Solar rechargeable fans become necessary for a common man. Especially, in summer, the power shortage is more. To overcome from the difficulties caused by power shortage this innovative project is designed. This project is designed for 12V motor.
This 555 timer based PWM controller features almost 0 to 100% pulse width regulation using a variable potentiometer, while keeping the oscillator frequency relatively stable. This project is designed to operate the motor with a frequency of about 170 to 200 Hz. Any 555 chip will do, CMOS is fine as well.
A rechargeable lead acid battery of 12V is used to power the circuit. A solar panel is connected to the battery for charging the battery by means of solar energy. A PN junction diode is used to control the charge current for unidirectional flow.
The battery also can be charged through 230V house hold supply. This charge circuit uses regulated 12V, 750mA power supply. 7812 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/18V step down transformer.