When light falls on the exterior side of the Light Dependent Resistor (here the 100K resistor), the circuit flashes. The 555 timer IC, which is wired into the circuit as an astable multivibrator, is an important aspect of the circuit. The circuit is controlled by a 100k variable resistor (LDR), which stimulates the flash frequency at the required amount of darkness. The circuit works with a DC voltage range of 9 to 12 volts.
