Automatic On/Off Temperature Sensor Fan

Controlled Automatic temperature- fan system. The primary objective is to create a low-cost, reliable circuit that automatically activates a cooling fan when the ambient temperature rises above a predetermined threshold and deactivates it once the temperature drops. This is achieved without using microcontroller or any programming. The core system is an NTC thermistor acting as the temperature sensor, which triggers a 5V relay module to switch a DC fan motor on or off. The project demonstrates a fundamental application of analog electronics for automated environmental control, offering simple and effective for cooling small spaces and electronic components.