opalec newbeam

Has anyone the newbeam kit to see if there is any lumen depreciation after a while and if so, how many hours? I have heard these led's are not being overdriven, so they should last a long time

Yup, check out
http://www.uwgb.edu/nevermab/battery.htm

Yes
No
10
Yes
Yes

I spoke with the people from Opalec. The NewBeam does not overdrive the LEDs because the current is regulated at 30 Ma. The LEDs
degrade significantly faster at higher currents.

Brock,

If you look at the bottom of the Spec Page , you can see that 30 mA is max. I was once told by Matt (formerly of Nichia) that the life will be diminished from the 100,000 max 1/2 life but even if driving them at 30 mA reduces the 1/2 life to 5,000 hrs; in a flash light that may not be too big of a problem.

Matt or someone else told me it was OK to hit one of the max parameters as long as you were below max on the other two; parameters - max Vf, If, and temp.

I tested one of the Photon type lights and as I recall, there was over 100 mA of current and the 6 volt battery! I recon that LED won't be a grandpa.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by McGizmo:
I was once told by Matt (formerly of Nichia) that the life will be diminished from the 100,000 max 1/2 life but even if driving them at 30 mA reduces the 1/2 life to 5,000 hrs; in a flash light that may not be too big of a problem. <HR></BLOCKQUOTE>wouldnt 50,000 be half life?

mrchri5,

As it was explained to me, when you hear a claim of 100,000 hours life on an LED that means that after 100,000 hours the LED will be putting out 1/2 the ilumination that it did initially so I guess it would make more sense to think of a LED's stated life as the time it takes for it to reach 1/2 brightness(50% change in luminous intensity).

Check out life-spec PDF file

I understand that the LED's will keep going, just getting dimmer and dimmer which I can relate to

Dimmer? Did somebody say "dimmer?"

mrchri5 - Don just beat me to it while I was off being busy. 50,000 hours would be half a standard LED half-life. A half-life of *anything* is the time it takes to reduce the item's emissions by half. The Tritium in glow rings have (I beleive) a half-life of 10 years.

I guess I learn something new here everyday. I was looking at Brock's page with the current measurements for some of the lights. I wonder how long my elite xray would last on lithium batteries before the leds started degrading noticeably.

mrchri5 ,

Since the Eternalight has PWM, if you use it on dim, depending on the duty cycle of the pulse, a bunch more current can be pumped through the LED's. That's my vague understanding anyway.

Aren't Nichia's rated at 20mA So wouldn't 30mA be overdriving them? Not that I am complaining, I like the level of light and they don't get hot at all. And as far as I know they are the driven at the lowest mA besides the CMG Infinity.