Automatic frequency tracking circuit for power supply of ultrasonic cleaning machine and frequency tracking method of automatic frequency tracking circuit

Abstract

The invention discloses an automatic frequency tracking circuit for a power supply of an ultrasonic cleaning machine. The automatic frequency tracking circuit comprises an output control module and an input sampling module, wherein the output control module comprises an EMI circuit, a rectification circuit, a full-bridge phase shift circuit, a matching circuit and a DSP main control chip, and the input sampling module comprises a sampling circuit, a phase detection circuit, a current effective value calculation circuit and a DSP main control chip. A frequency tracking method of the automatic frequency tracking circuit for the power supply of the ultrasonic cleaning machine comprises the following steps that S1, outputting the ultrasonic power supply at a certain step pitch from minimum frequency to maximum frequency in sequence to form a response curve; and S2, when a difference value delta Imax of a current peak value of a current period is smaller than the difference value delta Imax of a previous period, allowing the output frequency value of a next period to approach the output frequency value of the previous period; or otherwise, keeping the output frequency value of the next period away from the frequency value of the previous period, and repeating the step. The method has the advantages that the power conversion efficiency of the cleaning machine is improved, optimal working frequency is automatically tracked in real time, and cleaning effect is guaranteed.

Description

Technical field [0001] The present invention relates to the field of power supply automatic investment frequency, and specifically refers to an ultrasonic cleaning machine power supply automatic tracing circuit and its tracing method. Background technique [0002] The optimum operating frequency of the ultrasonic cleaning machine varies with the temperature of the cleaning liquid, the cleaning solution depth, and the size of the cleaning workpiece. In order to achieve the best cleaning effect, the ultrasonic power supply is required to automatically and real-time tracking the frequency of the cleaning machine. [0003] Currently, the current practice is a frequency point corresponding to the maximum current of the ultrasonic power supply. For example, the digital ultrasonic generator is the maximum current method used to recover, the maximum current, the corresponding active current is not necessarily the maximum, conversion efficiency Low, and the cleaning effect is not optimal....

AI Technical Summary

Problems solved by technology

[0003] At present, the usual practice is to track the frequency point corresponding to the maximum current of the ultrasonic power supply in real time. For example, the patent CN200720119112.4 digital ultrasonic generator uses the maximum current method to track the frequency. The active current corresponding to the maximum current position is not necessarily the largest, and the conversion efficiency Low, and the cleaning effect is not optimal

[0004] This frequency chasing method has the following disadvantages: the reactive power component of the output is large, and the power conversion efficiency is low; the larger the peak value of the output current does not mean the better the cleaning effect, but the excessive peak current will damage the life of the ultrasonic vibrator

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