ENERGY HARVESTING SYSTEM AND METHOD USING MULTIPLE ENERGY SOURCES

• US 20090085409A1
• Filed: 10/01/2007
• Published: 04/02/2009
• Est. Priority Date: 10/01/2007
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Thompson, Payton, Kearney-Fischer, Martin A.
• Granted Patent: US 7,834,483 B2
• Time in Patent Office: Days
• US Class Current: 307/115
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: H02S 40/44 Means to utilise heat energy, e.g. hybrid systems producing warm water and electricity at the same time directly associated with the PV cell or integrated with the PV cell H01L31/0525
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/60 Thermal-PV hybrids

Abstract

An energy harvesting system and method having improved efficiency. A primary energy harvesting device is used to generate a first electrical output signal. The first electrical output signal is applied to a first switching circuit. A secondary energy harvesting device is used to generate a second electrical output signal that is used to power a second switching circuit. The second switching circuit generates the switching drive signal for the first switching circuit, which in turn generates a final output signal. By using a second energy harvesting circuit operating in connection with a different structure, and a secondary switching circuit, less power from the signal generated by the primary energy harvesting device is needed to power the first switching circuit. This results in a greater percentage of the output power of the first signal being usable by an external device.

Claims

1. An energy harvesting system comprising:

a primary energy harvesting device for generating a first electrical output signal from energy harvested from a first energy source;

a secondary energy harvesting device for generating a second electrical output signal; and

a primary switching circuit adapted to be controlled by said second electrical output signal, and to receive said first electrical output signal, and to generate therefrom a final electrical output signal.

2. The system of claim 1, further comprising a secondary switching circuit interposed between said secondary energy harvesting device and said primary switching device, for receiving said second electrical output signal and generating therefrom a switched second electrical output signal for controlling said primary switching circuit.

4. The system of claim 1, wherein said primary switching circuit comprises a mechanical switch driven by vibration.

5. The system of claim 2, wherein said secondary switching circuit comprises a micro-electro-mechanical system (MEMS) switching component.

6. The system of claim 2, wherein said secondary switching circuit comprises a metal oxide silicon field effect transistor (MOSFET).

7. The system of claim 1, wherein said secondary energy harvesting device comprises a strain gauge.

8. The system of claim 1, wherein said secondary energy harvesting device comprises a piezoelectric device.

9. The system of claim 1, wherein said secondary energy harvesting device comprises a photodetector.

10. The system of claim 1, further comprising an amplifier for amplifying an output from said primary switching circuit.

12. The system of claim 10, wherein said primary energy harvesting device comprises a thermoelectric device, and said first energy source comprises a thermoelectric energy source.

13. The system of claim 10, wherein said primary switching circuit comprises a mechanical switch driven by vibration.

14. The system of claim 10, wherein said secondary switching device comprises a micro-electro-mechanical system (MEMS) switching component.

15. The system of claim 10, wherein said secondary switching device comprises a metal oxide silicon field effect transistor (MOSFET).

16. The system of claim 10 wherein said secondary energy harvesting device comprises a strain gauge.

17. The system of claim 10, wherein said secondary energy harvesting device comprises a piezoelectric device.

18. The system of claim 10, wherein said secondary energy harvesting device comprises a photodetector.

20. The method of claim 18, further comprising using a secondary switching circuit responsive to said second electrical output signal to drive said primary switching circuit.

3. The system of 1, wherein said primary energy harvesting device comprises a thermoelectric device, and said first energy source comprises a thermoelectric energy source.

11. An energy harvesting system comprising:

a primary energy harvesting device for generating a first electrical output signal from energy harvested from a first energy source;

a secondary energy harvesting device for generating a second electrical output signal;

a primary switching circuit adapted to receive said first electrical output signal and to generate therefrom a final electrical output signal; and

a secondary switching device responsive to said secondary energy harvesting device, and adapted to generate a second electrical signal for driving said primary switching circuit.

19. A method for harvesting energy comprising:

using a primary energy harvesting device to generate a first electrical output signal from energy harvested from a first energy source;

using a secondary energy harvesting device for generating a second electrical output signal; and

using a primary switching circuit adapted to be controlled by said second electrical output signal, and to receive said first electrical output signal, and to generate therefrom a final electrical output signal. amplify said final electrical output signal.