METHOD AND APPARATUS FOR ENERGY HARVEST FROM AMBIENT SOURCES

• US 20120032518A1
• Filed: 08/05/2010
• Published: 02/09/2012
• Est. Priority Date: 08/05/2010
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: HUANG, Ming-Chieh, CHERN, Chan-Hong, SCOTT, David Barry
• Granted Patent: US 8,432,071 B2
• Time in Patent Office: Days
• US Class Current: 307/81
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/30 using light, e.g. lasers
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 7/35 with light sensitive cells

Abstract

An energy harvesting system includes a plurality of transducers. The transducers are configured to generate direct current (DC) voltages from a plurality of ambient energy sources. A sensor control circuit has a plurality of sensors configured to detect the DC signals from the plurality of transducers. A DC-to-DC converter is configured to supply an output voltage. A plurality of switches, each switch coupled between the DC-to-DC converter and a corresponding transducer of the plurality of transducers. The sensor control circuit enables one switch of the plurality of switches and disables the other switches of the plurality of switches based on a priority criterion.

Claims

1. An energy harvesting system, comprising:

a plurality of transducers, the transducers configured to generate direct current (DC) signals from a plurality of ambient energy sources;

a sensor control circuit having a plurality of sensors configured to detect the DC signals from the plurality of transducers;

a DC-to-DC converter configured to supply an output voltage; and

a plurality of switches, each switch coupled between the DC-to-DC converter and a corresponding transducer of the plurality of transducers,

wherein the sensor control circuit enables one switch and disables the other switches of the plurality of switches based on a priority criterion.

2. The system of claim 1, wherein at least one transducer of the plurality of transducers includes an alternating current (AC) to DC rectifier.

3. The system of claim 1, wherein the priority criteria are predetermined.

4. The system of claim 1, wherein the sensor control circuit further comprises a comparator to determine whether any of the DC signals are above a threshold value.

5. The system of claim 1, wherein the sensor control circuit further comprises a comparator to determine which DC signal has the highest power among the DC signals.

6. The system of claim 1, further comprising a voltage regulator coupled to the output voltage, wherein the voltage regulator is configured to supply a regulated voltage using the output voltage when the output voltage is above a threshold value.

7. The system of claim 1, further comprising a battery charger coupled to the output voltage and a battery, wherein the battery is configured to be charged by the battery charger and to supply a battery voltage when the output voltage is below a threshold value.

8. A method comprising:

detecting direct current (DC) signals from a plurality of transducers using voltage sensors, the transducers configured to generate the DC signals from a plurality of ambient energy sources;

selecting one transducer from the plurality of transducers based on a priority criterion;

controlling switches to couple the selected transducer to a DC-to-DC converter; and

supplying an output voltage from the DC-to-DC converter.

9. The method of claim 8, further comprising determining whether any of the DC signals are above a threshold value.

10. The method of claim 8, wherein the priority criteria are predetermined.

11. The method of claim 8, wherein the priority criteria are based on comparisons of the DC signals from the plurality of transducers.

12. The method of claim 8, further comprising coupling the output voltage to a voltage regulator.

13. The method of claim 8, further comprising coupling the output voltage to a battery charger that is arranged to charge a battery.

14. The method of claim 8, further comprising supplying a regulated voltage from a voltage regulator using the output voltage when the output voltage is above a threshold value.

15. The method of claim 8, further comprising supplying a regulated voltage from a voltage regulator using a battery voltage when the output voltage is below a threshold value.

16. An energy harvesting system, comprising:

a plurality of transducers, the transducers configured to generate direct current (DC) signals from a plurality of ambient energy sources;

a sensor control circuit having a plurality of sensors configured to detect the DC signals from the plurality of transducers;

a DC-to-DC converter configured to supply an output voltage;

a plurality of switches, each switch coupled between the DC-to-DC converter and a corresponding transducer of the plurality of transducers;

a battery charger coupled to the output voltage and a battery, wherein the battery is configured to be charged by the battery charger; and

a voltage regulator coupled to the output voltage;

wherein the sensor control circuit is configured to enables one switch and to disable the other switches of the plurality of switches based on a priority criterion, and the voltage regulator is configured to supply a regulated voltage using the output voltage when the output voltage is above a first threshold value and using a battery voltage from the battery when the output voltage is below the first threshold value.

17. The system of claim 16, wherein at least one transducer of the plurality of transducers includes an alternating current (AC) to DC rectifier.

18. The system of claim 16, wherein the priority criteria are predetermined.

19. The system of claim 16, wherein the sensor control circuit further comprises a comparator to determine whether any of the DC signals are above a second threshold value.

20. The system of claim 16, wherein the sensor control circuit further comprises a comparator to determine which DC signal has the highest power among the DC signals.