Ultrasonic driving power supply for automatically tracking series resonance frequency of transducer

Abstract

The invention relates to the technical field of ultrasound and power supply, and provides a driving power supply with double-channel current sampling and precise frequency control functions, and a real-time tracking method of the series resonance frequency of a transducer, in order to realize an ultrasonic driving power supply for automatically tracking the series resonance frequency of the transducer. The ultrasonic driving power supply for automatically the tracking series resonance frequency of the transducer provided by the invention comprises the following four parts, that is, the first part is a driving circuit; the second part is a sampling matching circuit; the third part is a signal conditioning circuit; and the fourth part is a micro-control module that is composed of a microprocessor. The ultrasonic driving power supply provided by the invention is mainly applied to the design and manufacturing occasions of frequency-controlled power supplies.

Description

technical field [0001] The invention relates to the technical field of ultrasound and power supply, in particular, to an ultrasonic driving power supply for automatically tracking the series resonance frequency of a transducer. Background technique [0002] Power ultrasound has important applications in ultrasonic machining, ultrasonic casting, ultrasonic welding, ultrasonic cleaning and other fields. The driving power supply of ultrasonic transducer is an important part of the power ultrasonic system, and its key technology is to track the frequency of the transducer. A typical frequency tracking system is implemented in a phase-locked manner. However, due to the following reasons, there has been no good solution to the frequency tracking problem of the transducer. [0003] (1) The piezoelectric ultrasonic transducer itself has multiple characteristic frequencies, including resonant frequency, anti-resonant frequency, series resonant frequency, parallel resonant frequency,...

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Problems solved by technology

A typical frequency tracking system is implemented in a phase-locked manner. However, there has been no good solution to the frequency tracking problem of the transducer due to the following reasons

[0005] (3) It is a common method to use a matching network to tune the transducer so that the resonant frequency of the transducer is consistent with the series resonant frequency. The matching methods are divided into dynamic matching and static matching. Dynamic matching has complex systems and operations Difficulty, low degree of automation, etc., while the static matching parameters are calculated from the transducer parameters, which are greatly affected by the dynamic resistance. When the load changes greatly, the static matching will fail

[0006] (4) The phase-locked frequency tracking method needs to detect the phase of the voltage and current. Due to factors such as high-power signal interference, sensor errors, and high-order harmonics in the square wave drive signal, the error of the sampling signal is relatively large. In order to improve the accuracy of the sampling signal Accuracy, low-pass or band-pass filter circuit is often added, and in the process of frequency sweep, the sampling signal frequency changes as high as several hundred to several thousand Hz, and the filter with fixed center frequency cannot meet the requirements of use, thereby affecting the frequency tracking accuracy

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