How does the project work?
The project has a simple circuit that turns on the light automatically at night. It is based on 2 NPN transistors (BC547) used in Darlington configuration, and a photoresistor. With the help of POT1 the light sensitivity of the LDR photoresistor can be adjusted.
What is the Darlington configuration?
The Darlington configuration consists in connecting the load of a common collector transistor, of another transistor, thus multiplying the amplification factors in the current.
List of required components:
1 x R1 = 120k / 100k
1 x POT1 = 100k
1 x T1 = BC546 / BC547 / 2N2222
1 x T2 = BC546 / BC547 / 2N2222
1 x photoresist (LDR)
4 x LEDs
2 x Terminal contacts
1 x Breadboard test board + connecting wires
For a better understanding of the operation of the circuit and to make this assembly on the breadboard we will need electronic scheme presented below:
Placing components on breadboard
To better understand operation of this project, I have attached the video below:
