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LED Filament without phosphor This photo from a microscope shows the internal construction of an LED filament before application of its phosphor coating. In this particular filament (length 38mm) there are 25x 450nm blue-emitting die affixed to a strip of transparent sapphire, and interconnected in series with gold wires. Keywords: LED Filament

LED Filament without phosphor

This photo from a microscope shows the internal construction of an LED filament before application of its phosphor coating. In this particular filament (length 38mm) there are 25x 450nm blue-emitting die affixed to a strip of transparent sapphire, and interconnected in series with gold wires.

IMG_4168.JPG IMG_4169~0.JPG LED_Filament_Blue_Die_full.jpg LED_Filament_Blue_Die_individual.jpg Sylvania_LED_Filament_A60_Colours.jpg
File information
Filename:LED_Filament_Blue_Die_full.jpg
Album name:James / James
Keywords:LED Filament
Manufacturer:Sylvania
Wattage:1.5W
Date manufactured:2019
Filesize:6804 KiB
Date added:30 Apr, 2019
Dimensions:12844 x 919 pixels
Displayed:27 times
URL:http://80.229.24.59:9232/gallery/displayimage.php?pid=11320
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Comment 1 to 6 of 6
Page: 1

AngryHorse   [01 May, 2019 at 12:25 AM]
So did the Japanese abandon this concept James?, or was it we just never saw it in this country until recently?
FrontSideBus   [01 May, 2019 at 02:09 AM]
Quite a lot of engineering there!
James   [01 May, 2019 at 08:53 AM]
This filament concept was invented by Ushio of Japan in 2012, and the improved gas-cooling of LEDs by OsramSylvania of USA, but in the mean time only the Chinese are producing them due to the large volumes at low costs (some tens of millions per day from a typical factory).
FrontSideBus   [01 May, 2019 at 10:37 AM]
So what’s being dropped across the whole string? 75v?
AngryHorse   [01 May, 2019 at 11:22 AM]
Imagine how powerful you could make one of these if you used all four sides of the sapphire? Shocked or would this cause over heating problems?
James   [02 May, 2019 at 11:16 PM]
Vf is depending on drive current and heatsinking, but these ones drop about 67V in my application. Even with chips on one side they reach thermal saturation so adding more would sadly not help!

Comment 1 to 6 of 6
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