Posted by Tittu Thomas , 6/17/2012
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.
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.
Categories: 555 Timer, Alarm, infrared, projects, transmitter