Frequency variation of ultrasonic generator

With the development of modern electronic technology, especially the development of microprocessor (UP) and signal processor (DSP), the function of ultrasonic generator is more and more powerful, but no matter how it changes, its core function should be described as follows: only each part in the implementation of the technology is different. An ultrasonic generator produces a signal of a specific frequency. The signal may be a sinusoidal signal or an impulse signal. The specific frequency is the frequency of the ultrasonic transducer. The commonly used ultrasonic frequency in ultrasonic equipment is 25kHz, 28kHz, 35kHz, 40kHz. I believe that the use of 100kHz will gradually expand. A relatively complete ultrasonic generator should also have a feedback link, which mainly provides feedback signals from two aspects:

Is to provide an output power signal. We know that when the power supply (voltage) of the ultrasonic generator changes. The output power of the ultrasonic generator will also change. At this point, the size of mechanical vibration is reflected in the ultrasonic transducer, which leads to unstable cleaning effect. Therefore, it is necessary to stabilize the output power and adjust the power amplifier through the power feedback signal to make the power amplifier stable.

The second is to provide frequency tracking signals. When the ultrasonic transducer works at resonant frequency, it is efficient and works stably. The resonant frequency of ultrasonic transducer will change due to assembly and aging. Of course, the change in frequency is just a drift, and the change is not very big. The larger frequency tracking signal can control the signal ultrasonic generator, so the frequency of the signal ultrasonic generator can track the resonant frequency of the ultrasonic transducer within a certain range. Let the ultrasonic generator work in the state.