Circuit and method to improve energy harvesting efficiency in piezoelectric harvesters

• US 8,026,650 B2
• Filed: 09/14/2009
• Issued: 09/27/2011
• Est. Priority Date: 09/22/2008
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Chnadrakasan, Anantha, Ramadass, Yogesh
• Primary Examiner(s): Dougherty; Thomas M
• Application Number:
  US12/558,820
• Publication Number:
  US 20100079034A1
• Time in Patent Office: 743 Days
• Field of Search: 310/318, 310/319
• US Class Current: 310/318
• CPC Class Codes: H02N 2/181 Circuits; Control arrangements or methods

Abstract

An energy harvester circuit is provided. The energy harvester circuit includes a harvesting module for extracting energy from an ambient source. A bias flip module manages the manner in which voltage across the harvesting module transitions when input current from the harvesting module changes direction so as to allow a majority of the charge available from the harvesting module to be extracted. A voltage transitioning module is shared amongst one or more DC-DC converters for efficient energy management.

Claims

1. An energy harvester circuit comprising:

a harvesting module for extracting energy from an ambient source;

a bias flip module for managing the manner in which voltage across said harvesting module transitions when input current to said harvesting module changes direction so as to allow a majority of the charge available from the harvesting module to be extracted; and

a voltage transitioning module that is shared amongst one or more DC-DC converters for efficient energy management, said voltage transitioning module comprises an inductor mechanism being shared amongst said main DC-DC converter and said one or more secondary DC-DC converters.

2. The energy harvester circuit of claim 1, wherein said one or more DC-DC converters comprising a main DC-DC converter coupled to one or more of secondary DC-DC converters.

3. The energy harvester circuit of claim 1, wherein said inductor mechanism utilizes an arbiter to share inductance with said main DC-DC converter and said one or more secondary DC-DC converters.

4. The energy harvester circuit of claim 1, wherein said voltage transitioning module comprises one or more switches.

5. The energy harvester circuit of claim 1, wherein said bias flip module is coupled to a capacitance at its output.

6. The energy harvester circuit of claim 1, wherein said bias flip module comprises a plurality of diodes.

7. The energy harvester circuit of claim 3, wherein said arbiter receives input signals from said bias flip module and said one or more DC-DC converters as to determining sharing of inductance.

8. The energy harvester circuit of claim 1, wherein said harvesting module comprises a piezoelectric harvester.

9. A method of performing energy harvesting comprising:

providing a harvesting module for extracting energy from an ambient source;

implementing a bias flip module for managing the manner in which voltage across said harvesting module transitions when input current to said harvesting module changes direction so as to allow a majority of the charge available from the harvesting module to be extracted; and

implementing a voltage transitioning module that is shared amongst one or more DC-DC converters for efficient energy management, said voltage transitioning module comprises an inductor mechanism being shared amongst said main DC-DC converter and said one or more secondary DC-DC converters.

10. The method of claim 9, wherein said one or more DC-DC converters comprising a main DC-DC converter coupled to one or more of secondary DC-DC converters.

11. The method of claim 9, wherein said inductor mechanism utilizes an arbiter to share inductance with said main DC-DC converter and said one or more secondary DC-DC converters.

12. The method of claim 9, wherein said voltage transitioning module comprises one or more switches.

13. The method of claim 9, wherein said bias flip module is coupled to a capacitance at its output.

14. The method of claim 9, wherein said bias flip module comprises a plurality of diodes.

15. The method of claim 11, wherein said arbiter receives input signals from said bias flip module and said one or more DC-DC converters as to determining sharing of inductance.

16. The method of claim 9, wherein said harvesting module comprises a piezoelectric harvester.