Piezoelectric devices and methods and circuits for driving same
First Claim
1. A pump comprising:
- a pump body for at least partially defining a pumping chamber;
a piezoelectric actuator situated in the pump body and responsive to a drive signal for pumping fluid in the pumping chamber; and
a drive circuit which applies the drive signal to the piezoelectric actuator as a series of digital pulses.
3 Assignments
0 Petitions
Accused Products
Abstract
A drive circuit (18) produces a drive signal for a pump (10) having a piezoelectric actuator (14), with the piezoelectric actuator (14) forming a part of the drive circuit (18) and serving to shape a waveform of the drive signal. The drive circuit (18) comprises a pulse generator (100) which generates pulses; a converter circuit (102) which receives the pulses and produces charge packets at a rate which equals a desired drive frequency; and, the piezoelectric actuator (14). The piezoelectric actuator (14) receives the charge packets and, by its capacitive nature, integrates the charge packets to shape the waveform of the drive signal. Preferably, the piezoelectric actuator (14) integrates the charge packets to yield a drive field that approximates a sine wave. In one non-limiting example embodiment, the pulse generator (100) comprises a microcontroller-based pulsed width modulator (PWM) circuit (116) and the converter circuit (102) comprises a flyback circuit.
96 Citations
73 Claims
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1. A pump comprising:
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a pump body for at least partially defining a pumping chamber;
a piezoelectric actuator situated in the pump body and responsive to a drive signal for pumping fluid in the pumping chamber; and
a drive circuit which applies the drive signal to the piezoelectric actuator as a series of digital pulses. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a piezoelectric pump having a piezoelectric actuator situated in a pump body and responsive to a drive signal for pumping fluid, the method comprising:
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applying a series of digital pulses as the drive signal to the piezoelectric actuator;
operating the piezoelectric actuator in response to the drive signal. - View Dependent Claims (8, 9, 10)
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- 11. A drive circuit which produces a drive signal for a device having a piezoelectric actuator, the piezoelectric actuator forming a part of the drive circuit and serving to shape a waveform of the drive signal.
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23. A pump comprising:
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a pump body for at least partially defining a pumping chamber;
a piezoelectric actuator situated in the pump body and responsive to a drive signal for pumping fluid in the pumping chamber; and
a drive circuit which produces the drive signal, the piezoelectric actuator forming a part of the drive circuit and serving to shape a waveform of the drive signal. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A pump comprising:
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a pump body for at least partially defining a pumping chamber;
a piezoelectric actuator situated in the pump body and responsive to a drive signal for pumping fluid in the pumping chamber;
a power supply; and
a drive circuit which is powered by the power supply and which produces the drive signal;
wherein the piezoelectric actuator serves as a voltage storage device for the power supply. - View Dependent Claims (36, 37, 38, 39)
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40. A method of operating a device having a piezoelectric actuator which is responsive to a drive signal, the method comprising:
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(1) generating digital pulses;
(2) using the digital pulses of step (1) to produce high voltage charge packets; and
(3) using the piezoelectric actuator to integrate the charge packets and thereby shape a waveform of the drive signal. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48)
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49. A method of operating a device having a piezoelectric actuator which is responsive to a drive signal, the method comprising:
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using a power supply to power a drive circuit which generates the drive signal, the drive signal comprising charge pulses;
using the piezoelectric actuator to integrate the charge packets into an electric field;
using the piezoelectric actuator to store charge and thereby serve as a charge storage device for the power supply. - View Dependent Claims (50)
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51. A piezoelectrically-operated apparatus comprising:
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a piezoelectric actuator which is responsive to a drive signal; and
a drive circuit which applies the drive signal to the piezoelectric actuator as a series of digital pulses. - View Dependent Claims (52, 53, 54, 55, 56)
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57. A piezoelectrically-operated apparatus comprising:
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a piezoelectric actuator which is responsive to a drive signal; and
a drive circuit which produces the drive signal, the piezoelectric actuator forming a part of the drive circuit and serving to shape a waveform of the drive signal. - View Dependent Claims (58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
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69. A drive circuit which produces a drive signal for a piezoelectric actuator, the drive circuit comprising:
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a source of digital pulses;
a transformer;
a power switching element which receives the digital pulses and selectively applies current to the transformer;
means for using an electromotive force generated by parasitic capacitance of the transformer to provide a high voltage bipolar output to the piezoelectric actuator. - View Dependent Claims (70, 71, 72, 73)
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Specification