Automatic street light control circuit diagram

Automatic street light control circuit diagram, In this article I am going to post a very simple circuit diagram of automatic street light control using transistor and light dependent resistors. This is a very simple circuit of automatic street light control. I have already posted other articles on automatic street light control and auto intensity control of street lights. These articles used pic microcontrollers and Arduino Uno R3. But in this article only analog electronics components are used to control street lights. You may also check following articles on street light control:

• Automatic street light control using pic microcontroller and LDR
• Automatic street light control using Arduino and LDR
• Auto intensity control of street lights using pic microcontroller

What is automatic street light control?

Gone are the days when people used to control electrical devices manually. Today is automated age. People want things to control itself automatically. For this purpose automatic street lights projects have been designed. Automatic street lights turn themself on and off automatically by sensing intensity of light with the help of lights sensors. There are many lights sensors available in market. But in this project I have used LDR( Light dependent resistor).

Circuit diagram of automatic street light control:

Circuit diagram of automatic street light control is given below. This is very simple circuit with few electronics components.

LDR ( Light dependent resistor is used to sense intensity of light. When intensity of lights falls below minimum level. BC547 npn transistor turn on which in return turns on Q2 npn transistor. Three light emitting diodes are used this project. 12 volt battery is used to power this circuit diagram. You can increase number of LED’s also. Transistors are used as a switch. List of components of automatic street light control circuit is given  below:

List of components:

Category,Reference,Value,Order Code
Resistors,"R1",100k,
Resistors,"R2",1k,
Transistors,"Q1",BC547,
Transistors,"Q2",BC547,
Diodes,"D1",LED,
Diodes,"D2",LED,
Diodes,"D3",LED,
Miscellaneous,"BATTERY",12V,
Miscellaneous,"LDR1",LDR,