Automatic Fan for Transformer Cooling

Transformers experience continuous thermal stress due to load variations, copper losses, and environmental conditions. Excessive heat accelerates insulation ageing, reduces reliability, and can lead to catastrophic failure. This paper presents a low-cost automatic cooling system that uses a DS18B20 digital temperature sensor, Arduino Uno, and a relay-driven 12V fan to regulate transformer temperature without manual intervention. The system continuously monitors temperature and activates forced air-cooling whenever the preset threshold is exceeded. Software-based hysteresis prevents relay chatter and ensures smooth operation. The proposed solution is simple, economical, and well-suited for small distribution transformers in rural or unattended environments.