Patent ID: 9344022
Filing Date: 2016-05-17
CPC Classification: H02P

Claim Text:
1. A method comprising: applying a drive signal to an actuator during at least a portion of a plurality of half cycles of a period of the drive signal, wherein the actuator has a resonant frequency; detecting when an induced voltage on the actuator crosses a threshold after the drive signal is turned off; triggering a drive clock signal in a clock generator circuit in response to the detecting; and triggering the drive signal in response to the drive clock signal to align a frequency and phase of the drive signal with the resonant frequency and a phase of the actuator, wherein a positive polarity drive signal is triggered by the drive clock signal a fixed time after a rising edge of the drive clock signal and a negative polarity drive signal is triggered by the drive clock signal a fixed time after a falling edge of the drive clock signal.