Kelly bad os om at lave et projekt med en fjernbetjenings infrarøde styrke og notere hvordan eksperimentet gik - meeen det havde jeg helt glemt, så natten til deadlinen skrev jeg i stedet alt hvad jeg vidste om infrarød. Fik så det ubehageligeste svar tilbage nogensinde: "THIS IS NOT AN EXPERIMENT!" - like I didn't knew that already!
Infrared (IR) in remote controls
infrared is in between microwaves and the visible spectrum. This is why the wavelength is very long (compared to Gamma rays of course), more precisely it is 0.7 – 300 micrometers. The frequency range is somewhere around 1-400 THz (Terahertz-part corresponds the upper part of the microwave band and is called NIR, Near Infrared. The lower part is called FIR, Far Infrared).
Remote controls use IR as a data transmission. This only works in short-range communications, which is why you cannot stand in another room and turn on your television. The remote control uses light-emitting diodes to emit IR radiation and by a plastic lens, this is focused into a small beam. This beam is switched on or off to encode data and the receiver of this beam is a silicon photodiode (the photodiode is able to convert light into current or voltage) and convert the IR into an electric current, which basically is a flow of electric charge.
infrared is in between microwaves and the visible spectrum. This is why the wavelength is very long (compared to Gamma rays of course), more precisely it is 0.7 – 300 micrometers. The frequency range is somewhere around 1-400 THz (Terahertz-part corresponds the upper part of the microwave band and is called NIR, Near Infrared. The lower part is called FIR, Far Infrared).
Remote controls use IR as a data transmission. This only works in short-range communications, which is why you cannot stand in another room and turn on your television. The remote control uses light-emitting diodes to emit IR radiation and by a plastic lens, this is focused into a small beam. This beam is switched on or off to encode data and the receiver of this beam is a silicon photodiode (the photodiode is able to convert light into current or voltage) and convert the IR into an electric current, which basically is a flow of electric charge.
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