Direct Drive Reference Sheet

modamag

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directdrive2rc.jpg

* cummulative average of all data set
1st Data Set & 2nd Data Set

I haven't had the resource, time nor $$$ to complete all the usage case.

I would like to ask CPF members to amend and complete the test case for the LuxI, LuxV, Li-Ion, double stacking and any other possible configuration and usage.

I did the following measurements late after coming home from a wedding banquet. I'm sure the 1/2 bottle of Remy Martin Cognac /ubbthreads/images/graemlins/happy23.gif probably impared some of my response. If there is any discrepancies please let me know, since this reference sheet is intended to help modders with DD.

=== Test Equipment ===
Bel MERIT DX460L meter
Fluke 23 meter
Test Probes & alligator clip wires
4x TY0H Luxeon III Stars
4x TW0J Luxeon III Stars
4x TW0K Luxeon III Stars
1x TY0L Luxeon III Star
1x TY0M Luxeon III Star
3x PTS-C Multiple LS Heat Sink
7x AA Alkaline
3x D Alkaline
3x AAA Powerizer 750mAh NiMh
7x AA Energizer 2500mAh NiMh
4x C Powerizer 4500mAh NiMh
3x D Powerizer 9000mAh NiMh
1x AAA (10440) Li-Ion from AW
1x AA (14500) 800mAh Li-Ion
1x RCR2 Li-Ion from AW
1x R123 Li-Ion from BatteryStation

=== Test Conditions ===
In order to simulate the typical flashlight resistance battery adapters (3AA-1D and 4AA-1D) were used when performing 3|4 AA cells case. While all C & D cells are wired directly to the LEDs.

All single Luxeon were wired directly to the emitter legs using with a 12" alligator clip & 24G wire. All multi-star were mounted on a PTS and soldered to 4x 2" 24G wire (2+ & 2-). The 3xH-Vf however was connected with 6x 12" test probes due to time constraint.

The Fluke 23 meter is connected in parallel to the Luxeon for voltage measurements. While the Bel Merit meter is connected in series with the Luxeon for current measurement.

Voltage and current measurements were taken 5-10 seconds after the light was turned on and stabilized.

=== Results & Analysis ===
1. Can you believe 3.1A going thru a single Luxeon. It's true. I only dare to run it for 5 seconds (twice!) before my cold feet kicks in.
2. Alkaline batteries have an extremely high voltage drop when under heavy load. But the amount of current it delivered were comparable with NiMh in short burst.
3. The internal resistance of D-cell NiMh is similar to AA NiMh. The C-cell NiMh have the lowest internal resistance
4. The Luxeon resistance drops as the current load increases.
5. To estimate the resistor required to drive the Luxeon at spec use the following formula. <font color="blue">Resistor Required = ( Vf_lux / I_desired ) – R_lux</font>

=== Disclaimer ===
- Results may vary depending on batteries, adapter, and connection resistance.
- Resistance added due to the two meters could affect decrease the actual current draw by as much as 300mA.
- These test do not deal with the affect of Vf shift or thermal affect.
- No Luxeon or clones were injured in through out the experiment

* 04/10/05 update with low resistance for 3xH-Vf test, corrected H-Vf and 4C test case, and included the 2nd Data Set.
* 04/17/05 add 4xD Alkaline and NiMh test case
 

Fusion

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Thanks for doing this chart! Helps a lamen like me. /ubbthreads/images/graemlins/smile.gif

Kham
 

KevinL

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[ QUOTE ]
modamag said:
1. Can you believe 4.5A going thru a single Luxeon. It's true. I only dare to run it for 5 seconds (twice!) before my cold feet kicks in.


[/ QUOTE ]

Most of us wouldn't dare do that even while sober. Maybe if you finish up the rest of the bottle? /ubbthreads/images/graemlins/grin.gif

Those are really cool figures. I'll add this thread to the MicroFAQ.
 

AuroraLite

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Great work, definitely definitive! And my favorite line from the disclaimer:

"- No Luxeon or clones were injured in through out the experiment"

Hahaha...hope they are not mistreated too! /ubbthreads/images/graemlins/grin.gif
 

rick258

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Looks like an interesting chart but right now with the headache I have (migrane going on 4hrs) I cannot really decipher it. What do the different colors represent?

rick
 

Chop

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What I'd really like to see is a chart with the above information AND a repeat of the same tests after about 100 hours of runtime. I'd like to see the effects of Vf shift over time.
 

wquiles

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This is TOTALLY AWESOME /ubbthreads/images/graemlins/bowdown.gif

Thanks much for putting this together /ubbthreads/images/graemlins/buttrock.gif

I will soon be trying a DD 3D with one of those "L" voltage LIII's that Enrique is selling on the group buy and per your table they will draw a "fairly" safe 1A /ubbthreads/images/graemlins/grin.gif

Will
 

theepdinker

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rick258,
Green = good to go.
Yellow = caution
Red = danger zone

Check the mah rates.

Theepdinker
 

modamag

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KevinL: I had a buddy so have to share the wealth (Cognac).
greenlight: I don't think you need this info since most of your mods is Inova /ubbthreads/images/graemlins/grin.gif
rick258 & theepdinker: theepdinker is 100% correct. Green is driven at spec (700mA-1000mA), yellow is overdriven (1000mA-1500mA), and red means you're just as /ubbthreads/images/graemlins/crazy.gif like me driving it over 1500mA.
The first row indicate the current draw for that battery configuration. Second row indicate the average luxeon Vf and the third row indicate the calculated resistance (V/I).
Chop: Part of my intention of getting the MeterMan LM631 and DataQ is to do extensive runtime test. And ofcourse those test will only be performed for 1500 mA starting current draw or less. I'm not brave (nor rich) enough to leave my few TY0H at 4.5A for an hour. Well maybe they'll become one and only dead G-Vf LuxIII /ubbthreads/images/graemlins/wink.gif

What would be better is if each of us modders take 2 or 3 test case and perform extensive runtime test and analyze Vf shift, lumen (or lux) degradation and other valuable information for CPF.

This datasheet is intended to prevent the all too famous puff of magic smoke /ubbthreads/images/graemlins/Christo_pull_hair.gif

This is only one set of data. I intend to repeat the test 2x more time to validate and iron out inconsistencies.
 

Lightwave

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This is really excellent stuff.

I'm looking to build a direct drive 3 Lux3 light using alkalines. From the chart, it looks like there are no acceptable AA alkaline combinations, because they all either seriously underdrive the LEDS, and/or overtax the AAs at close to 2 amps. (Maybe lithium AAs would be able to handle that current.)

In terms of D cells, the chart looks like its halfway between the 3AA and 4AA in terms of current. The current levels per LED are still pretty low (for example 613 mA for H Vf), which I interpret as the LED being underdriven, but at least the D cells should be able to handle the approx 2 amps. It would be interesting to see what happens at 4D cells, or at 4C cells, which could fit into a Mag3D form factor.

Thanks for providing this info!

Tim
 

Pajamas

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That's interesting....as I'm working on a 3 x Lux III K bin in a 4D Mag.

Althought 4D is not on the chart, a slight shift to the right of the 3D numbers (notice the shift from 3AA to 4AA and you get the idea) may still suggest the luxs maybe a bit underdriven.

Did I interpret this right?
 

wquiles

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Pajamas,

I am not sure how to read the table if you have several LED's in parallel. Do the values to the right of the table mean parallel driving?

With a single LED, with 4D you have a higher voltage than with 3D so if it was OK with 3D you will be way too high with 4D.

I guess I need a little bit of help reading the table /ubbthreads/images/graemlins/confused.gif

Will
 

modamag

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I finally got around to perform the second test. This time I also include the currently available Li-Ion to the test. I was interested in this for my modded JIL light. Hopefully, it will help those who intend to give their Q3 and JIL (DD ver) a little more juice. Another surprise (not really!) the second data set is similar to the original run.

I also retest the 3xH-Vf with the low resistance connection.
Another side note, I guess I was more sobber on that day than I thought. When I transfer the hand written data to the excel spreadsheet, I swap the voltage and current column for the 1xH-Vf with 4C. So it's <font color="red">only 3120mA</font>.

Lightwave: Tim, if you want to do 3x3W and 4D, I would go with K-Vf, J-Vf will see over 1500mA during the initial burst. Guestimating 1300-1400 mA. I need an extra set of hands to do this test, maybe we can do it next time you drop by. The 4AA Alk|NiMh seems to be a perfect config for me with a bored Mag1D. It's more than enough lighting, heat becomes a major problem with extended runtime.
Pajamas: Your interpretation is 100% correct for NiMh, but with Alkaline it's will be overdriven.
wquiles: The last three columns are 3xLuxeon connected in parallel. The batteries are still connected in series. The 4th cell would significantly overdrive the system. At this point resistors should definitely be use.
 

VidPro

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Great Chart /ubbthreads/images/graemlins/thanks.gif

3LUXIII + Rechargables= easy stuff

so with 3X LuxIII running 3xAA Nimhys, you get a clean UNDERdriven 5W of unadulterated light :) for just about any bin of it.
which is (about) 45min run time (before it gets real dim and keeps going), with some nice 2500ma.
is that correct?

and its ABOUT the same (5W) if you shove 3x 9000-11000MA D Ni-Mhy cells in, which would give you about 3 HOURS of awesome light (till it runs for the next week at a dull glow).
adequite run time, adequite light, no losses, little overheating, underdriven .

and about the same AGAIN (5W), for 1/2 the amps of D with 3X C Ni-Mhy cells, giving you about 1.5hr of light

_______________________
theory: (corrected)
so parellel up a set of 2x 3xAAs (3.6v 6total) and you would ramp it up only a bit, because they are running at thier voltage anyways, it would increase the "3 AA NiMhy" run time, to a total of 1 1/2Hr , for them stuck with 2D units.

NOTES: NOT SERIES, unless you put the LUXIIIs in series, which means 2 or 4 or 6. the 3xAA packs would have to be parelleled for the 3 parelleled luxes.
___________________________


1 LuxIII

and running a Single LUXIII with 3X NiMhy AAA , gives you about
1.5-(almost)3w of unadulterated juice, depending a LOT on the BIN.
providing you with run times ranging from 20min to 40min (bin dependant).

And if you get 1X whatever li-ions he was using, then you could basically do the same with the 1X luxIII.
and so on, 2 li-ion for 2 parelleled luxes,
3 for 3.

so basically you could just slap that stuff together, and be done with it :) thanks to the chart.
 

Pajamas

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Is there anyway to add a few more data points to this awesome "kick@$$" chart?

Would love to see 4D alkies, 4D nimhs data added (but only for the triple lux configurations (3h,3j,3k).

Also, one last interpretation question - if you change from 3D alkies to 3D nimhs on a K bin, you go from yellow (1210) to green (910). Is there any change in light output ? I mean overdriving a lux adds more light at the expense of shortening its life, right?
 

modamag

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Pajamas, wish granted!
Data point for 4x Alk & NiMh have been added to the chart.

From the result I would recommend the use of 3xK-Vf if your battery source is NiMh. While almost anything would work with Alkaline, I would use the lowest Vf possible (H-Vf) because by the time the batteries completely drain you'll only get about 2/3 of the initial current.

Regarding your interpretation, There is definitely a difference from 910mA to 1210mA. Overdriving usually shorten the lifespan, with some increase light output, but it's diminishing returns.

With 3xD Alk it may start at 1210mA but that current output will quickly drop as the batteries heats up. The 3xD NiMh however will be more or less stable at 900mA due to their lower internal resistance.
 

cy

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Just killed tonight a TNC 2x CR123 DD to TWOK. purchased TNC light with luxeon almost dead. pulled out SWOK and replaced with TWOK. gave aprox. 2 minutes of bright runtime before going dead. each CR123 measured just under 3V.

Another death by DD is an original Mr Bulk SNII. I stuck 2x 18650 li-ion into 2C mag body. was real bright for less than one minute before going dead /ubbthreads/images/graemlins/icon15.gif
 
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