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

Picture of Make an Simple Motion Sensor Relay Board (PIR)

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

Picture of 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

Picture of 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

Picture of 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

Picture of Solder : Right Angle Header

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

Step 6: Solder : 10k Resistor

Picture of 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

Picture of Solder : BC547 Transistor

Make Sure you solder the Right Position.

(Flat Side Towards Relay)

Step 8: Solder : 1N4007 Diode

Picture of Solder : 1N4007 Diode

Check the Stripe at one End!

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

Step 9: Solder : Relay

Picture of Solder : Relay

Nothing to say on this :P

Step 10: Solder : Screw Terminals

Picture of Solder : Screw Terminals

Solder the Screw Terminals on both ends.

Step 11: Solder : PIR

Picture of Solder : PIR

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

Step 12: Finished!

Picture of 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 :)


jmamonong (author)2016-12-15

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

jmamonong (author)2016-12-15

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.

LucianoS39 (author)2016-11-22

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

Ayush Sharma (author)LucianoS392016-11-23

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.

arnold4u (author)2016-04-16

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

nicobo (author)2016-04-12


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)


ShinjiN2 (author)2016-04-12

hey guyz

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

jaxboy (author)2016-03-07

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.

Ayush Sharma (author)jaxboy2016-03-09

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

fmpo (author)2016-01-05

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!

Ayush Sharma (author)fmpo2016-01-06

Yes, You are Right.

hne (author)2015-12-23


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

hne (author)hne2015-12-23

Thank you.

Ayush Sharma (author)hne2015-12-23

I Hope this Diagram Helps.

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

ShashiY (author)2015-10-17

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

Ayush Sharma (author)ShashiY2015-12-23

I Hope this Diagram Helps.

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

poncos (author)2015-07-05

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

I'm just wondering why your schematic does not show the second two screw terminals?

Because Everybody knows we have to supply power on VCC and GND.

doctorlock (author)2015-06-02

you can buy a relay timer board off ebay for a buck! just takes from two to four weeks to get it from china. just got some and going nuts with this type of stuff.

good job anyway, comes out about the same as the online ones but without the adjustable delay to keep things on or off for a specific amount of time.

ABHINAV REDDY (author)2015-05-27

Why did you add diode, how to on or off using this module

UlyssesL (author)ABHINAV REDDY2015-05-28

Its to protect the left side circuitry from voltage spikes. You see coils(inductors) have a property that the voltage across it is proportional to how fast the current through it changes. Now when that coil is energized(has current) and suddenly the transistor switch turns off, the current in the coil will have nowhere to go... meaning it needs to suddenly drop to zero. This will cause a high voltage to appear across the coil which in turn might damage the circuitry on the left side of the drawing.

ABHINAV REDDY (author)UlyssesL2015-05-28

Thanks but when will the relay switch on

UlyssesL (author)ABHINAV REDDY2015-06-01

I havent tried it actually but in Step 2, under A Simpler Explanation for Everybody :the author said, when there is movement, the PIR outputs 3.3v which will turn ON Q1, and energize the coil turning ON the relay. hope it helps

klubonja (author)2015-05-30

Great job

samuel123abc (author)2015-05-27

Great job, tanks for sharing!

How to activate this module

diy_bloke (author)2015-05-26

nice. but can i suggest a female header so you can just push in the PIR, and remove it again if necessaty.

About This Instructable




Bio: Just a Small Tinkerer ;)
More by Ayush Sharma:Pocket ESP8266 Weather Station [No ThingsSpeak] [Battery Powered]Make an Simple Motion Sensor Theft Alarm! (PIR) (DIY) How to Make ESP8266 Ultra Mini & Simple Relay Home Automation Board
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