Introduction: Dark Sensor Using LDR(light Dependent Resistor)
This circuit sense the darkness and turn on the LED
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Components Required:
LDR - 1
10k trimpot - 1 or 10k resistor
1k resistor - 2
BC 547 transistors - 2
LED - 1
battery - 9v
Step 2: Dark Sensor Schematic Circuit Diagram
This is the schematic circuit diagram. it is drawn in eagle cad pcb software. also i have attached eagle schematic file here...
Step 3: Dark Sensor Pcb Board Layout Diagram
finally this is the pcb board layout for the dark sensor. also i have attached the eagle board layout file here
Step 4: Final Output
In this picture the LDR detects the dark and turn on the LED