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Hello friends! I'm Ostin,I ll demonstrate how to control a AC light with Arduino using relay module.It is a simple project and also very dangerous as we are going to deal with high voltage 220v . Do not attempt if you are a amateur in dealing with high voltage.

I'll answer few basic questions, which hits when you are novice!

Why to use relay for controlling AC light?

AC is alternating current 220v (india) which powers the ac lights. Arduino cannot control high volt n amp, but a relay can do this job, which is the sole design of it. so we are using relay as switch to control high power devices.

What is NO NC and COM in relay?

C = Common Connection

NC = Normally Closed Connection

NO = Normally Open Connection

I have explained NO NC COM elaborately in step 3, refer it -if you feel it bit confusing.

I'm going to use NO Normally Open Connection.

Step 1: Components Needed

1) Arduino UNO

2)5V Relay module 220v

3)Ac light

<p>Do you switch relay when AC voltage is crossing &quot;0&quot; ?</p>
Hello sir i tried this instructions but it is not working.....please check the connection...arduino to relay board works i suppose since the led of respective relay is working...<br>And if the wire connected to NO is connected to NC the bulb switches on....but does not blink...please help me as soon as possible.!!!
Check your code, leave the wire connected to NO since we want the Arduino to trigger it on when it sends current to the relay. I assume its a problem with the code or your relay maybe damaged
<p>hello sir i have an arduino r3,12v 4 channel relay and a 840 point bread board.i want to connect 2 ceeling fans and 2 tube lights.can u plzzzzzzzz guide me.plzzzz give me the circuit diagram and method how to connect all these.plzzzzz sir.THANK U</p>
I might be able to help with that how do you prefer me to send you the directions and steps
A really nice source of information in my next project :) thanks buddy!
<p>What if yo u connect it to normally close? Would it turn the bulb on if the code is digitalwrite(pinx,high)..?</p>
<p>sir i am a begineer.i want to connect 2 tube lights and 2 seeling fans using arduino.can u plzzz guide me. i am having arduino uno r3 and all things needed.but dont have idea how to connect with all.so can you please give some of your valuable time?plzz sent me all the idea how to make.my email is lokanathmishra12@outlook.com.sir please help me.THANK YOU</p>
<p>Okay</p>
<p>no sir im not using translator.</p><p>actually i want to make arduino control project.so i need your help.plzzzz sent me all about that project.i want to connect 2 tube lights and 2 seeling fans using arduino.plzzzz sent me the steps and process.my mail id is lokanathmishra12@outlook.com</p><p>thank u sir for your help</p>
<p>are you using a translater?</p>
<p>Helllo, I have a four channel realy. The output of all 4 channels should be connected to the same load. However, I will output only one channel at a time. Thanks in advance.</p>
Hi!<br>I wanted to connect a ceiling fan and aan AC light with the relay. I have a 2 channel relay module. Can you please tell me what should be connected to the COM pin of relay of the fan? I want to be able to control the fan and light separately.
<p>simply connect the positive trminal of ACsupply to the common and positive side of fan to the NO and negative with the AC Supply </p>
<p>YOU HAVE ONE 2 WIRE CABLE FOR POWER THE FAN , RIGHT? WELL CUT ONE OF THEM AND ATTACH ONE END TO THE COM AND THE OTHER END TO THE N.O. PORT OF THE RELAY, SO WHEN THE RELAY LATCHES YOUR FAN WILL TURN ON, MAKE THE SAME ARRANGEMENT FOR THE LIGHT.</p>
<p>This is not true. You need to connect one wire to the NO, and the other to the neutral wire of your main supply. It can be done as you describe but then you have two wires in you COM port, one of the main supply and one of the fan. This is not ideal, especially not with higher loads.</p>
<p>YOU HAVE ONE 2 WIRE CABLE FOR POWER THE FAN , RIGHT? WELL CUT ONE OF THEM AND ATTACH ONE END TO THE COM AND THE OTHER END TO THE N.O. PORT OF THE RELAY, SO WHEN THE RELAY LATCHES YOUR FAN WILL TURN ON, MAKE THE SAME ARRANGEMENT FOR THE LIGHT.</p>
<p>Hi! I was looking for some advice in my project. can i use 5V relay module 220V to automatically dim the light instead of SCR. thank you </p>
<p>My apologies if it's obvious, but I'm not clear how to connect the light and relay to the wall mains (AC supply). Thank you!</p>
<p>Very cool project, simple and easy to follow instructions! Thank you very much! :-)</p>
<blockquote> Hi, I was looking for some advice on my relay project. I can't seem to get it to work, and here's what I can see is happening:<p>I have the relay module connected through a breadboard to an Arduino MKR1000, which is running a simple wifi web server page that turns an onboard led on and off. From everything I can see, I have it all connected correctly, with 5v on relay to 5v on arduino, gnd to gnd, and the other pin to pin 7. The arduino is clearly giving power to the relay, which is connected to a mains lamp, turning it on. When I take one of the connected pins out, the relay (on COM and NO) switches off, thereby turning the lamp off. So, what I can tell is that it will work, I just can't change the state of the relay through the arduino's code. </p><p>Thanks Ostin, </p><p>-Spike</p></blockquote>
<p>Hey, great post !</p><p>Quick question, I have seen that the relay module has 2 outcome ports, is it possible to connect another lamp that will work independently from the first one?</p><p>thnsk !</p>
<p>Hi Claudio,</p><p>the happy answer for you is yes you can!</p><p>If you look to the relay PCB picture (1st pic.) you will see that there are three red wires connected (VCC, GND, IN1) and one pin left without wire (IN2). So as far as you connect both relays in parallel you can switch the lights independently.</p>
Hello I am Baguma Joseph from Uganda , but we use 240v AC and I love your projects what do I do with our high Voltage reply me
All you need to do is buy a relay with 240v AC. End of the story
<p>220 and 240 is practically the same voltage. The voltage goes up and down through the day and it's more like two ways to call the same thing.</p>
<p>great project i am doing it as my final eee project how ever i would love to control 3 separate lamp using a third party android blue tooth software any advice ?</p>
Bluetooth? Are sure with that? I think you should better use ir receiver .It is more cheaper
Bluetooth or wifi module boards are both available add ons you can buy that work with Arduino, and it's as simple as this project, just adding one more control module, code, etc. Here's a link to one of many Instructables I found when I googled your question... Which i really need to point out can answer questions for you a lot faster than asking it here or forums... like for real.. i REALLY wonder why people, not just yourself, waste time asking stuff online that have plausable answers to them, when they can just as easily Google it. Hmmmm....<br>https://www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://www.instructables.com/id/Connect-Arduino-Uno-to-Android-via-Bluetooth/%3Famp_page%3Dtrue&amp;ved=0ahUKEwjsocSy6LDPAhVo34MKHcItBQQQFgghMAA&amp;usg=AFQjCNFSoNuG3tsFAa1v51cpnF2fOuDKSg&amp;sig2=OeMtSV4DeR9TiQ2xiKbgtA
I forgot to mention that their are apps you can get that work with both of these modules. Happy Project
Could some one explaiin how to connect a led strip with arduino, does it require a relay module?<br>
<p>a relay is pretty much the same thing as a light switch. you use it as a contact closure to complete the power circuit to the light (be it bulb or LED strip)</p>
<p>good work</p>
<p>guys anyone can help me how to connect VCC to 5v relay (48 relay) i am using 6 pairs of 8 channel relay board and arduino 2560</p>
<p>hy when we connect the load to realy it work for 1 minuite and autmatically wifi module is resetting whats the problem............</p>
<p>Check the temperature of the voltage regulator (next to the barrel plug). Possibly getting too hot due to piping too many volts into it (you're probably using more than 5V power supply?) and heat dissipation occurs, making the board malfunction. Gently put your finger to the voltage regulator, and if it hurts, it's probably the cause.</p>
<p>Hi everyone! Great guide. I am only confused by the (+) and (-) terminals on the battery in the diagram? I would have thought batt NEG would be the common ground.<br>Anyway, my application is for an air pump on AC mains.<br>I have modified the diagram to my setup. Only not sure about one thing:<br>Should the phase (EU brown colour) wiring pass through the relay, or should it be the neutral (EU blue colour) that passes through the relay?<br>According to my interpretation, the air pump and mains should be:</p><p>-connected via NO/COM on the relay, via wire A, and</p><p>-directly wired via wire B<br></p><p>Just not sure if it makes a difference. My gut is saying Wire A= Phase, Wire B = Neutral.<br>Maybe it doesn't make a difference? Hope someone can help.</p><p>Supercosm</p>
<p>hi, im interest with your project, can you show me the picture about ur project. how to connect air pump with ac mains wall plug</p>
<p>switch on the hot. direct wire neutral.</p>
<p>Hi, it's worth noting that on the switch side you don't have a neutral, you only switch the live, which is where I think you are getting confused. You have a &quot;Live&quot; (Brown, from AC supply to the relay), &quot;Switched live&quot; (Also brown, from relay to AC pump) and the neutral (blue) will connect straight to the neutral of your AC pump.<br>I have attached a rough drawing of how it should look. I hope this helps.</p><p>Regards,</p><p>Paul.</p>
<p>If i want to replicate this project will this uno r3 clone work. I dont see the huge IC in center.<br>Uno r3 <a href="http://www.ebay.in/itm/171791478539?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649" rel="nofollow">LINK</a></p>
<p>that model board has the surface mount microcontroller IC. still has the same characteristics except its not really a prototype board because you cant remove the microcontroller itself. i have one of that same model. </p>
Yes
<p>your current run plan is not correct. you implented a pic of a battery ( dc ) and wrote ac next to it. lol</p>
<p>i caught that too. </p>
<p>Hi, can i replace the ac supply with 2 pins plug? which means the plug will be connected to home socket (240v).</p>
<p>Hi, can i replace the ac supply with 2 pins plug? which means the plug will be connected to home socket (240v).</p>
<p>Hi, can i replace cables to Arduino Relay for something wireless?</p>
<p>FOR ACTIVATE / DEACTIVATE YOU CAN USE HC06 BT MODULE, AND MAKE IT WORK WITH ARDUDROID BT APP IN ANDROID. REALLY CHEAP AND EASY AND WORKS REAL FINE</p>
<p>Hi, thanks for this Instructable !</p><p>I did it with a 220V AC Water Pump instead of a light. It works but I have a problem : each time the water pump stops, i hear a &quot;ploc&quot; on the speakers of my stereo...</p><p>So I'm worried about the damages this relay could cause to my amplifier or to other electronic product in my flat.</p><p>Is it due to current or voltage brutal variation ? Does it come from the relay, or the water pump ? Is there a way to stop it (some RC circuit for exemple ?)</p><p>Thank you for your help !</p>

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Bio: Hello I'm Ostin.A tyro techie living in India. I love messing around with electronics,Gadgets.
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