# INFRARED TRANSMITTER USING 555 Timer

Here i am going to explain INFRARED TRANSMITTER USING 555 Timer. I think you already know the applications of INFRARED RAYS, we can't see them directly with our eyes.
The timer NE555 is used here as an ASTABLE MULTIVIBRATOR, which will generate non sinusoidal (square) output waves.

The 555 timer is the core part of this circuit. The output from pin3 is given directly to the IR LED with the help of current limiting Resistor.

IR LED looks almost similar to an ordinary LED. And it is cheap.

## FREQUENCY DETERMINATION OF INFRARED TRANSMITTER CIRCUIT

The frequency of this circuit is determined by the value of Resistors R1, R2 and the capacitor C.

For normal purposes the IR frequency is about 38Khz.
To generate an INFRARED ray with frequency 38khz you have to select the values of R1, R2, and C as follows.

R1- 150K

R2- 1.5K

C- 0.01μF

You can use our ASTABLE MULTIVIBRATOR Frequency Calculator tool to determine the value of R1, R2 and C

## CIRCUIT DIAGRAM OF INFRARED TRANSMITTER

• To check the output you can use a Camera (Mobile).

• Power the circuit by a 6V battery

• Higher the Frequency, Longer the transmission range.
You may also like SIMPLE INFRARED REMOTE SWITCH

1. thank you..it helped me...
I was looking for something as simple as this...

2. @Raghav,

You are welcome....

3. can i build a audio transmitter with this circuit? ... and how can i build a compatible receiver with this? .. hoping that you could help me...

4. Hi Blaze,

I didn't get what you mean by "Audio Transmitter".....
Plz Try to explain your query in detail....

5. what i mean is to build a IR audio transmitter and receiver...can i do this with this circuit?? ...

6. what i mean is that can I use this circuit as a audio transmitter? ... if yes were could a attach the audio in? .. and how can i build a IR receiver ..

7. I think its not possible from this circuit.....

8. what possible circuit could i build with this?...and how to build a simple receiver to this? that could just detect the IR from far distances and light up the led if its detecting it..

9. Blaze, you can try IR Remote switch circuit or for long distance transmission, RF is suitable than IR so check it RF Remote switch circuit

10. can i use a normal IR receiver instead of tsp1738 for IR Remote switch circuit ?? .. .that part isnt available at my location

11. Normal IR reciever means.......???

12. what i mean is that i will use a IR receiver diode only...it looks like a IR but it does not emit infrared rays ..it only receives them... this is what I mean.. http://www.vtualerts.com/wp-content/uploads//2011/12/cropir-sensors.jpg
pictures of a receiver IR and transmitter IR

13. Lets Check whether the circuit works with your ir sensor.

Wireup the IR reciever section as shown in circuit diagram.

Replace the tsop sensor with your reciever module (PIR sensor)

check the voltage across PIR sensor, before and after giving IR rays. If the voltage drops after recieving IR rays the reciever section working finely.......

14. whats the exact value for your components because the values you gave on the r1,r2,c are only
947.3684210526314hz if calculated .. whats the exact value for r1,r2,c .. which R will be the potentiometer ?

15. yeah. same with me. i also got 947.3684210526314hz

16. How you select values of r1,r2 and c?

17. R1- 150K
R2- 1.5K
C- 0.01μF

18. @TITTU THOMAS

Hi,

Which type of capacitor do you use ?

1. Ceramic Capacitor (Capacitor without any polarity)

19. @Tittu Thomas

Are 1/4W resistors good for this circuit ?

1. Yeah, Sure......

20. @Tittu Thomas

Hello,

Thank you for this circuit, i was searching for a simlpe one like this one. I want to create a very basic remote. Do you think I can power the circuit with two 3v 35 Ma coin batteries (http://alimentations.e44.com/piles/piles-boutons/piles-boutons-3v/piles-12-5mm/pile-bouton-lithium-3.0v-35ma-12.5x-2.0mm-cr1220-5pcs-bl-CR12205.html#!prettyPhotos[productImages]/0/)? Does any 6v battery work ?

Thank you

21. First of all, Thank You 4 your comment.

I think its possible to power the circuit by a 6V coin type battery. If it works well i am sure, the circuit became more compact... Any way try your luck. Best wishes.....

22. hi...shud v provide 6v exactly...i guess tat doesnt matter right...coz capacitor charges and discharges from vcc/3 to 2vcc/3 right...

23. hi...thanks for ur circuit ....i tried ur circuit....i chose a value of R1=2K and R2=1K c=0.01uF...to produce 35.999Khz...but i checked with normal diode type IR reciever with 10K in series with a 6V battery....Its range is as low as 150cm...wat to do....?

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