[ale] way OT amazing new LED flashlight technology

[Alex Carver]

On 9/17/2012 21:16, Ron Frazier (ALE) wrote:
>I bought the Nebo 5610 220 Lumen Redline Tactical at Batteries Plus.  This unit costs about $30.  They warrant the unit for life.  It has a very bright LED emitter called a Cree.  I haven't done research into the merits of this, but it IS very bright.

Cree isn't a type of LED, it's the name of a major manufacturer of LEDs 
and other devices (the other major manufacturer is Philips Lumileds 
which makes the Luxeon brand of emitters).  Cree is based out of North 
Carolina and their primary area of expertise is in silicon carbide (SiC) 
based devices (of which certain types of blue and ultraviolet LEDs are 
made).  The LED in your flashlight is one of their UV models (probably 
an XLamp if it's a recently designed flashlight) down-converted to white 
using phosphor coatings (look closely at the LED (with the power off of 
course!) and you should see a pale yellow dot in the center -- that's 
the phosphor bead).  This UV-phosphor design is currently the most 
common white LED.

Cree's emitter gets its big power because SiC can handle very high 
temperatures without degrading but it does require a flashlight that is 
built properly to support a large LED like that.  SiC LEDs can pump out 
many watts of heat into their heatsinks.  Junction temperatures (the 
temperature at the diode chip inside) can reach over 150 degrees Celsius.

Cheaper flashlights or replacement modules use lower power LEDs because 
of the heatsink requirement.  They either don't have any heat sinking to 
keep manufacturing costs and retail price low or, in the case of the 
replacement modules, the flashlight doesn't have the proper design for 
keeping the diode cool since it was an incandescent bulb originally.

Enjoy the flashlights.  :)  LEDs have made some nice progress in the 
last few years.  I've got the LED Maglite (made with an LED from the 
start that also does the SOS flashing), and several LED desk/task lamps 
that work quite well.