Most TV sets can be controlled by an IR remote controller, which sends signals to control the volume, change the channel, and control all the other TV set functions.
IR remote controllers use a carrier signal (usually at 38 KHz) that is easy to isolate from noise and disturbances.
The carrier signal is turned on and off by following different rules (encoding) in order to transmit the 0 and 1 digital values.
The IR receiver removes the carrier signal (with a low pass filter) and decodes the remaining signal by returning a clear sequence of 0 and 1.
The IR remote control theory
You can find more information about the IR remote control at http://bit.ly/1UjhsIY.
Our circuit will emulate the IR remote controller by using an IR LED, which will ...