Humidifier working principle diagram

Household humidifiers currently on the market generally use ultrasonic methods to atomize water, and blow the atomized water vapor out of the housing through a fan to achieve the effect of humidifying the air. The electrical schematic diagram is shown in the attached figure. After the mains power passes through the switching power supply, it outputs two voltages, 36V and 12V. Among them, 36V supplies the water vapor atomization module. 12V powered fan. In the circuit, D1 and D2 are the water shortage indicator light and the work indicator light respectively; the reed switch is the liquid level detection switch; RT1 is the fog size adjustment potentiometer. Taking 02 as the core and its peripheral circuits are ultrasonic generating circuits.

1. Working principle of diffuser

After turning on the power. The switching power supply outputs 36V and 12V. When the water storage tank has not been placed on the base or there is lack of water in the water storage tank, the magnet moves away from the reed switch and the reed switch springs open. Ql is turned on, the water shortage indicator light Dl is on, and the work indicator light D2 is off; the base of Q2 has no voltage, and the ultrasonic generating circuit does not vibrate. When an appropriate amount of water is added to the water storage tank, the magnet is close to the reed switch, the reed switch is attracted, and QI is cut off because its base becomes high level. At the same time, D2 is on and Dl is off. The current passes through the reed switch and is divided by R3 and R6, and then sent to the ultrasonic generating circuit through R5 and RT1. The ultrasonic generating circuit starts to vibrate, thereby generating mist, which is blown out of the casing by the fan and reaches the room. The effect of humidifying the air.

2. Common troubleshooting

[Example 1] The atomized water vapor cannot be blown out of the casing.

Maintenance: Turn on the heater, plug in the power, and find that the fan does not rotate. After removing the fan, measure the switching power supply output 12V. If it is normal, it is judged that the fan is bad. After replacing the fan, the fault is eliminated.

[Example 2] No response when power is turned on.

Maintenance: Turn on the power supply, measure 36V and 12V, and there is no output. It is judged that the switching power supply is faulty. After disassembling the switching power supply and inspecting it, the rectifier part was blackened. After measurement, one of the rectifier diodes (1N4007) was damaged. After replacing it, the fault was eliminated.

[Example 3] The water vapor atomization is very weak and the adjustment knob does not work. 'Inspection and maintenance: After measurement, the output of 36V and 12V is normal, there is no breakdown phenomenon in Q2, and the resistors and capacitors are not burned black. However, it is found that there is a lot of dirt in the water storage tank, and it is accumulated on the surface of the transducer device and the bottom wall of the pool. A layer of scale will be removed completely after a meal and after being powered on, the atomization effect will return to normal.

Tip: In daily use, many malfunctions of humidifiers are caused by scale. Therefore, the water storage tank and liquid level detection part of the humidifier should be cleaned frequently to prevent dirt deposition. If conditions permit, consider using pure water as the water for the humidifier. .