The town of Ede in the Netherlands has installed the world’s first LED street lights.
Made by Philips at its plant near Lyon in France, the lamps use devices from Philips-Agilent joint venture Lumileds Lighting.
“A lot of design went into the luminair itself,” product manager Bram Lansink told Electronics Weekly. “One of the most important things is heatsinking the LEDs to the housing. The back of this looks like a radiator.”
Philips is marketing the street lamp as needing less maintenance thanmore conventional types by offering a light source life of 50,000 hours - every evening for 12 years. “An intelligent system in the luminair reduces current if the heat gets too high, otherwise we wouldn’t reach 50,000 hours,” said Lansink.
The colour temperature of plain white LEDs is too high (5,500k) for street lamp use. “It looks too cool,” said Lansink, “You need warmer light for street lighting.”
As such, the luminair has six 3W white Luxeon III LEDs and 12 amber 1W devices which brings the colour temperature down to 2,700k, 3,200k or 4,000k as requested.
With 8m between 4m high masts, ground illumination averages at 10Lux, which means the lamp posts are suited to pedestrian areas.
“It is expected that in 2008 luminaries incorporating LEDS will also be available for residential areas and major roads,” said Philips.
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