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Tighter binning yields more consistent HB LEDs for indoor apps - PowerSource - Blog on EDN - 1470000147

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Tighter binning yields more consistent HB LEDs for indoor apps - PowerSource - Blog on EDN - 1470000147: "Thursday, December 10, 2009
Tighter binning yields more consistent HB LEDs for indoor apps

Dec 10 2009 11:54AM | Permalink |Comments (3) |

HB (high-brightness) LED vendors make white HB LEDs by taking a blue LED and dosing it with a blob of phosphor that emits white light when illuminated by blue light. If cost were no object a manufacturing process could precisely control the LED chip/phosphor combination to get a completely consistent white light color temperature, but that level of control is prohibitively expensive. However, HB LED vendors do provide LEDs that fall within certain color ranges. These ranges are called color bins, and the process is called binning. If your end-fixture uses multiple LEDs, a common design technique for outdoor lights such as street lamps, the lighting will be consistent as the LEDs’ color temperature will average out. However, not all indoor app…

Cree R&D LED reaches 186 lumens per Watt - PowerSource - Blog on EDN - 1470000147

Cree R&D LED reaches 186 lumens per Watt - PowerSource - Blog on EDN - 1470000147 Tuesday, December 1, 2009
Cree R&D LED reaches 186 lumens per Watt

Dec 1 2009 9:35AM | Permalink |Comments (8) |

Cree's tests for the R&D device showed that the LED produced 197 lumens of light output and achieved 186 lumens per watt efficacy at a correlated color temperature of 4577K. The tests were conducted under standard LED test conditions at a drive current of 350mA, at room temperature. Cree says the 186 lumens/W is the highest in the industry to date. In the past, Cree has said that it generally takes only about 12 months before a lab-level LED is commercialized; Early 2011 for a product version?