LED based solar cell?

[arKzeRo]

Hi everyone

little led lights i have been playing with produce electricity when you illuminate them! How come?

I used a Tikka Xp head worn work light to illuminate them from the top close up.

I tried a clear one and got 1.31v on the Dc settings and 2.2v on Ac settings on my multimeter

next i tried an amber one and got 1.42v dc and 2.4v on Ac

next clear pale green i got 1.68v Dc and 2.9v Ac

Next Deep Red 0.5v Dc and 0.6v Ac

next i tried one of the tiny ones yellow 1.54v Dc and 2.6v Ac

I could not find any info on this on the net Is that a normal recognized effect from led lights or is my cheap multimeter damaged lol

if that is real energy being made is it usable say in an led based solar cell?
if that is possible then wouldn't an led based cell be cheaper than the current types available?

Best Regards
Jay

[patmac]

HEy! is good....

I've try it 2n3055 transistors too. Led is a good source, good volts. A simply solar cell only produces 0.5 volts. Very interesting, is possible use 100 LEDS in series and put capacitor discharger to recharge batteries.

[ewizard]

Yep LED's produce power when you shine enough light or sunlight on them. It was actually causing some weird things to happen with a multifunction LED flashlight that came out a couple years ago. I'm not sure how much actual current or power you'll get from them versus regular solar panels. I somewhat doubt it will be a cost effective way to generate power.

[ABCStore]

1N4148 and 1N914 work nice, too...

ABC

[gmeast]

semiconductor junctions

1N4148 and 1N914 work nice, too...

ABC

mono crystalline, poly crystalline, thin film & thin film amorphous PV components are all arrangements of semiconductor junctions ... just like your diodes. Depending upon how you load them and what kind of junction it is ... N, P, or Si or Ge (materials), you will see that your simple diode junctions will generate in multiples of 0.58 VDC to 0.625 VDC just like fully configured PV panels. It's very interesting !

Greg

[CosmicFarmer]

Rectify!

I think if you chain LEDs in series, that the power one led makes will be gobbled by the next one in series. Or if you have one led in a chain that isnt getting enough light to breakover, that might be a wall for the electrons to hit. a massive parallel led board might have the best overall gain IMHO?

Also I was thinking about the human hair solar panel, if you use conductive pen that would make it so you don't have to use hot solder.

Interesting! Thanks for bringing this back to my attention!

[arKzeRo]

Thanks very much for the informative replies guys!

I find this interesting so i will play with it a little more

I had not heard of the human hair cell before CosmicFarmer! i will be sure to take a look at that too sounds wonderful. Mind you, i am loosing my hair so i will have to chop a bug chunk of my wifes head

Best Regards

[Aromaz]

Just put a plain copper sheet in the sunlight, connect MMeter - Copper and Earth - you have electrical current. Use copper as radiator in dark room to keep plants photosynthesis - Part copper outside to capture sunlight, part inside above plant; dark room. Plants keeps growing, and remains green. Remove copper - plants go white and die.

Your LED probes are metal cathode and anodes.

Any metal, when exposed to light emits electrons. That is why the newer solar cells (NanoTubes) use carbon, Titanium, Cadmium Telluride, Copper-Indium, etc.

[Iotayodi]

Any metal, when exposed to light emits electrons

Yep. For every photon absorbed an electron is ejected.

Awhile back I took a pic of this using my back porch screening. I searched for weeks for a similar natural pic of the spectrum but could not find one. The clarity isn't good as it was a cheap digital camera. The spectrum is repeated. Also with the screening there is both a horizontal and vertical spectrum that shows like a cross. I found the smaller the piece of metal,and shiny.the more intense the clarity to the point of glowing. I found I could only get so close with a standard digital camera in order to observe it. At a distance its easier. Use binoculars and focus it using porch screening. Different mesh counts will give different views. Make sure the sun is hitting it right. A better camera with some type of telescopic lens might pick it up better. It really is a sight to see.

[Jules Tresor]

Lidmotor has a nice video with a red LED as sun power Red LED used as solar cell--powering an oscillator - YouTube

I think he measured the amperage to be around 5 micro amps.
1,000 such LED would give 5 milliamps
1 million LED shall give 5A x 1.5V = 7.5 Watts of power.

But it seems that with a Joule thief or other kind of oscillators you can "amplify" the energy, needing much less power input (have not verified that myself yet)

[boguslaw]

Lidmotor has a nice video with a red LED as sun power Red LED used as solar cell--powering an oscillator - YouTube

I think he measured the amperage to be around 5 micro amps.
1,000 such LED would give 5 milliamps
1 million LED shall give 5A x 1.5V = 7.5 Watts of power.

But it seems that with a Joule thief or other kind of oscillators you can "amplify" the energy, needing much less power input (have not verified that myself yet)

Was that original Joule Thief circuit ? Just curious how he was able to run it on so small power.

[Zardox]

About a year ago I played with using leds as photo cells. I got more out of the red ones. I found you could series them together to get a higher voltage but they break down if you go to high. You can also parallel them for more output. I was able to extend the run time of a Fugi circuit running a modified florescent bulb by about 3 hours using a breadboard filled with red leds connected in series parallel. After a while use they seemed to break down. Never the less they do work, however to actually do any real work you would need to have a lot of leds and it would be cheaper to have small solar panel. Also I did have success with extending the run of jewel thief using white leds feeding red leds and additional coils. I think it was 1 white for every 3 red if I remember right. Anyway that was my experience. I hope it helps someone.

[dutchdivco]

Something else

to 'throw into the mix'; With any solar panel, its often 'cheaper' to use a reflective panel, to increase the amount of sunlight hitting the solar panel, and therefore the amount of electricity produced. However, this increases the amount of heat. The more expensive solar panels can handle the higher heat, but not the less expensive ones; are LED's heat sensitive? If not, this may be an additional advantage to using them? Just a thought,..Jim

[Slider2732]

@Jay...many are finding this and enjoying it immensely. Just doesn't seem right does it
Try I/R LED's from old junk that used to have a remote control. In fact, the remote control I/R sender LED's themselves work great. Collecting up from old equipment, yard sales etc can see a whole bunch of such LED's acquired for practically nothing.
For anyone in Minnesota - don't forget 'Clean Up Week' for such things, which I presume they still have since I lived there in 2008. First week in May every year in the Moorhead/Fargo area. A whole week of people putting electrical and other household trash out on the streets and the finds are golden ! Legal dumpster diving lol

You might like to try the heating effect.
Go to Lidmotor's channel and have a look at the 'Penny' oscillator circuit diagram. Built in several configurations and sizes, i've found them ideal for such trials. I've built many that are approx the size of an actual American penny coin (one was posted unrelated in the Bedini Earth Light thread just now in fact running from a salts cell) and, you can use axial inductors or JT toroids or whatever in the coil section. The point - 0.4V and 1uA will start them running, gaining spikes good enough to light LED's. Chain even a bunch of such circuits together and you start looking at a good capacitor based generating system.
Many configurations of LED do indeed have that bugbear of 0.7V drop if you try to link them up anything but parallel...but the micro oscillator method could offer a (rather labour intensive) good solution in a power setup.

Here's a vid of mine, showing the effects of heat applied to an LED - output increases:
LED affected by heat ? - YouTube

Here we are running from solar, using an I/R LED and includes an explanation of that build:
Ha'penny solar oscillator - YouTube

[xee2]

Just put a plain copper sheet in the sunlight, connect MMeter - Copper and Earth - you have electrical current. Use copper as radiator in dark room to keep plants photosynthesis - Part copper outside to capture sunlight, part inside above plant; dark room. Plants keeps growing, and remains green. Remove copper - plants go white and die.

I read this in "The secret life of plants" but I did not believe it. Have you actually been able to do this?