IR circuits

[bullonwheels]

Hi guys, I would like to know, what exactly these attached circuit is exactly doing ?

From what I see I think it is decoding IR data and extracting the carrier signal. Correct me if I am wrong.
Also I am looking for a good IR learning circuit using discrete components. Can any one suggest me a tutorial or so ?

Screen 2 I think It is a IR pass through ?

[Paul Price]

Seems really a waste of time to try to build your own remote control IR receiver, these days, when you can salvage a tiny 3-pin complete IR receiver from any discarded DVD player, TV, or VCR.

You don' want to extract the carrier, you want to extract the digital data stream from the remote's ultrasonic freq. (38-43KHz) carrier.
But this circuit is not decoding the output digital data stream. The recovered digital output is just data, and without a decoder, could not be used to control anything.

The top circuit would function to extract the data from the carrier if the remote receiver is just using an infrared photo-transistor to detect the remote signal and you are satisfied with poor sensitivity, working only over a small range of remote Xmiter distance,  and also having poor immunity to room lighting or sunlight interfering with remote operation.

Google remote control circuits and you will find tons of info on how they work.