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Automatic Street Light

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Automatic Street Light Control System is a simple and powerful concept, which uses transistor/Ic as a switch to switch ON and OFF the street light automatically.

List of Components

  • 555 Timer IC
  • LDR (Light Dependent Resistor )
  • LED (Light Emitting Diode)
  • Potentiometer
  • Resistor 1* 1k ohm
  • Resistor 1* 220 ohm
  • 5V Battery
  • Printed Circuit Board


Easy to operate. Needs no manual operation for switching ON and OFF. When there is a need of light it automatically switches ON. When darkness rises to a certain level then sensor circuit gets activated and switches ON and when there is other source of light i.e. daytime, the street light gets OFF. The sensitiveness of the street light can also be adjusted.

555 Timer IC is the main part of the circuit that works as a comparator. All the working of this circuit depends on the working of the 555 timers Ic. In this circuit pin, 3 produce output which has just two states high and low. Output goes to high when trigger pin is at a lower level than the 1/3rd level of the power supply voltage and output goes low when trigger pin 2 is at above then 1/3rd of the power supply voltage. In this circuit pin, 4,6 and 8 are connected to the power supply. Here we use LDR to detect the presence of light which is formed a potential divider circuit with the help of 1k ohms resistor. LDR is a special type of resistor whose value depends on the light. The output of this divider circuit is given to trigger pin of the 555 timer IC.

Connection diagram



Streetlighting helps to reduce night-time crashes by improving visibility
Street lighting helps people to feel safe and can help to reduce crime.
Can reduce pedestrian crashes by approximately 50%. Can help to aid navigation
energy control base conservation