A very simple IR remote control switch for an electrical appliance



This project describes a technique of adding the remote control feature to an electrical appliance. The goal is to construct a black box where you can plug-in your 120V AC appliance (it can be easily modified for 220 V mains supply too) and control the ON and OFF operations with a TV or DVD remote that uses modulated infra-red (IR) pulse train of 38 KHz frequency. I did this project for my wife who studies late at night on her bed and later feels tired to stand up and turns the light off. Now she does it from bed with the TV remote. The good thing about this project is that it does not use any microcontroller and is only based on the CD4017 decade counter IC.

IR toggle switch for an electrical appliance

Circuit diagram

The original circuit diagram for this project was published in the May 2005 issue of the Electronics For You magazine. The circuit diagram below is mostly the same. It uses a TSOP1738 IR receiver module at the input side to receive the 38 KHz frequency IR pulses from the remote control. Under normal condition, the output pin of the IR module is at logic High, which means the transistor T1 (BC557 PNP) is cut-off and its collector terminal is at logic Low. The collector of T1 drives the clock line of the CD4017 decade counter.

Now lets see what happens when somebody faces a TV or DVD remote towards the TSOP1738 and presses any key on it. The TSOP 1738 module receives the train of 38 KHz IR pulses from the remote, that makes its output to oscillate too. These pulses are inverted at the collector of T1, which finally go to the clock input of the decade counter. The arriving pulses could increment the CD4017 counter at the same rate (38 KHz), but because of the presence of the RC filter circuit (R1 = 100K, C1 = 10 uF) between the collector and the ground, the train of pulses appear as a single pulse to the counter. Thus, on each key pressing, the CD4017 counter advances only by a single count. When the user releases the key, the C1 capacitor discharges through the R1 resistor, and the clock line is back to zero. So every time the user presses and releases a key on the remote, the CD4017 counter receives a single pulse at its clock input.

IR remote switch

Initially, when the circuit is just powered on, the Q0 output of the CD4017 decade counter goes high. The counter increments for each low-to-high going pulse arriving at its CLK pin (14). When the first pulse arrives, Q0 goes Low and Q1 is turned High. This activates the relay and the AC appliance connected to it is turned on. The status LED connected to Q1 also glows to indicate the appliance is switched on. When the user presses a key again, the second pulse arriving at the CLK line increments the counter by 1. This makes Q1 back to Low (which means the relay is deactivated and the appliance is turned off) and Q2 is pulled High. Since Q2 is wired to the Reset input, the second key press actually brings the CD4017 IC back to the power-on-reset conditions with Q0 High. Thus, it basically operates as an ON/OFF toggle switch controlled with any key of an infrared remote.

The power supply for the circuit can be derived from the mains AC itself using a step down transformer and a bridge-rectifier circuit. For +5V power supply, the LM7805 regulator IC can be used as shown below.

Power supply circuit

I have enclosed the circuit board with the power supply inside a wooden box as shown in the pictures below. The electrical appliance to be controlled can be powered from the AC outlet at the front side.

Circuit board and power supply enclosed within a wooden box

Finished project with AC socket at the front side

Testing the finished project with a TV remote

This was a very simple and fun project to do. If you are thinking about making this device for yourself, be careful with the direct 120 V AC lines used in the project.

148 comments

  • Can i make this ckt to control the whole power board. like i want to control fan, ac, tubelight etc from single ckt. is it possible? if it plz mail me the ckt manisha.bansal9012@gmail.com as soon as possible

  • dear sir,
    i have to control 3 light and fan from same TV remote using different keys.
    what modifications should have to do in that circuit.

  • good work

  • Hello, Is it possible to modify this so resets automatically after a set time of 15 minutes?

    Thanks,

    Dan

  • Hi sir!
    I have almost completed my project but i’m anble to give connection to Relay, so can you please solve my problum, my mail is prashant.ps74490@gmail.com
    THANKS!

    • SIR there is 8 pins in relay but we have to give connection in only 4 pins in which pin I should give that is my problem

  • how can this circuit be modified for 220V supply…..????? pls replyy…. :)

    • Hi There,
      Any success on making the same circuit to control 220V home appliances?
      Can you please help me out and give me the circuit diagram for 220V or at least let me know what are the changes I have to make in this 120V circuit to make it work for 220V appliances.

      my email is adeelnav@yahoo.com

      Best regards,
      David

    • Ajay,
      Any success if you found the solution for what you are looking for? I am also seeking the same.

      Thanks in advance!

  • good day sir. you have a good ckt here. :) I do have one request, may I have a copy of the PCB Layout or diptrace file? thanks for your kind consideration sir. (: kindly send it to my email, joab.torres@ymail.com…thanks!

  • Hi , I just made this circuit and it works but there’s an issue. When I connect it to any regulated power supply (Eg: 500mA Transformer cercuit with LM317 -Set to 5 V) it does not work and the relay switches on and off only once. But the same cercuit works perfectly fine when using 4 AAA Cells (i.e. Battery source). I am not able to understand hat is the problem? Any suggestions!!

  • i make it successfully but i have faced one problem

    its instantaneously on/off the load. when load is on suddenly off the load and do opposite also . its happen many times. could you please give any suggestion to me

  • Still waiting for reply

  • Plz sir i bought Tsop and it is 0038 on top is it the same with Tsop 1738. Thanks

  • Plz sir i bought a Tsop bt on it is written 0038 is it the same with Tsop 1738. Thanks

  • I love this

  • Thanks a lot for publishing this post along with circuit diagram and explanation. I found very few sites in which it is explained very clearly. I have also seen another circuit with good explanation on the same concept. If anybody interested, visit http://www.electronicshub.org/ir-remote-control-switch/

  • Thanx a lot it works fine for me

  • Sir,
    First of all thank You for Providing this Circuit…I want to know that my Appliance is not working.
    But led glows by remote.SO What should I do

  • Sir,thank you very much for this wonderful project,it working very fine.but i am facing false trigger problem in this circuit (but not due to ir) else the circuit is triggerd when there is voltage fluctuation occurs in home .How can i avoid this ? if any idea pls tell.Thanks

  • hello sir, i’m trying to make the project in the link you provided for 230V ac supply..now my problem is i cant find the exact part number for T1(BC558), can you give me any alternatives for T1? another problem is the D1, IN4007 is not available here so i bought IN4002,1A, is it compatible for the circuit? one last problem, 5V relay is not available here, can I use 6V instead??
    ..any reply for this post will be much appreciated.btw i need this circuit completed for my project..thank you! :)

  • can’t we use TSOP 1838 instead of TSOP 1738

  • Keene Edith Bontshitswe

    ok so this switch cant you use it in the whole house..meaning the normal house light bulbs?if yes,how?

  • can nyone provide me the PCB layout of this circuit…thnxx

Leave a Reply

Your email address will not be published. Required fields are marked *