Driver Circuit for an Ultrasonic Motor

Abstract: To make a camera more user friendly or let it operate without an user the camera objective needs to be able to put thecamera lens in focus. This functionality requires a motor of some sort, due to its many benefits the ultrasonic motor is apreferred choice. The motor requires a driving circuit to produce the appropriate signals and this is what this thesis is about.Themain difficulty that needs to be considered is the fact that the ultrasonic motor is highly non-linear.This paper will give a brief walk through of how the ultrasonic motor works,its pros and cons and how to control it. How thedriving circuit is designed and what role the various components fills. The regulator is implemented in C-code and runs on amicro processor while the actual signal generation is done on a CPLD. The report ends with a few suggestions of how toimprove the system should the presented solution not perform at a satisfactory level.