# Tri-Shark & Remora Wiring Diagram



## Nanomiser (Nov 13, 2008)

Being a newer member myself, I thought this may be helpful to other new folks in getting started with their mods. A BIG thank you goes out to *LED Zeppelin* for being gracious enough to hold my hand through this process and to *dat2zip *for his time spent in helping me to understand the fundamentals of the Shark and offering up this particular solution in the first place. Please feel free to offer any suggestions or improvements to this configuration. From original thread P.10 here.


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## DaFABRICATA (Nov 13, 2008)

Subscribed...Thanks!!

Nice easy to read lay-out!!


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## Nanomiser (Nov 13, 2008)

Glad I could help!

:thumbsup:


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## LED Zeppelin (Nov 13, 2008)

Mike, I just realized your P7s all need to be in series, not two strings. And you need to use Blue Sharks.

With a Shark Buck solution, you could use two strings, but each running independent Sharks that feed the strings separately. 

With the Blue Sharks and two unbalanced strings as pictured, the strings will share the current unevenly. With Shark Bucks and two unbalanced strings, the Sharks will still deliver regulated current to each string, but one Shark will pull more from the cells.


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## Gryloc (Nov 13, 2008)

It is great to see that you stitched that picture together. The wiring to the LEDs are kind of confusing since the lines were not as clean as what you would see in a circuit diagram (perpendicular lines running horizontally and vertically). It is still readable, though.

I did notice one glaring issue that has me troubled though. It seemed to be hidden in there, but once you straighten things out, you see it. I went ahead and re-drew the electrical paths in the following picture. I used to draw the little humps in my lines to show that they are not connected electrically, but in the following image, crossing lines do not mean that they are connected, but crossing lines with a dot does mean that they are connected.





That is my issue: Three LED emitters connected in parallel with four LED emitters. The Shark drivers are totally blind as to what is on their output. The Sharks will band together and they probably will deliver the same currents according to the signal from the Remora board. 

Actually, something undesirable can happen. I am not sure on the topography of the Shark board, but I thought that I heard it is sort of a voltage regulated board. Someone please clarify on this. If the Sharks is current regulated (say each delivers 1000mA), then the voltage will adjust automatically so one string will receive 3000mA. In this case, the string with three emitters (with a lesser combined forward voltage) will receive 3A of current, and because the string with four emitters have a large combined forward voltage, will get barely a trickle of current. On the other hand, the voltage may increase to try to cater to the string of four P7s and the drivers may damage the three P7s. I am not 100% sure about what will happen since I have not owned a Shark driver.


So, I think that you intended to connect all seven of the P7s in series, judging by your large bank of li-ion cells in series (over 22.2V worth). I am not familiar with the max voltage capabilities of the Shark driver, but something seems scary about this setup. I would re-check all of your specs if I were you! The Sharks are step up drivers, but they may be unable to handle such a high input voltage. Can the Sharks deliver ~26V on the output?

Once you can confirm these voltages, then I can see this working okay. Each emitter will see 3A each. With seven P7s at this current and some decent reflectors, then you are talking about some serious light output!! I hope that you are not trying to shove all this into a Maglite. That is way too much heat (~70W) unless you are going to make it a dive light where the body is suspended in some water.

-Tony

EDIT: I guess that I was way too slow on this one. LED Zepplin beat me by a mile (and with fewer words)!

LED-Zepplin, although you are walking Nanomiser through all of this, could you please explain how you can set up the Shark to be a buck mode driver? I know that many driver can be wired in a slightly different configuration to change its topography, but I am curious on how you can do so with the Shark. Is there advantages of using the Shark as a bucking driver? Out of curiosity, is there issues with having 6 li-ion cells in series (when it comes the cells depleting at different rates), even if they are high quality cells? I know it is safe to do with NiMH and NiCad. Thanks!


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## LED Zeppelin (Nov 13, 2008)

Gryloc,

The Shark Buck is a brand new converter just released by Wayne, it hit the shelf yesterday. It on the Shoppe's site here.

There's also a thread about it here.

I'm not a cell expert, but I don't believe there is any issue with 6 Li-ion cells in series. The issue is when charging - though they can all charged simultaneously with a charging jack-equipped holder, they should be balanced periodically so the states of charge are not dissimilar. If they get far out of balance there is a chance of reverse current which is the danger.


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## Gryloc (Nov 13, 2008)

I looked at the Shark Buck thread and found more info. Sounds awesome! In addition, I found more about your project, nanomiser. From just this thread, it was hard to see what your intentions were. Now it is more clear. You are also in great hands at the moment, so I won't interfere too much . It looks like you will have a real monster when you are finished. I cannot wait for beamshots. 

I am going to have to re-think some previous projects now that a 3A buck circuit is available :thinking:. I am so happy because usually to get any sort of dimming function (with a potentiometer), you had to use a boosting circuit if you would stick with dat2zips's or george's drivers. Thanks for the news!

As for the series connected li-ions, I just had some sour experiences with using cheap and unprotected cells. I could charge two cheap 26500 cells in parallel for guaranteed balancing, but after using them only once in series in a light that drew maybe 2A from the cells, one cell would lose its voltage faster than the other. Even with good protection (and still cheap cells), I could still see this happening. However in that case, the entire light would shut off if once the voltage of one cell drops too low. Now I have two of AW's C cells to replace those cheap cells and I will monitor this over the weeks. I probably will be fine. I guess, to me, balancing 6 cells sounds like a small chore unless you have the balancing connector built into the 6-cell li-ion battery carrier. Good luck, nanomiser!

-Tony


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## Nanomiser (Nov 13, 2008)

LZ,

Thanks for the correction and my apologies for the confusion on Shark type. Yes, my intensions are to use Blue Sharks so maybe I need to clarify that on the diagram. I will go back and revise the drawing again and post it here for more scrutiny. This is exactly the kind of response I was looking for, Thanks.

Mike



LED Zeppelin said:


> Mike, I just realized your P7s all need to be in series, not two strings. And you need to use Blue Sharks.
> 
> With a Shark Buck solution, you could use two strings, but each running independent Sharks that feed the strings separately.
> 
> With the Blue Sharks and two unbalanced strings as pictured, the strings will share the current unevenly. With Shark Bucks and two unbalanced strings, the Sharks will still deliver regulated current to each string, but one Shark will pull more from the cells.


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## Nanomiser (Nov 13, 2008)

Hi Tony,

Thank you for your input as well. I got a similar response from Wayne, but I think the Mammoth is just the host for this particular mod. I just need to make real sure I have all my ducks in row when I fire this one for the first time. That's were all of you expert come into play in helping newbie’s to learn and hopefully do it right the first time.

I always error on the side of caution when it comes to Li-ion cells and won't buy anything else but fully protected, preferably AW. Up until your last response I wasn't completely clear about cell charge balancing, but the parallel charging comment finally made it click! I will need to reconsider my approach to how I will be charging all of my cells. How often is it necessary to charge balance a Li-ion?

I guess I am back to the virtual drawing board for another revision. I'll post new drawing when I can.

Mike 



Gryloc said:


> I looked at the Shark Buck thread and found more info. Sounds awesome! In addition, I found more about your project, nanomiser. From just this thread, it was hard to see what your intentions were. Now it is more clear. You are also in great hands at the moment, so I won't interfere too much . It looks like you will have a real monster when you are finished. I cannot wait for beamshots.
> 
> I am going to have to re-think some previous projects now that a 3A buck circuit is available :thinking:. I am so happy because usually to get any sort of dimming function (with a potentiometer), you had to use a boosting circuit if you would stick with dat2zips's or george's drivers. Thanks for the news!
> 
> ...


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## Gryloc (Nov 13, 2008)

There are different ways to balance a pack of li-ion cells. Two that I know of is parallel charging, and by using a specialized charger. 

Charging in parallel requires (sometimes, depending on design) that you remove each cell from the pack (if using a battery holder/carrier) and charge them all in parallel. The problems with that is it takes a high amperage charger to charge many cells in a timely manner. I like the method when I charge two 18650 cells or two of AW's C-cells using a laboratory power supply (do not own a high quality li-ion charger). It does not take too much time for me. I do not own any series wired li-ion packs. Some day, when I have the funds, I desire making a light on the same scale as yours.

On the other hand, some chargers charge all of your cells in series, but they use an additional connector to properly balance the cells while charging. They require an additional connector with a wire (of smaller gauge) that connects between each cell. For example, for six cells (a cell is represented below as +{]- ), you would have two main power leads, and then an additional connector that has five wires (A-E):

+{]A{]B{]C{]D{]E{]-

main leads: (+) and (-)
extra connector: [A B C D E]

The electronics will monitor each cell and increase or decrease the voltage over every cell while charging to make sure that they are about the same voltage each (I thought that I heard that they balance withing 0.02V each). The connectors are pretty small, so if you have a pack made of you six 18650 cells, and the cells are permanently connected, then you can have a small male or female connector located somewhere that you can plug into the charger. I guess the only downside is maybe the cost of one of these chargers. I am not sure how much they are, but in comparison to the overall cost of your tremendous project, it will probably be small. Of course, there are many more knowledgable people here than me about the li-ion cell technology. Just snoop around the "Flashlight Electronics" area. Good luck!

-Tony


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## Nanomiser (Nov 15, 2008)

Hi LZ & Gryloc,

I hope this one has got it right! It's cleaner at least.






With this configuration wouldn't the P7 string see too much Vout from the 3 Sharks?


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## LED Zeppelin (Nov 15, 2008)

Looks good to me Mike. Just remember the two top trimpot pads should be soldered together:






With this setup the P7s should see 2.7-2.9 A each.


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## Gryloc (Nov 15, 2008)

Nice re-drawring. Very clean! 

The three Sharks will provide what ever voltage is needed on the output as long as the current stays at what it was set at. Everything should be great as long as the total Vf does not go beyond ~32V (the max rated output voltage). If that happens (lets say you attach 2 more P7s in series), then the current output from each Shark will not be the full 1A that you intended. Come to think about it, is there enough room in the very nice configuration of seven emitter for an eighth? Electrically, it should work. Now, where to fit/shove it... :laughing:

Led_Zeppelin, what about the input voltage? Is it too high? With 6x li-ion cells hot off the charger, that is 25.2V. According to jtr1962 in his White LED lumen testing thread, with seven P7s operating at 3A, they will have a combined forward voltage of 26.29V (3.755V x 7). Is that enough overhead? This is just from one sample P7s, so there could be a variation, so the total Vf could be slightly higher or lower. I can see the voltage dropping quickly on the fresh li-ion cells (sagging?), and the cells should settle down eventually to around 22V for a while. Now, what happens as V-in gets close to V-out? Even if this is perfectly safe (which I am sure it is), then I hope you do not intend to dim your seven P7s, Nanomiser. I remember that you need a pretty big overhead to dim the LEDs down to a miniscule current. For example, I believe that yout V-in has to drop below 19.8V (2.83V x 7) before you can reduce/dim the current to only 80mA to your seven LEDs (that is less than 3.3V per li-ion cell).

Well, all that aside, I am excited for you, Nanomiser! Out of curiosity, what flux bin of P7 emitters are you using? I have been communicating with jtr1962 lately, and he will be testing some D-binned P7s that I got from PhotonFanatic to make lumen measurements. He may post his findings on his thread. He told me lately that he found that the "C-bin" P7 that he tested (the one that I linked above) was actually a D-bin P7. I wonder when he will correct the post in his thread. It is sort of a bummer because I was hoping that the performance of the D-bin P7s would be better. Even if you use his measurements, that means 5,460 lumens at 3A!  Congrats! I hope the LED guys beat out the incan dudes...

-Tony


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## Nanomiser (Nov 15, 2008)

Hi Tony,

Thanks for the good charging information. So far I only own loose batteries, no packs. I do however have a few of FM's custom holders that I plan to use for charging a number of my AW cells. Some months back I did make a fairly good investment on a Triton2 Electrifly charger for a very reasonable price. 






I think this qualifies as a quality charger which should allow me to charge at least a couple of cells in parallel at a time or several in series. In addition I’ve also upgraded my cheap soldering irons with a hi-watt digital Weller that should enable me to achieve much better and smaller solder joints for all of these torch builds. Thanks again for your input here as it should prove to be helpful moving forward.

Mike 



Gryloc said:


> There are different ways to balance a pack of li-ion cells. Two that I know of is parallel charging, and by using a specialized charger.
> 
> Charging in parallel requires (sometimes, depending on design) that you remove each cell from the pack (if using a battery holder/carrier) and charge them all in parallel. The problems with that is it takes a high amperage charger to charge many cells in a timely manner. I like the method when I charge two 18650 cells or two of AW's C-cells using a laboratory power supply (do not own a high quality li-ion charger). It does not take too much time for me. I do not own any series wired li-ion packs. Some day, when I have the funds, I desire making a light on the same scale as yours.
> 
> ...


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## Nanomiser (Nov 15, 2008)

LZ,

Thank you for that important reminder and for all of your help.

Mike :thumbsup:




LED Zeppelin said:


> Looks good to me Mike. Just remember the two top trimpot pads should be soldered together:
> 
> 
> 
> ...


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## LED Zeppelin (Nov 15, 2008)

Gryloc said:


> Led_Zeppelin, what about the input voltage? Is it too high? With 6x li-ion cells hot off the charger, that is 25.2V. According to jtr1962 in his White LED lumen testing thread, with seven P7s operating at 3A, they will have a combined forward voltage of 26.29V (3.755V x 7). Is that enough overhead? This is just from one sample P7s, so there could be a variation, so the total Vf could be slightly higher or lower. I can see the voltage dropping quickly on the fresh li-ion cells (sagging?), and the cells should settle down eventually to around 22V for a while. Now, what happens as V-in gets close to V-out? Even if this is perfectly safe (which I am sure it is), then I hope you do not intend to dim your seven P7s, Nanomiser. I remember that you need a pretty big overhead to dim the LEDs down to a miniscule current. For example, I believe that yout V-in has to drop below 19.8V (2.83V x 7) before you can reduce/dim the current to only 80mA to your seven LEDs (that is less than 3.3V per li-ion cell).
> -Tony



Tony, I figure the voltage sag will be enough to keep the Sharks in boost and not in direct drive. 

And you're right about the dimming - at least on full cells I don't think that you'll get a low level with a Remora. You could use a dummy cell if that's an issue. It depends on how much the voltage sags and the actual Vf of the string. The Remora low isn't that low, so 18-19V should get you there.


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## Nanomiser (Nov 15, 2008)

LZ & Tony,

I've been thinking about the number of cells I plan to use and came to the conclusion that it may not work. With Sharks in parallel to 6 cells they would all see ~25.2 which would well exceed the Blue Shark 20Vin limit in addition to possibly putting them in DD because of the ~25.2 Vf, correct?. Since I will be using FM's 4x18650 cell holders populated with both live & dummy cells, Wouldn't I be better off only using five 18650 + 3 dummies? At full charge 5(4.2) = 21Vin enables boost mode and dimming as well as getting a end of charge 13.5Vin which is still above half the string Vf. However, that condition would create an ~5.25 current draw from cells through the drivers, but divided among the 3 Sharks should be safe, maybe? Or am I better off with my original 6x18650 design?


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## Nanomiser (Nov 15, 2008)

The dimentional design of the Mammoth head and the number of MCR27R reflectors I wan't to use limit me to seven P7s. Very interesting results from jtr1962 testing. I have also conducted an intial test on one of my D-bin P7s. Although not nearly as comprehensivew as jtr1962, I did observe some interesting results. My power supply would only allow the ~2.8A draw once I the P7 saw a 3.9Vin, why? If this is acurate then I should see a Vf sting well above the 25.2Vin keeping me in the window with 6x18650 cells. 


















Gryloc said:


> Nice re-drawring. Very clean!
> 
> The three Sharks will provide what ever voltage is needed on the output as long as the current stays at what it was set at. Everything should be great as long as the total Vf does not go beyond ~32V (the max rated output voltage). If that happens (lets say you attach 2 more P7s in series), then the current output from each Shark will not be the full 1A that you intended. Come to think about it, is there enough room in the very nice configuration of seven emitter for an eighth? Electrically, it should work. Now, where to fit/shove it... :laughing:
> 
> ...


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## Gryloc (Nov 15, 2008)

Nanomiser,

Boy that thing just seems so intense. Looking at the P7 in my Mag host, I don't think that I can imagine seven! 

That voltage you read is not the forward voltage of the LED. It is the voltage read across the thin positive lead wire, then the LED, then the negative lead wire. There is a voltage drop in the lead wires since the wires have a bit of resistance in them. It is easy to get the true Vf.

First, do you have a separate multimeter? Second, is that power supply provide both constant voltage and constant current? If you have a spare meter, then measure the voltage directly across the emitter (at the power legs). I learned from evan9162 a nice method to measure the correct Vf of an emitter when running V vs I tests.

If that the PS can provide a constant current, then as long as you set an amount of current, then it will care less about voltage out. In that case, you can use thin, high resistance power wires if you want. If the power supply just allows you to set voltage, then you may have to tinker with the voltage a bit to get the right amount of current. Either way, you will need a second meter.

So, what evan9162 told me to do was to use two sets of probe wires soldered onto the emitter. He told me that he used that thin gauged wire found in IDE ribbon cable that was left over from a computer. He stripped it so he had individual strands. These are really thin, but can handle more than 3A without increasing in temperature. Actually, any spare hookup wire will work. Solder the power wires coming from the power supply to the (+/-) pads on the star, then solder your thinner gauged wire onto the actual legs of the emitter. I say smaller gauge wire because if the wire you use is too thick (I mean like 18AWG), then you may but mechanical stresses on the legs if you move the wires around a lot. Finally, attach the thin hookup wire to your meter. Since there is absolutely no current going through the thin wires attached to the emitter's legs, then there will be absolutely no voltage drop! At this point, do not read the voltages that the power supply gives. I noticed with my power supply, that even with thick gauged wire, there is a big voltage drop.

I hope that helps. If you do not want to do all that, then just try to clip the probe wires from the multimeter to the legs of the emitter.

BTW, it does seem silly to have a huge battery compartment filled with so many spacers. The V of the fully charged cells is 25.2V, which is close may be at the max voltage, but you could always let the cells rest a bit before putting them in the light. If you are really worried, just put a load onto the battery pack before inserting for a few seconds (like an old 24V light bulb or something). Well, after the light runs for a few minutes, then the voltage will sag down some. When the li-ions are at more than their halfway point, then the voltages will only be 22.2V (3.7V x 7). Do not forget that the seven P7s will be running at around 26.3V at 3A. The circuit wont mind as it will have to boost the voltage.

I bet Dat2zip could tell you if the voltage is too high (only .2V). The 25V rating may be just what he tells his customers, knowing that the customers will most likely push the limits. The true max voltage may be 26V. You may be able to ask Dat2zip if there is a easy fix. I remember someone taking a boost circuit and wanted to add one extra li-ion cell to it. It would mean a voltage in being slightly over the max input rating. So, they placed a cheap 3mm red LED in series with the Vcc pin on the main IC chip. It made the chip happy, while the rest of the circuit handled the slightly higher voltage just fine. I think this was done on TaskLED's Fatman boost circuit. That is one thing you can do (just a thought)...

-Tony

EDIT:
I just seen that you do have a multimeter (is that a Fluke?). Great. I just asked jtr1962 in his thread about what bin of P7 he used. I noticed that the P7 you got from KD was an I bin. Well, if jtr1962 has tested a J-bin, then your total Vf of seven P7s (if an I-bin) may be a bit lower than 26.3V after all. We'll see.


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## Nanomiser (Nov 15, 2008)

Hi Gryloc,

When you say 25Vin limit are you sure your not thinking of the Shark buck? I just checked the Blue Shark specs at the Shoppe and I thought it said 20 volt max Vin. Maybe I'm missing something.

Mike


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## Gryloc (Nov 15, 2008)

Whoa! That is confusing. I opened every product in the Sandwich Shoppe that contained any form of "Shark" (the Shark products are scattered between all the other LED driver products). 

Here is what I found:

"Assembled BLUE Shark with Remora"
"Input voltage range: 2.7V - 20V"

"Assembled SHARK with Remora"
"Input voltage range: 2.7V - 20V"

"BLUE SHARK Step up Converter Board"
"Input voltage range: 2.7V - ~25V (Vin < Vout)"

"SHARK Buck"
"Absolute Maximum Input Voltage: 25 (Recommend max 24V)"

"SHARK Step up Converter Board"
"Input voltage range: 2.7V - 20V"
"***NOTE: All Shark sold after Oct 1,2007 are the from the new batch with the higher voltage ~26V and has no flicker. J1 is left blank.***"

Okay, now it is more clear after seeing the last page. (I will still leave all those links, unless the mods don't like it).

The first Shark driver had a max of 20V. Then Wayne revised it to be capable of handling "26V". Then, Shark "2.0" came out as the Blue Shark, which was designed to handle a max of "~25V". The Blue version also "Raises Vout from 22.5V and improves thermal performance over standard Shark."

That is helpful. So, I guess that either you had an old Shark page open, or the Shark with attached Remora board. 

Now, I do not know what to do about the Remora board if you plan on having one as a master controller, unless you just use an external potentiometer for your dimming. Will that red LED trick help, where you have a red LED or two in series with the Vin of the stacked Remora board? Instead of having the red power wired go from Vin of the Shark to the Vin of the Remora, just use two LED. Maybe green ones may work better due to their high Vf compared to the red. Then, wouldn't the Remora see ~20V (25V - 2.5V - 2.5V), while the main Blue Shark takes the 25V? 

Wayne, are you out there?


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## Nanomiser (Nov 16, 2008)

Gryloc,

Thanks for the great 411 on the Vf measurement technique; it makes allot of sense. Time to put that Fluke 189 to use and get the real numbers. Actually the P7 in the picture is a J-bin which should have a Vf of 3.50 to 3.75 so I will see what I get. I'll probably just clip on to the emitter legs and go from there. Before reading jtr1962 "White LED lumen testing thread" I had no idea that you could push an LED like the P7 to 7amps without grenading the thing. Sounds like fun!

As far as the Shark Vin limit is concerned it looks like the Remora is the bottle neck; I get it now. Thank you for doing the research and clearing this up for me. I may be looking at an external pot mod instead. I always wanted to do one of those anyways. However, the LED across Shark Vin / Remora Vin trick might also be a viable option.

Mike :twothumbs


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## Nanomiser (Nov 17, 2008)

Tony, here is what my DSXOJ P7 gave me for Vf; fairly close to the begining of the factory range.


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## Gryloc (Nov 17, 2008)

Sorry. I worry that I was unclear in that one post (my posts can be wordy). I am horrible at communication. 

Even though you are fine, I just want to clear anything up that may not have made sense. You can have the fat wires on the normal power pads on the star, but at least have the measurement wires as close to the emitter as possible. I was blabbing mostly, so you actually do not need thick wire at all because your power supply will not mind the slight increase in voltage. Your power supply will adjust the voltage to whatever to create your needed 2.8A. 

I brought this up with the intention to not measure any extra voltages, which can be caused when a current passing through a conductor. So, you can use two thin wires on each LED lead (lol). One to send the current through, and the other to measure voltage. Think of the wires in a K-shape (that is what evan told me). Just a quick and silly drawing of this configuration:





In your set up, you can wire it like this if you want, using thick wires or thin. 





Another reason you could use thin wire is because it puts less stress on the emitter, both thermally, and mechanically. This is especially true when testing bare emitters with fragile legs. With a star, it becomes less of a problem. All that matters is that you get the measurement wires as close to the emitter as possible.

So, in your current set up, your voltages will be just fine. There is no current passing through the copper traces on your MCPCB, so the voltage measurements will be accurate. If you wanted to make these measurements using a battery as a power supply, then I can see that the thick wires will help deliver more current to the emitter. In the future, when making Vf vs I measurements, it is just easier to use two thin wires. The thin ribbon cable wires that I use go through their abuse often. 5A of current barely makes them warm. I was playing around and found my plain old test leads add an additional 0.3V to the entire circuit at 3A. No problem, though.

Well, additional blabbering aside, 3.45V at 2.8A looks wonderful. It is very close to what I got with my P7s. I just love the low Vf of these parallel die P7s! Nice heatsink setup. I cannot wait for more pictures. 


-Tony


EDIT:
BTW, that power supply that you have looks very similar to mine (layout of fine & course knobs, power button, bannana plugs). With mine, though, I have only one LED display, and you have to slide a switch to switch between the voltage and current display. So now I see that you do have a nice CC/CV PS (I was wondering about that). I love mine to death. I would honestly sell any of my flashlights before I would sell my laboratory power supply. I guess that means that I need better flashlights because my power supply was pretty cheap on ebay.


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## Nanomiser (Nov 18, 2008)

Hi Tony,

Your communication is just fine and thank you for all of your encouragement. If it weren't for you I would have fried that Remora / Shark master right out of the gate. I think an external pot is the direction I'm going to go in. What size pot will I need for this set up, maybe something like this? I almost forgot that I'll need to update my diagram, yet again, to reflect these changes. However, I just noticed that LZ used a Shark/Remora master with 2 Shark slaves on his 9-Cree Moby **** 3" Delghi build. What cells did he used to power it?

I to enjoy having nice test equipment as it sure does come in handy for modding . I've spent a good amount of time acquiring this equipment over the years for just this type of work. Now I just need to learn how to use it more proficiently. Well practice makes perfect, but finding the time to practice is much easier said than done. It's hard to believe that I started my very first mod, Q5 Penta-Cree Chrome FM Tri bore 2.5 Mag-D 

 

 

 

 a year ago and I still haven't finished it yet. I guess it's been a really busy year. When I do get done I'll post some pics. All I have left is to wire up the Shark, functionally test the light, epoxy the driver to the light engine and then complete the mechanical assembly. Between that and the Mammoth I've collected enough parts to do another 3 to 4 other mods. 

Just got both of the FM 4x18650 cell holders that I'll use to power the Mammoth; man that guy makes some nice stuff. Also finished my drawing for the 18650 dummy cells and ordered the materials. Once the materials come in I got a local guy who will turn them for me and they should turn out something like these 17670 I did a while back. 




As I make more progress I will post more pics of the Mammoth, but I'm afraid it could be slow going as money is tight right now and the Mammoth still needs allot of parts.

-Mike


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## Gryloc (Nov 18, 2008)

When it comes to a potentiometer, I would sample quite a few different types (since they are not that expensive). The one you found looks pretty good, but you need one that is logarithmic, and not linear. A logarithmic pot will provide a more pleasing and apparently linear dimming action than what a linear pot would create (it is a mathematical thing with the driver circuit). I say sample different types because I think that you should try ones of different type and construction to see which one fits the best, while providing the kind of durability you desire. For example, get a few that are similar or smaller than this one, and then find the smallest one with a metal shaft and get a few sizes (more durable and less bendy). Finally, maybe grab one that is a little larger. It will be down to personal preference at the end on what looks and feels the best. Some turn easily, and some do not. The metal shaft ones could be used bare and still looks okay (when they have the star * shaped shaft and not the D shape shaft), however with the plastic ones, you can shorten the shaft easier if needed, and if you are not just plain mean to your lights, will hold up pretty well.

I looked up LZ's 9-Cree Moby **** again to see its battery configuration (here). He uses "(4) 18650 Li-ion cells, 2 series/2 parallel for 7.4 V operation". Of course, his LEDs draw a total of around 2.7 times less power than yours will. 

I was just thinking about your cells again. You are using 2 quad 18650 cell holders right? What if you used a 4 series/ 2 parallel 18650 cell configuration? I am not saying this in concern over your use of 6 series cells, but I though that you could gain a little extra runtime by filling those spots where the dummy cells were with li-ions. 

For example, if your LEDs drew 93W (assuming driver efficiency of 85%), then 93W / (3.7 * 4) = 6.28A. 6.28A / 2 parallel = 3.14A per cell. 6.28A / 3 sharks = 2.09A input per Shark. This will mean more current at the input of each driver, but as for runtime... 6S li-ion: 93 / 22.2V = 4.19A per cell. 2.2Ah / 4.19A = 31 minutes. 4S/2P li-ion: 2.2Ah / 3.14A = 42 minutes. Okay, I see that it isnt much of a gain in runtime, but I just noticed one possible advantage: charging. It seems like it would be easier to charge two similar 4S configured packs (either in parallel, separately, or with two chargers) that a single 6S pack. Maybe not. With two 4S packs in parallel, depending on charging current, may take a little longer. Can your charger handle six series cells? If it does, then I am not sure what would be best. I dont know. What do you think? Both have advantages.

Well, your FM Mag looks nice! You will be finished in no time the way it sounds. Where did you get that beautiful heatsink? It looks like heat will never be a problem with you with that finned head. Oh, and those spacers look nice as well.

I understand that this is the very beginning phase of a project. You got a while from now and a completed nightmare (for the night time animals). Please do keep us posted. The great thing about time is that it reveals newer and better components (and LEDs). Who knows, but by the beginning of next year, Seoul may sell E-binned emitters, or Lumileds may have a new offering. Also, AW may release a better 18650 cell, or Dat2zip may uprade his Sharks. We'll see.

I can say that money has got a lot of us in a strangle hold. I have three or four dream projects floating in my head and somewhat on paper, but none will happen any time soon due to money issues. I have a few smaller scale mod projects that have the priority now that are still sort of on hold because of money and waiting on parts on backorder. I will be happier once I get my newer P7 and my first MC-E in the mail. Then I can experiment and work them into my lights finally.

-Tony


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## Nanomiser (Nov 18, 2008)

Good advice on the potentiometers! Now that I consider these options I'm more partial to a D-shaped metal shaft pot with the logarithmic function. Now it's down to physical size, terminal/pin configuration and ease of rotation. Fortunately, because of the size of the Mammoth head, I think I will be able to mount all three Sharks just beneath the LED heat sink directly to the head internal wall. This will keep the body neck open allowing the accommodation of a large construction pot if I so choose. 

Actually the LZ build I was referring to was the 9-Cree Moby **** *3" Delghi head* he did. As it turns out he only used 2xA123 cells to power that thing pulling 5.4A @ 7.4 V on hi, unbelievable. I thought that would be in the danger zone for cell discharge? 

You are correct on the dual quad 18650 FM cells holders. Using a parallel / series configuration over a straight series sounds intriguing. Nice math work there; I would consider an 11 minute extension of run time to be significant. As far as charging goes I think my charger will do either 5 or 7 Li-ions in series, I'll have to verify that.

Thanks for your compliments on my FM D-mag. The heatsink is actually a 2-piece hybrid using the top portion of one of download's Multi-sinks and a modified CPU sink I had lying around in my garage, hence the blue anodization still visible in between the fins. I then used some Artic Silver epoxy to bond them together. Here are a couple of crossection views of the 3-D model during my design phase.


 


Esthetically it does look very sharp, but the design turned out not to be as practical as I thought. During my initial testing the entire heat sink got hotter than a banchy in spite of the cooling fan blowing on it. After looking at some of Mac's light engines I realized that I needed more mass and to increase the contactable surface area for optimal heat transfer to Mag head & body. In order to achieve this I had to create a miniature injection mold set up to fill in the first 4 grooves between the fins with Arctic Silver epoxy. Man talk about messy :sick2:. However, the 2nd burn-in yielded much better thermal management as a result of this epoxy back-filling. 

I'll keep things moving forward as quickly as funding allows and post my progress as I go. I totally agree, time can offer up some advantages and break through especially at the rate this group moves. On an exciting note, I just received my UltraFire MCU WF-1200L SSC P7-C torch; can't wait to load it with some AW RCR123a's and fire it up tonight! 





Let me know how your experiments go with the new emitters, especially the Cree MC-E.

-Mike


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