Help Needed - L4
I bought 2 units of L4 which both appears to have the SSC emitter with a square LED with a hotspot beam.
Tested both for the current draw with a multimeter using a 3.7v Rechargeable Lithium 17670 from AW. One gave a reading of 330mah and the other 1.4amps/h.
Can anyone shed some light into the readings?
Thanks
Re: Help Needed - L4
Different versions, possibly. I think that LED has a rather high Vf in the old version, so less than 6V will make it quite dim.Originally Posted by Benchiew
The usual suspects: Poor positive contact, damaged driver, etc.
My biggest light-hog is my camera.
You mean this can cause the consumption to spike upwards?
Re: Help Needed - L4
Have you tried taking the current measurements from using 2xCR123A?
The new L4s uses SSC P4s as opposed to LuxVs, the changeover resulted in the use of Buck converters as opposed to boost converters. Buck converters require significant voltage overhead to maintain regulation, and few goes into direct drive mode when the vin (3.7V) is very close to the LED's Vf (3.4V). Getting erratic readings at this point cannot determine whether the driver is faulty, only that there is a variance in the LED's Vf and the sensitivity of the individual drivers.
I think both the units tested are the same light having the same emitter.
Yes, I did test it out using 2 new primaries and the variance is also that great.
Could others that have an L4 get a reading. Then I will know which one of the 2 is abnormal.
Re: Help Needed - L4
My SSC L4 draws ~860ma on 2xCR123A, ~380ma on 1x17670... dimmer than CR123A. For reference my LuxV L4 draws ~1.2A on 1x17670s
Shouldn't the LuxV be drawing less than the SSC model?
Re: Help Needed - L4
The Lux V version is the first version of the L4 available, and the LED is actually 4 Luxeon III on one place. It'll take more power for the Luxeon V to reach the same output as modern emitters, at least twice the power, usually more if you are comparing with the top of the line LEDs today.
Luxeon V @ 700 mA = 87 lumen
Cree XR-E Q5 @ 350 mA = 104 lumen
Cree XP-G R5 @ 350 mA = 139 lumen
Seoul P4 U bin @ 350 mA = 91-100 lumen
(numbers from data sheet)
Visually, is the Lux V looks like 4 small led arranged in a square?
So which of the 2 that people rave about having a wall of light?
Re: Help Needed - L4
The LuxV. 4 dies clumped together produces a very large light emitting surface, which in term can't be collimated into a tight hotspot. So what you see is mostly flood, as opposed to a prominent spot in the beam.
Re: Help Needed - L4
You can also get a "wall of light" buy having a heavily textured reflector so both LEDs can create a wall of light.
Re: Help Needed - L4
One way to tell which is which, and therefore which one has the buck driver, is that the lux-v will have a warmer/greener tint, while the P4 will have a white/blue tint. Plus, the Lux-V will get a lot hotter (matter of minutes really).
Re: Help Needed - L4
Another way of telling.
The original L4s were literally a wall of light. There was virtually no hotspot.
The updated L4s kept the wall of light, but had a noticeable but gently hotspot.
(If you find an original L4 I'll buy it)
My Lux L4 was my first Surefire, but she's been sitting on her shelf throne for a long time as my loyalty has turned to newer, warmer, rechargeable powered engines.
What are the best (Safest? Brightest?) rechargeable options for this beauty?
17670 battery. If you can't fit it, locate an early E2E tube. They will take the 17670 without modification.
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