This circuit is used to indicate two different water temperature trigger points. When the temperature reaches the set value, the LED emits light. The circuit revolves around the LM2904 dual op amp, powered from a 12V automotive system. The thermistor is connected in series with a 10kΩ resistor and is connected to the positive pole of the 9.1V power supply and grounded. Automotive temperature indicator circuit composed of PTC thermistor: Nano atomization, the desktop will not be wet when humidified, and the water molecules are refined into fine particles, which are more easily absorbed by the skin. Touch button operation, press once to continuously emit fog, press twice to intermittently emit fog, different modes have different experiences. Intelligent power-off design, automatic power-off protection for water shortage, prevent dry burning, and use more assured. Home Humidifier,Air Evaporative Humidifier,Home Ultrasonic Air Humidifier,Portable Whole House Humidifier Guangdong Aiyimi Electronic Technology Co., Ltd. , https://www.seventreasuresfan.com