Circuit Diagram Knowledge

This is a simple LED flasher project that built uses a common 555 timer IC for its operation. It is configured as an unstable mode which means that its output is a square wave oscillator. Two LEDs are connected to its output in such a way that when one LED is ON, the other LED will turn OFF. It circuit uses only 10 simple parts that are easily available at any electronic shops. This is the simple figure of the circuit;


Principle work of this circuit is capacitor C2 charges exponentially through resistors R1, R2 and the resistance of the variable resistor. When C2 has charged to about 2/3 VCC it stops charging and it discharges to about 1/3 VCC through R2 and the VR resistance via pin 7. This is the standard operation of a 555 timer. When a Vcc of 5 V to 15 V DC is applied to the circuit, the LED will start to flash. The frequency of the flashing can be changed by varying the resistance of the potentiometer.