Make an Simple Motion Sensor Relay Board (PIR)




Introduction: Make an Simple Motion Sensor Relay Board (PIR)

About: Just a Small Tinkerer ;)

Hi Everybody,

After an Successful Hit & Featured with " Make an Simple Motion Sensor Led Light"

I Started thinking about anything else....

So , I am here with ' Make an Motion Sensor Relay Board! "

It's Just the Same but with a improvement which i got from previous instructable Comments.

In this instructable , you will need a knowledge of Transistor and Relay Coils...

So Everyone is Welcomed to Make this ....

I Hope everyone would Like this Instructable too.

if you like this then, Do Vote this instructable for 'Home Automation Contest' .....

Step 1: Gather the Parts

Many Items are Available on Ebay but Try getting most of the Stuff from Local Electronics Store Because they have comparatively lower prices.

Anyways Let's see the List:

1) PIR ( Main ) ( HC-SR501 )

Always check the Pinout of PIR ,Some Models have different Pinout.

Mine had (( VCC | OUTPUT | GROUND ))

2) 12v Relay 5A ( Often Called as Suger Cube)

3) 10k Resistor

4) Screw Terminal 2 Pcs.

5) 1N4007 Diode

6) BC547

7) Piece of Copper Clad PCB

Step 2: Circuit

So Here is the Schematic...

A Simpler Explanation for Everybody :

Here PIR, When senses Motion ,Outputs - 3.3v - so we would be using this output pin to turn on and off the transistor which is on board. In Return Transistor Will complete the Circuit and Relay will also turn on and off with transistor.

I Hope this can't be more simpler than this lol.....

Remember : Diode is necessary to control voltage spikes from relay .

Step 3: Artwork - Eagle .Brd File

Provided with Both .brd file and ready to print pdf.

Step 4: Toner Transfering, Etching and Drilling

I Forgot to take pictures of these steps but i have shown you 'how to do this' in my Previous Instructable.

Step 5: Solder : Right Angle Header

We would be using a Right Angle Header to Position Motion Sensor Towards us.

Step 6: Solder : 10k Resistor

Solder the 10k Resistor , it is needed for relay to function properly and for transistor to work.

Step 7: Solder : BC547 Transistor

Make Sure you solder the Right Position.

(Flat Side Towards Relay)

Step 8: Solder : 1N4007 Diode

Check the Stripe at one End!

Make sure it's soldered According to the Photo....

Step 9: Solder : Relay

Nothing to say on this :P

Step 10: Solder : Screw Terminals

Solder the Screw Terminals on both ends.

Step 11: Solder : PIR

Keep the PIR Header Parallel to the Header on Board and Solder it .

Step 12: Finished!

So Here we finish and Let's Test it!

Power it with 12v Adapter .(Nothing Higher Than this! Otherwise Relay will get damaged)

Give sensor a Warm-up time for 10-30Sec. and It's Ready.....

Please Vote this for Home Automation Contest :)



    • Metalworking Contest

      Metalworking Contest
    • Water Contest

      Water Contest
    • Tiny Home Contest

      Tiny Home Contest

    30 Discussions

    Will the light will stay ON until there is no motion detected?

    1 reply

    It senses someone it works /turn on Lamp as per delay setting.

    where do i power it where do i put the source?? and where do i put the AC or appliances im going to use? sorry im just a beginner.

    Bad circuit, no work..! Where is the voltage? The pir works with 5 volts, 12 would burn it , Pir module is 5 volts

    1 reply

    If you Ever Prototyped with HC-SR501 Modules Then you would have known that these have a OnBoard voltage Regulator which Accepts Inputs ranging From 5v - 12v.

    Please where will i connect the 12vdc to power the circuit?


    2 years ago


    i am new to this electronic thing, and would just like to know, (really do not want to sound stupid), but here goes ......

    i understand the complete circuit, except for where do you connect the 12vdc ? (from what i can see looks like (NC = 12VIN / COM = 12V GDN)


    hey guyz

    how many time the light stay on with this motion sensor ?


    2 years ago

    Outstanding 'ible! Very clear instructions, pictures and reasons for doing everything you did. You didn't assume that we were engineers (or idiots), as some do. I had bought the PIR board and relay a couple of years ago, but never was very good at interfaces, so they had just sat in a drawer, collecting dust and my disappointment that I couldn't make my project. Now I can, thanks to you.

    1 reply

    Thanks! I like People getting Helped by my Ibles ...


    2 years ago

    hi! I am a newbie! correct me if i am not on the right place. Is this light turned on if it detected a motion? (the relay word confused me) thanks!

    1 reply

    2 years ago


    I tried your very usefull project. I am new on circuit. I have a problem on your circuit.

    relay triggered coil poles have 12 volt but Com, NC, NO have no power.
    Actually when ı connect a strip led to coil poles, it lights or on. What
    is my wrong connection.

    I will be appreceiate.

    Thank you for sharing

    2 replies

    Reply 2 years ago

    Thank you.

    I Hope this Diagram Helps.

    You have to connect COM Pole to AC or DC Voltage according to your load device.


    bro plz let me know. how to connect this board to ac appliances like bulb aur fan

    1 reply

    I Hope this Diagram Helps.

    You have to connect COM Pole to AC or DC Voltage according to your load device.


    3 years ago

    sorry sir, i'm newbie and i want to ask why you use bc547 and 10k ? is there reason for that? thanks :)