POWER SOURCE SWITCHING UNIT WITH INTEGRATED CHARGING CIRCUIT FOR SELECTIVELY COUPLING AN EXTERNAL POWER SOURCE, A COMPUTER LOAD, AND BATTERIES, FOR PROVIDING TEMPORARY POWER DURING COUPLING, AND FOR CHARGING BATTERIES

• US 6,920,575 B2
• Filed: 01/02/2001
• Issued: 07/19/2005
• Est. Priority Date: 03/22/2000
• Status: Expired due to Fees

• Current Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Odaohhara, Shigefumi
• Primary Examiner(s): Vo, Tim
• Assistant Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US09/753,585
• Publication Number:
  US 20020124192A1
• Time in Patent Office: 1,659 Days
• Field of Search: 713/300, 713/330, 713/340, 714/14, 320/160
• US Class Current: 713/340
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24

Abstract

To obtain a power source switching unit that is capable of cost and size reduction, and also supplying electric power reliably even when external power supply is intercepted, and to obtain a computer that is capable of avoiding shutdown that results from the interception of the external power supply. The power source switching unit is equipped on a power supply line with an AC adapter detection circuit and outputting a #AC-ADAP signal, and a temporary power supply circuit for temporarily supplying electric power to a DC-DC converter when the power supply is intercepted. The switching unit is further equipped with a battery switching circuit for switching the states of FET1, FET2, FET3, and FET4 so that main and second batteries are both connected to the DC-DC converter in response to a change in the #AC-ADAP signal when the AC adapter is disconnected from the switching unit.

Claims

1. A power source switching unit with an integrated charging circuit for selectively coupling an external power source, a computer loads and one or more batteries, for providing temporary power during coupling, and for charging the one or more batteries, comprising:

an external power receiving unit to transfer-electric power from an external power source to a power output to which a computer load is coupled;

a detector, directly coupled to the power output of the external power receiving unit, to measure the voltage supplied by the external power receiving unit and detect a loss of the electric power supplied from the external power source to the external power receiving unit, wherein said detector detects the loss of the electric power supplied from the external power source to the external power receiving unit by measuring the voltage level supplied by the power output and comparing the voltage level to a fixed reference voltage, regardless of whether power is being supplied by the one or more batteries;

one or more battery power supply circuits to selectively couple one or more batteries to the computer loads and the one more batteries to an integrated charging device;

the integrated charging device, coupled to the power output and to the one or more battery supply circuits, wherein the charging device is capable of selectively trickle charging and rapid charging the one or more batteries with the electric power supplied from the power output;

a control unit to selectively cause the one or more battery supply circuits to couple the one or more batteries to the integrated charging unit during periods when the external power receiving unit is receiving electric power and to cause the one or more battery supply circuits to couple the one or more batteries to the computer load within a predetermined time in response to detector detecting a loss of the electric power supplied from the external power circuit; and

a rechargeable temporary power supply device to supply electric power to the computer load for at least the predetermined time in response to the detector detecting the loss of the electric power supplied from the external power circuit.

2. The power source switching unit of claim 1, wherein the rechargeable temporary power supply device further comprises a capacitor coupled to the power output and the computer load.

3. The power source switching unit of claim 1, wherein the external power receiving unit is removably coupled to the computer loads.

4. The power source switching unit of claim 1, wherein the rechargeable temporary power device further comprises a rechargeable battery.

5. The power source switching unit of claim 1, wherein the external power receiving unit is supplied with alternating current electric power and discharges direct current electric power through the power output.

6. The power source switching unit of claim 1, further comprising a switching unit coupled to the power output and to one or more of the battery-power supply circuits, wherein the switching unit prevents a short circuit of the integrated charging device while the integrated charging device is charging one or more of the batteries.

7. The power source switching unit of claim 1, further comprising a direct current to direct current voltage converter coupled between the power output and the computer load.

8. A method of using a power source switching unit with an integrated charging circuit to selectively couple an external power source, a computer and one or more batteries, to provide temporary power during coupling, and to charge the one or more batteries, comprising:

an external power receiving unit transferring electric power from an external power source to a power output to which a computer load is coupled;

a detector, directly coupled to the power output of the external power receiving unit, measuring the voltage supplied by the external power receiving unit and detecting a loss of the electric power supplied from the external power source to the external power receiving unit, wherein said detector detects the loss of the electric power supplied from the external power source to the external power receiving unit by measuring the voltage level supplied by the power output and comparing the voltage level to a fixed reference voltage, regardless of whether power is being supplied by the one or more batteries;

one or more battery power supply circuits selectively coupling one or more batteries to the computer load and the one more batteries to an integrated charging device;

the integrated charging device, coupled to the power output and to the one or more battery supply circuits, selectively trickle charging and rapid charging the one or more batteries with the electric power supplied from the power output;

a control unit selectively causing the one or more battery supply circuits to couple the one or more batteries to the integrated charging unit during periods when the external power receiving unit is receiving electric power and causing the one or more battery supply circuits to couple the one or more batteries to the computer load within a predetermined time in response to the detector detecting a loss of the electric power supplied from the external power circuit, and

a rechargeable temporary power supply device supplying electric power to the computer load for at least the predetermined time in response to the detector detecting the loss of the electric power supplied from the external power circuit.

9. The method of claim 8, wherein the supplying step further comprises a capacitor coupled to the power output and the computer load supplying electric power to the computer load.

10. The method of claim 8, further comprising removably coupling the external power receiving unit to the computer load.

11. The method of claim 8, wherein the supplying step further comprises a rechargeable battery coupled to the power output and the computer load supplying electric power to the computer load.

12. The method of claim 8, wherein the transferring step further comprises an external power receiving unit receiving alternating current electric power and discharging direct current electric power through the power output.

13. The method of claim 8, further comprising a switching unit coupled to the power output and to one or more of the battery power supply circuits preventing a short circuit of the integrated charging device while the integrated charging device is charging one or more of the batteries.

14. The method of claim 8, further comprising a high-voltage direct current to low-voltage direct current voltage converter, coupled between the power output and the computer load, converting voltage.

15. A data processing system including a power source switching unit with an integrated charging circuit for selectively coupling an external power source, a computer load and one or more batteries, for providing temporary power during coupling, and for charging the one or more batteries, comprising:

an external power receiving unit to transfer electric power from an external power source to a power output to which a computer load is coupled;

a detector, directly coupled to the power output of the external power receiving unit, to measure the voltage supplied by the external power receiving unit and to detect a loss of the electric power supplied from the external power source to the external power receiving unit, wherein said detector detects the loss of the electric power supplied from the external power source to the external power receiving unit by measuring the voltage level supplied by the power output and comparing the voltage level to a fixed reference voltage, regardless of whether power is being supplied by the one or more batteries;

one or more battery power supply circuits to selectively couple one or more batteries to the computer load and the one more batteries to an integrated charging device;

the integrated charging device, coupled to the power output and to the one or more battery supply circuits, wherein the charging device is capable of selectively trickle charging and rapid charging the one or more batteries with the electric power supplied from the power output;

a control unit to selectively cause the one or more battery supply circuits to couple the one or more batteries to the integrated charging unit during periods when the external power receiving unit is receiving electric power and to cause the one or more battery supply circuits to couple the one or more batteries to the computer load within a predetermined time in response to detector detecting a loss of the electric power supplied from the external power circuit, and

a rechargeable temporary power supply device to supply electric power to the computer load for at least the predetermined time in response to the detector detecting the loss of the electric power supplied from the external power circuit.

16. The data processing system of claim 15, wherein the rechargeable temporary power supply device further comprises a capacitor coupled to the power output and the computer load.

17. The data processing system of claim 15, wherein the external power receiving unit is removably coupled to the computer load.

18. The data processing system of claim 15, wherein the rechargeable temporary power device further comprises a rechargeable battery.

19. The data processing system of claim 15, wherein the external power receiving unit is supplied with alternating current electric power and discharges direct current electric power through the power output.

20. The data processing system of claim 15, further comprising a switching unit coupled to the power output and to one or more of the battery power supply circuits, wherein the switching unit prevents a short circuit of the integrated charging device while the integrated charging device is charging one or more of the batteries.

21. The data processing system of claim 15, further comprising a direct current to direct current voltage converter coupled between the power output and the computer load.