Battery charger and power source employing an environmental energy extractor and a method related thereto

• US 6,037,743 A
• Filed: 06/15/1998
• Issued: 03/14/2000
• Est. Priority Date: 06/15/1998
• Status: Expired due to Term

• Current Assignee: Synaptics Incorporated
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Johnston, James W., White, Stanley A., Siann, Jonathan I., Walley, Kenneth S., Andrews, Jr., Warner B., Henderson, P. Michael
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/094,735
• Time in Patent Office: 638 Days
• Field of Search: 320/101, 320/102, 320/166, 320/167, 323/906, 136/291, 136/292, 136/293
• US Class Current: 320/103
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

A power source employs an environmental energy extractor. The environmental energy extractor operates to extract energy from the environment and provides the extracted energy either to power an electronic device, or to a storage device coupled to a battery charger for storing the extracted energy. The environmental energy extractor can include one or more energy modules. Each energy module is for extracting environmental energy and for providing the extracted energy to either the electronic device or the storage device. When more than one energy module is employed, the energy modules are configured such that the extracted energy provided by each module is summed, and the collective extracted energy of all the energy modules is provided to the electronic device or the storage device.

Claims

1. A battery charger comprising:

(a) a first terminal for coupling to an anode of a chargeable battery;

(b) a second terminal for coupling to a cathode of the chargeable battery;

(c) a storage device coupled to the first and second terminals for storing charge; and

(d) an environmental energy extractor coupled to the first and second terminals for extracting energy from the environment and for providing the extracted energy to the storage device;

said environmental energy extractor including an energy module having;

(i) a first section for receiving an RF signal;

(ii) a second section, inductively coupled to the first section, for generating an output signal based on the RF signal; and

(iii) a third section, coupled to the second section, for rectifying the output signal of the second section.

2. The battery charger of claim 1 wherein the environmental energy extractor includes at least two energy modules, each energy module for extracting environmental energy and for providing an extracted energy to the storage device;

wherein the energy modules are configured such that the extracted energy provided by each module is summed and the collective extracted energy of all the energy modules is provided to the storage device.

3. The battery charger of claim 2 wherein each energy module is tuned to a predetermined frequency.

4. The battery charger of claim 1 wherein the energy module further includes:

(a) a compare circuit, coupled across the storage device, for providing a control signal; and

(b) a switch coupled to receive the control signal and responsive thereto for selectively contributing the extracted energy of that energy module to the collective extracted energy that is provided to the storage device.

5. The battery charger of claim 1 wherein the storage device is a capacitor.

6. The battery charger of claim 1 wherein the first section includes an antenna, an inductor, and a capacitor coupled in series.

7. The battery charger of claim 1 wherein the second section includes an inductor and capacitor coupled in parallel.

8. The battery charger of claim 1 wherein the third section includes a rectifier circuit.

9. The battery charger of claim 8 wherein the rectifier circuit includes a full wave rectifier circuit.

10. The battery charger of claim 1 wherein the first section includes:

(a) an antenna for receiving RF signals;

(b) an inductor coupled in series with said antenna; and

(c) a first varactor coupled in series with the inductor, said varactor having a control node for receiving a first varactor control signal, and a first sense node.

11. The battery charger of claim 10, wherein each energy module includes:

(a) an energy module output; and

(b) a measurement and control circuit, coupled to receive the energy module output and an initial frequency tuning parameter, and responsive thereto for generating the first varactor control signal and for providing the first varactor control signal to the first varactor control node.

12. The battery charger of claim 10 wherein the second section further includes:

an inductor, and a second varactor coupled in parallel with said inductor, said second varactor having a control node and a first sense node.

13. The battery charger of claim 12 wherein each energy module includes:

(a) an energy module output; and

(b) a measurement and control circuit, coupled to receive the energy module output and an initial frequency tuning parameter, and responsive thereto for generating the second varactor control signal and for providing the second varactor control signal to the second varactor control node.

14. The battery charger of claim 13 wherein the measurement and control circuit generates a control signal, and wherein each energy module further includes a switch coupled to receive the control signal and responsive thereto for selectively contributing the extracted energy of that energy module to the collective extracted energy that is provided to the storage device.

15. The battery charger of claim 1 further comprising a chargeable battery having an anode coupled to the first terminal and a cathode coupled to the second terminal.

16. The battery charger of claim 1 wherein the second section is inductively coupled to the first section.

17. The battery charger of claim 16 wherein the second section is electrically isolated from the first section.

18. In combination:

a device which requires energy for its operation; and

a power source coupled to the device, the power source comprising an environmental energy extractor for extracting energy from the environment and for providing the extracted energy to the device, the environmental energy extractor including one or more energy modules, each energy module extracting environmental energy and providing the extracted energy to the device, each energy module including;

(a) a first section for receiving an RF signal;

(b) a second section, electrically isolated from the first section, for generating an output signal based on the RF signal; and

(c) a third section, coupled to the second section, for rectifying the output signal of the second section.

19. A battery charger comprising:

(a) a first terminal for coupling to an anode of a chargeable battery;

(b) a second terminal for coupling to a cathode of the chargeable battery;

(c) a storage device coupled to the first and second terminals for storing charge;

(d) an environmental energy extractor coupled to the first and second terminals for extracting energy from the environment and for providing the extracted energy to the storage device;

said environmental energy extractor including at least two energy modules, each energy module extracting environmental energy and providing extracted energy to the storage device, each energy module being dynamically tuned to optimize the energy extracted from the particular energy module.

20. In combination:

a device which requires energy for its operation; and

a power source coupled to the device, the power source comprising an environmental energy extractor for extracting energy from the environment and providing the extracted energy to the device, the environmental energy extractor including one or more energy modules, each energy module extracting environmental energy and providing the extracted energy to the device, each energy module being dynamically tuned to optimize the energy extracted from the particular energy module.

23. The combination of claim 20, wherein the energy modules are configured such that the extracted energy provided by the energy modules are summed and the collective extracted energy of all the energy of the modules is provided to the device.

21. In combination:

a device which requires energy for its operation; and

a power source coupled to the device, the power source comprising an environmental energy extractor for extracting energy from the environment and for providing the extracted energy to the device, the environmental energy extractor including at least two energy modules, each module for extracting environmental energy and for providing the extracted energy to the device, each energy module including;

(a) a first section for receiving an RF signal;

(b) a second section, inductively coupled to the first section, for generating an output signal based on the RF signal; and

(c) a third section, coupled to the second section, for rectifying the output signal of the second section.

22. The combination of claim 21 further comprising means for coupling the power source to the device.

24. The combination of claim 21 wherein each energy module further includes:

(a) a compare circuit, coupled across the device, for providing a control signal; and

(b) a switch coupled to receive the control signal and responsive thereto for selectively contributing the extracted energy of that energy module to the collective extracted energy that is provided to the device.

25. The combination of claim 21 further comprising a storage device coupled across the device.

26. The combination of claim 25 wherein the storage device is a capacitor.

27. The combination of claim 21 wherein the first section includes an antenna, an inductor, and a capacitor coupled in series.

28. The combination of claim 21 wherein the second section includes an inductor and capacitor coupled in parallel.

29. The combination of claim 21 wherein the third section includes a rectifier circuit.

30. The combination of claim 29 wherein the rectifier circuit includes a full wave rectifier circuit.

31. The combination of claim 21 wherein the first section includes:

(a) an antenna for receiving RF signals;

(b) an inductor coupled in series with said antenna; and

(c) a first varactor coupled in series with the inductor, said varactor having a control node for receiving a first varactor control signal, and a first sense node.

32. The combination of claim 31, wherein each energy module includes:

(a) an energy module output; and

(b) a measurement and control circuit, coupled to receive the energy module output and an initial frequency tuning parameter, and responsive thereto for generating the first varactor control signal and for providing the first varactor control signal to the first varactor control node.

33. The combination of claim 31 wherein the second section further includes:

(a) an inductor; and

(b) a second varactor coupled in parallel with said inductor, said second varactor having a control node and a first sense node.

34. The combination of claim 33 wherein each energy module includes:

(a) an energy module output; and

(b) a measurement and control circuit, coupled to receive the energy module output and an initial frequency tuning parameter, and responsive thereto for generating the second varactor control signal and for providing the second varactor control signal to the second varactor control node.

35. The combination of claim 34 wherein the measurement and control circuit generates a control signal, and wherein each energy module further includes a switch coupled to receive the control signal and responsive thereto for selectively contributing the extracted energy of that energy module to the collective extracted energy that is provided to the device.

36. The combination of claim 21 wherein each energy module is tuned to a predetermined frequency.

37. A method of extracting energy from the environment, and providing the extracted energy to a device, comprising the steps of:

(a) providing an energy module having a first section having a current path and a second section having an output;

(b) receiving radio frequency (RF) signals;

(c) maximizing a current through the current path of the first section;

(d) maximizing the output in the second section; and

(e) rectifying the output of the second section.

38. The method of claim 37, wherein step (a) further includes the step of inductively coupling the second section to the first section.

39. The method of claim 38, wherein step (a) further includes the step of electrically isolating the second section from the first section.

40. The method of claim 37, further including the following steps:

(f) providing a second energy module having a first section having a current path and a second section having an output;

(g) receiving radio frequency (RF) signals at the second energy module;

(h) maximizing a current through the current path of the first section of the second energy module;

(i) maximizing the output in the second section of the second energy module;

(j) rectifying the output of the second section of the second energy module; and

(k) summing the outputs of the energy module and second energy module.

41. The method of claim 37, further including the following step:

(f) providing the rectified output to a storage device which is part of a battery charger.

42. The method of claim 37, further including the following step:

(f) providing the rectified output to a device which requires energy for its operation.

43. The method of claim 37, further including the following step:

(f) responsive to the rectified output, controlling a switch to either isolate the energy module or to connect the energy module to a series of other energy modules.

44. The method of claim 37, wherein step (a) further includes the step of pre-tuning the energy module to a predetermined frequency.

45. The method of claim 37, further including the following step:

(f) providing frequency tuning parameters to the energy module;

(g) optimizing a particular frequency based on the rectified output and the parameters.