Research On Control Circuit Of Ultrasound Generator

With the development of ultrasonic cleaning technology,ultrasonic cleaning machine has been more and more widely used in all walks of life,gradually replacing the traditional cleaning methods.However,with the influence of temperature,environment and other uncertain factors,the wear and aging of the hardware materials of the ultrasonic transducer will occur,which will affect the rated output frequency of the transducer.This frequency offset makes the output frequency of the ultrasonic generator unable to match it,which will affect the efficiency of the transducer,resulting in poor cleaning effect and even damage the transducer in serious cases.In order to solve this problem,this paper designs an ultrasonic generator based on ARM7 architecture,with adjustable input frequency and automatic tracking output frequency.Starting from the given frequency of the host computer,the system converts 220 V 50Hz city electricity through single-phase uncontrollable rectifier circuit,BUCK chopper circuit,MOSFET full-bridge inverter circuit and impedance matching network into controllable output signal and sends it to the ultrasonic transducer through the voltage regulator.The voltage and current signals acted by the transducer are continuously collected by the phase-locked loop circuit,and the results are fed back to the main control chip STM32.The main control chip uses the fuzzy PI adaptive control algorithm to compare the feedback results with the given values,adjusts the input signal,and then converts the drive circuit into trigger signal,which acts again on the single-phase full-bridge inverter circuit.In this paper,the functional modules of the system circuit are debugged.According to the above design,the circuit of each part is simulated on the platform of MATLAB/Simulink.The simulation results show that the phase of the voltage and current of the transducer keeps basically the same after the function of the frequency automatic tracking circuit,and the automatic control of the output frequency is realized.