In this project Solar panel of 3V is used and a rechargeable battery is provided to store the energy. An ON /OFF switch is provided for user controlled operation. The uniqueness of this project is, the cap can sense the intensity of the sun light temperature and automatically switches on the cooling fan without user’s interference. A temperature sensor is used to detect the hotness intensity of the atmosphere. The user can set the temperature value, at where he wants to switch ON the cooling fan, by adjusting a preset.
A battery charger circuit is designed to charge the battery with the help of house hold AC supply for emergency conditions. This circuit uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.