IMPROVEMENTS IN AND RELATING TO ULTRASONIC CLEANING

摘要

An ultrasonic cleaning apparatus comprising: a tank for in use receiving a cleaning liquid and an item to be cleaned; a plurality of transducers arranged, when driven, to direct ultrasonic pressure waves into the tank; and a controller arranged in use to drive the transducers. First and second transducers from the plurality of transducers are arranged in use to direct ultrasonic pressure waves into an overlapping volume; and the controller is arranged in use to drive the first and second transducers to produce ultrasonic pressure waves at different frequencies from each other. The controller is arranged to in use produce first and second drive signals for the transducers using first and second frequency generators to each switch between primary and secondary operation, with the sequential switching taking place to cause different combinations of primary and secondary operation for the first and second frequency generators to occur over time.