The principle of frequency chasing of humidifier aroma diffuser atomization film is revealed

May 17, 2021

The principle of frequency chasing of humidifier aroma diffuser atomization film is revealed

Humidifiers and aroma diffusers are small household appliances that we often use. The principle is very simple. MCU is the main control. The MOS tube is driven by PWM through the triode push-pull circuit, so that the atomizer works near the resonant frequency, and the atomizer generates high Frequency vibration makes the water atomized to produce water mist, which humidifies the air.

Among them, the principle of water detection and frequency tracking of the atomized film is involved. Many MCU manufacturers encapsulate this part of the code, so many small partners are not clear about the basic scheme of water detection and frequency tracking through the atomized film. Analyze it.

◆Frequency chasing principle:

The humidifier developed based on the single-chip microcomputer can automatically chase the frequency to the resonance point. Its realization principle is as follows:

The relationship between the voltage across the atomizer sheet and its oscillation frequency is in a normal distribution, as shown in the figure below:

Through the change relationship between voltage and frequency, the software algorithm can be used to track the best frequency point, so that the atomization film always works at the best frequency point.

◆Principle of water inspection:

The humidifier developed based on the single-chip microcomputer uses the change of the voltage characteristic of the atomizing film when there is water and when there is no water to detect whether there is water. During normal operation, the oscillating voltage of the atomizing film is stable within a normal range, with little change. When the water volume is reduced to a certain level or there is no water, the voltage across the oscillating plate will suddenly increase or rise. Through such a change law to determine whether there is water in the humidifier.