Posted on 12/06/2007 5:00:32 PM PST by decimon
The six and ten clusters in new flashlights are unbelievably birght.
Schroedinger, is that you?
.....and last almost forever. LED’s are not loved by the Energizer Bunny.
bump
“LEDs are made from two halves of a special material called a semiconductor. One half is filled with negatively-charged electrons and the other with positively-charged areas called holes.
Where the two halves meet, the positive and negative charges join together - causing the electrons to emit energy as photons of light.”
Yup, according to the article, no batteries are even necessaary! /nitpick
Well, it was famously just used in the October elections in Geneva, Switzerland so perhaps it's not quite as pie-in-the-sky as the BBC article makes it out to be. For instance, from http://www.physorg.com/printnews.php?newsid=115571103:
Cryptic messages boost data security
The Swiss national elections in October 2007 provided the opportunity to witness quantum cryptography in ‘real-life’ action for the first time. Geneva was first in line to test the unbreakable data code developed by Swiss start-up company id Quantique, paving the way for a new era in data security.
The canton of Geneva became a world pioneer when it decided to use quantum cryptography to protect the dedicated line used for counting votes in the October national elections. The world’s first commercial quantum random number generator and quantum cryptography system was developed by the Swiss company id Quantique – a spin-off company of the University of Geneva – so the choice of Geneva to test the system in action was only appropriate.
...
(Not everyone was so impressed; Bruce Schneier certainly didn't rate this usage very highly in this article.)
Say that again.....I can't see ya....
The security folks at work had these, I asked to borrow a "flashlight".....when I returned it, I said, "You didn't tell me I needed to wear my sun glasses when using this thing..."
Holy crap that thing was bright.
And for a 'what the heck' - I bought out the local Rite Aid supply of multi-color LED Christmas lights - half off.
I thought it was a rather bright idea!
I have one wind-up LED flashlight. Its light is not very bright but it's adequate and needs no batteries. It cost five dollars.
I was but now that you've noticed me I've changed to a cat.
I just bought an Eveready flashlight at Target. It has a single 1-watt LED. It puts out just about as much light as my old 3 D-cell Maglite, but in a white rather than yellowish light. The 2 AAs will last something like 25 hours. It cost $10.
What an improvement over the older tech!
Related:
http://www.freerepublic.com/focus/f-news/1804814/posts
Planet Earth banning common light bulbs
I just bought a Streamlight Stinger-LED rechargeable flashlight. WOW! Different modes —— hi,med,lo plus strobe.
The local Wal-Mart was clearing out some Brinkman LED replacement bulbs for their aluminum flashlights. They were marked down from around $20 to $5. I replaced the Krypton bulb in two of them and the LED is quite a bit brighter. Also last practically forever and use far less battery power.
I just changed out a months-old CFT and wondered why we don’t have LED lights that fit into regular sockets.
They are available but hard to find and expencive.
Currently they are not suited for that application.
After getting his EE degree in the early 80s my Nephew’s first job at HP was designing a machine to sort LEDs for brightness and color spectrum.
Yet the government is in the process of enshrining use of CFLs as the law of the land.
BTW, I haven’t seen much discussion of why LEDs are so much more efficient. Tungsten bulbs put out something like 95% of the energy they use in the infrared spectrum and only 5% in visible light. Fluorescents are something like 65% visible light, while at least some LEDs are above 90%, I believe.
I work with infrared imaging systems, and incandescent bulbs are amazingly bright in infrared, while LEDs are just about invisible.
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