Working Principle of Ultrasonic Humidifier （one）
1. Power supply
The power supply part is generally two-way input. One way is to supply power to the fan. One way is to supply power to the shock board. If the shock board and the fan voltage are the same, you can do it all the way. If the power board uses a transformer, it supplies power to the oscillating circuit and the fan after step-down, rectification, and filtering. This relative switching power supply circuit is relatively simple, but the transformer is also too bulky, especially for a mini humidifier. It is a burden, but the use of switching power supply circuit design is sometimes more complicated, depending on the actual situation.
2. Power switch
Here, the power switch function is to turn on the power. If the potentiometer adjusts the amount of fog, the position at which the potentiometer starts is the position where the power is turned on. When the rotary potentiometer turns on the power, it also starts to adjust the amount of humidification, but if it is controlled by PWM signal If this connection position is directly short-circuited.
3. Water level detection
Water level detection is now mostly used with a reed switch and a magnetic ring to detect the lack of water. The reed switch is a magnetically sensitive switch, usually made of two soft magnetic materials. Simply put, the two reeds are not in contact when there is no external magnetic field, and will close when a sufficient magnetic field is encountered. Therefore, when there is no shortage of water, the magnetic ring is floated by the water, the magnetic field causes the reed switch to close, the control board detects a change in the signal, the oscillating circuit starts to work, the green indicator light illuminates, and at the same time, humidification is turned on; when the water is deficient, the water surface drops. The magnetic ring is moved away from the reed switch. At this time, the reed switch contact is opened, the humidifier stops humidifying and disconnects all outputs, and the red color indicates a water shortage state. Another is the surface probe to detect water shortage, which is less of an application.