Its function is to convert the commercial power (220V or 380V, 50 or 60Hz) into a high-frequency AC signal matched with the ultrasonic transducer. From the form of amplification circuit, linear amplification circuit and switching power supply circuit can be used, and high-power ultrasonic power supply generally adopts the circuit form of switching power supply from the perspective of conversion efficiency.
The principle of the generator is that the signal generator first generates a signal with a specific frequency, which can be a sine signal or a pulse signal. The specific frequency is the frequency of the transducer. The ultrasonic frequencies used by general ultrasonic equipment are 20KHz, 25KHz, 28KHz, 33KHz, 40KHz and 60KHz. /kloc-above 0/00khz is not used much now.
Extended data:
When ultrasonic is working, the natural frequency of the vibration system drifts due to the changes of temperature, stiffness, static load, machining area and tool wear, which requires the ultrasonic generator to have the function of automatic frequency tracking. At the same time, in order to ensure the processing quality and protect the ultrasonic system, the generator is required to have the function of adjusting the output power according to the load.
In industrial production, even if the frequency of ultrasonic transducer is well tracked, the change of AC voltage provided by ultrasonic generator and the instantaneous change of ultrasonic from no-load to load from tens of watts to several kilowatts in a few milliseconds make the amplitude and power of ultrasonic transducer change, and the transducer can't work efficiently, which makes the products processed by ultrasonic wave inconsistent. This is a common problem in ultrasound equipment.
In order to adapt to the industrial production process, the ultrasonic frequency electric energy transmitted by the generator to the transducer is not affected by the change of load power and input voltage, and the automatic amplitude modulation and constant amplitude function of the generator changes within 1 millisecond.
References:
Baidu encyclopedia-ultrasonic generator