Green LED turns red!
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- čas přidán 27. 08. 2011
- Normally rated for 20mA. When 100mA is flowing it turns from green to yellow. At 150mA, it slowly and permanently turns yellowy-orange. At 200+mA it permanently turns red and soon fails.
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I finally knew why robots in movies turn eyes red when they become evil :-)
And burn his eyes?
their brain sent a little bit more power to their eyes
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@@big_o1952 Submit please
don't apply too much voltage otherwise you ded XD
Green LED turns dead!
+OK2BCK Green LED's are the hardest to kill. You know stressed ones from new ones by how cool the green color looks, as they tend towards yellow as they age or get stressed by too much current. I had one that got hit by too much current that went yellow, and it continued working for months.
I think I know what that LED is thinking.
Better red than dead!
From green, to red, to dead...
Austin Hayducky like a car crash
Red Dead LEDemption
@xmaams It's 66% of an RGB LED's functionality for 1/10th the price!
I like overvolting LEDs because they sometimes pop off in one direction.
This way you can create 'Whose LED shoots the farthest?'-contests.
When my led blew up, it sound like a taser
With higher temperatures, the semiconductor bandgap gets smaller due to increased lattice constant. Light emission shifts to lower photon energies, that is green->yellow->red.
Sorry to reply to such an old comment but I love your explanation!
@@Scyth3934 No problem. [troll face] *afrotechmods pikachu shooting thunderbolts out of his arse*
i havent pushed my greens this far but its tempting. ive seen them get orange but i never thought you could push them to red.
0:29 the led kind of start to 'bleed'
You can do the opposite by driving an orange LED at it's correct current and dipping it in liquid nitrogen - it turns green. But shortly after removing, it changes back to its original orange color. (Search it on youtube, it's pretty cool)
I wonder why the change is permanent, when you overrun green LEDs though?
Is it actually permanent? It could just be that the LED was still hot when he tried it again.
Believe me,I cannot see this.I am color blind
+Yodabula You're not alone buddy. Trying to find the right value color resistor is just the funnest thing ever eh?
+317andrew317 lol me too I always mix up the green with red and brown
Not much of a loss, I'm not color blind, but there never was any green at all.
There is a remedy for color blindness. They inject a virus into the eyeball.
a predecessor of the modern RGB LED
LOL I did this once by accident.
i have once but it just blue in half when it was connected. made a heck of a bang.
earendil calmia Blue?.....Do you mean "blew"? I know colours can be confusing but seriously???
Me to. I connected it to a 9v battery pack and forgetting. It turned orange. And then I realized. Yep. It almost burned and went on fire. oops!
Once I powered an led on 5v usb. It made a loud sound before becoming hot and burnt.
At the end it had rainbow colors and then it turned black.
The red glow probably was the LED emitting so much heat it became an incandescent light.
Back when I was a teenager, I burned many LED like that, by connecting them directly to a 9 VDC battery, before I learned about the current limiting resistor needed to power LED. lol !
@AcousticBruce they are diodes... the only resistance is the tiny cables to connect wich is arround 1 ohm...
depending on what AMP the led can handle you should use a resistance.. about 300ohms or so for ordinary leds
@AcousticBruce There are formulas to compute a diode's effective resistance at different currents and temperatures, but for simple projects it's generally faster to just look at the diode's forward voltage drop. (See my video on diodes)
@ReallyCreamy Actually you can use AC mains. But you'd need a high value resistor (around 10Kohms with a power rating of >1Watt) and a diode/rectifier--both in series with the LED--to limit the current and convert AC to DC. Or you can dispense with the rectifier and use two LEDs in parallel but with their anodes and cathodes in reverse from one another. But a resistor wastes too much power. An AC mains rated capacitor would be a better choice. Its power dissipation is negligible
you know why maybe, the burning of the metal changes the material properties causing a greater resistance, V=IR, if the Resistance increases that means the current lowers(I), current is the same as frequenzy causing the wavelength to expand and thus it turns to the left side of the wave spectrum, or reder in this case.
The led chip was still hot when you turn the current up at second time, if you let it cool after overclocking to orange glow, it restores the green colour back.
reason it turns red is because the LED color is determined by the space between the anode and cathode. As it is burning out the gap expands creating different colors.
The LED color is not determined by the space between the anode and cathode. It's determined by the energy gap amplitude between the p and the n regions.
@@ioncasu1993 the mytocondria is the powerhouse of the cell just do you know too.
this explains why green and orange/red lights are a common indicator on small electronic devices for battery life
heat causes greater resistance too so maybe is not just the material obtaining more carbon particles.
Weirdly enough, a red led actually turns yellow when overpowered
you can see the life of a LED from 50k hours to 15 seconds with bit over voltage and no limiting the current flow
@ronmann606
you can increase the voltage or you can use a constant current source, you know with a pnp and emittor determines the current, put a pot there and change the current, put your led in the collector branch. make sure your tor has a heatsink
I found this the hard way in my first electronics class when I used 15V instead of 5V to power a circuit
Now all we need is an applicable cooling solution and we can harness the fullest potential of overclocking LEDs.
I would love to see this magnified and shot in more fps
When supply voltage is anything greater then the total voltage your LED(s) can handle, it must be reduced with a resistor, or this is the result. For example, if using a single LED (3V, 20mA) on a 9V battery, a 300ohm resistor is needed to drop the voltage down to the safe 3V. If you are using multiple LEDs, you can add the voltage in series- 3 LEDs (3*3V=9V) can safely be powered by a 9V without the need for a resistor.
It's turn red because of the high current that heat up the internal unit and change it during the brake down the LED material
I did something similar to this once with a kid's electronics set I once had and had no clue what I was doing. I simply wired my green LED straight up to my 12V battery and noticed it glowing orange. I only disconnected it once I saw smoke coming out and a very small flicker of a flame. Needless to say, I couldn't get it to glow again after that.
Electronics and I don't mix, but I'm still cool with software.
Thanks, I just learnt the meaning of two new phrases today!
changing the band gap energy by overheating them? Might return to normal if you left it to cool down (then again it's just as likely permanent).
Use an 1A and it will work again! (mostly red with a little bit of magic smoke)
Im looking for a good camera to film this stuff. The picture quality here is excellent. What kind of cam did you use for this?
At 100mA, even a dog will shine like that.
Poor little guy, he never even had a chance.
Probably the funniest thing I have ever seen.
What's the science behind it?
@B1r6m4n it will return to original color but will not emit at max(since led is already defective)
over-voltage LEDs =funky colors followed by death.
@AcousticBruce diode has no resistance if it reaches the breaching voltage, voltage only stays on it constantly ...
Does the chemistry of the LED change?
wow,i never thought i was going to see something of a color going as a other color
@ReallyCreamy To high voltage, "Normal" leds require 2 - 3 volt
Having only one resistor means current does not get divided evenly among LEDs. This way one led might burn brighter than others, fail soon and then next one will start burning brighter and fail etc. Having ten resistors means every LED can have (roughly) equal current. Your LEDs will be fine, as 12V/1kOhm = 12mA, and most LEDs can handle that much.
Just found out today when playing with a potentiometer. Turning it down made the led go yellow then red and I was like huh? that can't be good so I came looking for someone finishing their LED off hahaha
As you said, U = R*I, so R = U/I, so for 10A the resistance of the LED would only be max. 9V/10A = 0.9 Ohms, in reality much lower because the battery has an internal resistance (e.g. if the battery has 0.5 Ohms internal resistance, the resistance of the LED would only be 0.4 Ohms, because otherwise the current would be lower). Do LEDs really have a that much lower resistance just because of a slight overvoltage? I mean, according what you say the LED normally runs at 8.3V.
It is more fun to crank up the voltage and watts as high as you can as fast as you can to get it to POP!
i wonder if the plastic casing around the actual diode can be removed, and if it is, will it still work or does it need to be sealed off from the air? arent some LEDs actually white in color or something, and the color of the LED determined by the color of the plastic casing?
That brown liquid that starts to squeeze between the epoxy and the metal, is that the chip melting? I'm surprised it's still lit up at that point.
It's strange, that the wavelenght of the light gets longer, not shortter, this means that each photon has lower energy when the LED has more voltage and current, i.e. more power...
How does overcurrenting change the properties of the band gap so that a higher wavelength (thus lower energy) than usual is emitted?
Is a resistor and yes is ohm theory, more voltage more amps you get...
What voltage/amperage do i need to get a nice bright green as the led i have is can do green/orange/red in that order. its an led from the on/off button onfront of a sky+ box.
Reminds me of all my laser pointers.
Oh, I thought this was one of those two-way red-green leds, in which you input an alternating blockwave, and sweep the dutycycle... I hope you understand what I mean, as far as I can tell, I used the correct terminology... ;)
@Afrotechmods dosnt the color change back if the led cools down to ambient temperature?
Got this on recommended for some reason
Hardcoding LEDs.
"Smoke Emitting Diode" = Man, You've made my day!
8 years late, so SED...
This comes because you change the pn-junction's physical properties such as size due to the heat which results into a different energy for the optical transition.
To all the people who directly connect a LED to a 9V battery: Learn electronics. You have to limit the current via a resistor. Otherwise the Battery will deliver as much current as it can (which can be in the range of up to 10 A) so your LED burns instantly. Use U = R*I where U = (9V - 0.7V). If you need 20 mA for the LED, calculate R
I made a project for school in first grade with LEDs... the 9 volt shorted or something and sent all power to one LED. It promptly exploded :D
Be aware that overloaded LEDs sometimes explode. Would be very bad for the camera lens.
good point! I hadn't thought of it that way but you're absolutely right! :3
yeah i did this once. put a 9V battery to the ends of a yellow and green LED... turned red and yellow respectively
I swear I can see the epoxy encapsulant outgassing at one point
It turns from green to red to show that it's almost dead!
It is now a DED
One-shot traffic signals
well, ive done this with my christmas lights, they have water cooling system inside each one and i think we could adapt it over
Oh A color-chaning LED !!!
So, it's changing colour because the energy per electron is decreasing?
I hate when that happens accidentally. As in selected wrong resistor or errant blob of solder on the board caused full 12V to hit the LED.
unfortunetly for purple , 1 it;s hard to see to the human eye, 2 , the best way to shift is left on the light spectrum, purple is in the right.
a classmate tried to hook a led up to a 20 volt transformator...
almost exploded into my face
That happened with my green led rated for 3v I was using it with a 4.5v battery, as a small light, if I happened to need one in the darkness of night.
It slowly turned into yellow, and then stopped working.
I overloaded an LED just like that once, and at around 9V the thing exploded and shot a piece about 20 feet.
always connect LED with a resistor in series
thats pretty cool! I have seen a vido of leds changing colour in liquid nitrogen, but this is more accesible i guess
Ladies and gentlemen,
This is a simulation only... No LEDs were harmed in the making of this video!
So this is where al those bad red LED's come from on eBay.
what is the science behind the change in colour?
Cool, so you can have multi-color/flashing LED, if you change the current(mA) from
R.I.P. LED
I know something that if I overpower it, it turns red. :P
I've done this before. Granted, it wasn't intentional, but it was cool.
Here's a tip, kids- don't connect an LED directly to a 9-volt.
Do LED's have any resistance?
it would be cool if you could superimpose the power supply readings!
Tried it myself. Quite interesting.
Old Soviet AL102 red LEDs turned almost GREEN at 40..60 mA...
Alive LED turns dead.
But will it blend?
Hi there, I have regular 5-LED bicycle lights, Chinese-made ($1/unit) sporting Red-Amber-Blue-Amber-Red colors instead of all-red. I detached an LED of a certain color, but apparently all of them lights red when attached directly to 2×1.5V batteries :( I'm still using that bicycle lights until now (I have bunch of them).
I thought I would be able to attach colorful LEDs for specific applications, but they all glow red. Of course it's not an RGB LED.
Question... So greed and blue LEDs generally use 3V, wheras red and yellow use around 2V... So if you did this to a greed LED and changed it to yellow, would the voltage over the LED drop to 2V? Try it!!
to force more miliamperes through the led, a higher voltage than factory rated was applied, is that true?
@Afrotechmods except that its permantly changed :D (aka one use of the yellow to red function)
I guessing that the red effect comes from incandescence.
i once shorted out a 1.5V LED with 400 volts :D
green led, yellow light
mind=blown
green means go yellow is caution and red means hope you don't break anything