Newbie question on Aleph 1 build

[mountaineer]

I need some help picking the converter board for an Aleph 1/LUX III/2X123´s build . I know I need a Downboy but which one ? I have read here that the 917 is good for all around use but how about the 750 or the 1000 ? /ubbthreads/images/graemlins/confused.gif I want this light for EDC and need some good throw . This is my first build BTW so I want to get it right . /ubbthreads/images/graemlins/help.gif Thanks for any help !
Kenny

 

[McGizmo]

compromise and go with the 917! /ubbthreads/images/graemlins/tongue.gif I did! (A couple times! /ubbthreads/images/graemlins/grin.gif )

 

[GeforceFX]

i have the db917 works great /ubbthreads/images/graemlins/smile.gif You want be sorry ! competes on same level as an e2e in brightness to me ? but that just might be me i love your reflectors mcgizmo and 2 stage /ubbthreads/images/graemlins/smile.gif module

 

[Catman10]

If you really want the throw, consider getting an Aleph 3 head, too! Makes a big difference, I think.

 

[Darell]

Personally, I'd go with the 750. 917 in a pinch. The A1 head has some stellar throw, but the A3 head is in a class all its own. If you want throw and can handle the bulk, the A3 is awesome. Truthfully though, I'm not sure I could carry that monster though.

 

[Chop]

917 is a good middle of the road bias.Going with 750 will get you a bit more runtime. All of the current levels that you mentioned will get you monster throw.

I prefer the 700mA bias for all around use. You should get over two hours of runtime on 2X123 and it isn't much less bright than the DB917.

At the point where you are, it's just a matter of preference. Close your eyes and pick one. You won't be disappointed. What is great about the 917 (this is just my personal logic) is that it is bright; and if you want something more practical, you can then get an LE in a DB500 flavor for good brightness and throw and rediculous runtime.

The way that LEDs incrementally increase output with increases in current and the way that the human eye perceives brightness works out in this way.

If you have a DB biased for 500mA, you will have what you have. A nice, bright, long runtime light. If you want to get a meaningful increase in brightness, you have to double the current to the LED to get a roughly 50% increase in light output. I've found that my "eyes" tell me that this is true. I'm not saying that you have to double current to get a comparatively noticable increase in brightness, but a "meaningful" increase in brightness.

That being said, having LE's running at 500mA and something approaching 1A will allow you to have all bases covered, so to speak.

 

[Miciobigio]

you don't need the Aleph3 to smoke the E2 ...

Aleph1 NG1000 Vs SF E2 /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

NB : the first 2 pics are in B&W the other 2 are full color !

 

[Chop]

A picture is worth a thousand words!!

 

[mountaineer]

Thank´s alot you guy´s . /ubbthreads/images/graemlins/thanks.gif Im going with a 750mA .
Like I said this is my first build . If this one works out , I will build another LE with a 917mA later . Just to compair for myself .
I think im Hooked ! /ubbthreads/images/graemlins/grin.gif

 

[Haesslich]

That's the nicest part of the Aleph system - it's like Lego for Flashlights. /ubbthreads/images/graemlins/grin.gif

"Make it bigger? Switch the body out. Brighter light? Switch the LE out. The low-level light too bright? Switch the head or just the resistor out. Need more throw? Switch the head out. You want it to say Surefire on the body? Switch that out too."

 

[BigGuy]

I am another newbie who built an amazing Aleph1/DB917/TYOJ/BE2.

If you shine the light on the wall, the hotspot is pretty yellow with a slightly bluish corona. Does that sound right or am I underdriving the DB917? At a distance you can't tell.

 

[Haesslich]

[ QUOTE ]
BigGuy said:
I am another newbie who built an amazing Aleph1/DB917/TYOJ/BE2.

If you shine the light on the wall, the hotspot is pretty yellow with a slightly bluish corona. Does that sound right or am I underdriving the DB917? At a distance you can't tell.

[/ QUOTE ]

That's about right for the Y0-tint that you got, IIRC. They tend towards yellow with a hint of blue, and if you're using a Balrog 2x123 body, that'll drive it just fine on a DB.

 

[McGizmo]

BigGuy,
What you describe, I have now see with a few LED's. I think it is specific to the particular LED and not what I consider typical. I have encountered this with a couple TY0J's and recently with a couple TW0K's as well. In three cases, the contrast is quite strong. I have taken to thinking of them as "sunshine" LED's because they look like a spot of sun surrounded by blue sky /ubbthreads/images/graemlins/smile.gif.

 

[BigGuy]

The contrast in mine is also quite pronounced. Of the "sunshine" LEDs you have seen, how was the overall brightness? Should I consider replacing the LED? I have no basis to judge. In general, I am very pleased with the light. And it was great dealing with you.

Scott

P.S. If you are looking for yet another career, you might consider becoming a "spin doctor."

 

[McGizmo]

BigGuy,
I ran across one of these just recently and it was a DB917 LE and in a Aleph 1 head, it luxed at just over 3000 at 1 meter so I would consider it a bright fellow. If you look at the spectrum output of these LED's, you see a spike in both the blue and yellow range (no surprise really: blue LED with yellow phosphor) and my gut guess is that the phosphor coating on these LED's is on the thin side or the LED is bright enough that a significant amount of blue light is escaping. /ubbthreads/images/graemlins/icon3.gif

I don't know if it is due to the tint or because the LED is relatively bright but red targets at a distance do appear to have a better return with one of these compared to a LED with a cooler hot spot. The other thing is that the center yellow is more noticibly so due to the contrast with the blue corona. Look at the center beam through a "masked" hole through your fist that blocks out the blue corona. I won't pretend to know how the optical illusion VS physical reality actually weigh in.

Should you replace the LED? Heck, I don't know! I think it depends on whether or not you are satisfied with what the beam shows you tempered by what the beam itself looks like. /ubbthreads/images/graemlins/icon3.gif

I would suggest that you replace the LED immediately if you plan on using the light for targeting and identifying white walls! /ubbthreads/images/graemlins/nana.gif If you are a great white wall hunter, build a better tool! /ubbthreads/images/graemlins/blush.gif

"spin doctor" ? Ouch! /ubbthreads/images/graemlins/tongue.gif

 

[BigGuy]

First that was "spin doctor" in the most positive sense of the term. /ubbthreads/images/graemlins/happy14.gif

Blocking out the blue corona doesn't really affect the yellow color. Also, the yellow is slightly more apparent with the 30 Ohm low power, that is why I speculated that it might be due to be underdriven - But I guess not.

One question, if I were to try to replace the LED (which I seriously doubt), given that I used a thin layer of 50/50 epoxy and Artic Alumina, how hard would it be to get the LED off the E-screw without tearing up the emitter PCB?

Thanks again for all your help.

Scott

 

[McGizmo]

If you heat the LE up to say 180F, after first unsoldering the LED leads, you can likely pop off the LED without any significant damage to the emitter PCB. Not knowing the bond strength or HDT of whatever epoxy you used, this is a guess.

No surprise in the color shift on low current and yes, I understand that the yellow is still yellow. With any time spent using the light however, your eyes can adjust to the tint and somewhat "normalize" or at least that has been my personal experience. I used to wear amber tinted sunglasses and I was alway surprised at how the initial awareness of tint would quickly go out of mind until I removed the glasses and again had to adjust to the change. Half the time I am working with finger printed and smeared reading glasses and "adapted" to an amazing amount!! /ubbthreads/images/graemlins/blush.gif

 

[McGizmo]

I forgot to mention that the McR-27 is the least "forgiving" of the Aleph reflectors. I believe you will find that what is an obvious contrast in corona and hot spot in the A-1 beam will be significantly less obvious if even noticible in conjunction with the 20 mm reflector or the 38 mm reflector.

 

[Kiessling]

Scott ... IMHO this LED is a cool anomaly! I'll get one of those myself an dI am looking forward to it, should be beautiful! All-white you can have anyday, but a sunshine happening on your white wall in your room ... priceless! /ubbthreads/images/graemlins/grin.gif
bernie

 

[Darell]

Hey, if we're comparing spins, let's not forget that it was me who was convincing folks that the donunt hole of 5W beams was a *desirable* thing. /ubbthreads/images/graemlins/smile.gif

In all seriousness, the best solution to just about any "white" LED beam issue is to AVOID the white wall test! I have an L4 that is about the greenest thing anybody has ever seen in a "white" emitter. Yet the spread of the beam is flawless, and it is a great light to read with (on low) and I use it all the time in the shop and working on the cars. Not once, since my initial white wall test has the color of the thing ever been a problem. Hell, it is still "whiter" than any of my incandescents that we all used to think were white! Oh... and it seems like any emitter that isn't "pure white as virginal snow" seems to be somewhat brighter on a lux meter (than its bin cousins) for whatever reason.

So bottom line: Be happy, don't worry. And you certainly are not *underdriving* the emitter at 917mA!