How can LEDs be used to detect light?

A visual explanation of how LEDs can be used to detect light.

Category:

Science & Technology

Tags:

• electronics
• howto
• tutorial
• led
• sensor
• light
• explanation
• atmel
• avr
• pic
• ldr

[JHsadler]

ar clever but are you shure that its a normal led?

[jollino]

Absolutely positive. It works with any led, albeit different leds will give different values.

[firedude201234]

@jollino

fuck.....im trying this out right now lol

[definitionofis]

I use this LED sun tracker to run my

solar panel tracker:

redrok com/electron.htm

[nymphetamine001]

awesome



[Dark0Lord7]

@HMInnovations In theory yes, but LEDs are too expensive, and generate less voltage than a solar cell.

[ORMEntertainment]

the exactly opposite of photovoltaic solarmodules. an led is a small silicium cube with 2 charged sides. negative electrones and positive "holes". If you put an current on it, the negatives fusing with the holes and escape as an photon (light) Like a solarmodule using a silicium plate. if photons hit the silicium, they split into negatives and positives, now you simply connect both sides and you have a circuit. I think if you connect a solarmodule to a poweline they ll be the brightest LED ever.

[KennyCieux]

what is the direction of the current flow? The conventional way or the opposite?

[DonOfIstSarajevo]

THIS IS FAKE !!!

[AHProduction1214]

very good job.Come and join us.

plz subscribe ahproduction1214

[fennecfanatic]

2:30 Happy to help with the theory there. The reason is because the LED is not producing current. Rather, the presence of light of the same wavelength range as the LED produces causes the resistivity to change, essentially deadening the diode effect that normally prevents current from flowing that direction.

[gnomadrocketry]

A white LED should probably not be used for this purpose as a white LED is actually (internally) a blue LED that shines on a a phosphorescent material that emits multi-spectral light.

A single color LED with a clear case is generally preferred for this application, and LEDs are most sensitive to the color they emit when supplied with power.