A simple dark sensing circuit.

Below you will find the circuit schematics and list of parts for this setup, and also a video showing step by step how to build the circuit on breadboard.

Darksensor.PNG

Components list:

T1 - BC547

R1 – 330Ω

R2 – 56KΩ

LDR - LDR

L1 - LED

I used a 56KΩ resistor in this example for increased sensitivity to darkness. You can use a 100KΩ POT to make an adjustable sensor.

 

Step by step video guide on how to build the circuit according to the schematic above: