US 2011/0256004 A1 · Piezoelectric devices and methods and circuits for driving same

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.

Claims70

Dependent claims

A pump comprising:

a pump body for at least partially defining a pumping chamber and an inlet and an outlet which communicate with the pumping chamber;
a piezoelectric actuator situated in the pump body and responsive to a drive signal for pumping fluid between the inlet and outlet;
and
a drive circuit which applies the drive signal to the piezoelectric actuator as a series of digital pulses.

1 more element

Dependencies are inferred from the claim text.

Piezoelectric devices and methods and circuits for driving same

Life of this patent

Piezoelectric devices and methods and circuits for driving same

Life of this patent

Abstract

Claims70