IR Transmitter and Receiver Circuit

IR Transmitter and receiver are used to control any device wirelessly, means remotely. TV remote and TV are the best example of IR transmitter and receiver. TV generally consist TSOP1738 as the IR receiver, which senses modulated IR pulses and convert them into electrical signal. Here in our circuit we are building IR remote and its receiver.  We are using IR LED as transmitter and TSOP1738 as IR receiver.



IR LED emits infrared light, means it emits light in the range of Infrared frequency. We cannot see Infrared light through our eyes, they are invisible to human eyes. The wavelength of Infrared (700nm – 1mm) is just beyond the normal visible light. Everything which produce heat, emits infrared like our human body. Infrared have the same properties as visible light, like it can be focused, reflected and polarised like visible light.


Other than emitting invisible infrared light, IR LED looks like a normal LED and also operates like a normal LED, means it consumes 20mA current and 3vots power.  IR LEDs have light emitting angle of approx. 20-60 degree and range of approx. few centimetres to several feets, it depends upon the type of IR transmitter and the manufacturer. Some transmitters have the range in kilometres.



IR Receiver (TSOP17XX)

TSOP17XX receives the modulated Infrared waves and changes its output. TSOP is available in many frequency ranges like TSOP1730, TSOP1738, TSOP1740 etc. Last two digits represent the frequency (in Khz) of modulated IR rays, on which TSOP responds. Like for example TSOP1738 reacts when it receives the IR radiation modulated at 38Khz. Means  it detects the IR which is switching On and Off at the rate of 38Khz. TSOP’s output is active low, means its output is remains HIGH when there is no IR, and becomes low when it detects IR radiation. TSOP operates on particular frequency so that other IRs in the environment can’t interfere, except the modulated IR of particular frequency. It has three pins, Ground, Vs (power), and OUTPUT PIN.



IR Transmitter Circuit Diagram

We are using TSOP1738 for receiver, so we need to generate the modulated IR of 38 kHz. You can use any TSOP, but you need to generate IR of respective frequency as TSOP. So we are using 555 timer in Astable mode to oscillate the IR at 38KHz frequency. As we know oscillation frequency of 555 timer is decided by resistor R1, R2 and capacitor C1. We have used 1k R1, 20K R2 and 1nF capacitor to generate the frequency of approx. 38 KHz. It can be calculated using this formula: 1.44/((R1+2*R2)*C1).

IR Transmitter Circuit Diagram

Output Pin 3 of the 555 Timer IC has been connected to IR LED using 470 resistor and a push button switch. Whenever we press the button, circuit emits modulated IR at 38 KHz. A 100uF capacitor is connected across the supply to provide the constant supply to the circuit, without any ripple.


IR Receiver Circuit Diagram

IR Receiver circuit is very simple we just need to connect a LED to the output of the TSOP1738, to test the receiver. We have use BC557 PNP transistor here, to reverse the effect of TSOP, means whenever the output is HIGH LED will be OFF and whenever it detects IR and output is low, LED will be ON. PNP transistor behaves opposite to the NPN transistor, it acts as open switch when a voltage applied to its base and acts as closed switch when there is no voltage at its base. So normally TSOP output remains HIGH and Transistor behaves as open switch and LED will be OFF. As soon as TSOP detects Infrared, its output becomes low and transistor behaves as closed switch and LED will be ON. A 10k resistor is used for provide proper biasing to transistor and a 470ohm resistor is used at LED for limiting the current. So whenever we press the Button at IR transmitter, it is detected by TSOP1738 and LED will glow.

IR Receiver Circuit Diagram

We have further modified this circuit by using a relay to operate the AC mains appliances by an IR remote, in this remote controlled switch circuit. Check out our electronic circuits section to learn and build more interesting circuits and simple projects.


Comments (79)

  • Daniel's picture

    The code is as follow :

    Option Explicit
    Define uC as None

    If ((Abukar sees an uC) == True) {
    Echo "Houston, we have a problem !"
    Echo "Please help Abukar to search for datasheets !"

    Seriously !

    Jan 08, 2018
  • Liam's picture

    Would it be possible to switch out from IR to some form of Bluetooth remote control?

    Nov 17, 2015
  • Jayant's picture

    This is completely a different circuit, you need to use Bluetooth module with some micro-controller to achieve this.

    Nov 21, 2015
  • sourabh 's picture

    can you send this alarm circuit done without using any ic's

    Dec 20, 2015
  • slady's picture

    pls is there any circuit that can produce free energy? If you use up to 20 red led connected in series. I need the circuit diagram pls help.

    Dec 29, 2015
  • Krishnamurthy V R's picture
    Krishnamurthy V R

    Hello Dear
    I was trying to work with TSOP1738. I used Attiny85 to generate IR signal. Receiver out put is fed to a simple transistor that drives a led. When circuit is switched on the receiver LED lights up for a brief period. The program is given below
    void loop() {

    Pl help me to correct the mistake .

    Jan 06, 2016
  • Aditya Anshul's picture
    Aditya Anshul

    Sir can use ldr in the transmitter section that will power the circuit when dark( means when there is no light then the circuit will start emitting rays)

    Feb 05, 2016
  • Maddy's picture

    yes, you can use LDR as a switch, which turns on the Circuit in darkness. But for this purpose instead of using IR sensor, build it with 555 timer like here: Dark and Light Indicator Circuit

    Feb 08, 2016
  • midhun 's picture

    nice work sir,
    pls help to make a audio transmitter and receiver above 60m range

    Feb 13, 2016
  • Karthik's picture

    Hi, I have two wire terminals. I need an IR controlled device to close the circuit (connect the terminals) ONLY when I command from a remote. How can we do this or how to modify the above circuitry to achieve this?

    Feb 21, 2016
  • Karthik's picture

    Hi Abhishek, that's a good idea, thanks. I want one improvisation. I need the connection function like a calling bell arm. The moment I press the remote button, the receiver should connect and disconnect it when I release the button.Can I not connect the terminals in place of the LED per the current idea. It connects when remote button is pressed and disconnects when released?

    Feb 23, 2016
  • Ajay's picture

    This circuit is already working as per your need.

    Feb 24, 2016
  • CYRUS KING&#039;ORI's picture

    Please can you email me a circuit diagram that produces IR signals at 38kHz.I have one that isn't working.

    Mar 10, 2016
  • Binu P Kumar's picture
    Binu P Kumar

    Is it possible to work ir led and tsop using a single power supply?

    Apr 09, 2016
  • Binu P Kumar's picture
    Binu P Kumar

    Thanks maddy!!
    But then how is it possible?
    if i want to take the readings of tsop using arduino..
    Can u suggest me a circuit in which both the tsop and irled use single powersource and the readings of tsop is measured by arduino.
    I have tried one but once the reflection from irled occurs,the tsop output remail zero even when there is no reflection on to the tsop.
    Please help me..

    May 01, 2016
  • Aditi's picture

    if we want to connect the output of the receiver circuit to the microcontroller can we directly do that by connecting just the output pin of the tsop to the microcontroller.

    Apr 18, 2016
  • Maddy's picture

    Use Transistor in between, like shown here.

    Apr 18, 2016
  • Shruti's picture

    How do we transmit continuous IR pulses from IR Led without using the push button, but using the Arduino in place of the push button ?

    May 03, 2016
  • grmatsion's picture

    sir....!!!instead of decoder (receiver )we can use microcontroller but how we integrated transmitter or what type of IC could we use instead of encoder transmitter
    that can operated with microcontroller?

    May 07, 2016
  • Maddy's picture

    Leave the Transmitter part as it is, just change the receiver part according to your requirement.

    May 21, 2016
  • kashyap's picture

    howto increase or decrease the ir receiving range in ir receiver using tsop 1738 as i do not get any other receivers

    May 08, 2016
  • Maddy's picture

    You need to increase the range of Transmitter part, not receiver part. To increase the range, use convex lens at Tsop or use a powerfull IR LED

    May 21, 2016
  • Mihai's picture

    Really appreciate your work man, thank you. I have only one question, what is the emitor voltage for the Q1 transistor ?

    May 31, 2016
  • Arijit Das's picture
    Arijit Das

    Up to how much distance between sender and receiver it will work??

    Jun 03, 2016
  • Abhishek's picture

    It should work for 10-20 feet, like a simple TV remote.

    Jul 09, 2016
  • Alfred Manyahi's picture
    Alfred Manyahi

    In my the LED stays on even when the transmitter is off

    Jun 13, 2016
  • Abhishek's picture

    Check circuit at Receiver part, connect transistor BC557 properly.

    Jul 09, 2016
  • Roy Z's picture
    Roy Z

    Help. Anyone know where i can get the IR transmitters mentioned in the article that will work in the kilometer range? The usual places I order parts (Mouser, Digikey,etc) doesn't have anything close.

    Jul 07, 2016
  • Shrikant's picture

    Sir, as per circuit diagram if press button prsent in transmitter circuit then IR led will glow and it will detected at IR receiver. But if i have multiple buttons at transmitter (e.g. matrix keyboard) then how can differentiate one button from another. Can is it possible to trasmitte addree of perticular button through IR Transreceiver ?

    Jul 09, 2016
  • Tejaswini's picture

    What is the maximum operable distance for this device to work efficiently?

    Jul 19, 2016
  • omar's picture

    If I require to transmit this code 0x25FC without microcontroller what I have to change or add to the transmitt circuit?

    Jul 25, 2016
  • sivasankar's picture

    why the led is blinking uneccessarily before giving the ir trigger in the receiver circuit

    Jul 27, 2016
  • Mr Muniko's picture
    Mr Muniko

    Im not understand well about pnp transistor or npn?
    why if it is pnp transistor,why collector is in positive way? explain me plse if in this circyit we must reverse a transistor.

    Aug 04, 2016
  • Maddy's picture

    Circuit is correct, PNP transistor is used here because normally TSOP output remains HIGH and when it detects IR, the output becomes Low. This is clearly explained in the article.

    Aug 20, 2016
  • Dheeraj's picture

    Hello dear,
    Can anyone tell me why we use capacitor in TSOP circuit

    Sep 05, 2016
  • MANUEL's picture

    Hello sir
    I have a problem regarding the receiver I use sliding switch instead of tact switch but when I switch on the transmitter for very long the led of the ir receiver will only stay for about 1 second how can i fix this?

    Sep 13, 2016
  • d.kupar's picture

    anyone can you please tell me... the capacitor c1 of 1uF in the above ir receiver circuit is used for what purposed???

    Sep 19, 2016
  • Abhishek's picture

    @Dheeraj @d. kupar: C1 is connected in receiver circuit for the same reason as we connected C3 100uF in Trasnmitter across the supply, to provide the constant supply without any ripple.

    Oct 01, 2016
  • B.Rauer's picture

    Hello creator, good job
    Just please correct the wiring of the receiver part. The junction points are missing and the Q1 emitter is on the wrong side, connected this way, it will not work. Emitter to +5V, Collector to R2 ;-)

    Oct 02, 2016
  • Maddy's picture

    Circuit Diagram is correct and its a PNP transistor.

    Oct 07, 2016
  • B.Rauer's picture

    Sorry Maddy, it is really wrong.
    PNP-transistor: the Emitter is connected to a more positiv voltage than the Collector
    NPN-transistor the Collector is connected to a more positiv voltage than the Emitter
    see also

    Oct 11, 2016
  • John Anderson's picture
    John Anderson

    Maddy, are you sure? I agree with Bernd, it looks back-to-front. If the circuit is correct, could you explain how any current can ever flow through the transistor, please? With respect, I don't think the article is clear on this point.
    Thanks, John

    May 02, 2017
  • gopi's picture

    Really it is too useful for all students

    Oct 14, 2016
  • HENRY's picture

    I love this job
    but I have a question

    Oct 19, 2016
  • aryan's picture

    I have a device which used to scan invisible bar code. But now its not working at night but works day time. What's the problem. I can send its image if you please feel to help me out. Pls

    Nov 06, 2016
  • manoj kumar's picture
    manoj kumar

    do the circuit works perfectly at strong sunlight? i want a ir transmitter and receiver which works at sunlight ,so can u please refer me some other circuits....

    Nov 09, 2016
  • Abhishek's picture

    Yes IR sensor get affected with sunlight, what kind of circuit do you want to build, we have lot of wireless circuits, just do search.

    Dec 02, 2016
  • neranjan's picture

    i have problem please help me,,,,,your some code delete please reply me my email address

    Nov 28, 2016
  • Katie's picture

    If I were to have multiple transmitters with receivers in the same room all using the TSOP17xx's as receivers at different frequencies, do you think they would cross-talk? Are the frequencies too close together? I see a 30, 33, 36, 38, 40 and 56 kHz. Looking forward to using this for a fun project.

    Dec 07, 2016
  • sashank's picture

    Can we use multiple switches from this circuit? If yes,then please mention tye circuit diagram.

    Jan 01, 2017
  • Ben's picture

    A friend gave a sat decoder. This decoder doesnt have a ir sensor insted it has a port named Display IR. how does it work, and can i fix an IR reciver?

    Jan 02, 2017
  • SAYYAD ALTAB's picture


    Jan 18, 2017
  • Lango's picture

    Hi, i have a tsop4838 receiver and a 6v supply and i want to use it to not blink a led but any switch other 6v device or a relais when i want to switch a separate powersupply.
    It only has to respond when the reciever receives. it doesnt have to stay switched on or off.

    So basically use it as a remote switch that only works when a button is pressed.

    Jan 27, 2017
  • Madalin's picture

    If i put an LED in series with ir led, should the LED flash at a frequency of 38khz?

    Feb 06, 2017
  • Maddy's picture

    It will flash but our eye can not detect this high frequency so LED will be appeared to be continuously glowing.

    Mar 04, 2017
  • chumani's picture

    greetings m doing a mini project for opto electronics ,the project requires me to build a transmitter and receiver using a 555 timer,2* 120 ohm resistors,photo LED and TEPT 5600 photo transistor.
    your help will be much appreciated.

    Mar 01, 2017
  • joe 's picture

    i want to make a IR receiver to drive a relay.
    i want to make similar IR receivers to drive different relays when different IR signals are given to it.
    my budget is around so low. can you please help me?

    Mar 17, 2017
  • maria's picture

    this is such a great works.and i want to ask, how can i do to increase the frequency from 38kHz to reach up to 300GHz? is it possible to do that?your help will be much appreciated.tq

    Apr 06, 2017
  • Abhishek's picture

    TSOP for receiving IR of 300Ghz might not be available.

    Jul 05, 2017
  • Preethi's picture

    What if I've to use multiple transmitters and a single receiver using Arduino? How do we encode the IR LED output such that we can decide the codes at the receiver part by Arduino?

    Jun 19, 2017
  • goli's picture

    I used tsop38238 receiver and an arduino to check the receiver output(on serial monitor) using irRemote library. Each time the push button is pressed , different outputs were displayed. Why is it so?(Isn't it supposed to give the same pattern?).

    Jun 21, 2017
  • Ibrahim's picture

    Please send me long distance ir circuit diagram

    Jun 23, 2017
  • Nouman's picture

    Is it possible to use this circuit for a line follower robot?

    Jun 30, 2017
  • romz's picture

    Hi, is there a way to amplify the IR led transmitter so that I can place the IR receiver(e.g TSOP17XX ) 2-3 meters apart from the IR led?

    Jul 12, 2017
  • Abhishek's picture

    Please read the previous comments before asking, your question might has been already answered.

    Jul 12, 2017
  • Prajju's picture

    Ur project lks osm
    Can u please help me find where I can get a similar bread board presentation for ir people counter prepared using non programmable ic's please

    Aug 21, 2017
  • cruzersfy's picture

    Hi, I want to ask.
    What simulation software you used in to create that IR tx/rx circuit? I have a problem when create in proteus. There is no component name TSOP1738.
    Where can I get that component? Thanks

    Oct 02, 2017
  • raj's picture

    can we use bc547 instead of bc557?

    Oct 10, 2017

Leave a comment