LED Turn on and off depending on the light.

This is very simple circuit build with 555 Timer IC and a LDR, heart of this circuit is 8 Pin DIP IC 555, Pin 1 for Ground power supply & Pin 8 used for positive power supply Pin 4 is for reset purpose, Variable register use here for adjustment of the LDR (light Dependent register) pin 3 is out put for this IC, 4.5 volt DC power supply use here but you can use more voltage like 6 to 12 Volt using proper register in the series of LED