Sourcing the latest LEDs...

I have been reading in the news since 2009 about a company in Japan called Showa Denko KK coming out with a new 660nm LED with better heat dissipating ability.

"SDK has achieved output of 11 mW at the drive current of 20 mA by developing a new light-emitting layer"

Also have heard luminous efficacy figures of around 80 lumen/watt

I read that they were supposedly teaming up with Ushio for "marketing"


Does anyone know where to find such an LED? AlGaInP high efficacy 660 nm? I have contacted Showa Denko US with no luck.

Thanks

uvb4less said:

"SDK has achieved output of 11 mW at the drive current of 20 mA by developing a new light-emitting layer[/I]"

Also have heard luminous efficacy figures of around 80 lumen/watt

Thanks

Click to expand...

20 ma at what forward voltage, that tells you the power consumed.

LEDengin has 660 nm LEDs that give 550 mw at 700 ma input. That is equivalent to 16 mw at 20 ma.
http://www.ledengin.com/products/emitters#LZ1

According to this table:
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/efficacy.html#c1
660 nm light gives 42 lumens per watt.

David_Campen said:

20 ma at what forward voltage, that tells you the power consumed.

LEDengin has 660 nm LEDs that give 550 mw at 700 ma input. That is equivalent to 16 mw at 20 ma.
http://www.ledengin.com/products/emitters#LZ1

According to this table:
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/efficacy.html#c1
660 nm light gives 42 lumens per watt.

Click to expand...

The very best Osram Hyper Red 660nm LED has a wall plug efficiency of around 40%(slightly higher at lower drive currents). In the next few months this is supposed to increase to 50% and the underlying thin film tech is to be applied to the rest of their colored LEDs.
Here is a summary WPE chart. Please note the Golden Dragon values are not for the highest available bins.
http://ledlight.osram-os.com/applic...led-lighting/horticultural-lighting-products/

On a side note, the efficacy table you pointed to contains a very insignificant(well 3 digits significant) error. The max efficacy value should be 683.002 - not 683.

Stephen Lebans

David_Campen said:

20 ma at what forward voltage, that tells you the power consumed.

LEDengin has 660 nm LEDs that give 550 mw at 700 ma input. That is equivalent to 16 mw at 20 ma.
http://www.ledengin.com/products/emitters#LZ1

According to this table:
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/efficacy.html#c1
660 nm light gives 42 lumens per watt.

Click to expand...

Thanks for the information, the news article didnt give the forward voltage and I have been unable to locate a part number.
Iis it possible that this SDK 660nm AlGaInP LED is running at an unusually low voltage, giving it a greater efficiency than the LEDEngin chip?

uvb4less said:

Iis it possible that this SDK 660nm AlGaInP LED is running at an unusually low voltage, giving it a greater efficiency than the LEDEngin chip?

Click to expand...

The lowest possible Vf for a 660 nm LED would probably be something like 1.5 volts, so even best case the efficiency would only be about 37%.

jtr1962 said:

The lowest possible Vf for a 660 nm LED would probably be something like 1.5 volts, so even best case the efficiency would only be about 37%.

Click to expand...

Thanks, I didn't think to calculate that. According to this link:
http://www.pveducation.org/pvcdrom/properties-of-sunlight/energy-of-photon
the energy of a photon is 1.24 electron-volt divided by the wavelength in microns. So the energy of a 660 nm photon is 1.24/0.66 eV = 1.88 eV. So I would think this means that the minimum Vf would be 1.88 volts.

So 11 mW emitted from 20 mA across 1.88 volts gives an efficiency of 11/(20*1.88) = 29%. As Stephen stated, Osram has production 660 nm LEDs operating at 40% efficiency with 50% soon to come.

The LEDengin LZ1-00R200 that I referenced earlier is producing (using stated typical values) 525 mW from 1000 mA across 2.5 volts, so the efficiency here is 21%. LEDengin does not fab their own chips so they don't have the cutting edge versions. I reference LEDengin only because I am familiar with their datasheets. I am using the LEDengin LZ4-4 emitters because they come nicely mounted on a low thermal resistance MCPCB star board and have available matching TIR optics with several beam divergence values.

Well I found the Osram Hyper REds for sale individually but I have never attempted any LED project nor am I a reflow solder expert...more importantly, in the videos, they show these LEDs already in operation. So someone has probably built the whole apparatus and sold it somewhere I'm just curious what manufacturer is producing the light with driver resistors heatsink etc already incorp.