first impressions of an amber lambertian LS...

papasan

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got an amber lambertian luxeon star with the optics a couple days ago from Mark Hannah Surplus Electronics...quick shipping, packaged very well (wrapped 3 times in static resistant materials)...good transaction...

first thing that struck me was the size...it's smaller than i imagined it would be, smaller accross than a quarter...the optics seem to be glued onto these new ones, there was what looked like silver silicone at the base of the black plastic housing...i didn't try to pry it off...

after i got it fired up (being very careful to get the polarity correct and not jump the poles through the heatsink backing) the next thing i noticed was the color...amber just isn't for me i guess...i would probably classify this as more of a light orange color...more 'pure' than incandescent, but still not pleasing to my eye, i much prefer the 'moonlight' white of the nichia's...

running off of 2 fresh AAs (1.56v & 1.53v) after it was running i measured about 2.6v~2.7v...my fluke has 2 fused terminals for measuring amperage, a 10A hole and a 300mA hole...hooking it up to the 300mA read overload and hooking it up to the 10A sucked so much juice the LS went out...i don't have any precise low-R/hi-W resistors so i couldn't check that way either...so it was something over 300mA but not sure by how much...after about an hour of running it (still over 300mA draw) i took it apart...it was actually cold to the touch which indicates to me that it could be driven much harder...

brightness was somewhat dissapointing for a LED that's supposed to put out [email protected], it's hard to compare with other LEDs tho...the beam was very smooth, very 'clean'...a nice sized diamond shaped hot spot in the middle with decent roll-off (the optics are supposed to be 10 degrees, i think, but it seems a little wider)...it seemed about as bright as maybe 4~6 overdriven 5600s but much smoother in the beam...not too bad for being straight off of 2 AAs i suppose...perhaps i was just expecting too much as i've heard this compared to a LW4000 and an E1...

soon i'm going to put this into a double-barrel 4xAA, perhaps the 2 sets of batteries in parallel will beef up the beam a little...even better, perhaps as it gets more fully driven the color will brighten up...we shall see =)...
 
Hi there again papasan,

Did you order a white one or an amber one?

You may have to step up the voltage
with the converter we have been talking
about in the Zetex 300 chip thread.

I have now found out that the LS
has a much flatter curve then the
typical Nichia white 20ma LED once it
starts to conduct heavily, meaning
a small increase in voltage around 3 volts
could mean a huge increase in brightness,
relatively speaking.

Good luck with it,
Al
 
i got the amber one...as far as i know there is no white 'high dome' out yet...that will be a most excellent LED when it's released...

yes, i was hoping that this was the case, that's why i started following the zetex thread so closeley...well, one of the reasons...electronics has always been interesting to me but i've never gotten very hands on before now...i like the idea of a regulator anyways, you can make cheap old alkalines act like lithiums =)...after the 300/310 chip gets hashed out i'm hoping to add a PWM dimming circuit as well, but one thing at a time...
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by papasan:
i got the amber one...as far as i know there is no white 'high dome' out yet...that will be a most excellent LED when it's released...

yes, i was hoping that this was the case, that's why i started following the zetex thread so closeley...well, one of the reasons...electronics has always been interesting to me but i've never gotten very hands on before now...i like the idea of a regulator anyways, you can make cheap old alkalines act like lithiums =)...after the 300/310 chip gets hashed out i'm hoping to add a PWM dimming circuit as well, but one thing at a time...
<HR></BLOCKQUOTE>


I was under the impression that the
LS/o was a white LED with optics.
Is this correct?

Is that why you got the Zetex 310 chip so
you could dim the LED eventually using
PWM?

--Al
 
the LS/o designation is any luxeon star with optics, either the old 'batwing' or 'low dome' die or the new 'lambertian' or 'high dome' die...and it's irregardless of the color...

if you look at the LS data sheet (1st chart, page 3) it lays em out for you pretty well...i've heard rumours that the white lambertian should be out by the end of the year, but perhaps they've been having difficulties...it has a projected lumen of 31.68~32.4...cross your fingers...

i chose the 310 (well, i haven't yet, digikey still shows none cut off the reel) because it seemed newer than the 300 and because it costs less...now if i can figure the PWM to take advantage of it's on/off pin, so much the better =)...i was thinking that a pot after the resistor might work okay, but with the small resistance amounts we are dealing with i'm not sure that would work well, plus i'm not sure how that effects effeciencey...
 
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