| In recent years, the Ultrasonic cleaning equipment has reached widespread application. This paper has researched into high frequency of Ultrasonic power supply. In the first chapter, it introduces the history and basic knowledge of ultrasonic cleaning, Ultrasonic power supply's present situation and the trend of development.The basic principals of the resonant tank and the two main topologies are analyzed in detail. This paper selects the series-resonant inverter because it is more suitable to high frequency power supply and easy to enhance power capacity and enable the power supply to work on higher frequency, while power is regulated in the rectifier. So uncontrolled rectifier and Buck chopper constitute DC circuit are selected as rectifier circuit.In the design of inverter control circuit, the frequency self-following system with optimal dead time based on DSP is researched. The core instrument of frequency-following system is the PLL. DSP is used to realize the regulating of dead time on-line. The hardware control system based on TMS320LF2407A is designed, including sampling circuit, protective circuit, phase-compensated circuit, driving circuit and so on. The program of system is compiled. The strategies of closed loop control for Ultrasonic power supply and the fuzzy control for power control are introduced to the power control. The hardware and software realization scheme are given.In order to improve the efficiency of Ultrasonic cleaning system, the Ultrasonic power supply should include two kinds of match circuits. They are impedance match circuit and harmonious match circuit. The impedance match circuit can cause the output impedance of Ultrasonic power supply to be equal to the load impedance.The harmonious match causes the load of circuit to present the pure sesistance and the circuit present resonant condition.This paper has separately given the design method of these match circuit.In the end of this paper, the experiment results are provided. |
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