How to Make an Automatic Light On/Off Switch Circuit | DIY Electronics Tutorial

In this video, I demonstrate how to build a simple automatic light switch circuit using an LDR (Light Dependent Resistor), BT136 TRIAC, and other basic components. This circuit automatically turns the light on in the dark and off in the presence of light.

Components Used:

LDR (Light Dependent Resistor)

BT136 TRIAC

100K Preset

DIAC (DB3)

47K Resistor

220V Power Source


This project is perfect for beginners in electronics and helps save energy by automating the lighting process.

🔧 What you'll learn in this video:

How an LDR works in light-sensing circuits.

The role of TRIAC and DIAC in controlling AC loads.

Step-by-step assembly of the circuit.


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