Patent ID: 6946773

Claim:
A system for delivering ultrasonic energy to a liquid, comprising; A. two or more ultrasonic transducers adapted for coupling to said liquid, wherein (i) each ultrasonic transducer is capable of producing ultrasonic energy in said liquid at two or more resonant frequencies, each resonant frequency being within a range of frequencies, said range of frequencies extending about said resonant frequency, and (ii) the two or more ultrasonic transducers are electrically coupled; B. two or more ultrasonic generators, each ultrasonic generator being adapted for producing a drive signal within one of the ranges of frequencies associated with one of the two or more resonant frequencies; C. a multiplexer for receiving the drive signals from the two or more ultrasonic generators and for electrically coupling the received drive signals, one at a time in a time sequence, to the electrically coupled two or more ultrasonic transducers; and D. a controller for controlling the multiplexer in a first state, so that one of the two or more ultrasonic generators drives the coupled two or more ultrasonic transducers to produce ultrasonic energy in said liquid characterized by a frequency that sweeps across one of the frequency ranges, and in a second state, so that another of the two or more ultrasonic generators drives the coupled two or more ultrasonic transducers to change frequency to a different frequency range, to produce ultrasonic energy in said liquid characterized by a frequency that sweeps across at least another of the frequency ranges.