CIRCUITS FOR HARVESTING ENERGY FROM PIEZOELECTRIC DEVICES
First Claim
1. A circuit for applying electrical charge collected from a piezoelectric device to a charge storage device, the circuit comprising:
- a switch configured to initiate transfer of the electrical charge from the piezoelectric device to the charge storage device upon detection of a peak voltage across the piezoelectric device;
a peak detector configured to detect the peak voltage across the piezoelectric device, the peak detector comprising;
a peak-detection capacitance configured to be charged by voltage across the piezoelectric device until the voltage across the piezoelectric device reaches the peak voltage across the piezoelectric device;
a non-linear PN junction circuit connected in series with the peak-detection capacitance and configured to turn off the switch while the peak-detection capacitance is charging and to turn on the switch substantially upon detection of the peak voltage.
2 Assignments
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Accused Products
Abstract
Circuits (20, 220, 320, 420) are provided for applying electrical charge collected from a piezoelectric device (22) to a charge storage device (24, 224, 424). The circuits comprise a peak detector (32, 232) and a switch(es) (34, 134, 234, 434) which is/are operated to initiate transfer of the electrical charge from the piezoelectric device to the charge storage device upon detection by the peak detector (32, 232) of a peak voltage across the piezoelectric device (22). In an example embodiment, the peak detector (32, 232) comprises a peak-detection capacitance (C4); a gain element (42, 242); and a non-linear PN junction circuit (40). The circuits can also comprise charge multiplier circuit (300) configured to continue application of the electrical charge to the charge storage device (224) after the switch (262) has been turned off and/or after a point in time when magnitude of the voltage across the charge storage device (224) equals the magnitude of the voltage across the piezoelectric device (22).
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Citations
22 Claims
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1. A circuit for applying electrical charge collected from a piezoelectric device to a charge storage device, the circuit comprising:
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a switch configured to initiate transfer of the electrical charge from the piezoelectric device to the charge storage device upon detection of a peak voltage across the piezoelectric device; a peak detector configured to detect the peak voltage across the piezoelectric device, the peak detector comprising; a peak-detection capacitance configured to be charged by voltage across the piezoelectric device until the voltage across the piezoelectric device reaches the peak voltage across the piezoelectric device; a non-linear PN junction circuit connected in series with the peak-detection capacitance and configured to turn off the switch while the peak-detection capacitance is charging and to turn on the switch substantially upon detection of the peak voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A circuit for applying electrical charge collected from a piezoelectric device to a charge storage device, the circuit comprising:
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a peak detector configured to detect a peak voltage across the piezoelectric device; a switch configured to initiate transfer of the electrical charge from the piezoelectric device to the charge storage device upon detection of the peak voltage across the piezoelectric device; a charge multiplier circuit configured to continue application of the electrical charge to the charge storage device after the switch has been turned off and/or after a point in time when magnitude of the voltage across the charge storage device equals the magnitude of the voltage across the piezoelectric device. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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- 21. A circuit for applying electrical charge collected from a piezoelectric device to an energy storage device, the circuit being configured both (1) to provide bidirectional control of energy flow for causing charge on the piezoelectric device to go through an increased potential difference and thereby provide increased voltage on the piezoelectric device, and (2) to collect the increased charge from the piezoelectric device in the energy storage device.
Specification