example of led dimming due to age

We've heard that leds dim with age. Now I can show you an example of this in real life.

Look at your keyboard. Typically most people leave their numlock on. Compare the brightness of this led to that of the capslock or scrolllock.

Obviously, you won't see any if the keyboard is new. But I can tell a good bit of difference in mine. The numlock looks about 30% less bright than the others.

But my keyboard is a nice one, and is not made anymore, so I have kept it a while. I'd say it's 7 years old, and has been left on for 90% of that time.

Good example, but both of my computers have wireless keyboards and neither have those LEDs(or any LEDs of mention). I'm guessing the manufacturers left those off to minimize drain on the batteries.

Strange, my 13 (Yes) year old keyboard looks fine.
Same with a few other keyboards I have, the manufactures of these keyboards must REALLY underdrive them.

Neat test! I just tried it on a 10 year old keyboard and the shift lock is twice as bright.

My keyboard is 18 years old (* 22.feb.1988, cherry G80-1000), all three leds look the same.

6 yr old KB, i would say at least 25-30% loss. seem's to mirror my ultra G's amount of loss when it was hung over my computer space and ran on nimh's for 6 mth's.
(as compared to a newer G) VDG

My num lock is defintely dimmer, and this keyboard is only 2 yrs old!

Must be variation in quality of leds! My IBM keyboard uses the old school greenyellow leds. Of course it's only been used for a little over a year.

My 5.5 year old Microsoft Natural keyboard is hard to judge. The Caps lock LED is perhaps a bit brighter, but it is less yellow-green than the number lock. So I suspect it's well within the brightness variations of new LEDs.

Greg

JasonC needs to post a beam shot of his Arc AAA which is SERIOUSLY overdriven..it's yellow and sickly looking. (daily ontime for a few months)

yellow?

GarageBoy said:

JasonC needs to post a beam shot of his Arc AAA which is SERIOUSLY overdriven..it's yellow and sickly looking. (daily ontime for a few months)

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I saw it -- I think it's still usable, although kinda greenish-yellow and funky.

Stock Arc? I'm glad they use nichia and nothing else!

Yea, stock arc, old style. Remember, the LED is pretty over driven in that

Great test! I checked a couple of no-name keyboards that have a few years on them. The numlock key is slightly dimmer than the others. Brightness perception isn't terribly linear, so I don't know how this translates in terms of the half-brightness rule.

Mine seemed fine. Maybe a hair of difference, but now I'm looking for one and may see something that is not there.

Hey, maybe the people who have dimming LED's have cheaper ones, ones that were over driven, or just have a 10,000 hour life instead of 100,000.

I can't believe I never thought of this!

My keyboards probably about a year and a half old. The Capslock and Scroll lock is about 15-20% brighter than the Numlock.

All three of mine are the same . I just replaced them with Luxeons last month.:lolsign: :lolsign: :lolsign:

Don't think anyone has a 10k hour led. That's just over a year, with a year being 8760 hours.

I've also got a red led on an air purifier. It has completely dimmed down to nothing. It's absolutely gone out. Only took ~9 years!

tron3 said:

Mine seemed fine. Maybe a hair of difference, but now I'm looking for one and may see something that is not there.

Hey, maybe the people who have dimming LED's have cheaper ones, ones that were over driven, or just have a 10,000 hour life instead of 100,000.

Click to expand...

Intersting observation. Doesn't put me off LEDs in the least. Find me an incandescent bulb that lasts that long? The plus point is that dim or not it's still working!

Doug