1W vs 3W @ low drive rates

[chimo]

I have question for anyone who has some first hand experience underdriving emitters and measuring light output.

Let's say you are going to drive an emitter in a small light at about 200-300 mA. You have both 1W and 3W emitters at hand.

1W Q/R binned for flux and J/K for voltage
3W S/T binned for flux and J/K for voltage

Is there any real benefit from using a 3W (other than perhaps color) in an application like this? Has anyone done some intensity checks for various drive currents? I suppose I could deduce some info off the spec sheets. Thanks,

Paul

 

[greenLED]

Luxes are binned while running at spec, so if you underdrive it, their color may change. The LuxIII would be the most affected, IIRC.

There are a couple of good threads on the Shoppe's forum about this. The discussion was about which MadMax board was best to use with what type of Lux, and the issue of color shift was brought up. Sorry, I don't have a direct link for the threads, though.

 

[3rd_shift]

I had a few Nuwai TM115's that had TX1K and SXOJ's in them.
The TX1K's were greenish on low mode, and not pretty.
The SXOJ's didn't get green at low levels, but if anything lost some of thier bluishness and were nice and white.

 

[chimo]

Thanks for passing on your observations, guys. I was curious about light intensity from a 1W and a 3W running at the same current. Will a 1W R-bin run much brighter at 350mA than a 3W S-bin? I tried them in series at 350mA current but I don't have a light meter and it's hard to tell by eye. In the pic below there is a standard minimag with a TW0J MiniPro3. The little Dorcy single AAA next to it has a similar pill but with a 1W R3KW. The Dorcy is nice and small but the tail switch takes up a quarter of its length. I am trying to decide if the 1W R bin was the best choice.

Paul

 

[evan9162]

Here's my data:

<font class="small">Code:</font><hr /><pre>
Lux (1m, bare emitter)
130mA 310mA
Lux 1 Q2J 4.9 10.3
Lux 1 Q2J 4.9 10.7
Lux 1 Q2J 5.0 10.6
Lux 1 Q2J 5.0 10.3
Lux 1 Q2J 4.6 9.7

Lux III TWOK 6.0 12.4
Lux III TV1K 5.9 12.3
Lux III TV1K 6.3 13.0
Lux III TV1K 6.3 12.7
Lux III TY0L 6.6 13.6
Lux III TY0L 6.2 12.8
Lux III TX1J 5.7 12.1
Lux III TX1J 5.8 12.2

</pre><hr />

 

[chimo]

Thanks evan9162,
That's exactly what I was looking for. /ubbthreads/images/graemlins/clap.gif

Paul

 

[bhvm]

evan9162,
Would you explain what that data is?

can you plot a Vf vs Current plot for these LEDs + SSC P4?

 

[Marduke]

evan9162,
Would you explain what that data is?

can you plot a Vf vs Current plot for these LEDs + SSC P4?

Do you even look at the date before reviving an extinct thread? Seems to be quite a pattern.

 

[HarryN]

I think we should actually thank people who take the time to do some searching, rather than creating the 4,000th thread with the question - "what is the best battery / cheapest price."

bhvm - Thank you for the question. You are in luck actually, JTR1962 has made an excellent database / plot set for LEDs like you are searching for. It is in the "LED" section.

Here is the link.

http://www.candlepowerforums.com/vb/showthread.php?t=89607

Evan also did quite a few posts regarding output info, some of which was lost. Perhaps someone else knows where it is posted.

 

[VidPro]

heck yes, i would far rather drive a 3W at 1W than a 1W at 1W, most of the higher powered stuff, is better cooled/synced, and underdriving is longevity.
output from underdriving is usaully better, to a point , like >10ma into a high power led thing.
i even replaced a few 5mm (20ma) leds with 1W (350ma) leds (raw emitter), and the 1W has run non stop much longer than the dwindling output of the 5mm.