what current for a lux five

[kenny]

I'm trying to figure out how hard to drive my lux V. On one hand I hear about the life of the V's being shorter, and I'm thinking over-driving them ain't going to help that any. :On the other hand -- why get a V if you aren't going to try and make a significant light. I'm open for suggestions. I been thinking of using one of Georges Fatman boards, but just need to figure out the current. I'll probably drive it with 2 or 3 D cells. Opinions?

 

[Doug S]

What you do depends upon your objectives. FWIW, I can tell you that the peak efficiency measured in lm/watt will occur at a drive current somewhere in the range of 40-160 mA.

 

[Mark_Paulus]

Normal current for the Portable Luxeon V is 700 mA. I do believe that others have driven their V at 1000 mA. However, you should be aware that with a Lux V, heat is a SIGNIFICANT factor, and you had better make sure you design in a good, no make that a GREAT heatsink solution. Or else, you won't even get your advertised 500 hours....

 

[KevinL]

Running a WX1U Luxeon V here on a BB917 (~917mA). The host is a 4 D cell Mag with Hotlips heatsink. Thermal management is not a big issue with that kind of host because of the sheer mass of aluminium behind it. I figure that by the time it burns out, LumiLEDs will have other goodies for me to play with.

 

[kenny]

Thanks boys. I think I'll keep it around 750 then -- close to the Normal, but I would think plently of light. 4 D Mag would be easier, but (4) 1/2 D batteries in a 2 D Mag would be slick too. What to do, what to do... Anyway, thanks for the input and I'll get the boards, ordered.

Fatboy for (3) Lux III's (T bin, J Vf) in series (8) AA input
Fatboy for 1 Lux V (4.5 or 6V)

I'm thinking of a VIP board as well so I can have one with adjustible output. I appreciate the input from Doug S as well since that would kind of set the low end of the VIP (I was thinking around 200mA in low, and 500 for medium, and 1000mh for high!

 

[3rd_shift]

Only 3 half D's will fit in a 2d light.
5 half D's will fit in a 3cell.
I have 5 nimh 9000mah Full D's in a 5d magg direct driving a lux5 at 700 milliamps.
The highest I have seen is 1100 milliamps, batteries hot off the charger.
I also have a 6d with 6 nimh d's driving a lux5 with a 1 ohm series resistor at about 750 milliamps.

At about 700 milliamps, the temp of the dome is usually about 24 degrees F above room temp with a Hotlips. /ubbthreads/images/graemlins/smile.gif
(there's plenty of room for overdrive here) /ubbthreads/images/graemlins/evilgrin07.gif

 

[Flatscan]

One of the Fatman's features is its adjustable current via external resistance.

I think you can set the maximum (e.g. 750mA) by using the trim pot. If you don't have room or don't want adjustability, forego the external parts, and you have a locked-in Fatman. Add a pot to the proper connections, and you can adjust the current from very low to whatever max you set.

 

[modamag]

Kenny, if you using a LuxV then you can do either one of these configuration for a Mag2D. I "assembled" both of these and absolutely love them. Use them at least once a day. /ubbthreads/images/graemlins/grin.gif

For a FatMag you can use any of the following "standard" battery configuration 2D, 3AA+1D, 4AA, 5AA+1Dummy. Personally I would go with 5AA, less stress on the boost and uniform discharge acrosss all the batteries.

Personally, I would prefer the FlexMag due to the 8 different level of brightness. Small tradeoff for 5% less efficiency and tight battery tolerance. And besides 120 lumens (1000mA) of light just wake up the entire family at night . /ubbthreads/images/graemlins/wink.gif

FatMag ($84 [$94])
- Mag2D Host with cutdown reflector ($17)
- LuxV ($30)
- O-Sink or Hotlips ($15)
- Fatman driver ($22)
o 2x ElectroLumens 3AA-D battery adapter ($10)
o AA dummy cell

FlexMag ($100)
- Mag2D Host with cutdown reflector & modified momentary switch ($17)
- LuxV ($30)
- O-Sink or Hotlips ($15)
- nFlex driver ($25)
- fivemega 8AA-2D battery adapter ($16)