Power supply apparatus and method based on parasitic power extraction

• US 20040256915A1
• Filed: 06/17/2003
• Published: 12/23/2004
• Est. Priority Date: 06/17/2003
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Phinney, Thomas L.
• Granted Patent: US 7,291,938 B2
• Time in Patent Office: Days
• US Class Current: 307/43
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• 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: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode

Abstract

Power supply apparatus and method based on parasitic power extraction is disclosed. Power is extracted from signals that are inbound and/or outbound from an equipment. The extracted power is converted to dc voltages for a device associated with the equipment. The positive portions of the extracted power are combined in an additive manner to provide a first potentially time-varying signal and negative portions of the extracted power are also combined in an additive manner to provide a second potentially time-varying signal. The two potentially time-varying signals are also combined in an additive manner and divided into the desired number of dc voltages and magnitudes. An optional dc voltage power source is provided should the extracted power be inadequate to provide the do voltages.

Claims

1. Apparatus for supplying power to a load device comprising:

a power extractor that extracts voltage/current from a plurality of potentially time-varying signals and provides first and second voltage/current signals; and

a power conversion circuit for converting said first and second voltage/current signals to a plurality of dc voltages that are provided to said load device.

2. The apparatus of claim 1, wherein said power extractor provides said first and second voltage/current signals based on positive and negative-going portions, respectively, of said potentially time-varying signals.

3. The apparatus of claim 2, wherein said positive-going portions are combined in an additive manner to provide said first voltage/current signal and said negative-going portions are combined in an additive manner to provide said second voltage/current signal.

4. The apparatus of claim 3, wherein said first and second voltage/current signals are each limited in magnitude.

5. The apparatus of claim 1, wherein said power extractor comprises a diode network for each of said potentially time-varying signals.

6. The apparatus of claim 5, wherein said diode networks are connected in parallel between first and second lines that carry said first and second voltage/current signals, respectively.

7. The apparatus of claim 2, wherein said first and second voltage/current signals have a common reference potential.

8. The apparatus of claim 1, wherein said power conversion circuit further comprises a transformer circuit that combines said voltage/current signals in an additive manner into said dc voltages.

9. The apparatus of claim 8, wherein said power conversion circuit comprises a switch that simultaneously switches said first and second voltage/current signals to said transformer circuit.

10. The apparatus of claim 1, further comprising a separate power source and means for coupling said separate power source to said power conversion circuit when said plurality of potentially time-varying signals provide inadequate power for generating said plurality of dc voltages.

11. The apparatus of claim 10, wherein said means for coupling comprises an array of diode pairs, each connected as a half bridge to a corresponding input signal, and an additional diode pair connected as a half bridge to the common ground.

12. The apparatus of claim 1, further comprising a first device that provides at least one of said potentially time-varying signals.

13. The apparatus of claim 12, further comprising a second device that provides at least another of said potentially time-varying signals.

14. The apparatus of claim 13, wherein said load device is interconnected with said first and second devices via said plurality of signal lines.

15. The apparatus of claim 1, wherein said first and second voltage/current signals vary in magnitude based on a combination of said potentially time-varying signals.

16. The apparatus of claim 1, wherein said first voltage/current signal is more positive than said second voltage/current signal.

17. The apparatus of claim 1, further comprising a feedback circuit responsive to a first one of said dc voltages to provide an error signal, and wherein said power conversion circuit responds to said error signal to regulate said first dc voltage.

18. The apparatus of claim 17, wherein said feedback circuit comprises an error amplifier that has an output capacitance and a stable voltage supply connected in circuit with said error amplifier to substantially remove the effect of said output capacitance upon said power conversion circuit.

19. The apparatus of claim 18, wherein said stable voltage supply provides a stable voltage to said error amplifier, and wherein said stable voltage is derived from said first and second voltage/current signals.

20. The apparatus of claim 19, wherein said error amplifier comprises a transistor having its collector connected in circuit with said stable voltage supply and its emitter connected to provide said error signal to said power conversion circuit.

21. The apparatus of claim 20, wherein said transistor is a phototransistor that is optically coupled to a light emitting diode that is controlled by an active device in response to said first dc voltage.

22. Apparatus for supplying power to a load device comprising:

a plurality of input stages and a plurality of output stages connected in circuit with a transformer; and

a switching circuit that switches said input stages to combine a first voltage/current signal and a second voltage/current signal in said transformer to provide a plurality of dc voltages in said output stages for said load device.

23. The apparatus of claim 22, wherein said input stages extract power from a plurality of potentially time-varying signals to produce said first voltage/current signal and said second voltage/current signal, and wherein said plurality of dc voltages is provided when each of said potentially time-varying voltages has a non-zero magnitude or when some but not all of said potentially time-varying voltages has a magnitude of zero.

24. The apparatus of claim 22, further comprising an optional input stage for connecting an optional input voltage source in circuit with said transformer, and wherein said optional input stage, said transformer and said output stages co-act to provide said plurality of dc voltages.

25. The apparatus of claim 22, wherein at least one of said dc voltages is positive and at least one of said dc voltages is negative.

26. A method for supplying power to a load device comprising:

extracting first and second signal portions from a plurality of potentially time-varying signals;

combining said first and second signal portions to provide first and second voltage/current signals; and

converting said first and second voltage/current signals to a plurality of dc voltages that are provided to said load device.

27. The method of claim 26, wherein said first and second signal portions are positive- and negative-going portions, respectively.

28. The method of claim 27, wherein said positive-going portions are combined in an accumulative manner to provide said first voltage/current signal and said negative-going portions are combined in an accumulative manner to provide said second voltage/current signal.

29. The method of claim 26, wherein said dc voltages are provided both when each of said potentially time-varying signals has a non-zero magnitude or when at least one, but not all, of said potentially time-varying signals has a magnitude of zero.

30. The method of claim 26, wherein said first and second voltage/current signals vary in magnitude and polarity based on a combination of said potentially time-varying signals.