The Mark XII - 3x neut MC-E regulated on the cheap cheap cheap

Techjunkie

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For the most part, my mods are all done with hand tools and with economy a top priority. While when taken apart and examined internally, they don't comapre to the craftsmanship of the big-shots here at CPF, I think they provide some serious bang for the buck. On that theme I offer...

The Mark XII (so named for the 12 LED dies):
Mag 3C host
3x neutral white MC-E emitters
3x DX 8.4v 3A (2.59A really) buck regulators
2x Sony LiNiCoMn 26650 batteries
DX 3*CREE solid AL reflector

I had to bore the battery tube to fit the diameter of the batteries. I also had to bevel the inside edge of the Mag head and knock the threads off of the DX reflector module to make a nice fit. The spring had to be stretched to compensate for the 20mm difference between the two Sony batteries and 3 C cells.

The MC-E emitters are mounted directly to a 3*CREE MCPCB using solder and a small blowtorch (very carefully). I tapped 3 new holes in the bottom of the solid reflector and used another 3*CREE MCPCB to make a spacer by drilling holes larger in diameter than the emitter and leads. The spacer was filed down to remove the pcb coating and reveal the metal core. Silver thermal compound was applied on both sides of the metal spacer before tightening down the screws. In this way, heat is transferred from the emitter PCB to the solid AL reflector and then to the head.

To provide thermal contact with the Mag neck, a stack of washers are fastened to the center screw, with the last washer extending slightly into the threads at the bottom of the head. The wires pass around two narrow washers and then through wider washers that have holes drilled to allow the wires to pass through and avoid being crushed by the tube.

A triple stack of DX MC-E/P7 single mode 3A buck regulators are fit in the neck between the top of the Mag switch and the top of the tube. One edge of each regulator PCB is trimmed to allow wires to pass around it. At the fully tightened position, a small hole is drilled through the threads between the head and tube and a small finishing nail inserted in the hole to keep the head from twisting (and non-flashaholics from destroying everything inside by trying to "focus" the head).

Each regulator powers a single MC-E. Current provided by each regulator to each single MC-E was measured at 2.59A. All three together draw a little over 4A current from the 2500mAH batteries for total full brightness regulated runtime of about 40min.

The full assembly is then dropped in from the top, the grub screw tightened to hold the switch in place and the bezel tightened down.


Pics:
3neutralwhiteMCEinstalled.jpg

TheMarkXXII.jpg

3Chostwith2x26650batteries.jpg

roomtospareintube20mm.jpg

triple-stackofdrivers.jpg

twist-stop.jpg


This triple neutral white MC-E torch completes my multi-MC-E collection.

---

In truth it no longer exists as pictured. This last batch of DX drivers that I received create an annoying high pitched whistle. It sounded like three kettles were boiling inside the torch. Not so audible when used outdoors, but inside a still quiet house it sounded as if the flashlight were about to explode. The assembly, drivers removed, was relocated to a beat up old Mag 3C that I had been running a P7 D-bin directly driven off of 3xAccupower Evolution LSD NiMH C-cells. All three MC-E are now wired in parallel and together pull 6.4A from the 3xNiMH C-Cells for around 2.2A each. It's just as bright on a full charge and as the cells deplete and the current drops, I estimate over an hour of diminishing brightness runtime. On the plus side, I've got another fantastic beater that novices can use without fear of damage to batteries, drivers, or host. :D
 
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smopoim86

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Knoxville, TN
Re: The Mark XXII - 3x neut MC-E regulated on the cheap cheap cheap

Does this make it about 50 MCEs you have in your lights? I'd love to have one of the penta reflectors loaded with MCEs, but haven't gotten around to spending the money. You're making me reconsider buying the parts every time i read one of these threads.
 

^Gurthang

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Maine, deep in the Darkness of the North
Re: The Mark XXII - 3x neut MC-E regulated on the cheap cheap cheap

TJ,

Nice work! I'm in the same mode as you, keep it simple and cheap. I just tried out my M@G 2D w/ 2X 18650s and SSC P4 DD w/ resistor padding. Did you use the DX 20330 buck driver? I'm planning another 2D host w/ P7 so info like yours is useful. Keep on modding and posting. Any beamshots?

^G
 

Techjunkie

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Messages
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Location
in the brightly lit suburbs of NYC (Long Island)
TJ,

Nice work! I'm in the same mode as you, keep it simple and cheap. I just tried out my M@G 2D w/ 2X 18650s and SSC P4 DD w/ resistor padding. Did you use the DX 20330 buck driver? I'm planning another 2D host w/ P7 so info like yours is useful. Keep on modding and posting. Any beamshots?

^G

Yes to the 20330. I've ordered several of these on separate occasions. This latest batch is very noisy. I'd try the KD buck driver for a few dollars more if I knew how to bypass the modes.

I'll have to do some new beamshots, I know. I think I compared my cool white version of this torch to the XX-Ray (see link in my sig). This performs about the same but with warmer color.
 

wquiles

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Jan 10, 2005
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Location
Texas, USA, Earth
Very nice and affordable project :thumbsup:

I did not realise that these drivers were noisy. I wonder if potting them would help some?

Will
 

Techjunkie

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Messages
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in the brightly lit suburbs of NYC (Long Island)
Very nice and affordable project :thumbsup:

I did not realise that these drivers were noisy. I wonder if potting them would help some?

Will

Thanks, Will.

I had the same idea about potting. I was going to try encasing the whole stack in heat resistant putty epoxy (I have this stuff called PC-Farenheit that works like the one advertised on TV). I wasn't sure they wouldn't overheat that way but I was going to take the chance anyway.

I removed the assembly to trim the plastic lip atop the Mag switch to buy some more head room and when I reasembled again, two out of three had gone :poof:. They lit the LEDs but very little output, maybe just a few mA. A little fiddling and the third went :poof:. I don't think that anything that I did caused a short or anything but for whatever reason, they didn't survive more than a day from installation. I've used the 20330 drivers several times before and never had any of this trouble (the dying or the whistling) so I'm chalking it up to a bad batch.

I've opened a ticket to DX to get them replaced. If they do replace them for me I might try this one more time, or I might just leave this as NiMH direct drive and use them in something else, I haven't decided yet.
 

wquiles

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Messages
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Man, I am sorry to hear about these driver problems that you are having. So far I have been using only drivers from George (Www.taskled.com), and had no problems, but I also spend more money on the drivers. For me that is a good tradeoff as I will pay more for higher reliabity.
 

Essexman

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U.K.
Nice project, thanks for sharing it with us all.

I like the creative thinking you have used, it shows that you don't have to spend mega bucks (or pounds) to make a great light and have fun making it yourself.
 

Techjunkie

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Messages
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in the brightly lit suburbs of NYC (Long Island)
Man, I am sorry to hear about these driver problems that you are having. So far I have been using only drivers from George (Www.taskled.com), and had no problems, but I also spend more money on the drivers. For me that is a good tradeoff as I will pay more for higher reliabity.

Yep. I've been itching to try one of those. I'll probably go with a HipCC and 5 or 6 batteries when I do. Three HipCCs seemed excessive for this project and I couldn't fit anymore batteris or a ccHipo. I'm willing to experiment if it could mean the difference between $15 and $75 on drivers.

Nice project, thanks for sharing it with us all.

I like the creative thinking you have used, it shows that you don't have to spend mega bucks (or pounds) to make a great light and have fun making it yourself.

Thanks. Total cost for everything including batteries and charger was < $100.
 

jar3ds

Flashlight Enthusiast
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Sep 12, 2005
Messages
1,988
Location
USA
Man, I am sorry to hear about these driver problems that you are having. So far I have been using only drivers from George (Www.taskled.com), and had no problems, but I also spend more money on the drivers. For me that is a good tradeoff as I will pay more for higher reliabity.

word... if your gunna take the plunge... might as well support george and avoid possible headaches...

nobody makes better electronics for flashlights...
 

HarryN

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Pleasanton (Bay Area), CA, USA
Hi - I don't think potting will help much with the whining noise, and might in fact mess up the driver. (changes the inductance of the coil.) I try hard to not buy drivers with inductors that are open wound like that.

AFAIK, the whine is from the coils rubbing as the inductor charges / discharges. IMHO, this is one of the downsides of PWM current control - it takes real life experience to design around that dang hum.
 

Techjunkie

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Location
in the brightly lit suburbs of NYC (Long Island)
Hi - I don't think potting will help much with the whining noise, and might in fact mess up the driver. (changes the inductance of the coil.) I try hard to not buy drivers with inductors that are open wound like that.

AFAIK, the whine is from the coils rubbing as the inductor charges / discharges. IMHO, this is one of the downsides of PWM current control - it takes real life experience to design around that dang hum.

That might explain why they sometimes shut up for a while if I shake the flashlight.

EDIT: Good news is that I've used new DX20330 drivers several times since and haven't had the noise problem (or failure problems)
 
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