Diyprojectslab is an education website in Electronics Engineering Site related to Projects & Tutorials in Embedded, Arduino, Internet of Things (IoT), Tips, Tricks, How It Works, Projects..

Make Anti Thief Alarm Device

Pinterest LinkedIn Tumblr +

Hey guys let’s make anti thief alarm device in this project tutorial which i explained in very easy and short steps

Sometimes we hear in news thief entering house and stealing valuables we need some device to alert us or scare them away

Hence this problem led to origin of this idea to make small and portable thief alert device

In this article we will make a device that alerts you by making loud buzzer noise if any human is detected

What is anti thief alarm device

It’s a device which alerts by buzzer noise when it detects human

It’s a natural tendency of people to always remain tensed while going out of house

Thinking about what if some intruders enter our house

Don’t worry if you are one of them this device can help you!

Hence in that situations this device is very helpful

Why make anti thief alarm device

There are already plenty of alarming device commercially available in the market but the price of the can go little bit high which most of us couldn’t afford

No problem! here we teach you how to make on your own

There are plenty of other tutorials available online which shows to make anti theft alarm device but most of them use arduino or other micro controller board 

If Arduino was use to make this project it would add a layer of complexity as it requires coding so we came up with easy alternative

In this project we are using easily available electronics mainly cheap ones to make this which ensures most of the people can afford to build this

Supplies required

  • Rechargeable battery
  • Container from old LED box as an alternative MDF box or cardboard does the job
  • PIR Sensor module
  • Simple on off switch
  • Buzzer
  • Transistor 2N2222A
  • Wires for conection
  • Hot glue or double side tape
Distance alert Device

Supplies for Distance alert Device

Before starting to build circuit let me go through basic functions of each component

PIR Sensor

It is a device which detects obstacle when something in front of it passes by

It uses infrared signals to detect presence of any object

From below visual you can see how does PIR sensor looks like you might be wondering what that white color bulb thing does

It prevents interference of Infrared signals from outside environment so we get accurate response from this sensor

Coming to circuitry part this sensor has 3 terminals, Gnd, positive and signal output

PI SENSOR for social distance alarm device


Gnd and positive will be for providing power to this sensor

when its on it passes ir signals continuously as soon as something obstructs this signal deflection occurs

Deflection in signal causes output signal which will be processed further

Output signal coming out of this will be very weak hence not suitable for further use

This problem is overcome by using amplifier in our case Transistor 2N2222A

Transistor 2N2222A

This amplifies the signals so that it can be sent to buzzer for some sound output

Circuit to make social distance alarm device

making steps

Making steps

Circuit is very simple to make as you can see from image above best part here is no pcb is used to make this

For beginners to electronic this might seem little bit of complex so here is decode of circuit diagram!

  1. Power supply from battery will be connect to PIR sensor via switch as barrier to control power supply
  2. To end of output from PIR we will add transistor to amplify weak signals
  3. One end of buzzer will be given to battery (For protection i use resistor)
  4. Other end of buzzer is connect to transistor output part where we get amplified signals
  5. If wires are not pre soldered make sure to do it by yourself before building circuit

We have our circuit ready for this project now final step is to put all this together in a box

finishing part

Finishing part

I use transparent plastic case from my old led light box, use double side tape or hot glue to fix parts in place

For switch i made small hole in box

The box which i use come with clips to lock which i found additional advantage!

Finished project is as seen above, hope you will definitely try to make this

How to use anti thief alarm device

Just turn on the device and place your hand in front of the sensor at this point buzzer will start to make sound (it definitely will)

This can also be hidden on side of door so that nobody easily notices

When some intruders enter this will make noise and scare them away

If you want arduino version of the same project let me know

This project works fine without any issues, if you have any problem when making this please feel free to convey in comment box

That ends our project consider checking out our recent top rated article which shows how to make mini Bluetooth boom box here 


About Author

Leave A Reply