IR Transmitter and Receiver Circuit for Best Remote Control System

A remote control system for appliances makes our life smarter and easier. The wireless remote control circuit may be based on IR waves or RF waves, IR being cheaper. An IR emitter circuit is based on TSOP at the receiver section. Each TSOP operates at a particular frequency which depends on a number present on it. So each TSOP requires specific remote controller for its operation. There comes the importance of IR universal remote control which can be used to operate all normal hobby circuits.Here the basic principle of operation is Frequency Shift Keying (FSK). It enables to generate variable frequency so that it can detect different TSOPs.We are using two 555 timers here, both operating in astable mode which then drives the IR led.We shall discuss another transmitter circuit with microcontroller later in another article, which due to presence of crystal can generate the exact frequency.

TSOP Frequency range

Reason for this article:
In our previous articles on remote control lamp and remoter controlled DC motor we received some comments asking how to build a remote control, that’s why I decided to publish this one here.

My story:
My bathroom light used to be ON almost all the time as my family members were lazy enough to OFF the switch positioned a little bit away. So I decided to save the electricity by designing this IR TSOP loop to OFF the lamp. Firstly I used a 38 khz IR transmitter circuit for which I had to design an astable to generate that frequency. For this I used a potentiometer, but it was not working properly. It worked only when the potentiometer was being varied. So I implemented FSK to vary the frequency continuously.

Remote control transmitter schematic

IR remote control circuit

Click on the image for enlarged view

Components Required

  1. NE555 IC X2
  2. Transistor BC107; BC557
  3. Resistors (100KΩx2; 10KΩ; 470Ω; 100Ω; 1KΩx2; 330Ω 2.2KΩ)
  4. Capacitors (0.01uFx3; 2.2uF; 1uF)
  5. IR Led
  6. IN4148
  7. 9V battery
  8. TSOP
  9. LED

Working of infrared remote control


  • One astable output is at lower frequency and other one at a higher frequency.
  • Lower frequency multivibrator controls the frequency of the other.
  • From the basic working principle of astable multivibrator, resistors R3, R4 and capacitor C4 determines the frequency, so the frequency can be changed by varying R3. This can be done simply by connecting a NPN transistor (BC 107) in parallel with R3 with a series resistance R5 to limit the current.
  • Output of 555 is connected to the base of transistor through a current limiting resistor R7. When the output of first astable is high, the transistor BC107 becomes ON which in turn makes R5 parallel to R3. Then the total effective resistance goes below the resistance of lower resistor value, which reduces the time of astable 555. Thus increase frequency.
  • Just the opposite process takes place when the first 555 output is low (OFF).
  • Output of the second 555 is connected to an IR Led through a current limiting resistor R6. Led glows in accordance the output frequency which is then detected by the TSOP.
FSK modulation output

IR Sensor Circuit

IR detector circuit
  • Here is a simple infrared detector circuit which gives a LED indication.
  • TSOP gives active low output. So we are using a PNP transistor.
  • When IR rays fall on the TSOP, then by the switching action of the transistor LED glows. You can remove the LED and resistor and connect any appliance you want with the help of relay.

Components Pinout

555 pin outTSOP pinout

63 thoughts on “IR Transmitter and Receiver Circuit for Best Remote Control System

  1. dear sir,
    what is the need of using two 555 timer ic in the transmitter circuit.
    Can’t we made same output frequency with only one 555 ic.

    • Hi Dk,
      Of course, It can be used to switch 500 Watt load. But for such application you have to modify the circuit with adding powerful relay.

  2. Sir;
    circuit ma switching ka leya koi button ya switch nai ha to ham signal kasey creat karey ga or dono circuits ki frquency kasey match karey gi

  3. i want to build IR transmitter and receiver..IR transmitter connect to weight sensor..and receiver connect to TV( Television ). any suggestion sir?

  4. I have seen the video demonstration its nice,but I wanted to know more about R3, “by varying the effective resistance of R3 wouldnot change pulse width and not a frequency isn’t it?” plz ans me.

  5. hi i reli admire your work but could u plz show on your circuit diagram where uve placed your button on the transmitter!! thanking u in advance

  6. sir,
    I want to control many home appliances with a single remote (remote controller with many buttons like TV remote) So how can i vary the transmitter frequency and same like that how can i detect it in the reciever circuit. For eg. I want to control 3 lights, in the transmitter circuits I should have 3 bottons, each for corresponding light, if I press1st botton, the 1st light should glow, and if i press 2nd botton, the 2nd light sould glow. This is my app, So can u help for this

    Thanks in advance

  7. Hi Admin,
    I have designed an LED Downlighter in single colour, Now the idea is that, i have to design it in dual colour in single piece and should be controlled through IR Remote .
    For that we have taken two led strings in parallel of two different colors and want to switch ON single colored light at one time ,can we use this concept for our application .Kindly advise.

    Thanking in advance.

    Best Regards
    Anshul Tyagi

  8. How to make ON and OFF the dc motor of the receiver using this transmitter? Where the switch is placed in the diagram of transmitter circuit ?

  9. Can we use concave lens to scatter the ir rays emmiting from ir transmitter & can we use convex lens in front of ir reciever to converge to diverged ir rays????????

  10. Hi, pankaj. There will many appliance (by using higher rating relays for high current load) can control, but they’ll start equally.

  11. Admin.sir….thanks for this but I get a idea to a simple motor toy car control revrse and forward motion and left and right.pls tell me how modificaton in this circuit

  12. Am not able to understand,how FSK is making transmitter usable for various TSOP. Could someone please elaborate giving an example . like how it will work for let say TSOP 38 and TSOP 40

  13. this sensor is on when remote switch ramains on ,but how can i make a circuit which become on for first trigger and become off for second trigger

  14. Hello sir
    I have created your circuit exactly as shown, using exact parts, but it is not working. It is for my project and I need it to work urgently. The receiver LED is blinking on and off rapidly instead of your receiver in the video.

    Could you upload a clearer image/video of the receiver? I shall be very much thankful for that.

  15. how to interface the IR transmitter and receiver using remote control to mbed lpc 1768,
    any information regarding tell me sir.

  16. HI Sir,
    i am doing project based on microprocessor using mbed lpc 1768.
    in this project we control lamp and fan automatically and also remote control,
    in remote i using IR transmitter and receiver sensor but i do not know how to interface IR sensor to mbed lpc 1768.
    send me some information about interfacing ckt with explanation.

  17. Hi Sir
    Please I need the circuit diagram for an Rc Plane remote…….its a very compulsory project Please I need that urgently

  18. Hi sir, my is different loads are controlling with ir transmitter and to give different address In the transmitter side .please any one send sample code.

  19. Hello, I had made same thing but with a microcontroller, which costs me a lot. So now i am gonna reduce its price by using your circuit. But i have a doubt. Can more than one relay be controlled? I mean different buttons on ir remote for different relays?

  20. admin I wanted to ask that what will be the overall cost of the things u have used because I also have the same problem.

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