Comparison Request: LS vs mag AA

Greetings everyone, been a lurker around here for a while so I thought I'd introduce myself first

Anyways, I received my LS modules yesterday and have been playing with them quite a bit. I'm somewhat disappointed in the output. After all that I've seen around here I thought it would be much brighter.

I modded my white LS into a double barrel in parallel @ 2.4V and the output is much less than my regular maglight AA and my turquoise arc. I also connected the LS to my 3V mag AA and it was still very weak)Seeing that the output was relatively weak, I placed the light in my series wired double barrel (4.8V) and the output greatly increase, but still unsatisfactory to me. Yes I know thats alot juice In that same series double barrel I have only four blue led and the output is significantly brighter (at least 3 times more). I was using 1.2v AAA nicads rated at 300mA. Is the 300mA the limiting factor? I've been reading that the LS is somewhat equivalent to 10 white nichia so this doesn't make sense to me. So right now I'm thinking it would have been better to gett an array of white nichias for my double barrel.

Also, to test if it wasn't just that LS, I hooked up my second LS for a brief second and got the same result. The second LS went back into the safe until I destroy this one

Bottom line question is: Which produces more output? A "standard reference" mag AA or and LS running on two 1.5V AA?

I'd do the comparison for you, but I've only got one white LS/O to work with, and I simply can't take the off chance it might get destroyed by 2 AAs.
I know it isn't very probable, but it is possible if it happens to be one of the lower voltage LS lamps made.

This test will have to be up to somebody with deeper pockets, sorry.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by gx93117:
Greetings everyone, been a lurker around here for a while so I thought I'd introduce myself first

Anyways, I received my LS modules yesterday and have been playing with them quite a bit. I'm somewhat disappointed in the output. After all that I've seen around here I thought it would be much brighter.

I modded my white LS into a double barrel in parallel @ 2.4V and the output is much less than my regular maglight AA and my turquoise arc. I also connected the LS to my 3V mag AA and it was still very weak)Seeing that the output was relatively weak, I placed the light in my series wired double barrel (4.8V) and the output greatly increase, but still unsatisfactory to me. Yes I know thats alot juice

In that same series double barrel I have only four blue led and the output is significantly brighter (at least 3 times more). I was using 1.2v AAA nicads rated at 300mA. Is the 300mA the limiting factor? I've been reading that the LS is somewhat equivalent to 10 white nichia so this doesn't make sense to me. So right now I'm thinking it would have been better to gett an array of white nichias for my double barrel.

Also, to test if it wasn't just that LS, I hooked up my second LS for a brief second and got the same result. The second LS went back into the safe until I destroy this one

Bottom line question is: Which produces more output? A "standard reference" mag AA or and LS running on two 1.5V AA?<HR></BLOCKQUOTE>


gx93117:

I hope you are wrong or something is wrong with the led you used. I'd be pretty disappointed if the LS had less output then my maglite. From what I've heard about the LS, I would imagine it should be brighter then the maglite.

Sylvestor

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Stingmon:
I'd do the comparison for you, but I've only got one white LS/O to work with, and I simply can't take the off chance it might get destroyed by 2 AAs.
<HR></BLOCKQUOTE>
Craig, how is it possble to wreck a White LS/O with just 2 AAs in series (3V.-right?) -considering that DB-2AAA of mine works great, and BTW only is drawing 80mA or so?

-for gx93117-the white LS/O will definitely light up very POORLY on the 2.4v of Nimh/Ncd in series. it needs at LEAST 2.55v)

p.s.-My DB-2AAA LS unit puts out superior light compared to my 2AA Mini-Mag (in amount, color and usable) beam quality.
p.p.s.-that DB also easily blows away the Lightwave 2000 as well.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by videocal:
Craig, how is it possble to wreck a White LS/O with just 2 AAs in series (3V.-right?) -considering that DB-2AAA of mine works great, and BTW only is drawing 80mA or so?

<HR></BLOCKQUOTE>

These LEDs have a wide variance in operating voltage, ranging from around 2.7 volts to nearly 4 volts; and a low tolerance for abuse. Gransee smoked a bunch of these things working on the Arc-LS project.

If I happened to be unlucky enough to get a 2.7 volt one, there's a chance I could damage or even toast it. Since I only have one of them, it's a chance I'm simply not prepared to take.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Stingmon:
These LEDs have a wide variance in operating voltage, ranging from around 2.7 volts to nearly 4 volts; and a low tolerance for abuse. Gransee smoked a bunch of these things working on the Arc-LS project.

If I happened to be unlucky enough to get a 2.7 volt one, there's a chance I could damage or even toast it.<HR></BLOCKQUOTE>
Realizing that you have a lot of testing to do, if you did have the time, how would you feel about trying your LS with the more modest voltage of 2 Ncds or Nimhs?

I too got my LS's yesterday, but I got an amber and cyan one.

Starting with a 22-ohm resistor and carefully monitoring the current, I worked the cyan one down to no resistor at all at 3.0 volts, at which point it was drawing 150 mA.

The amber one was more efficient. It drew 150 mA at only 2.5 volts.

Both performed pretty much according to the spec sheet, although even at less than 50 mA, they're very bright

My heatsinks haven't arrived yet, so I didn't want to go higher than 310 mA.

However, your results may vary!

Well, I've recharged the nicads and the output still unimpressive in the mag AA, but at 4.8V in the DB, its a killer. Its overwhelmingly brighter than the mag. Still not as bright as I hoped. I think i just had too high an expectation for these torches.

At best, the LS rivals the lumen/watt output of a halogen bulb, which is actually quite an accomplishment for an LED.

However, your simple maglite comparison isn't fair---the maglite bulb is designed for maximum brightness at 3 volts, whereas the white LS wants something like 3.4 volts.

At just 3 volts, you're driving the LS at less than 100mA, and at 100mA it's only putting out 1/3 of its rated output.

All this is described in the spec sheet.

If you want maximum brightness out of an LS with 2 AA cells, you really need one of the boost circuits described on this forum.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Duggg:
At best, the LS rivals the lumen/watt output of a halogen bulb, which is actually quite an accomplishment for an LED.

However, your simple maglite comparison isn't fair---the maglite bulb is designed for maximum brightness at 3 volts, whereas the white LS wants something like 3.4 volts.

At just 3 volts, you're driving the LS at less than 100mA, and at 100mA it's only putting out 1/3 of its rated output.

All this is described in the spec sheet.

If you want maximum brightness out of an LS with 2 AA cells, you really need one of the boost circuits described on this forum.<HR></BLOCKQUOTE>

How do you reconcile that info. with what Stingmon posted in this thread??
Btw-I increased the voltage to 3.75v on my own white LS and it's measured output only went up by 60%.

What Stingmon (and PeLu) are saying is that not all LS's conform to the spec sheet.

Some underperform, and some overperform.

He's concerned that his particular sample is an overperformer and may draw more than 350 mA at 2.7 volts, whereas the measurements I made with my sample (an underperformer) show it draws only 44 mA at 2.7 volts.

I might also point out that my sample is cyan, not white.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Duggg:
What Stingmon (and PeLu) are saying is that not all LS's conform to the spec sheet.
Some underperform, and some overperform.
<HR></BLOCKQUOTE>
This is why I'm going to wait a while before ordering any-(for the batwing to be more consistently predictable)-I HOPE!-or more probably, by that time that Lambertians will be available and more uniform in specs.
--For 15-$20.ea, I want 'em considerably more consistent than what I've been hearing.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Duggg:
What Stingmon (and PeLu) are saying is that not all LS's conform to the spec sheet.
<HR></BLOCKQUOTE>

Actually the other thread was about an amber Luxeon, which have a much lesser volatge at all (and I'm doubting if all people who replyed there were referring to amber LEDs).