Cree reveals 170 lm/W light bulb
Cree is claiming 170 lm/W with good colour rendering from a lab prototype LED light bulb, writes Steve Bush.
“LED lighting at this level of performance is only made possible by advancements across all elements of the LED lighting system: lighting-class LEDs, optics, drivers and thermal management,” said the firm.
“Optimising each LED design element was critical in achieving the performance,” added v-p R&D Nick Medendorp.
The bulb was tested by independent lab OnSpeX.
According to Cree, OnSpeX found the prototype delivered more than 1250 lm from 7.3W.
Perhaps the most remarkable figure, is that this performance is delivered at a CRI over 90, well above that delivered by ‘cool white’ LEDs that generally deliver peak efficiency.
The bulb uses Cree’s ‘TrueWhite’ technology, which just for once in the world of LEDs is not a meaningless brand.
“TrueWhite specifically refers to a technology. It uses a greenish-white from BSY [blue + saturated yellow] LEDs, mixed with red from red-emitting LEDs,” Cree marketing manager Paul Scheidt told Electronics Weekly a year ago. “It is a very efficient way to create warm white colours and gives a very high CRI – over 90 – with broad spectrum as well as high red content.”
It is also close to a year since Cree revealed another record-breaking prototype, this one inspired by the US Department of Energy (DOE) ’21st century lamp’ challenge.
Confirmed by OnSpeX again, this one delivered 1,330 lm from 8.7W (152 lm/W) at 91CRI and a colour temperature of 2,800K – see this video.
The US Energy Independence and Security Act of 2007 directed the DOE to establish the ‘Bright Tomorrow L Prize’ competition which had prizes for a 60W bulb (eventually won by Philips) and a PAR 38 bulb.
No one could hit the required PAR 38 specification, so its competition was suspended until it was re-opened in March this year with similar technical specs and slightly different US content requirements.
The ’21st Century Lamp’ was a further aspiration of the L Prize, whose preliminary specifications include: >1200 lm, >150 lm/W, >90 CRI, and 2,800-3,000K colour temperature.Tags: colour temperature