D Mag mod dive light

[sailor612]

I have been searching non-stop on how to convert a 4D mag into a LED canister dive light. I've found plenty of post, but all of them seem to be started by someone who know's what they are talking about....thats not me!!
I already have converted a 4D into a 50W halogen canister light, but decided that i'd be happier with LED instead of halogen, because of burn time!
Honestly, I don't even know where to start!
What is the best route for me? I want PLENTY of light/burn time, but think it would be nice if I could control the levels of light (unless that is too difficult for a LED beginner to attempt to accomplish).
Any suggestions on how to accomplish my goal of a LED D-mag canister light?!
I don't understand much of the LED talk that i've read....
What type of LED, reflector, driver?, batteries, and whatever else...should I get? I have a 12v SLA battery but would prefer to switch to NiMH (so I can put it into a tube instead of a box).

I've thought about just using this: http://www.dealextreme.com/details.dx/sku.14645 , trimming it to size, adding ambilical cord to canister, replacing lens with glass and epoxying all joints... ?
If you've got other ideas to get me started that'd be great!!!
Thanks!
Mike

[Packhorse]

2 dive maglites I have done.......
http://www.candlepowerforums.com/vb/...d.php?t=203029

[sailor612]

Thanks Packhorse! I really like the one in the video: 4 X Q5 Aspherics!
Would you be willing to help "walk" me through how I do that? I have the Mag already modded for halogen (except a switch), but don't know anything about LED's?

What kinds of things do I need to purchase to get my project started?

[sailor612]

Ok, I'm new to this...but this is what i'm thinking. Let me know if i'm on the right track and if you have some helpful hints!

THis is going to be a modified Mag canister dive light, so the switch must me easily waterproofed, and the battery pack size isn't really an issue (smaller is better though...)

I'm going to use 3 of these: http://ledsupply.com/luxeonv.php Luxeon star 5W (side emitting)
Focused with : http://ledsupply.com/l2-op-015.php 15degree w/ http://ledsupply.com/l2-oh-s35.php to hold it.
The specs for the Luxeon Star 5W can be found here http://ledsupply.com/docs/Luxeon-StarVW.pdf

It is going to be mounted to aluminum plate that contacts all sides of mag head for a heat sink.

What type of driver should I use for the (3) Luxeon star 5W? I want it to have as much power as possible, and be dimmable for atleast high, low.

What battery size should I use if i'm using NiMH; volts, aH....? I'm looking for atleast 2hr burn time, but 1 FULL hr will be ok if thats my only choice!

What type of switch do I need for a high, low, off settings?

Thanks ahead of time for any help or pointers!!!

[Mike Painter]

5 x 3 watts = 15 watts of power
15 watts for 2 hours gives a need for a battery that has 30 watt hours available.
If you use a 6 volt battery 30/6 means you need at least a 5 ampere hour battery.
You also need to add a fudge factor because drivers are not 100% efficient.
A 90% efficient driver for your six volt battery would need
30/.9 = 33.3 watts or (33./6) about a 5.5555555 ampere hour battery.

Push button switches have big problems under water so a toggle, slide or magnetic switch is needed.

Waterproofing a mag head will not be fun especially at the lens.

Underwater it is unlikely that you need worry about additional heat sinking. Add that at teh end if need be. Just hold it in your hand and unless it actually burns you you will be alright.

[sailor612]

Great! Thank you! Will a 6v battery be sufficient enough to power those 3? That is one of the biggest things tripping me up....power/driver info. From what I can gather, a driver is just used to regulate (or step down..?) amps? from the power supply to the LEDs. Is that correct? I've attempted to google everything that will give me info on: what a driver does/what size is required for "X" setup..but i have been unsuccessful at finding information. (maybe i'm just using the wrong wording...)

When I look at drivers I see info that says stuff like 2.3v/30v, is that the range that the driver can handle? The lesser number being the lowest voltage?
Also, how do you know how much output is required for each individual emitter to operate at optimum capacity?

[Mike Painter]

Note that the six volts were used because I am lazy and can do that math in my head. You get the power requirements from the LED you will be using by multiplying the current and voltage it uses.
Next you decide if you are going to use the LEDs in a series, parallel, or some combination of the two. That gives you the voltage and current you need. Drivers can increase or decrease the voltage. Some can also dim and hold the current steady.

My first post was becasue I have not seen what I presented all in one place before (but it probably is in dozens of threads.)
There are also a ton of threads on how to build a specific light, including a dive light. Your best bet is to probably find tutorials that shows how to build a light with three emmitters and build the light around that.

[divinginn]

I would use different leds,either cree q5 or better or a single ssc p-7,which I used in my cannister light. I ran mine direct drive off two 6.6 amp amp 3.7 volt lithium ion battery pack wired in parallel,have not done a burn test yet but should last 4+ hours.

[Packhorse]

Maglites are a easy choice for a dive light and very easy to waterproof.
There are several threads on here on how to do it.

[Packhorse]

Would you be willing to help "walk" me through how I do that? I have the Mag already modded for halogen (except a switch), but don't know anything about LED's?

All the info is on that threas or this one

[Photodiode]

Dear fellows
Why all of the modders of mags are using li-ions (like 18650, or cr123's), but not normal cells? I mean 4,or 5 cells (on a D sized mag) makes 4.8 or 6.0 volts with big capacity. These cells i think they can feed a single Seoul P7 with a buck converter, or I'm wrong?

[LEDmodMan]

May I suggest a different LED. Lux V was the king in its day, but now there are other LEDs with MUCH higher luminous efficiency. The Cree MC-E (here it is at LED supply) gives you about 3 times the light output at twice the power of the Lux V, so a 50% increase. Here is the datasheet.

So, for what you had listed previously you can either have a light that is three times brighter and lasts half as long, or only use a single Cree LED and have it just as bright as the 3 LuxV's and last 50% longer (not to mention a LOT cheaper).

Of course, your battery requirements could then shrink too.

The Cree is a tad tougher to solder, but because each LED die is addressable separately (there are 8 leads), your options for drivers abound. You can power the LED in increments of 3.2-3.4 volts, so driving it at spec. is 3.2v @ 1.4A (all LEDs parallel), 6.4v @ 700mA (2 parallel strings of 2 LEDs), or 12.8v @ 350mA (all LEDs in series).

Also, you can easily overdrive the LED at double the power, with approximately double the flux value as well. I would suggest a single Cree MC-E, overdriven to 700mA per die (which equates to just under 10W of total power), a good driver and heatsink, and use the Mag reflector instead of an optic. Hope this helps. Have FUN!!!

[Packhorse]

Dear fellows
Why all of the modders of mags are using li-ions (like 18650, or cr123's), but not normal cells? I mean 4,or 5 cells (on a D sized mag) makes 4.8 or 6.0 volts with big capacity. These cells i think they can feed a single Seoul P7 with a buck converter, or I'm wrong?

Size and capacity.
In a all in one dive light using 5 D's make for a very long cumbersome light.
In a canister light its a different story and the cannister size isnt as important.

[darkman0101]

I would use different leds,either cree q5 or better or a single ssc p-7,which I used in my cannister light. I ran mine direct drive off two 6.6 amp amp 3.7 volt lithium ion battery pack wired in parallel,have not done a burn test yet but should last 4+ hours.

Divinginn - where did you source a 6.6Ah Li-ion pack from?

[Amonra]

Ok so here's my suggestion:
Use one pc Cree MC-E LED found here http://www.cutter.com.au/proddetail.php?prod=cut817 but choose one mounted on a star board with individual wire configuration as this makes soldering easier. Make sure you mount the star to a nice and chunky heatsink thermally connected to the mag body.

Im not sure of the quality of the beam but you could use the stock mag reflector to direct the light.

The easiest method to drive the MC-E is in direct drive, so here's one way how you could do it.
Now each individual die within the MC-E ( it has four dies in one package much like the luxV you mentioned but much more powerful and individually addressable ) can be connected separately and turning them on two at a time will give you 2 seperate levels of light ( i will explain later why 2 and not 4 )
since the voltage of each die is approx 3.6V you can connect them directly to a 3-cell nimh pack but since the fresh batt voltage should be about 4.1V you will need to add a 1 Ohm resistor for safety, this should drive each individual die with 700mA. I would suggest a 3x D-size nimh pack wired in series as that should give you runtimes in excess of 3 hours.

For a switch you could use magnetic reed switches as they do not penetrate the body in any way and are therefore your safest bet for waterproofing. you will need two of them placed close together touching the inside wall of the body and each connected to two dies. now when a magnet passes next to the first one ( from outside the body ) it will turn it on ( turning on 2 dies 50% ) and as the magnet keeps moving toward the second one it will turn that on too ( turning on the remaining two dies 100% ) as it moves further away the first reed will turn off while the second stays on ( back to 50% ) and then as it moves even further away the second reed turns off ( 0% ).

Here's a quick schematic of how to wire everything up:


As for waterproofing the mag body i am assuming that you already know how as you have already done it in your 50W light.

Hope it helps

[sailor612]

AMONRA-
What mAh batteries should I use to provide the 3hr burn time for the setup you have?

I really like that idea, It seems simple and much cheaper than I orginally estimated, yet effective!

From what I gathered on the data sheet; each die has about 3.4 Vf @ 700mA (max mA drive), If I did (3) D size in series at __?__mAh then i'd have 4.5V, then add the 1ohm resistor on EACH "+" die then i'd be ok? At what point would I start seeing a drop in lumens? Doesn't a resistor waste power?

Would the other route be using a 700mA constant current driver? If I used a driver, how would I wire it up with the 2 reed switches (or is that even possible?)? What driver would work for that?
THanks for the HELPFUL! write up with an easily understood schematic!!!
Look foward to seeing your reply!!!

[Amonra]

well each resistor will eat up a max of 1W each but probably the voltage of the led's will be a bit higher and the batt voltage under load will be lower so the resistors will eat up a bit less. a driver will probably be more efficient but it will still eat up 15-20% so maybe 2W.
So at this point you have to decide if you want it simple and cheap but sacrifice 4W, or a slightly more complicated and expensive and sacrifice 2W.

That being said, you could use this driver: http://www.dealextreme.com/details.dx/sku.1886 there are probably better drivers but this is the cheapest and the first one i found
you will only need 2 but they are sold in 10 packs. you would need to wire them like this:

the junctions in the red circles are not connected.

I think nimh D size nimh batts are usually 10Ah capacity and the light will draw around 2.8A - 3A. since nimh have a reasonably flat discharge curve you should expect around 3 hours of stable light output both with resistors and with drivers.
have a look at this: http://www.candlepowerforums.com/vb/...ad.php?t=79302 scroll down to Accu Power D 11.5Ah
Since you have such a large capacity sacrificing a few watts is not such a big problem, but remember that whichever you choose they will heat up so connect either the resistors or the drivers thermally to the mag body.

hope it helps

[sailor612]

Awesome! If i use the drivers do I take out the resistors (or was that accidently left out of the schematics?) Would those 1400 mA drivers not be too much for that cree? Its max drive is 700mA...i would want to use a driver that doesn't produce more than 700mA, correct? (DX does carry one, i just wanted to make sure i'm correct in saying that)
I got to thinking about heat sinking the resistors/driver to the mag...whats the easiest way to go about that?
What about "securing" the reed switches inside? Just epoxy them to the body?

How did you calculate the numbers for amps, watts, etc with the information of the data sheets? Are you just using 3.4v (driving volts @700mA) X 4 for the total volatge? Or are you actually breaking it down into individual Volts per die?
Thanks again for ALL the help! Keep it coming as you think of it! I love learning new things like this...thats why my 50W was fun to make. I didn't know a lick of how to calculate data or anything except minor machining/minor electrical/soldering until i started working on that!!!

[sailor612]

If I increase voltage, I MUST increase resistor to accomidate for voltage change too, correct? It wouldn't really do me much good to use 9v instead would it...for a direct drive...?
If I use a driver, then i'd want to get it close to the correct voltage, correct? Would it be better to use (3) 1.2v=3.6 OR (4) 1.2v=4.8. Does it matter...will 4.8v (power source) hurt the die, they run at 3.4v @ 700mA according to the data sheet?

[Amonra]

If you use the drivers you have to take out the resistors.
They need to be 1400mA since they are each connected to 2 dies wired in paralell therefore the current is split in half so there is actually 700mA going into each die.
The best way to thermally connect the drivers is to machine a semicircular shaped aluminium piece where there is a curved side and a flat side. the curved side matches the curve of the inside wall of the body. you then use thermal epoxy to glue the curved side to the body and glue the driver to the flat side. as for the resistors, it would be sufficient to just thermal epoxy them to the body. the reed switches can be epoxied too but make sure you get their placement right beforehand.
Calculating the wattages is as you said, but these are just approximations, you would have to test individually to get the exact measurements.

Yes you must increase the values of the resistors if you increase the voltages but if you want to go DD you need the batt voltage close to the led voltage otherwise the resistors will have to dissipate large quantities to bring down the voltage and that would make the system very inefficient. if you want to increase the batt voltage you will have to go with the drivers, but not the ones i suggested as they work best with a max batt voltage of around 4.5V.
4.8v will kill the die without the correct resistors or drivers.
keep in mind that freshly charged batt voltages are always higher than the normal running voltages. so generally a 4x1.2v ( 4.8v) is really 4x1.35v (5.4v) when freshly charged.

One more thing, do not expect the MC-E to give more output than a 50W halogen outside the water, however underwater the perceived output should be similar as water eats up halogen light whilst led light is less effected.

[Packhorse]

however underwater the perceived output should be similar as water eats up halogen light whilst led light is less effected.

Left 50watt (35wtt driven at 14.4v) Halogen 8deg Philips masterline ES MR16 Centre 21w Salvo Right P7

Conclusion
P7 does not give out as much light as the other 2 but its tight focus and better colour makes it a far better dive light than the halo.

[sailor612]

Ok...
This is what i've decided...
I'm going to go with 1 MC-E wired as you have in the schematic. I'm going to use (2) 1400mA drivers like you showed wired as the schematic. And (3) D-NiMH batteries in series at 10000mAh (that will be 3.6ish volts) to supply the required 3.4v for the cree. And 2 magnetic reed switches...

I guess that if the est. lumens @ 350mA for the cree is 370lm , 700mA will give me close to 650-700 lumens total, and about the equivelent of 10W (i've tried to base my opinion of watts on a 15W led my buddy has) total, correct?

Sound good?

[LEDmodMan]

That sounds about right. With losses, you'll probably see about 550-600 lumens out the front (depending on the bin of the LED too); similar to a Surefire M6 but in LED instead! The better the heatsinking, the brighter the LED will be. Good luck!

[sailor612]

[quote=LEDmodMan;2808353] (depending on the bin of the LED too)quote]

I was looking at that earlier this afternoon...what is the best bin? The one i'm thinking about getting is: MCE4WT-A2-WG0-K0-0-00001, Cool white, WG. I had trouble figuring it all out, and found a post on here that suggest that bin for "better colors." That one is the 370min lm, they also have one that is 430 min lm, i just didn't know if that would effect the setup I already have planned (lower battery life, require more battery voltage, change driver needed....or whatever could effect what I have planned) If not, then maybe i'll go with the 430lm bin instead! What does the WG, WG Tint, WH Tint, WC Tint, WC...mean? THe 430lm ones are "cool white __ tint"

[LEDmodMan]

You're missing the "[/" after "too)" which is why you're quote isn't working.


Anyway, the best flux bin you can get is the "M" code flux bin. 430-490 Lumens powered at 700mA per die.

The Cree page for the MC-E is here, and you want to have a look at the binning and labeling sheet.

In my opinion, the two best Cree bins are WC and WD. They will be the purest white of all. Of course, that's my preference; some people like "warmer" or "cooler" colors. Have a look at the old Luxeon binning chart laid over the 1931 CIE chromacity diagram (I did some of the work on the chart) HERE at Wayne Y's place. This chart is by FAR the easiest way to explain color binning to most people.

The Cree WC bin occupies the same color space as the old XO Luxeon bin, and the Cree WD bin is the same as the old WO Luxeon bin. From there you can see how the rest of the Cree bins will line up as far as colors go. Notice how the color changes as you move away from the Planckian (locus for black body radiation). Also note that the Cree "cool white" color bins WH and WJ overlap with the "neutral white" 3A and 3B. Sunlight is approximately 5,800 degrees Kelvin color temperature (4,800-6,500), FYI.

Anyway, the main reason the "cool white" WC-E's are brighter than the "neutral white" WC-E's is because there is a thicker phosphor layer applied over the neutral white LED dice. More phosphor absorbs more of the blue light, therefore making it dimmer.

Hope that helps you out.

[Amonra]

the 370 lumen bin and the 430 lumen bin will not make any difference in the setup you decided to use. they both use the same power but one is more efficient than the other i.e. more light for the same wattage. Cool white colour would be fine for diving

[nwbrewer]

Ok...
This is what i've decided...
I'm going to go with 1 MC-E wired as you have in the schematic. I'm going to use (2) 1400mA drivers like you showed wired as the schematic. And (3) D-NiMH batteries in series at 10000mAh (that will be 3.6ish volts) to supply the required 3.4v for the cree. And 2 magnetic reed switches...

I guess that if the est. lumens @ 350mA for the cree is 370lm , 700mA will give me close to 650-700 lumens total, and about the equivelent of 10W (i've tried to base my opinion of watts on a 15W led my buddy has) total, correct?

Sound good?

I run this setup with a DSWOI P7. I like it a lot, works well for crappy puget sound vis. Last time I went out though, I had some issues where the LED would flicker a bit. I turned the light off, couldn't get it back on. Waited about 2 minutes, and it turned on fine. This repeated a few times during the dive. I think it was the AMC drivers overheating as they are not currently heatsinked. Anybody have any thoughts?

Jake

[Amonra]

Jake, i suppose heatsinking the amc's would be a start, otherwise it could be a dry joint that appears when it gets hot.

[sailor612]

Awesome! Thanks yall!

What is the best way to heatsink this setup well? I've seen some "DIY" heat sinks on the forum for sale, but most of the DIY ones are for the die only, not for stars or round...

[nwbrewer]

Jake, i suppose heatsinking the amc's would be a start, otherwise it could be a dry joint that appears when it gets hot.

You mean like a bad solder joint? Hmmm, possible, I'm still learning here. Thanks.