Explain how a TV remote control unit controls the TV set/video recorder using diagram to illustrate the answer

Answer 1

Well I'm not sure how I'm going to make a diagram on Yahoo Answers, but I'll try and explain it clearly for you.

Modern TV/VCR remote controls use invisible infrared light to control devices. This invisible light is "seen" by electronic eyes in the devices. The device knows what you're pressing because the light flashes on and off fast, in a code. Imagine someone sending morse code with a flash light, it's quite similar to this. A microchip inside both the remote control and the device knows all of the codes so when you press a button on the remote it starts flashing the invisible light at the end of the remote in that code, and the electronic eye in the device decodes that and performs the desired function. I guess in a pseudo-diagram, this is how it would look:

User presses button
Microchip picks code depending on button pressed
Microchip flashes IR light in the coded sequence
Electronic eye in TV detects coded light flashing and passes it to microchip
Microchip looks up the code, cross references it with a specific function and then perfomrs that function.