To act on a remote machine, the radio remote control contains an infrared ray emitter; it's a kind of light bulb (visible or hidden behind a plate, depending on model).The formal name for this little bulb is "LED". A radio remote control sends signals to the device it is supposed to control. These signals can be two very different natures: either they are light signals but are not visible to the eye (see below) or as radio signals or microwaves. In fact, it is quite the same thing since the light and microwaves are electromagnetic waves. Their behavior is almost the same except for what is their interaction with objects. Radio waves can penetrate walls for example. It is convenient to control a device that you can not see, or you might use to being away. These signals are transmitted by an antenna located in the Radio remote control and emits in all directions. The Radio remote control is not directive and the signal easily fills all space, like waves from a pebble is thrown into the water: the waves diverge in concentric circles. A radio remote control works differently. The infra-red are generated by a light-emitting diode (LED it's called) at the front of the Radio remote control. There is a way to see what makes Radio remote control signal: it is to use a digital camera! The sensors of this device are able to see the near-infrared ... Look at the front of your remote control while watching the screen of your camera. You will see the LED light up and emit a signal - if you are unable to interpret it, the device is concerned will, he. The infra-red has the interesting property of being reflected by the surfaces (including white). You can order your electronic device by reflecting the laser beam! The rays emerge from the Radio remote control and enter the infrared receiver of the machine. This receiver is a photo diode that is capable of transforming light signal into an electrical signal it receives. Then, the electrical signal passes through the electronic circuit television ... So obeying the order that you gave him at a distance!