How to make Motion Sensor light Homemade | PIR light sensor | Automatic light switch

(Last Updated On: February 13, 2020)

motion sensor


In this Tutorial you will learn how to control a 110 or 220vac Disco Light using only PIR Sensor. PIR Sensor is one of the most commonly used sensors for motion detection. So far this is my third tutorial on a PIR motion sensor.

In first tutorial I covered all the basics, including the pinouts, the purpose of the variable resistors, and how to use a PIR sensor with Arduino.


While in the second tutorial I used this PIR sensor with GSM SIM900A module and designed a security system.


In this Tutorial we are not going to use Arduino or any other microcontroller. We will only be using a PIR sensor to control a 12v relay. This tutorial covers

  1. Circuit explanation
  2. Interfacing and finally
  3. Testing

Let’s get started!!!!!

The components and tools used in this project can be purchased from Amazon, the components Purchase links are given below:

Arduino Uno:
Mega 2560:
terminal block connector:
Disco light:
lm7805 Voltage Regulator:
330 ohm resistors pack:
5v 2A adaptor:
2n2222 npn transistors:
10k Resistor:
lm7805 Voltage Regulator:
330-ohm resistors pack:
female DC power jack socket:
470 uf capacitors:
5×7 cm vero board:
female headers:
connection wires:
Super Starter kit for Beginners:
Jumper Wires:
Bread Board:
12v Adaptor:
PCB plate:
Variable Supply:
Digital Multimeter:
Vero Board / strip board:
Soldering iron kit: “best” You guys should definitely purchase this:
Solder wire:
Wire Stripper:
wire cutter:
PCB small portable drill machine:


Please Note: these are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!


Circuit Diagram:

motion sensor

This is the regulated 5v power supply based on the LM7805 voltage regulator. This power supply will be used to power up the PIR Sensor Module. This is the dc female power jack. A 10uf capacitor is connected at the input side of the 7805 voltage regulator. Another 10uf capacitor is connected at the output side of the voltage regulator. A 330 ohm resistor is connected in series with a 2.5v led. This is a current limiting resistor. I have a very detailed tutorial on led and how to calculate the value of the current limiting resistor; the link   is given in the description.

A wire from the output of the voltage regulator is connected with the Vcc pin of the PIR sensor module, and also make sure you connect the ground of voltage regulator with the ground of the PIR Sensor module. The Out pin of the pir sensor is connected with the base of the 2n2222 npn transistor through a 10k resistor. the emitter of the 2n2222 npn transistor is connected with the ground while the collector side is connected with one side of the relay coil and the relay coil other side is connected with the 12 volts.

For the Interfacing and Testing watch video tutorial given at the end.

Watch Video Tutorial:

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About the Author: Engr Fahad

My name is Shahzada Fahad and I am an Electrical Engineer. I have been doing Job in UAE as a site engineer in an Electrical Construction Company. Currently, I am running my own YouTube channel "Electronic Clinic", and managing this Website. My Hobbies are * Watching Movies * Music * Martial Arts * Photography * Travelling * Make Sketches and so on...

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