Smart Street Light (Without Microcontroller)

The function of smart street light can be controlled by a simple Transistor. It is a very interesting project, and it is very simple to construct. Here in this topic i'll explain how to make it without any IC and microcontroller.

Not using a microcontroller results in smaller form factor and reduces costs as well.

Material Required:

NPN transistor(BC547)
LDR
Resistor(250E)
AC / DC source to swich on the bulb.
5 volt relay.
Bulb
power supply

Step 1: Connect Components

Connect the transistor in voltage divider bias condition.

Here the proteus diagram is showing that you've to use two 5 volt power supply. You can use only one 5 volt source to make this circuit, so follow the breadboard circuit. Connect transistor base to the LDR as it is connected in above pictures.

Step 2: Connect the RELAY

In RELAY there are 5 pin. The [+ve terminal of DC circuit ] and [- ve terminal of DC circuit ] is allotted for relay switch on purpose, which is coming from the transistor.

Just follow the breadboard circuit. The yellow wires indicates which pin you've to connect to the relay for giving supply 5 volt to relay.

COMMON and NC will link the main supply + ve terminal of supply voltage which is used to turn on the bulb.
and the supply -ve terminal will directly connect to the ground of supply voltage.