Difference between revisions of "Cree"

Cree (view source)

Revision as of 10:38, 22 June 2016

63 bytes added , 10:38, 22 June 2016

working towards changing bins to 85 degrees

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 [[File:Ansi-white.jpg|thumb|Chromaticity chart with tint bins used by Cree]]Cree is a [[LED]] manufacturing company based in Durham, North Carolina. They produce a number of different models of high output LEDs that are widely used in flashlights. They do not actually make flashlights, though some companies will describe their product as a "Cree flashlight." This refers to the LED inside the flashlight.
-Cree bins individual models of LED on the basis of total flux or light output, typically measured at 350mA. Bin numbers might be P4, Q2, Q3, Q4, Q5, R2, R3, R4, and R5 with each bin being about 5% additional flux. The P4 is 80 lumens, a Q5 would be 107 lumens, and the R5 bins are 137 lumens. At higher amperage than 350mA, the brightness goes way up, with the XP-G producing 3 times as many lumens at a maximum current of 1500mA.
+Cree bins individual models of LED on the basis of total flux or light output. Individual flux bins are about 7% apart taken at some reference current like 350mA or 750mA, but at higher currents the output goes up, up to some maximum current. Cree measures output at a reference temperature 85&deg; Celsius, which is a more realistic operating temperature, but in the past they measured at 25&deg;. Output is typically higher at a lower temperature.
-Cree classifies tints of white LEDs as being warm, neutral, and cool, but has recently added "outdoor white" in between and overlapping neutral and cool (4000-5300K). Tints are binned using a system based on the [[ANSI White]] standard. Cree's tints subdivide and expand on the ANSI regions giving bins such as cool 1B, neutral 5B1, and warm 7D2, though many other tints and subdivisions are available. Click on the graphic at right to see all of the bins, though not all bins are available.
+Cree classifies tints of white LEDs as being warm, neutral, and cool, but also "outdoor white" in between and overlapping neutral and cool (4000-5300K). Tints are binned using a system based on the [[ANSI_White]] standard. Cree's tints subdivide and expand on the ANSI regions giving bins such as cool 1B, neutral 5B1, and warm 7D2, though many other tints and subdivisions are available. Click on the graphic at right to see all of the bins, though not all bins are available.
 In addition, Cree produces High [[Terminology#CRI|CRI]] LEDs, with CRI values of 80, 85, and 90 represented by bins H1, P1, and U1 respectively (separately, L1 represents normal CRI white LEDs, and O1 is outdoor white).
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 Below are output numbers for different currents for the various brightness bins of more current LED models. There is more information available with the '''[http://pct.cree.com/ Cree Product Characterization Tool]''', an online calculator that allows you to look up output based on more factors. The numbers on this page, like those given by the PCT, are based on charts in the LED datasheets.
-'''Older models of Cree LEDs have been moved [[Old Cree LEDs|here]].'''
+'''Older models of Cree LEDs have been moved [[Old Cree LEDs|here]].''' For bins at 25&deg; see [[Cree 25 degree bins|this page]].
 ==MT-G2==