Method and apparatus for reducing power consumption for power supplied by a voltage adapter

• US 6,754,092 B2
• Filed: 06/27/2002
• Issued: 06/22/2004
• Est. Priority Date: 06/27/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Nassif, Sani Richard, McDowell, Chandler Todd
• Primary Examiner(s): Patel, Rajnikant B
• Application Number:
  US10/185,707
• Publication Number:
  US 20040001346A1
• Time in Patent Office: 726 Days
• Field of Search: 363/89, 363/85, 363/95, 363/98, 363/69, 363/52, 323/280, 323/284, 323/281, 323/275, 323/272, 323/276, 320/139, 320/116, 320/160, 320/164, 307/66, 307/39, 307/35
• US Class Current: 363/89
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

Power consumption is reduced for power supplied by a voltage adapter, such as an AC/DC adapter. A power source is connected to a power unit, including the voltage adapter and control circuitry. The voltage adapter supplies power to a load, such as a computer system. A load current supplied by the voltage adapter and an output voltage of the voltage adapter are measured by the control circuitry, and a control device of the control circuitry selectively disconnects the voltage adapter from the power source. The disconnecting is responsive to the control circuitry inferring from the measured current and voltage that the load is turned off, or at least operating in a reduced power consumption mode.

Claims

1. A method for reducing power consumption of a voltage adapter connected to a power source, the method comprising the steps of:

a) supplying power to a power unit, wherein the power unit includes a voltage adapter and control circuitry;

b) measuring a load current supplied by the voltage adapter and an output voltage of the voltage adapter; and

c) selectively disconnecting the voltage adapter from the power source by a control device of the control circuitry, wherein the disconnecting is responsive to the control circuitry inferring from the measured current and voltage that the load is low based on output voltage and load current thresholds.

2. The method of claim 1, wherein the control circuitry infers that the load is low if the comparing indicates that the output voltage is greater than its threshold and the load current is less than its threshold.

3. The method of claim 2, comprising the step of selectively disconnecting the power line from the voltage adapter responsive to the control circuitry inferring from the measured current and voltage that the power unit is on and in an overloaded condition.

4. The method of claim 3, wherein the control circuitry infers that power unit is on and in an overloaded condition if the output voltage is less than its threshold and the load current is greater than its threshold.

5. The method of claim 1, wherein the voltage adapter converts AC voltage to DC voltage.

6. The method of claim 1, comprising the step of determining the voltage threshold, wherein the determining includes measuring a voltage drop across at least a diode, the diode being connected in parallel with the voltage adapter output, and wherein measuring the output voltage includes measuring a voltage drop across at least a portion of at least a first resistor, the first resistor being connected in parallel with the voltage adapter output.

7. The method of claim 1, wherein measuring the load current includes measuring a voltage drop across at least a portion of at least a second resistor, the second resistor being connected in series between the voltage adapter and a load, and wherein the method comprises the step of determining the current threshold, wherein the current threshold determining includes measuring a voltage drop across at least a portion of ax least a third resistor, the third resistor being connected in parallel with the voltage adapter output.

8. An apparatus for reducing power consumption of a voltage adapter connected to a power source, the apparatus comprising:

a voltage adapter; and

control circuitry, wherein the control circuitry is operable to measure a load current supplied by the voltage adapter and an output voltage of the voltage adapter and selectively disconnect the voltage adapter from the power source by a control device of the control circuitry, wherein the disconnecting is responsive to the control circuitry inferring from the measured current and voltage that the load is low based on output voltage and load current thresholds.

9. The apparatus of claim 8, wherein the control circuitry infers that the load is low if the comparing indicates that the output voltage is greater than its threshold and the load current is less than its threshold.

10. The apparatus of claim 9, wherein the control circuitry selectively disconnects the power line from the voltage adapter responsive to the control circuitry inferring from the measured current and voltage that the power unit is on and in an overloaded condition.

11. The apparatus of claim 10, wherein the control circuitry infers that power unit is on and in an overloaded condition if the output voltage is less than its threshold and the load current is greater than its threshold.

12. The apparatus of claim 9, wherein the voltage adapter converts AC voltage to DC voltage.

13. The apparatus of claim 9, wherein the control circuitry determines the voltage threshold responsive to measuring a voltage drop across at least a diode, the diode being connected in parallel with the voltage adapter output, and wherein the control circuitry measuring the output voltage includes measuring a voltage drop across at least a portion of at least a first, resistor, the first resistor being connected in parallel with the voltage adapter output.

14. The apparatus of claim 9, wherein the control circuitry measuring the load current includes measuring a voltage drop across at least a portion of at least a second resistor, the second resistor being connected in series between the voltage adapter and a load, and wherein the control circuitry determines the current threshold responsive to measuring a voltage drop across at least a portion of at least a third resistor, the third resistor being connected in parallel with the voltage adapter output.

15. A computer program product for reducing power consumption of a voltage adapter connected to a power source, the computer program product comprising:

instructions for causing control circuitry of the voltage adapter to read a flint control circuitry input signal, the first control circuitry input signal being responsive to measuring a load current supplied by the voltage adapter, and to read a second control circuitry input signal, the second control circuitry input signal being responsive to measuring an output voltage of the voltage adapter; and

instructions for causing the control circuitry to selectively disconnect the voltage adapter from the power source, wherein the disconnecting is responsive to the control circuitry inferring from the measured current and voltage that the load is low based on output voltage and load current thresholds.

16. The computer program product of claim 15, wherein the control circuitry infers that the load is law if the output voltage is greater than its threshold and the load current is less than its threshold.

17. The computer program product of claim 16, comprising instructions for causing the control circuitry to infer that the power unit is on and in an overloaded condition and to responsively disconnect the power line from the voltage adapter.

18. The computer program product of claim 17, wherein the control circuitry infers that power unit is on and in an overloaded condition if the output voltage is less than its threshold and the load current is greater than its threshold.

19. The computer program product of claim 15, wherein the voltage adapter converts AC voltage to DC voltage.

20. The of computer program product of claim 15, comprising instructions for determining the voltage threshold, wherein the determining includes measuring a voltage drop across at least a diode, the diode being connected in parallel with the voltage adapter output, and wherein measuring the output voltage includes measuring a voltage drop across at least a portion of at least a first resistor, the first resistor being connected in parallel with the voltage adapter output.

21. The computer program product of claim 15, wherein measuring the load current includes measuring a voltage drop across at least a portion of at least a second resistor, the second resistor being connected in series between the voltage adapter and a load, and wherein the computer program product comprises comprising instructions for determining the current threshold, wherein the current threshold determining includes measuring a voltage drop across at least a portion of at least a third resistor, the third resistor bring connected in parallel with the voltage adapter output.