9v Battery with strip Switch L.D.R (Light Depending Resistance) I.C NE555 with Base L.E.D (Light Emitting Diode) 5 pieces. Variable Resistance of 47 KΩ P.C.B (Printed Circuit Board of 555 or Vero board. Voltage regulater (7805). COMPONENTS : a) Battery: For 9v power supply we can use 6pcs dry cell or 6F22 9v single piece battery. b)Switch:Any general purpose switch can be used. Switch is used as circuit breaker. c) L.D.R: (Light Depending Resistance) it is a special type of resistance whose value depends on the brightness of light which is falling on it. It has resistance of about 1mega ohm when in total darkness, but a resistance of only about 5k ohms when brightness illuminated. It responds to a large part of light spectrum. d) L.E.D: (Light Emitting Diode) A diode is a component that only allows electricity to flow one way. It can be thought as a sort of one way street for electrons. Because of this characteristic, diode are used to transform or rectify AC voltage into a DC voltage. Diodes have two connections, an anode and a cathode. The cathode is the end on the schematic with the point of the triangle pointing towards a line. In other words, the triangle points toward that cathode. The anode is, of course, the opposite end. Current flows from the anode to the cathode. Light emitting diodes, or LEDs, differ from regular diodes in that when a voltage is applied, they emit light. This light can be red (most common), green, yellow, orange, blue (not very common), or infa red. LEDs are used as indicators, transmitters, etc. Most likely, a LED will never burn out like a regular lamp will and requires many times less current.
