Controlled charging and use of power source

• US 7,888,907 B2
• Filed: 10/30/2007
• Issued: 02/15/2011
• Est. Priority Date: 10/30/2007
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Litovsky, Roman N., Greenberger, Hal P.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Fantu; Yalkew
• Application Number:
  US11/929,842
• Publication Number:
  US 20090110214A1
• Time in Patent Office: 1,204 Days
• Field of Search: 320/103
• US Class Current: 320/103
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A circuit to supply power to a load incorporates a first power source, a second power source that may be detachable, a power converter and at least one capacitor (capacitive element), where the first power source is capable of powering the load when charged, where the second power source is not capable of powering the load, but the second power source is capable of trickle-charging the first power source at a time when the first power source is not powering the load, where the power converter may impose a limit on a flow of current through the power converter, and where the at least one capacitor may cooperate to temporarily support a flow of additional current that circumvents the power converter at a time when the load attempts to draw a relatively greater amount of current.

Claims

1. An apparatus comprising:

a load;

a first power source capable of providing the electric power required by the load when at least partially charged;

a second power source that is intermittently available, wherein the second power source is unable itself to provide the electric power required by the load, and wherein the second power source is selectively employed to charge the first power source;

a capacitive element; and

a power converter interposed between a pole of the load and the first and second power sources, imposing a limit on an amount of current permitted to flow through a portion of the power converter to thereby limit an amount of current permitted to flow through the load, causing the capacitive element to charge at a time where the load attempts to draw a relatively small amount of current, causing the capacitive element to discharge at a time where the load attempts to draw a relatively large amount of current such that the load is supplied with the relatively large amount of current as the capacitive element discharges, and changing the limit imposed by the power converter in response to receiving a signal indicating an availability of the second power source.

2. The apparatus of claim 1, wherein the intermittent availability of the second power source arises from the second power source being detachable from the remainder of the apparatus, and the signal received by the power converter indicates that the second power source is attached.

3. The apparatus of claim 1, wherein the first power source and the capacitive element are coupled in parallel through the power converter.

4. The apparatus of claim 1, wherein the first power source and the capacitive element are coupled in series to provide the load with electrical power having a voltage that is the sum of the voltages of the capacitive element and the first power source.

5. The apparatus of claim 1, further comprising a power control to control charging of the first power source by the second power source.

6. The apparatus of claim 5, wherein the power control discontinues charging the first power source in response to receiving a signal indicating that the load is drawing power.

7. The apparatus of claim 1, wherein the load alters an amount of power required by the load in response to receiving a signal indicating an availability of the second power source.

8. The apparatus of claim 1, wherein the load alters an amount of power required by the load in response to receiving a signal indicating a changing of the limit imposed by the power converter.

9. The apparatus of claim 1, wherein the power converter is structured to allow current to flow from the capacitive element to the first power source to recharge the first power source at a time where the load draws substantially no power.

10. The apparatus of claim 9, further comprising a power control to control charging of the first power source with power provided by the second power source and the capacitive element.

11. An apparatus comprising:

an amplifier to amplify an audio signal to be output by an acoustic driver, wherein the amplifier changes an amount of power required by the amplifier to amplify the audio signal in response to receiving a signal indicating an availability of electric power to the amplifier;

a first power source capable of providing the electric power required by the amplifier when at least partially charged;

a second power source that is intermittently available, wherein the second power source is unable itself to provide the electric power required by the amplifier, and wherein the second power source is selectively employed to charge the first power source;

a capacitive element; and

a power converter interposed between a pole of the amplifier and the first and second power sources, imposing a limit on an amount of current permitted to flow through a portion of the power converter to thereby limit an amount of current permitted to flow through the load, causing the capacitive element to charge at a time where the load attempts to draw a relatively small amount of current, and causing the capacitive element to discharge at a time where the load attempts to draw a relatively large amount of current such that the load is supplied with the relatively large amount of current as the capacitive element discharges.

12. The apparatus of claim 11, wherein the audio amplifier comprises an audio compressor, and wherein the audio compressor compresses the audio signal amplified by the amplifier in response to receiving a signal indicating an availability of electric power to the amplifier.

13. The apparatus of claim 11, wherein the audio amplifier comprises a gain control, and wherein the gain control reduces a gain employed in amplifying the audio signal in response to receiving a signal indicating an availability of electric power to the amplifier.

14. The apparatus of claim 11, wherein the intermittent availability of the second power source arises from the second power source being detachable from the remainder of the apparatus, and the signal received by the amplifier indicates that the second power source is attached.

15. The apparatus of claim 11, wherein the power converter alters the limit imposed by the power converter in response to receiving a signal indicating an availability of the second power source, and wherein the signal received by the amplifier indicates an altering of the limit imposed by the power converter.

16. A method comprising:

setting a first limit on an amount of current permitted to flow through a portion of a power converter such that a capacitive element is caused to be charged when a load draws a first amount of current through the portion of the power converter and such that the capacitive element is caused to be discharged when the load draws a second amount of current through the portion of the power converter;

awaiting a signal indicating an availability of a detachable power source; and

in response to receiving the signal indicating an availability of a detachable power source, setting a second limit on the amount of current permitted to flow through the portion of the power converter such that the capacitive element is caused to be charged when the load draws a third amount of current through the portion of the power converter and such that the capacitive element is caused to be discharged when the load draws a fourth amount of current through the portion of the power converter, wherein the second limit is higher than the first limit, wherein the third amount of current is larger than the first amount of current, and wherein the fourth amount of current is larger than the second amount of current.

17. The method of claim 16, further comprising:

awaiting a signal indicating a drawing of current by the load;

charging a power source with power from the detachable power source in response to receiving both a signal indicating an availability of the detachable power source and a signal indicating a lack of a drawing of current by the load; and

providing power from both the power source and the detachable power source to the power converter in response to receiving both a signal indicating an availability of the detachable power source and a signal indicating a drawing of current by the load.

18. The method of claim 17, further comprising:

charging the power source with power from the capacitive element in response to receiving a signal indicating a lack of drawing of current by the load; and

coordinating charging of the power source with power source with power from the capacitive element with charging of the power source with power from the detachable power source.

19. The method of claim 16, further comprising changing an amount of current drawn by the load in response to receiving a signal indicating an availability of the detachable power source.

20. The method of claim 16, further comprising changing an amount of current drawn by the load in response to receiving a signal indicating a change between the first limit and the second limit on the amount of current permitted to flow through the portion of the power converter.