Article’s

Temperature control is an important requirement in electronic systems to ensure stable operation and to prevent damage caused by excessive heat. This work presents the design and development of a temperature-based fan controller using an IC 741 operational amplifier and basic analog components. An NTC thermistor is employed to sense ambient temperature variations and convert them into corresponding electrical changes. These changes are processed using a comparator circuit, where the sensed signal is evaluated against a predefined reference level adjusted through a potentiometer. When the temperature exceeds the set limit, a transistor switching stage activates the cooling fan automatically. The proposed system operates entirely in the analog domain and does not require any programmable devices, making it simple, economical, and suitable for educational applications. Experimental observations indicate reliable switching behavior and effective thermal response, demonstrating the practicality of the design for basic temperature control applications.