Components :
1.LED (2)
2.Transistor - BC547 (2)
3.Capacitor - 10UF (2)
4.Resistor - 100k ohm (2)
5.Resistor - 330 ohm (2)
Input Supply : 5 - 9 V DC
Circuit Diagram :
Concept:
Switching principle of transistors
Charging and Discharging principle from Capacitors.