Automatic street light |LDR Sensor|Automatic Light Switch

#automaticlight
#streetlightswitch
#ldrswitch
#nightswitch
This is very simple circuit based on ldr sensor.Ldr is known as light dependent resistor.When falls on ldr then switch will be open and lamp will be off.When there is darkness on ldr then switch will be on.Such type of circuits are use for street lights.
Require Components
1.2x2N 3904 transistors
2.Breadboard
3.Connecting Wires
4.Relay
5.Lamp
6.Power Supply.