Patent ID: 6285115
Filing Date: 2001-09-04
Classification: H02N

Abstract:
An apparatus for controlling position of a piezoelectric device, comprising:a position control circuit operable to receive and compare a first control signal corresponding to a desired position of the piezoelectric device and an estimated position of the piezoelectric device and to generate a second control signal in response to the first control signal and the estimated position of the piezoelectric device;a piezoelectric device control circuit coupled to said position control circuit and operable to receive the second control signal and generate a third control signal in response to the second control signal that is adapted to drive the piezoelectric device to the desired position;wherein said position control circuit includes a first data structure operable to correlate an applied voltage to the piezoelectric device with a charge existing on the piezoelectric device to generate the estimated position of the piezoelectric device; andwherein said position control circuit further includes a current integrator circuit operable to integrate current flowing through the piezoelectric device to determine the charge existing on the piezoelectric device.