery;

a primary-function module coupled to the voltage regulator; and

a controller coupled to at least one of the two data terminals and to the voltage regulator, the controller responsive to signals at the data terminals, indicating an inactive period, to switch the voltage regulator to a charge mode during which it charges the rechargeable battery and responsive to signals at the data terminals, indicating an active period, to switch the voltage regulator to a battery supply mode during which it transfers energy from the rechargeable battery and from the power lines to the primary-function module, thereby providing the primary-function module power in excess of the predetermined power limit.

2. The computer peripheral of claim 1, wherein the primary-function module includes components of a printer, scanner, fax machine, or speaker.

3. A system comprising:

a computer for processing data;

a bus, coupled to the computer, for communicating data;

a power supply for supplying a limited amount of power;

power-extension means, coupled to the computer via the bus and to the power supply and including a supplemental power source, for supplying more than the limited amount of power; and

a computer peripheral coupled to the bus via the power-extension means to receive power concurrently from the power supply and the supplemental power source, and thus able to receive more than the limited amount of power.

4. The system of claim 3, wherein the power supply is part of the computer.

5. The system of claim 3, wherein the supplemental power source comprises a rechargeable battery and the power-extension peripheral further comprises:

a power terminal coupled to the power supply;

a data terminal coupled to the computer to receive signals;

a voltage regulator coupled to the power terminal and the rechargeable battery, and having an output terminal coupled to the computer peripheral; and

a controller coupled to the voltage regulator and responsive to signals at the data terminal to switch the voltage regulator between a charge mode that connects the rechargeable battery to the power terminal for recharge and a supply mode that connects the rechargeable battery and the power terminal to the output terminal for supplying power concurrently from both the battery and power supply to the computer peripheral.

6. A method of operating a computer peripheral connected to a computer via a bus having a predetermined nominal power limit, the method comprising:

transferring power and data via the bus to the computer peripheral;

operating at least a part of the peripheral with power transferred via the bus; and

charging a battery with at least a portion of the power transferred via the bus; and

concurrently supplying first and second amounts of power to the part of the peripheral, with the first amount transferred via the bus and the second amount derived from the charged battery, and with a sum of the first and second amounts exceeding the nominal power limit.

7. The method of claim 6, wherein operating at least a part of the peripheral and charging the charging the battery occur concurrently.

8. An apparatus comprising:

a peripheral device for communicating with a host device via a peripheral device bus, the peripheral device being capable of communicating with the host device via the peripheral device bus and further being capable of receiving operational power via the peripheral device bus; and

a controller for causing a battery to be charged via the peripheral device bus during a lower power consuming period of the peripheral device, the controller causing the battery to provide supplemental power to the peripheral device in the event the peripheral device requires operational power at a level greater than a specified power limit of the peripheral device bus.

9. An apparatus as claimed in claim 8, wherein while being charged via the peripheral bus, the battery is charged at a rate within the specified power limit of the peripheral device bus.

10. An apparatus as claimed in claim 8, wherein while the peripheral device requires operational power greater than the limit of the peripheral device bus, the battery and the peripheral device bus simultaneously provide operational power to the peripheral device without causing the peripheral device bus to provide power at a level greater than the limit of the peripheral device bus.

11. An apparatus as claimed in claim 8, the peripheral device being capable of operating at a power level greater than the limit of the peripheral device bus without causing the peripheral device bus to provide power beyond the limit by receiving supplemental power from the battery.

12. An apparatus as claimed in claim 8, the controller causing the battery to cease providing supplemental power to the peripheral device in the event the peripheral device requires operational power at a level within the limit of the peripheral device.