# Tripple X-ML Driver information please.



## ljw2k (May 18, 2011)

I intend to try and build a tripple X-ML after i have managed to build a single X-ML and i wanted mome information on driving the 3x X-ML's and would it best be wired in series or parallel and would this driver below give 2.5A to each led if it was wired in series.


http://www.lck-led.com/p863/Constan...--5Modes,-6-9v,7.5A,-SST-90/product_info.html

What would i do without this forum and the people


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## The_bad_Frag (May 18, 2011)

No it would give 7.5A to each led when wired in series. And its 9V max so you cant wire 3 XM-Ls to it in series.


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## xed888 (May 18, 2011)

Isnt the voltage rating for the batteries? I was under the impression that if you wired the 3 XMLs in parallel, you need 3.3V (min voltage for regulation) and 7.5A is split among the 3 XMLs? So each gets 2.5A.

Please correct me if I am wrong.


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## The_bad_Frag (May 18, 2011)

Correct it is the voltage rating for the batteries. But if you wire the 3 XM-L in series as ljw2k said you would need a lot more than 9V input because its a buck driver.

If you wire them in parallel each led will not get exactly 2.5A. The 7.5A current from the driver will not split even because each XM-L has a slightly different Vf. If you have bad luck and use some XM-Ls with a lot different Vf some leds will be brighter than others.


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## Justin Case (May 18, 2011)

Without a way to heat sink the critical components on the driver, I doubt it will survive for long running at 7.5A and ~3V to the triple XM-Ls. That's at least 22W to the LEDs. And even if the driver is 90% efficient, you are looking at about 2.5W of waste heat, which is a lot. You need to remove that waste heat from the driver or it will roast itself. I would get a TaskLED H6Flex if you want a 6A-7A, multimode buck driver.


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## xed888 (May 18, 2011)

Justin Case said:


> Without a way to heat sink the critical components on the driver, I doubt it will survive for long running at 7.5A and ~3V to the triple XM-Ls. That's at least 22W to the LEDs. And even if the driver is 90% efficient, you are looking at about 2.5W of waste heat, which is a lot. You need to remove that waste heat from the driver or it will roast itself. I would get a TaskLED H6Flex if you want a 6A-7A, multimode buck driver.



Could we not use a shark sink and epoxy it to the body?



The_bad_Frag said:


> Correct it is the voltage rating for the batteries. But if you wire the 3 XM-L in series as ljw2k said you would need a lot more than 9V input because its a buck driver.
> 
> *If you wire them in parallel each led will not get exactly 2.5A. The 7.5A current from the driver will not split even because each XM-L has a slightly different Vf. If you have bad luck and use some XM-Ls with a lot different Vf some leds will be brighter than others.*



That is interesting. No idea it did that. Any way of making sure that each LED gets the same Vf?

Also, before i am accused of hijacking this thread, ijl2k and I are working together on this build


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## ljw2k (May 18, 2011)

Thanks for the replies and can the TaskLED H6Flex be used with the current maglite switch or do i need to converted to a momentary switch.

If i used the H6Flex Driver would i need to wire the LED's in series to get around 2.4A to each one and would it be best with 2x 3.7v lithium batteries or 3.


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## ljw2k (May 18, 2011)

Iv'e just come a Flashaholic


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## Justin Case (May 18, 2011)

xed888 said:


> Could we not use a shark sink and epoxy it to the body?



What are you going to epoxy to the SharkSink to remove the heat? Glue the tops of the inductors to the SharkSink?

The way the Shark Buck and Blue Shark are designed, there are silver-filled thermal vias that thermally connect the critical components on those drivers to a "copper C" thermal interface on the non-component side of the driver. The TaskLED drivers are similarly designed (without the copper C, but you can see the filled thermal vias on the non-component side of the TaskLED drivers).

For about the same price as that lck-led.com driver, you can get an H6CC or H6Flex. I don't really see the point of getting some driver that seems like it was not well-designed from a thermal management point of view. When you are dealing with 7.5A drive current, you have to have good thermal management (among other things).


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## Starlight (May 18, 2011)

You really need to look at this thread. You can run 3 XM-L's with 12v input and a cheap driver. http://www.candlepowerforums.com/vb/...x-setup-method


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## Justin Case (May 18, 2011)

ljw2k said:


> Thanks for the replies and can the TaskLED H6Flex be used with the current maglite switch or do i need to converted to a momentary switch.


 
Read the technical data on the TaskLED web site.



ljw2k said:


> If i used the H6Flex Driver would i need to wire the LED's in series to get around 2.4A to each one



Read post #3 above. Do some research to understand how current divides for series vs parallel components.



ljw2k said:


> and would it be best with 2x 3.7v lithium batteries or 3.


 
Read the H6Flex technical section and do some research to understand what it means when a driver is described as a buck driver.


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## xed888 (May 18, 2011)

Justin Case said:


> What are you going to epoxy to the SharkSink to remove the heat? Glue the tops of the inductors to the SharkSink?
> 
> The way the Shark Buck and Blue Shark are designed, there are silver-filled thermal vias that thermally connect the critical components on those drivers to a "copper C" thermal interface on the non-component side of the driver. The TaskLED drivers are similarly designed (without the copper C, but you can see the filled thermal vias on the non-component side of the TaskLED drivers).
> 
> For about the same price as that lck-led.com driver, you can get an H6CC or H6Flex. I don't really see the point of getting some driver that seems like it was not well-designed from a thermal management point of view. When you are dealing with 7.5A drive current, you have to have good thermal management (among other things).


 
Ah no. I was thinking of the taskled driver when I wrote that.


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## ljw2k (May 18, 2011)

I understand that the " Buck Driver " is used to regulate a DC to Dc supply and can switch modes and it manages the energy from its supply ( Batteries ) as it manages the energy it does waste some which then turns to heat.
I also understand that the Buck Drivers are very efficient at what they do.

I understand if anything is connected in Series the Voltage doubles and if wired in parallel then the voltage stays the same and the current doubles.

Looking on the TaskLED technical Data sheet is ok if you have a very good knowledge of electronics and understand the maths and physics side of things which is why i asked here as i know people would be able to explain much better than trying to educate myself to try and understand data sheets.


Don't get me wrong i am Johnny5 ..> More info and all that but being an Old Fart i don't take things in like i used to


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## Justin Case (May 18, 2011)

I don't think a SharkSink by itself is tall enough. The H6Flex is 1.3" diam. A D Mag tube is about 1.4" ID. To use a SharkSink, the driver is oriented vertically in the Mag tube and glued to the flat side of the SharkSink. The curved side of the SharkSink is glued to the inside wall of the Mag tube. That means the H6Flex would have to be positioned close to the centerline of the Mag tube to fit, requiring a SharkSink height of about 0.7". IIRC, a SharkSink D is about 3/8" tall. So you'd have to make a separate standoff and glue that to the SharkSink.


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## Justin Case (May 18, 2011)

ljw2k said:


> I understand that the " Buck Driver " is used to regulate a DC to Dc supply and can switch modes and it manages the energy from its supply ( Batteries ) as it manages the energy it does waste some which then turns to heat.
> I also understand that the Buck Drivers are very efficient at what they do.
> 
> I understand if anything is connected in Series the Voltage doubles and if wired in parallel then the voltage stays the same and the current doubles.
> ...


 
Frankly I don't buy it. Your questions have simple answers that are easily understood just by reading. Try researching first, then asking if you don't understand.

You asked about the need for a momentary switch and what batt configuration would work. Here are the simple answers directly from the TaskLED web site. For the batt config, all you need to know is how to multiple either 2xLi-ion voltage or 3xLi-ion voltage and compare that to the Vf of your triple XM-L either in series or parallel and ensure that you have at least 1V headroom.

http://www.taskled.com/leds/h6flexuni_v2.00.pdf
H6Flex requires a user provided momentary action switch that must be connected via leads soldered​to the holes SWA and SWB.

http://www.taskled.com/techh6flex.html
*Note*, H6Flex is a Buck regulator (step down), so input voltage must be greater than the output voltage to ensure H6Flex remains in regulation. If the input voltage drops within 1V of the LED Vf (at the specified current) H6Flex will no longer regulate and the output voltage will drop and output current will also drop.​


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## xed888 (May 18, 2011)

Thanks Justin. But since you recommended the Task LED, I assume it should do the triple parallel XML just fine? So no need to heatsink it?

Vf of 3XML in parallel = min. 3.35V to drive at 3A

Vin provided by 2 Li-ions in series (fully charged) = 4.2V x2 = 8.4V

Is that too much for the XMLs? I didnt see a max voltage rating on the XML leds but the HFlex will work just fine.


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## monkeyboy (May 18, 2011)

Have you seen Der Wichtel's thread?


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## xed888 (May 18, 2011)

oh yes, but his setup requires at least 4 Li ions to run properly whereas I would like only 2 Li-ions. His LEDs are wired in series, thats why.


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## Justin Case (May 18, 2011)

xed888 said:


> Thanks Justin. But since you recommended the Task LED, I assume it should do the triple parallel XML just fine? So no need to heatsink it?



Why would parallel vs serial matter? Sure, in parallel, you'd probably sent up the H6Flex current table to 6600mA drive, to deliver 2.2A nominal to each XM-L. At about 3.2V Vf for each XM-L, that's about 21W of power to the LEDs. In series, you'd probably use the 2800mA current table. At Vf of ~3.3V for each XM-L, that's about 28W. Either way, for a 90% efficient driver, you are looking at a min of 2W of waste heat which needs to be removed.


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## xed888 (May 18, 2011)

the parallel vs series setup of the LEDs matter cause I want to drive the triple using 2 Li-ion cells only. I understand that there will be massive heat generated at the LEDs and the driver.

So i guess we should heatsink the Hflex then?

Der Wichtel has this driver: http://www.candlepowerforums.com/vb...icient-5A-9A-Buck-Converter-for-SST-50-SST-90

Reckon this can be used instead of the Task LED HFlex?


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## Justin Case (May 18, 2011)

xed888 said:


> oh yes, but his setup requires at least 4 Li ions to run properly whereas I would like only 2 Li-ions. His LEDs are wired in series, thats why.



For 2xLi-ion and three XM-Ls in series, you need a boost driver. The hard part is finding one at a decent price point and that can deliver 3A drive current. I could suggest a triple Blue Shark in parallel to deliver a nominal 3A, but that's an expensive solution.

If you use 3xLi-ion, you may be able to use Download's Poorman's multi-LED setup method using an 8x7135 driver to run a triple XM-L.


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## xed888 (May 18, 2011)

Justin Case said:


> For 2xLi-ion and three XM-Ls in series, you need a boost driver. The hard part is finding one at a decent price point and that can deliver 3A drive current. I could suggest a triple Blue Shark in parallel to deliver a nominal 3A, but that's an expensive solution.
> 
> If you use 3xLi-ion, you may be able to use Download's Poorman's multi-LED setup method using an 8x7135 driver to run a triple XM-L.


 
Ah Justin, but the thing is I want to use 2 Li-ions in series and 3 XML's in parallel. 

Also please look at this link: http://www.candlepowerforums.com/vb...icient-5A-9A-Buck-Converter-for-SST-50-SST-90

Can I use this instead of the Hflex?

Of course, with the need to drive 9A, I would use IMRs.


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## ljw2k (May 18, 2011)

Justin Case said:


> Frankly I don't buy it. Your questions have simple answers that are easily understood just by reading. Try researching first, then asking if you don't understand.
> 
> Good job this forum does not have a time counter on it as mine would need resetting
> I have read many many posts and threads but did not get any information i wanted hence started my own thread.
> ...


 
Might just be an easy option to buy DW drop in Tripple X-ML and 4D maglite and some nice IMR batteries and have done with it


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## Justin Case (May 18, 2011)

xed888 said:


> the parallel vs series setup of the LEDs matter cause I want to drive the triple using 2 Li-ion cells only. I understand that there will be massive heat generated at the LEDs and the driver.


 
I understood your question to involve the need to heat sink the driver. Thus, parallel vs serial XM-Ls is irrelevant. It is true that the H6 driver efficiency, as shown in the TaskLED web site, is higher for 2.8A drive to 3 LEDs in series (~92%) than for 6.6A drive to one LED (about 84% to 90%). But either way, the amount of waste heat is just about the same.



xed888 said:


> Der Wichtel has this driver: http://www.candlepowerforums.com/vb...icient-5A-9A-Buck-Converter-for-SST-50-SST-90
> 
> Reckon this can be used instead of the Task LED HFlex?



Voltage overhead is stated to be 2V in the datasheet. Plus it is a *buck driver*. If you want to run three XM-Ls wired in series using 2xLi-ion, you need a *boost driver*.


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## Justin Case (May 18, 2011)

xed888 said:


> oh yes, but his setup requires at least 4 Li ions to run properly whereas I would like only 2 Li-ions. His LEDs are wired in series, thats why.





xed888 said:


> Ah Justin, but the thing is I want to use 2 Li-ions in series and 3 XML's in parallel.




Make up your mind. Series or parallel LEDs?


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## xed888 (May 18, 2011)

Never said I wanted XMLs in series, always wanted them in parallel. Just said that DW has them in series. So its 3 XMLs in parallel.


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## tx101 (May 18, 2011)

I am actually planning my own triple XML build ... on a budget 
The DW and H6Flex are buck drivers which will require 4 cells to run
which for me will make the Mag a tad too long for my taste.
So the solution I have been looking at is CPFer Downloads "Poormans Multi-Lux setup"

See here

http://www.candlepowerforums.com/vb/showthread.php?201392-Poorman-Mutli-Lux-setup-method

His first example with the P7s would be ideal for the XMLs
My concern would be whether or not 3 x 18650 cells would have the capacity
to drive the XMLs at the full 2.8A for any reasonable amount of time.
Would substituting the 18650s for IMR 26650s be worth the additional expense ?

JC ... any thoughts on this setup :thumbsup:


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## xed888 (May 18, 2011)

what kind of host are you thinking of using, tx101?

Ma_sha1 has used Poorman's triple set-up but said that a resistor is needed as the Vin is way higher than the Vf of the Xml's in series (Vf=3.35V for 3A)


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## tx101 (May 18, 2011)

Maglite .... what else ???


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## xed888 (May 18, 2011)

LOL

I know that!!! I mean length. 4D? 3D?


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## tx101 (May 18, 2011)

3D

Just had a delrin 18650 sleeve made up and I'll have to do a tailcap mod
so that 3 x 18650s work in the 3D


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## Sway (May 18, 2011)

tx101 let us know how the Poorman 3x XM-L turns out on 3 cells, I'm thinking about the same build in a 2D Mag with 3x25600 IMR cells.......

I have a H6CC now that I could use but it would need 4 cells thus 3D Mag not really what I want to use on this project.

Later
Kelly


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## Al Combs (May 19, 2011)

TaskLED has a relatively new driver called LFlex that might be ideal for a triple XM-L with 3 IMR's. It's much smaller than an H6CC. The LFlex is only 0.78" diameter. That would easily fit in a Mag-C. It has most of the features of the H6Flex but at a much lower price. It's a linear regulator. The manual says the board if it is mounted with the standard thermal tape can dissipate 5 watts. That would be about 3.9 volts per battery figuring an XM-L triple Vf is ≈ 3.3 volts for 3 amps per LED. So you might need additional heat sinking. The manual doesn't say what the drop out voltage is for the FET. I'm guessing that wouldn't be an issue with a triple.

It has the same user interface and features of many other TaskLED boards. It will lower current when a user selectable temperature level is reached. Monitor battery voltage and shut off or warn by blinking when the level is too low. A nice feature for the unprotected IMR's. About the only thing it doesn't seem to have the the stat output for an LED battery voltage indicator. IMO, if you looking down the barrel of an almost 3,000 lumen flashlight, you're much more likely to see it blink occasionally that to see a tiny red LED on the battery tube.


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## xed888 (May 19, 2011)

Thanks Al for the heads up. It seems that wiring 3 LEDs in parallel might lead to uneven voltages if the Vf arent the same, so thanks for letting me know, Bad Frag.

I guess its back to 3 in series then 

Using the Lflex, I assume one has to convert the mag switch into a momentary switch?

Thanks


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## tx101 (May 19, 2011)

The LFlex looks like an even better option ....
thanks Al Combs

Yes ... Xed888, the Mag switch has to be coinverted to monetary


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## ljw2k (May 19, 2011)

Thanks Al Combs for the above and @ $25 it is not so expensive and more in my price range ,I just have to make a nice heatsink for it.
The Drivers i have been using for the single X-ML builds have the same features as the Lflex where it flashes to show you the batteries are getting low and automatically switches to low mode.

So Conclusion:

3x X-ML's wired in Series with a momentary switch mod........ Powered with 3x IMR batteries and the driver to be heatsinked to it's own heatsink to get rid of the wasted energy/watts.


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## Sway (May 19, 2011)

ljw2k said:


> Thanks Al Combs for the above and @ $25 it is not so expensive and more in my price range ,I just have to make a nice heatsink for it.
> The Drivers i have been using for the single X-ML builds have the same features as the Lflex where it flashes to show you the batteries are getting low and automatically switches to low mode.
> 
> So Conclusion:
> ...



Thats still going to be a little over the 5 watt maximum by 1.5 watts +/- a little with the LFlex backside heatsink, looks like the FET will need a way to dissipate a little heat from the front also.


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## xed888 (May 19, 2011)

if the LFlex was potted to the underside recess of a heatsink, will that be enough? When you guys say that it needs to dissipate heat, are you referring to the driver being potted or just hanging in the cavity of the mag body tube?


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## Sway (May 19, 2011)

Driver heatsinks, they need to be mounted on a sink that makes contact with the body as for mounting them on the back of the LED sink some do and some say not to...At this power level I would think the driver needs it's own.....


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## Justin Case (May 19, 2011)

xed888 said:


> if the LFlex was potted to the underside recess of a heatsink, will that be enough? When you guys say that it needs to dissipate heat, are you referring to the driver being potted or just hanging in the cavity of the mag body tube?


 
Potting a board that has to dissipate a lot of waste heat to the LED's heat sink is a major mistake IMO. The LEDs will already be pulling lots of wattage, with most of it going to waste heat. No need to add an even greater thermal burden. For the size of the LFlex, use a SharkSink and sink the board to the Mag tube.

Letting the board hang free in air is not my idea of thermal management.

Did you read the TaskLED technical section on the LFlex?

For fresh 3xLi-ions, you are looking at a power dissipation of:

(Vbatt-Vload) * drive current = (12.6V - 9.9V) * 3A = 8.1W

This level of waste heat requires topside and bottomside sinking.

In quasi-steady state, you might have

(11.1V - 9.9V) * 3A = 3.6W

This level of waste heat requires bottomside sinking.

How quickly the cells drop down to this quasi-steady state condition depends on what cells you use and how well they can hold their voltage. I would probably use both a SharkSink and a topside piece of copper to sink the FET to the Mag tube as well.


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## tx101 (May 19, 2011)

Sway said:


> Driver heatsinks, they need to be mounted on a sink that makes contact with the body as for mounting them on the back of the LED sink some do and some say not to...At this power level I would think the driver needs it's own.....



That is the way I am thinking of heatsinking the LFlex but with an additional tab of the opposite side of the copper tube
to heatsink the FET as well.


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## Justin Case (May 19, 2011)

tx101 said:


> I am actually planning my own triple XML build ... on a budget
> The DW and H6Flex are buck drivers which will require 4 cells to run
> which for me will make the Mag a tad too long for my taste.
> So the solution I have been looking at is CPFer Downloads "Poormans Multi-Lux setup"
> ...


 
It's all about the tradeoffs you are willing to accept vs the ones that are unacceptable.

ma_sha1 needed a dropping resistor for his 3xP7 Mag mod.

If you need to use a dropping resistor because the XM-L Vf is just too low for the Download method to work well (which may depend on what Li-ion cell size and chemistry you select), then IMO you are going to sacrifice run time in regulation. I see it this way. The dropping resistor is taking away voltage headroom that you normally would have had to stay in regulation with a 7135 driver. An illustrative example is VanIsleDSM's FETtie switch. Imagine that the case with the FETtie switch is your Mag mod case with no dropping resistor. You get long run time in regulation. Now insert the dropping resistor (the FETtie case of using a McClicky switch). With the higher system resistance, run time in regulation is noticeably shorter.

Do you care? Would you even run in High mode for very long anyway, or would most of your usage be in Medium or even Low.

What is your budget?

If a 4D Mag is too long, then are you willing to buy a FiveMega or mdocod 6AA->2D holder? Wire the XM-Ls in series and load the Mag with AW14500s to power a Shark Buck 3A. The downside is that you are very close to the max Vin for the Shark Buck (25V absolute, 24V recommended), and thus may have to use a hobby charger or the like to keep the cells at 4.10V max. If we assume 90% driver efficiency, 3.7V AW14500 voltage per cell under load, 3A drive, and Vf=3.3V, then

0.90*22.2V*Ibatt = 3*3.3V*3A = 29.7W

and Ibatt ~1.5A. That is pushing the 2C limit for the 14500s. So this solution should work, but it has multiple aspects that may be too close for comfort to component design limits.


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## xed888 (May 19, 2011)

Justin Case said:


> Potting a board that has to dissipate a lot of waste heat to the LED's heat sink is a major mistake IMO. The LEDs will already be pulling lots of wattage, with most of it going to waste heat. No need to add an even greater thermal burden. For the size of the LFlex, use a SharkSink and sink the board to the Mag tube.
> 
> Letting the board hang free in air is not my idea of thermal management.
> 
> ...



Did you mean something like this? 







The spaces will be epoxied. Is it ok to smother the front of the driver with epoxy to stick the copper on?Or just epoxy on the FET?

Looking at MA sha's triple XML mode, he needed the resistor to prevent the driver from getting too hot?

If i did like in the pic, I shouldnt need to add a resistor, should i?

Thanks for all your input, guys!


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## tx101 (May 19, 2011)

Al Combs suggested using Taskleds LFlex and it just so happens I have one
sitting in my parts bin that I totally forgot about. After my disappointment
with the XML 2.8A Tower module, I am a little shy about using the 2.8A 7135 board.
Its just a case of wanting to do a lot but having very little time to do it, so for now
I'll move on and try the LFlex board out. 
This triple XML I am planning is more of a "wow" light than anything else, honestly
I do not see myself needing 3000 lumens .... I stick with my Ra Clicky or Malkoff MD2
for more practical use 
Its more like .... thats cool, I'll build one.


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## xed888 (May 20, 2011)

Hi guys

George of taskled told me that the lflex loses too much heat when using three li ions to drive 3 xmls in series. He recommended the hflex instead.

Any thoughts in this Justin?

What would you do if you wanted to do this build?


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## Justin Case (May 20, 2011)

You could use the 3A current table, start at a lower powered mode to let Vbatt drop down, and then go to High.

The problem I see with the H6Flex is that you don't have a lot of voltage headroom to stay in regulation at 3A per XM-L. You need about 1V over Vload, which is about 9.9V. So you need 10.9V. So when the battery stack hits about 3.6V per cell under load, you've fallen out of regulation. I don't have a discharge curve of bigger cells like IMR26500 and IMR26650, but the Redilast 18650 hits 3.6V at about 1/3 of its total run time, and that is for a 2A draw. For ~3A, I would assume that the run time in regulation is even shorter. For an IMR18650, the cell lasts for about 1/2 its run time at a 3A draw.

IMO, if you use a buck driver, you really should use 4xLi-ion. 

You are asking a lot -- you want 3A drive to three XM-Ls, which will draw close to 30W. This is demanding on the cells and on the driver. The usual solution for delivering high current is a buck driver. But you have to feed it appropriately. If you can't, then a linear regulator or a boost driver are your choices. The linear regulator needs careful Vbatt/Vload matching. If that can't be done, then you are left with a boost driver. Finding a small, 3A boost driver is very difficult.

One solution is to use multiple drivers, e.g., multiple Shark Bucks, multiple Blue Sharks, or a combination. But that can get expensive and somewhat more complicated in terms of wiring.

Edit: Several months ago, I tested an IMR26500 at 3.6A constant current discharge and it held above 3.6V for about 12 min. For a 3A discharge rate, an IMR26500 might hold a bit longer. But that is cancelled out by the reality that in a typical real-world flashlight, there is parasitic resistance that will drop the input voltage even more. My IMR26500 test involved inserting one freshly charged IMR26500 into a Bulgin BX0036 C cell holder, with nickel/silver battery contacts. Two six-inch lengths of 12 gauge Deans noodle wire were soldered to the holder's contact connections. The noodle wire terminated into Emerson Network Power 15A nickel/silver banana plugs (spec'ed at 0.010 ohms contact resistance). This plugs in directly to my iCharger 208B hobby charger to charge/discharge cells. At least based on specs and calculations, I'm probably losing ~0.1V at 3A draw.

If your flashlight has even just 0.1 ohms of parasitic resistance, you can get at least 0.3V of additional voltage drop. Thus, instead of having to deliver 10.9V, your cells have to deliver 11.2V to stay in regulation. That means at least 3.7V per cell, not 3.6V. The impact of this on run time in regulation can be significant. For my 3.6A discharge test, the IMR26500 held above 3.7V for only about 8 min.


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## xed888 (May 20, 2011)

Deleted


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## xed888 (May 20, 2011)

Thanks JC. I decided to use 4x 26500 IMR cells in a modded MAg 3D. With 3 x XMLs in series D) and driven to 2.8A using Der Wichtel's driver. I should get about 2800 LED lumens using U2 binned XMLs. I know I said i wanted 3 cells in a 2D but you guys are right.

Any thoughts?


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## xed888 (May 20, 2011)

I wanna ask about making the momentary switch? Has any one just glued the two pieces together? You know, the clicky mechanism of the switch?


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## ljw2k (May 20, 2011)

If you do that it does not operate as a momentary switch ..........it still needs to act like a switch just not the clicky and lock type if that makes sense.


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## xed888 (May 20, 2011)

Thanks for that mate. I assume the switch in my mag wasn't modded to momentary by you?


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## ljw2k (May 20, 2011)

No mate it only needed to have a basic Mod to pick up the switch wire and ground to feed the driver and the momentary switch just involves a little more work but duable.


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## ljw2k (May 20, 2011)

Have a look at these threads listed on this page ..> http://www.candlepowerforums.com/vb/showthread.php?223518-Different-Momentary-D-Mag-Switch-Mods


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## Sway (May 20, 2011)

You really don't have to mod the clicky part if you don't want to, just use a half cycle press for momentary instead of a full press and "click" for on........Either way will work.


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## xed888 (May 20, 2011)

Sway said:


> You really don't have to mod the clicky part if you don't want to, just use a half cycle press for momentary instead of a full press and "click" for on........Either way will work.


 
PERFECT! Just what I wanted to hear! or read! No need for switch mods! Hurrah!


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## Sway (May 20, 2011)

It makes for a little nicer mod when you remove the splines in the clicky part, you just have to remember not too do a full press "click on" if you don't do the mod.

Now for the slick tip of the day that saves drilling a hole through the blue switch core part.

As in other instructional threads you need to trim off the back + (positive) switch contact that presses against the + (positive) battery contact slug so you can isolate the switch from the power path. Now instead of drilling a hole through the blue part and pulling the wire through it, pull it down the back of the switch core and solder to the ground anchor.

I'm not very good at writing instructions so maybe a picture will help 

This is the back side of the switch core that did make contact with the + power from the batteries.





It looks like this from the bottom.





And from the front.





On the Der Wichtel driver the front switch contact wire should go to (S3) and the black wire from the switch anchor to GND.

Hope this helps.

Later
Kelly


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## js-lots (May 20, 2011)

to get over the 11 volts I suppose you could try 4x 18350's. That would give you roughly the same length as two 18650's and about the same amps.


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## xed888 (May 21, 2011)

Thanks Sway. That does help a lot.


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## Aepoc (May 22, 2011)

xed888 said:


> Ma_sha1 has used Poorman's triple set-up but said that a resistor is needed as the Vin is way higher than the Vf of the Xml's in series (Vf=3.35V for 3A)



I am using an 8x7135 from Kaidomain with 3 lithium cells and 3 XM-L's with everything wired in series. I had to use Ma_Sha1's poorman's wiring, although the two XM-L's before the board provided enough of a voltage drop so that I did not have to use a resistor. The light works great and after heat sinking my driver, I have had no problems. The light does get pretty warm though...


Edit: After about 5 minutes of runtime, the light drops out of regulation... I measured a current of around 2.2 A at about 5 minutes.


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## xed888 (May 23, 2011)

Aepoc said:


> I am using an 8x7135 from Kaidomain with 3 lithium cells and 3 XM-L's with everything wired in series. I had to use Ma_Sha1's poorman's wiring, although the two XM-L's before the board provided enough of a voltage drop so that I did not have to use a resistor. The light works great and after heat sinking my driver, I have had no problems. The light does get pretty warm though...
> 
> 
> Edit: After about 5 minutes of runtime, the light drops out of regulation... I measured a current of around 2.2 A at about 5 minutes.


 
the reason the driver gets really hot is because that driver from KD is a linear regulator, isn't it?That just spews excess V as heat. Please correct me if I am wrong. I think DW's driver is a buck so it shouldnt release as much heat?

Thanks


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