New LED-Lensers: 1xaa Luxeon lights

Zweibrueder Germany offers three new lights, the "David"-Line (Inspired by David and Goliath) . All of them use 1aa-cell and probably Luxeons. (Zweibrueder never uses the word "Luxeon" but speaks about "power chips" or some other nonsense).

Zweibrueder (Only German text for now)

All of them use some kind of optics, no reflectors as far as I can see. :ironic:
They advertise the lights as "42 lumens" "special forces ready".
They also rate them as "splashproof" but not dunkable as far as I can tell, not sure wether they have glass or plastic windows (probably none at all) protecting the optics.
Two models are made of aluminium, the only difference seems to be in the size of the head/optics. The one in the middle is made of stainless steel and though it looks like a twisty, it seems to have some kind of tail-switch. As far as we now from earlier models, they will use a reverse clicky in all of those lights.

Once again, Zweibrueder offers some very nice looking lights, but I really doubt they managed to avoid old mistakes like unprotected optics, insufficient protection against wanter entry and so on. I'd like to see some runtime plots though, since this is only the second "zweibrueder" line of lights that needs some kind of regulator to work. The first one, the V² lithium suffered from all the mistakes mentioned before. It never got any attention. (And rightly so, as I might add.)
The "David" lights are sold for about 45 to 55 Euro by some retail sites in germany, which makes them direct competitors for the Fenix L1P. I really doubt they are prepared to fight this new CPF-Goliath though. :touche: :naughty:


Chrisse

As I am really tired of buying LedLensers ... you could check them out, Chrisse !?!?!
bernie

Using a battery that is easy to find and affordable would be a nice change for LED Lenser.

Kiessling said:

As I am really tired of buying LedLensers ... you could check them out, Chrisse !?!?!
bernie

Click to expand...

Well, I doubt I'll be buying them, but I'll sure check them out if I happen to find some in a local shop. Of course I can only provide a first insight, it would be up to the master of Lenser reviews to make a final judgement. :nana:

Chrisse

I have a Sears 7840 it looks to be the same as the David. My tests show it to have about the same throw as a Fenix L1P or Q3. It has less spill. I am happy with mine.

Chrisse ... :whoopin: ... be a man and buy one!
bernie

Had the chance to handle a David 15 today. Good news and bad news, but overall, still not the light I'd buy.

First of all, brightness seems to be OK and the biggest surprise: It has a regular momentary clicky. Very good switch in my opinion but no tail-standing ability.
They seem to use a new optic, much smaller than the nx05 or similar optics, smaller than everything I've seen before. The beam looks like with most other optics. You can clearly see the image of the square die in the beam, when pointing it at something close up. The bad news: Still no glass or plastic window in front of the optics, nothing to protect it from getting scratched, nothing seems to keep water from leaking into the light at the business end.

Without the fenix around, I'd possibly recommend this light to someone looking for a single-aa light, but the fenix is here and, the missing momentary switch aside, it's much better.

Chrisse

Hi all
I bought David 19 from local Scouting store at Monday.
Price was regular 44€, I qot it for 40€. Packed in plastic blister pack with test battery and one new AA alkaline.
It uses Fraen Lp optic. Brightness and beam is similar to Nightcutter P20 but color is more yellow.
With fresh alkaline current draw was 800mA and with nimh only 500mA so the boost circuit is very voltage sensitive.

Well, after 15minutes I was already thinking how to get it brighter.
Circuit board is attached with retaining ring and under board is brass pill which is in same thread as ring.

I was able to get it draw more current by swapping resistors but it did't came much brighter so today I'll propably change the emitter.
Tried last night board with TYOH and current draw was 1.2A with nimh.

I was't able to open bezel completely to see if lens could be added to protect optic.

More to came(but no photos)

Juha

I too have massive probs with zweibrüder, because most of their lamps do not offer any protection against the elements (remember those lights using Optics with the "photon tunnel" and NO lens at all).
There is the price also.

And finally the runtime thing: 42 lumen AND 12 hours on a single AA ??

Why are there only very few makers who officially state real runtimes (SF and PT come to mind)?

LedLenser do have the funniest runtime claims I think ... :green: ... but they seem to get better and better. Maybe one day they'll be there finally.
bernie

Changed the emitter to TYOH and also changed the value of second resistor to 90kOhm. Original was 240kOhm.
Now with fresh nimh the current draw is 1.8A.
Wonder what the efficiency is at those current levels.

Today my friend at work went and bought one for himself so we could compare. Mine is much whiter and probably about 30-40% brighter.
So I'm happy with mine.

About those runtimes: There is no lumen/ runtime claims in the package.
Only: Long battery life and 12 brighter than standard led(5mm)

Juha

I originally liked the LED LENSER lights. reliability is a problem with nearly ALL of the ones I've bought. German engineering can do MUCH better!!!!

@ Jumi

Does it use the LTC3490?

I don't know what the type is.
It's 14 pins and the markings are made unvisible.

Juha

I have one of these lights, the black "David 15" LL7840. Brightness is surprising considering its current, using less than half of the current that the SL JR Luxeon has yet it's at least as bright or even brighter with a fresh battery. Clickie switch works nicely with a turbo mode if you press the switch in all the way. This may make the switch look unreliable, but there is only one level of output before the turbo mode, no dimming or flickering or anything like that. I don't know about water resistance since the switch is not completely sealed, there are holes around the front of the bezel, and the optics are exposed with no lens shield. I do know however that I like the light very much. The knurling on the case and the tailcap is nicer than on most lights, there is a very slight diamond appearance to the beam but only when you shine it very close to a surface, farther than 8 inches out results in a nice circular and smooth beam, not to mention the massive runtime and whitest light I've ever seen from an LED. I think I might know how this output is achieved with this runtime. Do any of you remember someone talking about a light that would use pulses of light instead of a continuous beam to provide higher percieved brightness with less power consumption? I think this is that light. On both the Zweibrueder pdf catalog ( http://www.zweibrueder.com/downloads/catalogue2005.pdf ) and the Led Lenser ( http://ledlenser.com ) website they discuss "nanosecond clock timing" and on the Zweibrueder one they even discuss that the light is generated in "nanosecond intervals". Any thoughts, anyone?

David 15 (black) looks VERY much like the light I saw at Frys for $39.99. I was tempted for sure, but have other plans and ideas in mind just now.

Finished a little "runtime test" of my own. Definitely regulated, constant brightness light for 2 and a half hours, with a slight drop from the start to one hour to around 85 to 90 percent brightness (eyeballing only, I don't have any fancy testing equipment). That brightness is then maintained dead flat for the rest of the one and a half hours, after which a "moon mode" kicks in which would probably last for another 3 or 4 hours. IMHO very very nice runtime considering the output. How did they do this??? Anyone find out anything about the "nanosecond intervals" yet?

Seriously, getting this output WITH this runtime could not be possible with just a regular circuit. The dang thing is brighter than a SL Jr Lux while only using 320 miliamps on 1.5 volts (1AA), with the SL JR Lux using 650 mA PLUS a higher voltage to start out with.. If they used whatever technology the David (Digi-Tac) series uses on the Fenix L1P's circuit, they could easily get the same brightness with at least double the time to 50 percent output (currently there's an hour and a few minutes before the Fenix's output drops to half), I think. Anyone know what's going on here??

PlayboyJoeShmoe said:

David 15 (black) looks VERY much like the light I saw at Frys for $39.99.

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