What is the structure and working principle of the ultrasonic humidifier mist maker?

What is the structure and working principle of the ultrasonic humidifier mist maker?  

Whether it is a tube type or a transistor type ultrasonic nebulizer, it basically consists of four parts, namely: power circuit, high frequency generator, atomization cylinder, heat dissipation, and air supply device and circuit. 

Some ultrasonic humidifier mist makers are also designed with water level and water temperature automatic control alarm circuits. In the power supply circuit of the electronic tube ultrasonic nebulizer, the circuit is different, some are to double the voltage after boosting the 220V mains, and some are to directly triple the mains to provide the electronic tube with a screen voltage of about 600V or 700V and The grid voltage is about 300V. The power circuit of the transistor-type ultrasonic atomizer is to step down and rectify the 220V mains to a DC voltage of about 40V. The power circuit is the source of energy for the high-frequency generator. The  Oscillation frequency is designed according to the natural frequency of the piezoelectric wafer, generally selected between 1.4MHZ-1. 7MHZ. The high-frequency electric energy output by the high-frequency generator is added to the positive and negative poles of the piezoelectric wafer, and the piezoelectric wafer will generate mechanical oscillations. In this way, the high-frequency electrical energy is converted into ultrasonic waves along the thickness direction of the wafer through the piezoelectric wafer. Because the ultrasonic wave destroys the liquid surface inertia and surface tension and produces cavitation, when the liquefied surface tension wave is sufficient, the aerosol will fly out at the wave peak. The above is the structure and working principle of the ultrasonic nebulizer.