Maker Pro
Maker Pro

LED Output in Lumens

V

Victor Roberts

OK, we have been having a lot of fun, but this is a serious question.

I am collecting some LED data as part of a project and found that the
availability of efficacy data is even worse than I had thought. I have
looked at Lumileds, Nichia, Toshiba, Gelcore and a bunch of places
that sell products from smaller companies. The ONLY LED manufacturer
who provides comprehensive output data in Lumens for their LEDs is
Lumileds. Everyone else gives the output intensity in mcd, which is
almost useless since we are interested in lumens. If they gave good
intensity vs. angle data we could calculate lumens, but all they seem
to give is peak intensity and a viewing angle. Nichia does have a new
series of high brightness LEDs that are listed as "under development".
They operate at 350ma, like the original, and now three-year old
Luxeon Start devices, but their efficacy is lower than comparable
power Luxeon devices, 17.3 lm/W "typical" vs about 22 lm/W for the
current Luxeon Star.

If anyone knows of any other vendors who provide output data in Lumens
instead of intensity in mcd, I would appreciate a link.
 
V

Victor Roberts


Thanks John! I like the data presentation from Norlux. They even give
curves if efficacy vs. drive current. All do have lumen data and some
even bother to calculate efficacy. All are significantly worse than
the Luxeon devices. Typical efficacy values are about 10 lm/W with one
near 7 lm/W and the tri-color Norlux operating at about 13.7 lm/W.
(all at 25C of course.)
 
J

JB

Victor Roberts said:
df

http://www.osram.convergy.de/upload/documents/2003/06/30/12/10/LW_T673.pdf

Thanks John! I like the data presentation from Norlux. They even give
curves if efficacy vs. drive current. All do have lumen data and some
even bother to calculate efficacy. All are significantly worse than
the Luxeon devices. Typical efficacy values are about 10 lm/W with one
near 7 lm/W and the tri-color Norlux operating at about 13.7 lm/W.
(all at 25C of course.)
The Osram LEDs are particularly good on lumen maintenance also. I spent some
time with a couple of their LED specialists earlier this week and looked at
a range of new products in some detail, which are to be launched in April.
If you haven't planned already to visit the Frankfurt show, it would be just
another good excuse to go. There will be some *very* exciting products
launched there this year from several European manufacturers.
http://light-building.messefrankfurt.com/frankfurt/en/home.html

cheers,
JB
 
V

Victor Roberts

The Osram LEDs are particularly good on lumen maintenance also. I spent some
time with a couple of their LED specialists earlier this week and looked at
a range of new products in some detail, which are to be launched in April.
If you haven't planned already to visit the Frankfurt show, it would be just
another good excuse to go. There will be some *very* exciting products
launched there this year from several European manufacturers.
http://light-building.messefrankfurt.com/frankfurt/en/home.html

Well, the Frankfurt show is out this year since I am going to Light
Fair and then to LS:10 in France in July. This will just about drain
my conference budget for 2004 :) Do you think they will show the
same products at Light Fair?
 
J

JB

Victor Roberts said:
Well, the Frankfurt show is out this year since I am going to Light
Fair and then to LS:10 in France in July. This will just about drain
my conference budget for 2004 :) Do you think they will show the
same products at Light Fair?

--
Almost certainly on the LED front. I'm not too sure as to whether they'll
show all of the newer HID and compact fluorescent products in the US yet. If
I get any 'public domain' info, I'll post a link.
regards,
JB
 
V

Victor Roberts


Nice, but no data for the future device you reference. I also could
not find any white LEDs on Cree's Web site, but perhaps I didn't look
hard enough. Cree does give the output in mW for their blue LEDs, so
with some phosphor efficiency data I could computer lumens for a white
LED made from these devices.
 
Top