# Direct Drive Reference Sheet



## modamag (Mar 28, 2005)

* 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_


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## Fusion (Mar 28, 2005)

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

Kham


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## KevinL (Mar 28, 2005)

[ 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.


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## AuroraLite (Mar 28, 2005)

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


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## PEU (Mar 28, 2005)

/ubbthreads/images/graemlins/happy14.gif

Pablo


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## greenlight (Mar 28, 2005)

interesting chart, I get it now.


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## rick258 (Mar 28, 2005)

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


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## Chop (Mar 28, 2005)

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.


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## wquiles (Mar 28, 2005)

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


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## theepdinker (Mar 28, 2005)

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

Check the mah rates.

Theepdinker


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## rick258 (Mar 28, 2005)

theepdinker === Thanks.
Rick


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## modamag (Mar 29, 2005)

*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.


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## Lightwave (Mar 31, 2005)

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


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## Pajamas (Mar 31, 2005)

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?


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## wquiles (Mar 31, 2005)

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


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## modamag (Apr 11, 2005)

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.


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## VidPro (Apr 11, 2005)

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.


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## Pajamas (Apr 17, 2005)

Is there anyway to add a few more data points to this awesome "[email protected]$$" 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?


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## modamag (Apr 17, 2005)

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.


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## cy (Apr 18, 2005)

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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## Pajamas (Apr 18, 2005)

Modamag - You're awesome, as usual. Thanks for the info. Will give me something to think about.

I had also thought about getting away from the whole nimh/alkie problem by trying to use non-rechargeable lithium AAs in a 3D so I can leave it in my car without worrying. I'll have to experiment.

Thanks!


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## VidPro (Apr 18, 2005)

[ QUOTE ]
*cy said:*
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 

[/ QUOTE ]

time to buy CY a wire wound adjustable potentiomiter , and a ammmeter, so he can speramint more carefully /ubbthreads/images/graemlins/help.gif


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## HgRyu (Apr 29, 2005)

Sorry for my ignorance.
I don't understood the chart exactly.

Is it okay if I DD H-bin Lux-III with 4.2V R123A ?

Chart show current draw as 910mA and according to my short knowledgy, recommanded max current draw is 1000mA by Lumileds.

Am I correct ?

Thanks


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## luminaria (Apr 29, 2005)

Yesterday I tested a DD J-bin Lux-III with 4.15v R123 (MP brand, 700mah) and the current draw I got was 1440mah /ubbthreads/images/graemlins/ooo.gif when I was expecting 790mah according to the reference sheet.

As modamag says, results are variable depending on the batteries used, and it seems that the R123 he used had a greater internal resistance than mines. 

So be careful with your H-bin.


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## HgRyu (Apr 29, 2005)

luminaria,

That's to bad.
I have a H-bin sandwich (for 3V DD) and I just test with R123A(MP brand) for just a second, a second, a second... (not for seconds continuously) /ubbthreads/images/graemlins/grin.gif

It was terribly bright ! Maybe brighter than Surefire L4 !
(I don't have electronic tester)

But...........

I have to give up looonger test for seconds. /ubbthreads/images/graemlins/grin.gif


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## Halibut (Apr 29, 2005)

I hooked an unprotecfted 700maH r123 to a TX1H star and also got close to 1.5 A. I was contemplating upgrading the star in my LionHeart but thought better of it...

-Dan


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## modamag (Apr 29, 2005)

Did you guys let the current stablelize after 5 seconds?
I'll do another Li-Ion data set test this weekend if time permits.


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## luminaria (Apr 29, 2005)

The current does not seem to stabilize, it slowly goes down but after 10 seconds is still around 1.38A. 

By the way, in the Lioncub thread there is a report of TXOH taking a draw of 2.1A from R123


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## Halibut (Apr 29, 2005)

I'm not using a heatsink (*ugh*)so the measured current holds steady at 1.55A for 10 seconds then slowly starts to climb. But let me tell you--that little sucker is bright bright bright! It's a good thing that T**H stars are so common now...

-Dan


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## wquiles (Apr 30, 2005)

As a data point, on Direct Drive with a 3xD cell M*g body, using a 3W LIII UX1L on an O-sink, I got about 860mA with 3 cheap D alkalines, but got a very nice 1010 with crappy Energizer 1.2v 2200mAh NiMH rechargables (fresh from the charger). Like modamag said, although the NiMH have a lower voltage per cell, the Alkalines have significantly higher resistance /ubbthreads/images/graemlins/grin.gif

Will


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## Halibut (May 1, 2005)

One more data point:

3D Mag, fresh D-cell Energizers, UX1L Lux3: 1.08A

-Dan


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## wquiles (May 13, 2005)

modamag,

One more simple question: Is the current shown for the 3x LIII in parallel the current going into each of the LED's or the total/combined current coming out of the battery pack?

Another way to ask: I look at your chart, with 3x LIII and Vf=H, with 4xD Alkalines, current shows as 987mA. If this current is per/LED that would mean that at least initialy (before the batteries heat up and drop their current) the 4xD's are delivering close to 3amps?

Will


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## VWTim (Jun 21, 2005)

Another spot that isn't on the chart. 3x TWOJ running off 3 C Alkalines, 2.4A draw total from tailcap. Giving 800 Ma each.
hth,


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## mateen (Jun 21, 2005)

1xUX1L on 3D Alkaline, 1050mA.
1xUX1L on 3C Alkaline, 840mA.
3xTW0K on 3C Alkaline, 1400mA (465ma/Lux).

Thanks for the chart - really a big help!


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## modamag (Jun 22, 2005)

Thank you all for additional data points

*luminaria & Halibut:* I finally figured out how both of you were able to achieved higher current output with the R123. Could it be that the light (eg Q3) not provide enough heat sink? As heat build up in the emitter/star the current draw will continually increase. For this chart I utilized Luxeon stars, clamped to an aluminum block keeping close to room temp.

*wquiles:* The current for ALL of the above are per/LED. eg 3xH-Vf with 4xD Alk will get 987mA/LED for a total of 2.961A.


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## Ledean (Jun 22, 2005)

Great stuff. /ubbthreads/images/graemlins/clap.gif


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## luminaria (Jun 22, 2005)

[ QUOTE ]
*modamag said:*
Could it be that the light (eg Q3) not provide enough heat sink? As heat build up in the emitter/star the current draw will continually increase. For this chart I utilized Luxeon stars, clamped to an aluminum block keeping close to room temp.

[/ QUOTE ]

If that were the explanation I would see an initial value similar at the ones in your table and then a raising value. I see the contrary, a instantaneous high value that slowly goes down.

And now I am using copper heatsinks from ViReN and I see the same.

Since I posted here I have seen many samples posted in CPF with values well above the ones in your table for a R123. The last one has been a measure of 1.8A in a lioncub with a full loaded R123 and a T*J star.

I think that the most logical explanation is that the R123 you used have higher internal resistance that other ones.


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## mateen (Jun 23, 2005)

[ QUOTE ]
*mateen said:*
1xUX1L on 3D Alkaline, 1050mA.
1xUX1L on 3C Alkaline, 840mA.
3xTW0K on 3C Alkaline, 1400mA (465ma/Lux).

Thanks for the chart - really a big help! 

[/ QUOTE ]

Few more tests:
Runnning 3x'TV1J'bin stars DD on PTS.
3xC 600mA each
4xC 1000mA each
3xD 770mA each
4xD 1150mA each.

(Alkaline batteries)


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## LITEmania (Jun 23, 2005)

good job. /ubbthreads/images/graemlins/smile.gif


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## wquiles (Aug 23, 2005)

As a recent data point, using a UX1L star, I got about:

800mA on a charged 4.2V RC123 cell
790mA on a charged 4.2V PILA168S cell
820mA on a charged 4.2V bare 16750 cell 
940mA on a charged 4.2V bare 18650 2400mAH cell

With these numbers, who needs a regulator? /ubbthreads/images/graemlins/wink.gif

Will


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## evan9162 (Aug 23, 2005)

[ QUOTE ]
*wquiles said:*
As a recent data point, using a UX1L star, I got about:

800mA on a charged 4.2V RC123 cell
790mA on a charged 4.2V PILA168S cell
820mA on a charged 4.2V bare 16750 cell 
940mA on a charged 4.2V bare 18650 2400mAH cell

With these numbers, who needs a regulator? /ubbthreads/images/graemlins/wink.gif

Will 

[/ QUOTE ]

You will after 100 hours.

And if you used a generic DMM with a 10A scale, you probably introduced 0.1 or more ohms of resistance, dropping the voltage by 0.1V or more. An 0.1V difference can easily cause a difference of several hundred mA.


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## wquiles (Aug 23, 2005)

What would you estimate the increase to be after 100 hours?

Will


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## evan9162 (Aug 23, 2005)

600-700mA - so a 66% increase. 

This is based on the two TY0L Lux IIIs that I burned in for 100 hours at 750mA. Note that using at higher currents usually results in a higher Vf drop after 100 hours - so the current might increase even more.

This illustrates one reason why direct drive is, IMO, a really *bad* idea.


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## winny (Aug 23, 2005)

/ubbthreads/images/graemlins/bowdown.gif to you modamag!
Nice colors also! I suppose red for the real hard core LEDheads? /ubbthreads/images/graemlins/crazy.gif


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## IsaacHayes (Aug 23, 2005)

evan, have you tried a burn in on something with a low VF like a J or H? Does it drop the same amount as a higher Vf Luxeon?


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## evan9162 (Aug 23, 2005)

Lux I J-Vf bin dropped 0.1-0.2V at 350mA test current
Lux III J-Vf bin (equivalent to a Lux I H-bin) dropped 0.1-0.15V, at 750mA test current.

There was a general trend of higher Vf -> higher drop, and higher current -> higher drop -- though the higher current could have simply accelerated the Vf drop, rather than amplified it.

This is especially dangerous for DD modders - they think they're safe with an L Vf bin, but in reality, the current is going to change a great deal in the first amount of the LEDs life, and what may be "safe" initially (I use "safe" loosely in regards to DD) won't be after a while.


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## wquiles (Aug 23, 2005)

Thanks much evan9162 - I will reconsider my Aleph LE as I don't want to end up with 1.5Amps or so /ubbthreads/images/graemlins/crazy.gif

Will


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## IsaacHayes (Aug 24, 2005)

higher vf, higher drop. Makes sense as things settle down better, and the lower vf from the factory is just "settled" in better... What's odd is I did DD luxIII with a Jvf once and finaly got ~900ma to it! (after using .47 ohms for the longest time at 500-600ma).


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## evan9162 (Aug 24, 2005)

What batteries were you using? What host? Did you investigate all contacts/wiring? How much resistance were you introducing with your meter?


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## IsaacHayes (Aug 25, 2005)

It was a mag, soldered directly to the switch with fat multistranded wire. Not sure on my meter. I'm now using a craftsman. When shorting the leads I get less resitance reading than with my old 1980's Minolta. /ubbthreads/images/graemlins/icon3.gif I used both NiMH and alkaline. Anyways with 3 C fresh alkalines it was at ~1100ma and dropping fast after I took out the resistance. It was a cyan luxIII... /ubbthreads/images/graemlins/icon3.gif My guess was it was really a K bin, even though the star said J...


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## balazer (Aug 30, 2005)

Can anyone point me to information about what happens when I overdrive a Luxeon? E.g., what current levels are safe? What kind of increase in brightness can I expect? What kind of heat sink do I need?


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## DUQ (Apr 6, 2007)

Just diggin up more great modding info.


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## bhvm (Nov 9, 2009)

Sorry for being late to the party.

Someone try and give me a reading on 9v 'Transistor battery' 6F22
I guess 2 LEDs in series should do nicely, and battery is very small.


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