After hundreds and thousands of hours on an LED...

joshwang

Newly Enlightened
Joined
Oct 12, 2004
Messages
115
We all know that LEDs have an extremely long lifetime when compared to an incad, but has anyone actually driven an LED to the point where it had to be replaced? Also, the SF2005 catalog stated that "the usful light for an LED is defined as the calculated time for the light level to decline to 50 percent of its original value" How will we know when it has reached this line? Thanks!!!
 

cheesehead

Flashlight Enthusiast
Joined
Oct 29, 2003
Messages
1,189
Location
the dairy state
I'd suspect if it's overdriven, yes, it may be "used up". Otherwise, it's like with a fluorescent, sometimes it's hard to know when it's "done".
 

idleprocess

Flashaholic
Joined
Feb 29, 2004
Messages
7,197
Location
decamped
Re: After hundreds and thousands of hours on an LE

How will you know? You'll check it on a lightmeter ... or compare a sample with thousands of hours of usage to a new one...
 

elgarak

Flashlight Enthusiast
Joined
Jul 30, 2004
Messages
1,045
Location
Florida
Re: After hundreds and thousands of hours on an LE

I once worked in a lab where we had a team developing lifetime calculating models for LEDs. Those people routinely have driven LEDs do the breaking point, by overdriving it or heating the LED to accelerate the aging. So it's done routinely by manufacturers and scientists. The models are than of course compared to LEDs who aged during normal operation.
 

NewBie

*Retired*
Joined
Feb 18, 2004
Messages
4,944
Location
Oregon- United States of America
Re: After hundreds and thousands of hours on an LE

Of course, some implementations do a poor job of keeping the LED cool, then they overdrive it on top of that, so light decrease is going to happen alot sooner than normal
 

joshwang

Newly Enlightened
Joined
Oct 12, 2004
Messages
115
Thanks nerdgineer, i'll look into the post.
No offense, Photonboy, but I don't actually believe that a light will be obsolete, i mean, it's actually just a tool. Yes there will be new features, but a light unlike a computer does not have the upgrade-software-upgrade-hardware process. Just as if you were using a using a 20 year-old screwdriver. As long as cr123 cells don't die, neither will lights that use them. /ubbthreads/images/graemlins/nana.gif
 

cia

Newly Enlightened
Joined
Aug 26, 2004
Messages
160
Re: After hundreds and thousands of hours on an LE

[ QUOTE ]
ACMarina said:
I still use a Beta VCR. .

[/ QUOTE ]

Sure you do, but for what?
 

joshwang

Newly Enlightened
Joined
Oct 12, 2004
Messages
115
Re: After hundreds and thousands of hours on an LE

hehe...a bit off topic but i would sure like to copy my video cassettes onto VCDs, but the machines cost /ubbthreads/images/graemlins/mpr.gif
 
Top