# D-mini + Q5 + 5 mode driver! A guide.



## StefanFS (Oct 9, 2007)

*D-mini + CREE R2 + MM Driver. A guide.*

There has been some requests for a guide doing this "simple" mod recently. I use the 1000 mA AMC7135 five mode Pic driver available from several HK webshops. It is simple for those who have been modding for a while, but it does require some patience and exact planning to get it right. And basic soldering skills. I use No. clean lead free solder and liquid flux for electronics, that's why the joints sometimes look dull. It's easier to use normal 60/40 solder and rosin solder paste.

This driver works best with one LiION cell. It will deliver light with one CR123 primary, only very little light.

What you need, one cut down Q5, one driver, some teflon wire and solder.







Use a small drill bit and make two holes in the plastic cover by twirling the drill bit between your fingers. Remove the aluminium tabs holding the cover. Lift the cover with something like the bent paper clips in the picture.






Desolder the connections on the star.






Start preparing the driver leads, presolder the connections on the driver and trim the leads. Then solder the leads to the driver. It pays to use a solder station and high temp for quick and efficient solder points.






Push the desoldered leads from the stock driver down into the pill, use a small screwdriver and find the ledge of the contact ring surrounding the driver, tap the driver out of the pill. Sometimes the original star overlap the holes in the pill, then you can put the pill in your vise and use the same screwdriver and tap the star out with a hammer. If not I twist it out with a pair of pliers






Desolder the stock driver from the contact ring. Use some solder wick to suck up the solder on the ring.






Solder the new driver to the ring with a few points around the circumference.






Push the driver with the contact ring back into the pill, on the D-mini I use a pair of needlenose pliers and on Tiablos or MRV I use a hammer and a piece of wood.






Mix some of your favourite thermal epoxy to go under the new star. Install the star with epoxy under it into the pill (while observing that the correct lead reaches the correct contact on the star) and then use the head & reflector to find the correct centering. Finding the correct centering will take a few tries. And don't use too much epoxy under the star, it needs to be a thin layer. Let it set overnight when centered.






Time to solder the leads to the star. Presoldering the contacts on the star and the leads will make things easier. High temp soldering will also make it easier






I don't bother with the stock covers. Thin plastic from eg. microwave dinner boxes work well. I use a 7 mm punch for the emitter hole.






This is the result. Up from 7800 Lux to 13 000 Lux in throw @ one metre.





This mod does take some patience and planning, but it's not difficult to do.

I have installed a UCL type lens with AR coating on both surfaces since beginning this mod. This upped the throw Lux @ one metre from ~13 000 Lux to 14 700 Lux.

Runtime on high. BatteryStation RCR123. Throw Lux 14 700 @ 0 minutes.






Runtime on medium. BatteryStation RCR123. Throw Lux 4600 @ 0 minutes.






Runtimes are considerably longer on low & medium level, it's also better regulated on low & medium. But the circuit is dependant on the cell for regulation. On high it's very bright for the first 20 minutes. 52 minutes to 50%. The stock D-mini driver runs regulated for 25 minutes on RCR123 LiION and then shuts off completely. With this driver and a new led my D-mini is as bright as the stock light at 50 minutes.

Stefan



*Update 2008-07-16*


I decided that I had to modernize my edc d-mini to it's limits. That means an efficient driver (eg. DX SKU: 7882. Others also carry this product.) I also used a new star mounted CREE R2 WG led.








Removing the old stuff from the light engine








Fixing the new star with AA epoxy and centering it with the plastic cover.








Preparing the driver with emitter leads and a copper wire for ground soldered to a hole in the ring around the driver. The ground wire replaces the brass contact ring for battery negative.








Driver leads soldered to the new star. I always use long emitter wires in case of future led upgrades.








The ground wire is wrapped around the light engine. A simple solution. Since the board with the led is thinner I wrapped a few extra turns of thin copper wire around the light engine/pill where the ground wire is in this pic to get the emitter to the correct height. That differs a bit with different D-minis, some need adjustment for focus and some don't.








The driver sunk into the light engine/led pill. Awaiting epoxy.








Potted/epoxied into the pill. It's very important to keep the variable resistor clear of epoxy since you want to use that to tune the drivers output.








That's it. It now throws ~24 000 lux on high. That's like a Raidfire Spear in your pocket . However, at that level you will get very short runtimes. I'll use it with high set to somewhere around 10-12 000 lux in throw to get good runtimes on one rehargeable RCR123 or primary CR123. Output is about the same on both RCR 123 or primary CR123.








Stefan


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## Scattergun (Oct 9, 2007)

Aaaaw maaan!!!:shakehead Now I´ll have to disassemble my D-Minis!!!

Great tutorial!!!:thumbsup:


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## AlexGT (Oct 9, 2007)

Darn good tutorial! Thank you so much! BTW PM sent regarding the 7135 board

AlexGT


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## cranphin (Oct 10, 2007)

Won't be doing this myself, but wow that's a great guide 
:twothumbs


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## vetkaw63 (Oct 10, 2007)

What is the run time on high with your Q5 and AMC7135? What was the stock run time ?
I have used this board with an 18650 but I have been hesitant to use it with an rcr123. I am afraid of the higher forward voltage of the Q5 combined with the voltage drop across this board. I thought that it might only current regulate for about 10 minutes. Have you had any such problems or issues?
Thanks,
Mike


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## nanotech17 (Oct 10, 2007)

Thank you StefanFS.
Thank you for the effort.


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## Essexman (Oct 10, 2007)

Do you know I was just thinking "there's been no tutorials for ages", and then I found this.
Very nice.
Thanks


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## StefanFS (Oct 10, 2007)

vetkaw63 said:


> What is the run time on high with your Q5 and AMC7135? What was the stock run time ?
> I have used this board with an 18650 but I have been hesitant to use it with an rcr123. I am afraid of the higher forward voltage of the Q5 combined with the voltage drop across this board. I thought that it might only current regulate for about 10 minutes. Have you had any such problems or issues?
> Thanks,
> Mike


 
I updated the first post with a runtime on high. CREE seems to be working on the forward voltage problem. My latest batch of Q5 are all ~3.55 Volt @ 1 A. I tested this particular Q5 to be 3.56 Volt at about 1 A. Others are also reporting lower vf values for recent Q5 emitters. I think runtimes are very good with this driver in a D-mini, it's not perfectly regulated but it performs very well.

Stefan


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## vetkaw63 (Oct 11, 2007)

Thanks StefanFS,
Thats very reassuring results. I will be ordering a couple for RCR123 lights.
This tutorial was very helpful.
Mike


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## StefanFS (Oct 11, 2007)

vetkaw63 said:


> Thanks StefanFS,
> Thats very reassuring results. I will be ordering a couple for RCR123 lights.
> This tutorial was very helpful.
> Mike


 
Thanks, 
I'm not sure if you mean Q5 or drivers, but I recommend both. I'm working on a runtime on medium level with one RCR123 since I'm curious myself about the actual runtime.
Stefan


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## vetkaw63 (Oct 11, 2007)

Stefan,
Actually I have some Q4's so, I will use those. I used 1 in a jet beam and it was no brighter. I figured it was because of the forward voltage issue. I was afraid to use the AMC7135 drivers with the Q4's in an RCR123 light. I thought the runtime might suffer from the forward voltage issue. Your runtime is way better than the 25 minutes that I get now.
Thanks,
Mike


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## StefanFS (Oct 11, 2007)

Updated post #1 with runtime on medium.


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## bessiebenny (Nov 24, 2007)

Thanks for this tutorial. I might mod my Mini 3W Cree light by following this mod. =)


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## selfbuilt (Dec 5, 2007)

Just saw this thread - very well done Stefan! :thumbsup:

Good to see this kind of step-by-step mod being posted here. I've been meaning to do exactly the same thing to my original D-mini, now that I have the new digital version to compare it to. But frankly, I just haven't had the time to do any modding in awhile (and usually just stick with simpler emitter swaps when I do). But I've got at least half a dozen AMC 7135 stockpiled, waiting to be put to use! :laughing: 

I've bookmarked this one for future reference, and will make sure to direct people here who are curious to give it a try. 
:twothumbs

P.S.: Good idea about the microwave dinner plastic cover, should withstand heat well. I usually just use some kapton tape to cover the contacts, and cover it all with one of Kai's shiny adhesive discs for Cree emitters.


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## Ganp (Dec 6, 2007)

:goodjob: Excellent tutorial on a very worthwhile mod' Stefan.

What is the tint like from the new led ... any beamshots?


Colin.


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## StefanFS (Dec 6, 2007)

Ganp,
The tint is a good WG, very creamy white. That particular light has a new owner, I don't have it any longer and I never did any beamshots with it. I still have it's black twin which I use everyday, and the beam is very close to the one in this tutorial. Here are some beamshots with that identical D-mini mod.

Selfbuilt, 
I used a plastic disc to protect the emitter from possible pressure from the reflector etc. in case of free fall incidents terminating in a hard surface. Some time ago I saw high temp tape (kapton type) sold by one of the largest electronics distributors for the nordic area, ~$145 for a 33 meter roll! When I saw that I felt satisfied that such products are available for $3-$5 in other venues.
Stefan


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## Ganp (Dec 6, 2007)

Thanks for the link Stefan ... great beamshots.:thumbsup:



Colin.


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## Patriot (Jan 23, 2008)

Thanks for all of your helpful and instructive threads Stefan. You've inspired me to attempt the 7135 mod. I do want to make sure that I get the right parts to begin with though. Can you recommend a source for the Q5WG and 7135 driver.

If that goes successfully, I'd like to give one of my MRVs a boost and will need guidance on a driver for that as well.

Thanks


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## StefanFS (Jan 25, 2008)

Patriot36 said:


> Thanks for all of your helpful and instructive threads Stefan. You've inspired me to attempt the 7135 mod. I do want to make sure that I get the right parts to begin with though. Can you recommend a source for the Q5WG and 7135 driver.
> 
> If that goes successfully, I'd like to give one of my MRVs a boost and will need guidance on a driver for that as well.
> 
> Thanks


 
You're welcome.
I got the hardware from DX. There's a nice 3 level 1.2A driver at KaiDomain. Modding is fun!:twothumbs
Stefan


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## TranquillityBase (Jan 25, 2008)

Great tutorial Stefan:thumbsup:

That driver looks pretty nice too...


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## StefanFS (Feb 6, 2008)

TranquillityBase said:


> Great tutorial Stefan:thumbsup:
> 
> That driver looks pretty nice too...


 
Thanks,
if anyone is wondering this is the three mode 1.2A driver:
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3256
When compared to a FluPic it has a similar discharge curve on 18650. But it does lose some few tenths of a Volt in the process, so it's not as bright as a FluPic driven CREE Q5-R2. It differs on the scale of a few hundered Lux. Maybe ~ten lumens. It's a cost effective solution with emitters that have reasonably low vf (less than 3.8V).
Stefan


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## discoverEDC (May 15, 2008)

StefanFS, thanks for the tutorial. I am thinking about taking a perfectly good Digital D-mini Q5 and installing the DX 1.4 A 7135 driver which would make it a one mode screamer(with SMO reflector) . Do you think an RCR123 will keep up with the demand? On the other hand I don't anticipate running it more that 5 minutes at a time. I would appreciate any thoughts :thumbsup:


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## nanotech17 (May 16, 2008)

discoverEDC said:


> StefanFS, thanks for the tutorial. I am thinking about taking a perfectly good Digital D-mini Q5 and installing the DX 1.4 A 7135 driver which would make it a one mode screamer(with SMO reflector) . Do you think an RCR123 will keep up with the demand? On the other hand I don't anticipate running it more that 5 minutes at a time. I would appreciate any thoughts :thumbsup:



1.4A would be great.
I can't wait to see


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## StefanFS (May 16, 2008)

discoverEDC said:


> StefanFS, thanks for the tutorial. I am thinking about taking a perfectly good Digital D-mini Q5 and installing the DX 1.4 A 7135 driver which would make it a one mode screamer(with SMO reflector) . Do you think an RCR123 will keep up with the demand? On the other hand I don't anticipate running it more that 5 minutes at a time. I would appreciate any thoughts :thumbsup:


 
Sorry, I don't think it'll work with a lowly RCR123 cell. It's difficult for the RCR123 to supply 1A for very long, let alone 1.4A. I think you need a bigger LiION cell or three NiMH cells for that. But I'd love that kind of setup.
Stefan


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## discoverEDC (May 19, 2008)

StephenFS, you're right, I got a tailcap reading of 1,030 mA. So you think an 18650 might have the horsepower to push 1.4A? I've been trying to avoid a new battery type and also getting the extension tube. But if it will push 1.4A I might have to....


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## StefanFS (May 20, 2008)

An 18650 cell can do that, it can supply considerably more than 1.4A. I get amazing runtimes in my 2.4A SSC P7 Tiablo A8 with one AW 18650.
Stefan


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## warlord (May 20, 2008)

Cool tut. I used the same driver (well the 16mode) and a Q5 to upgrade mf WF-602D. The fit wasn't as straighforward as the driver board had to be ground down considerably to fit the ring. Love the good info.


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## TorchBoy (May 20, 2008)

Excellent write-up and photographs Stefan. Those graphs imply the board isn't running in regulation even with a fresh battery. What's the Vf of your LED?


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## StefanFS (May 20, 2008)

TorchBoy said:


> Excellent write-up and photographs Stefan. Those graphs imply the board isn't running in regulation even with a fresh battery. What's the Vf of your LED?


 
The problem here isn't emitter vf, it's the RCR123 that has too little capacity to hold up for very long. Vf was quite low (I don't remember exactly as it was quite a while ago), I measured that batch and they were ~3.6V @ ~1A. But it's still a lot better than the original driver. This driver works best with a bigger LiION cell, in the D-mini it's a good compromise as it uses the RCR123 to it's limit. The price is that you pay is the ski slope discharge curve. The original runtime on RCR123 was about 25 flat minutes and then nothing, at 50 minutes this one is still as bright as the stock D-mini was when it shut off. 

Stefan


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## TorchBoy (May 20, 2008)

StefanFS said:


> The problem here isn't emitter vf, it's the RCR123 that has too little capacity to hold up for very long. ... The price is that you pay is the ski slope discharge curve.


That ski slope discharge curve is a ski slope intensity curve, unless I'm misreading something badly there. :shrug: But if so, that means - because there's no flat section at the top - that the thing isn't in regulation even at the start. Even with more capacity the graph would still be going downhill, just more slowly. More voltage is required to keep the board in regulation and thus keep the graph flat.

Nice graphs, though.

Here's a thought - because of the way the AMC7135 works at low voltage the graph might be flatter with just a resistor. :naughty:


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## StefanFS (May 21, 2008)

TorchBoy said:


> Here's a thought - because of the way the AMC7135 works at low voltage the graph might be flatter with just a resistor. :naughty:


 
It's a choice I made to get more runtime out a lousy little RCR123, I also like levels and strobe which I don't get with a resistor. If I want flat regulation I would pick a boost driver.
Stefan


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## TorchBoy (May 21, 2008)

StefanFS said:


> I also like levels and strobe which I don't get with a resistor.


Ah, of course.


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## discoverEDC (Jun 17, 2008)

Stefan,
I took out the AMC driver I put in my D-mini Q5 and went to direct drive using 17670. Tailcap readings after stabilizing for a minute or two are between 1.35 and 1.45 A(freshly charged). My light meter died, but based on guestimation I estimate 230 Lum and 20,000 lux out the front end :twothumbs

There won't be much regulation to speak of with this setup but I only use it for quick long distance looks at things. Rides in my front pocket next to my wallet with no problems.


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## StefanFS (Jul 16, 2008)

Post #1 updated with a new mod of my trusted D-mini.

I moved the content (the new mod) of this post to post #1 for obvious reasons.


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## 12Johnny (Jul 16, 2008)

StefanFS said:


> I decided that I had to modernize my edc d-mini to it's limits


 
Thanks again for the GREAT tutorial! :thumbsup:




StefanFS said:


> Potted/epoxied into the pill.


 
Very interesting... could you please let me know the exact material that this "white" thing is, and the reason why you applied it? Is it "soft" to the touch when cured, or "solid"? As you can see, I am an absolute noob... :sigh:

Thanks in advance!


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## climberkid (Jul 16, 2008)

i am on DX as we speak.....man this is bad. lol

where did you get the R2?


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## StefanFS (Jul 17, 2008)

12Johnny,

It's Arctic Alumina epoxy, but any decent epoxy will work as long as it's hard. The reason is to fix the driver in the pill/light engine as I don't use the brass contact ring that the stock driver used.


Climberkid,
It's an emitter I put on a spare small board I had. A Q5 on a small board works just as well.


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## 12Johnny (Jul 20, 2008)

StefanFS said:


> 12Johnny,
> 
> It's Arctic Alumina epoxy, but any decent epoxy will work as long as it's hard. The reason is to fix the driver in the pill/light engine as I don't use the brass contact ring that the stock driver used.


 
Thanks for the explanation!


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## Nake (Jul 20, 2008)

Stefan,

I noticed on DX's site the wires on the 7882 board are already soldered on. Did you replace them with your own? Does the copper ground wire go into anyone of the holes around the perimeter of the board?

Can this board be changed to just high level only, by soldering the negative wire to the perimeter?


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## StefanFS (Jul 21, 2008)

On the one I used on the D-mini there were no wires at all, on the newer I have now I'm replacing the wires with teflon wire. Yes, the ground wire is soldered to one of the holes in the perimeter.

It's possible to make it a one level driver by soldering the led negative to pin number 4 on the PIC processor, which is a way of bypassing it. Pin #4 is the pin/leg closest to the battery spring, when reading the text on the PIC it's the first pin on the upper left. Check that it works before potting it.

The levels on this one are really good, I use the low-med-high interface which has a quite low low level for really long runtimes on one RCR123.

Stefan


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## Tatjanamagic (Oct 24, 2009)

Thank U on this post...


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