# How do you want to get your Cree MC-E?



## ifor powell (May 31, 2008)

OK lets have a poll to see what people want for mounting options, maybe we can influance what gets made... Should be multi vote so you can choose board sytle and wiring...

Ifor


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## znomit (May 31, 2008)

1s3p to give an asymmetric hotspot.
I guess a star with 8 pads.


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## Erasmus (May 31, 2008)

Raw unmounted to keep the thermal resistance as low as possible. S or P depends on the application


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## longleg (May 31, 2008)

4S - this will mean huge possibilities when it comes to small DIY bikelights. As long as there will be made some good not-too-large optics of course..


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## spencer (May 31, 2008)

Definitely 4S because there would be no worries of bad die matching like the P7 and it could be run off of drivers that are already out there.


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## Tekno_Cowboy (May 31, 2008)

Mounting isn't really my concern, but I'd prefer to do the wiring myself. Mounted on a board that give you solder pads away from the emmiter would be nice though.


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## IMSabbel (May 31, 2008)

For me, 4S, plus mounted in _some_ way.
This things have way to much connections to be comfortable otherwise.
(Well, perfect would be a distribution board where you can just re-set some jumpers to change between 4s,4p, 2s2p. Doesnt need any electronics for that...)


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## Calina (May 31, 2008)

IMSabbel said:


> For me, 4S, plus mounted in _some_ way.
> This things have way to much connections to be comfortable otherwise.
> (Well, perfect would be a distribution board where you can just re-set some jumpers to change between 4s,4p, 2s2p. Doesnt need any electronics for that...)


 

+1 on a board with jumpers.


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## jtr1962 (Jun 1, 2008)

4 independant is the best way so the end user can choose the configuration best suiting their application. 4S is the next best way as there are no inherent disadvantages as with 4P or 2S2P.


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## jabe1 (Jun 1, 2008)

+1 for 4 independent!


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## rizky_p (Jun 2, 2008)

from the vote, it seems that some people still prefers the 4P setup :thinking: we have P7 for that right?

4 Independent is best i think

Thanks.


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## ifor powell (Jun 2, 2008)

rizky_p said:


> from the vote, it seems that some people still prefers the 4P setup :thinking: we have P7 for that right?


 
Are you looking at the same results as me??? 4s is up at 43% 4p is only 10%

I figure I will have to do my own if I want 2 * 2s which I have a plan for...

Ifor


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## WeLight (Jun 2, 2008)

So we are going to redesign our star board to suit. Possible options with the current 4 pads would be to leave one set of +/- as a single pad for 4S and the other broken into 4 to address each die so they could be S/P as required 

any other thoughts, suggestions ?


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## spencer (Jun 2, 2008)

You should also make a third board that does 4P just as another option for those who want that. I can see your 4 independent being most popular.


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## WeLight (Jun 2, 2008)

spencer said:


> You should also make a third board that does 4P just as another option for those who want that. I can see your 4 independent being most popular.



Im thinking like this


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## Jarl (Jun 3, 2008)

My option isn't there- 1s 3s.



longleg said:


> 4S - this will mean huge possibilities when it comes to small DIY bikelights. As long as there will be made some good not-too-large optics of course..



I'm thinking one 18650 with a linear dropper powering 1 die at 350ma regardless, with a boost circuit sending 0/350ma/700ma to the other 3 dies depending on how much light you want, with a 3mm thick copper tube containing everything- optic plugs one end, and an end cap for the other end, witht battery/drivers/emitter/switches in the middle.

Not sure if I can ever make this light a reality, but coupled with an R2 to helmet mount in a similar design with a narrower optic (6 deg?) would be pretty awesome


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## ifor powell (Jun 3, 2008)

WeLight said:


> Im thinking like this


 
I don't realy see how you could make this work... You need some way of opening the 4p conections when you want to use 4s and vice versa you can not have both connected at the same time, if you do what you have is a short with no die at all...

The best you could do to be flexible with 4 pads would be 2 * 2S which would be striaght forward to use as is or as 4S or 2S2P


Sorry Jarl I could not do all the options in the poll as well as adress the board style bit. I had never even considered your 1S 3S or znomits 1S 3P but I suspect you would have trouble getting someone to do a board that style. Of course the raw led or a 4 independent board will keep you both happy which is one of the cool things about this over the P7....

Personaly I am keenly waiting to see what optics become avalible. I still have not found anything online althiugh the original press release indicated that some were on show at the show...

Ifor


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## Tekno_Cowboy (Jun 4, 2008)

4 independent would allow you to wire it in any combination you want :twothumbs


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## 2xTrinity (Jun 4, 2008)

IF this is going to be mounted on a star or board, it woudl be a crime to not have separate pads to allow the user to determine wiring, as soldering EIGHT separate leads on an emitter the size of an XR-E would be a major PITA.


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## longleg (Jun 5, 2008)

2xTrinity said:


> IF this is going to be mounted on a star or board, it woudl be a crime to not have separate pads to allow the user to determine wiring, as soldering EIGHT separate leads on an emitter the size of an XR-E would be a major PITA.


 
Hear, hear! 
I gave up soldering a regular XR-E emitter, so I can just imagine how it would be like soldering an MC-E emitter..


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## ifor powell (Jun 5, 2008)

I have to agree about soldering the raw emiter, it will be beyond my skill...

On a board with 8 pads the order of the pads for hand wiring is an issue. For the raw emiter wiring in series you would have to keep going from the one side to the other as all the anodes are on one side and all the cathodes on the other. I would not want to have somthing like this on a board there would be wire everywhere...

I wounder if it would be possible to do somthing with multiple configuratuions avalible via being able to cut tracks just to leave the one you want? Is theat what you meant WeLight?

Ifor


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## Bimmerboy (Jun 5, 2008)

I was going to add my bit of pessimism here last night, decided not to, and have decided to again.

In trying to think through various scenarios other than 4P, I see nothing but highly increased cost factors in a number of areas, and/or undue complexity with even a single MC-E. One obstacle among many, is PCB layout ideas that won't work, and the ones that do work will likely be larger than we're used to.

All in all, I believe (but will welcome being shown wrong) that if one wants to keep costs down, you're gonna' have to break out the solder paste, fine chisel-tip irons, and deal with a crapload of skinny, little wires running all over the place.

In other words, creative DIY solutions that won't be for the faint of heart, _especially_ with tubular shaped flashlight mods.

Got a couple ideas for multi quad-emitter builds myself, and the biggest advantage of this thing I see for most people in the practical sense, is I suspect the base is electrically isolated (not mentioned in the datasheet). At least we won't have to worry about anodized heatsinks, or overly thick layers of AA.

All that being said, I hope some wild stuff starts appearing in both mods, and production lights, because the MC-E really does open up new possibilities.


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## FredM (Jun 5, 2008)

I would like to do 2S2P then I could run it at 7.2 volts with 6AA in a 2D mag.

Around 1.5 amps should give over 1 hour runtime!


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## IMSabbel (Jun 7, 2008)

Bimmerboy said:


> In trying to think through various scenarios other than 4P, I see nothing but highly increased cost factors in a number of areas, and/or undue complexity with even a single MC-E. One obstacle among many, is PCB layout ideas that won't work, and the ones that do work will likely be larger than we're used to.


I am sure you mean 4S, right?
Because 4P is the worst of both worlds...


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## rizky_p (Jun 7, 2008)

i am wondering how hard/easy it would be to solder all externals connector to each LEDs in order to configure the connection.


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## Bimmerboy (Jun 11, 2008)

IMSabbel said:


> I am sure you mean 4S, right?
> Because 4P is the worst of both worlds...



I did, in fact, mean 4P. Reason being that it provides the easiest, and/or cheapest means to an end.

It's been said for a long time now, at least since the Lux V days, that parallel emitters are bad, bad, bad. But is that really so? I mean, I don't remember hearing about everyone's Lux V lights all going up in smoke. Sure, there were some instances of dice being mismatched enough to cause noticeable degredation, but I think that has been the exception rather than the rule.

Seems to be a similar story _so far_ with the P7. I've not yet seen any mention of this sort of problem. Of course, more time will provide better data. 

So long as multi-die emitters continue to perform well in 4P over time, then my plans for an upcoming multiple multi-die mod running as few batteries as possible, will remain unchanged.


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## Jonster (Sep 16, 2009)

jtr1962 said:


> 4 independant is the best way so the end user can choose the configuration best suiting their application. 4S is the next best way as there are no inherent disadvantages as with 4P or 2S2P.



At the risk of resurfacing an old thread ...
Can anyone enlighten me as to what the disadvantages of 4P or 2S2P are?
Cheers,


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## Dexter (Dec 13, 2009)

I would also love to know what the differences are betwen 4s and 4p (and which one I should buy to put in a 4d maglite)


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## Jonster (Dec 13, 2009)

Dexter said:


> I would also love to know what the differences are betwen 4s and 4p (and which one I should buy to put in a 4d maglite)



I've ended up choosing 4P for my build ... I'm then wiring two of these stars in series so in effect I'll end up with 4P2S.

From ongoing research I believe the theoretical problem of wiring 4P is due to the total available current being divided between the four dies. So if the Vf of one die is higher or lower than the other three it will draw more or less power.
This can cause one of the dies to be brighter or dimmer than the others (however they are all so tightly packaged that you might not notice).
Also it can cause one of the dies to be hotter than the others (however ... again they are so tightly packaged that the heat will be shared and actually an increase in heat in the other three dies would reduce the resistance in them and increase the current draw thereby having a small effect of "balancing" the dies).
That said ... I understand the 'binning' of MC-E's is so close that in reality you don't see the effects of what I've mentioned.
BUT, BUT, BUT ...I know its all basic maths so if anyone out there could confirm, deny or shed a little more light on this that would be cool ... hey after all I'm a mechanical not an electrical engineer

Another thought is that the SSC P7 is only available in 4P config. So if your design could be flexible enough to swap this in instead of the CREE MC-E then you have more choice for future repairs and replacements.
I've noticed some European sites considerably dropping the price of the MC-E of late so this remains a fav' for me.

The advantage of 4P (over 4S or 2S2P) is that the battery voltage can be kept down and gives you more choice for your power supply.

Regarding you Maglite issue ... in simple terms go for 4P!
If you have a 4D then I assume your total supply voltage will be 6V fully charged and 4.8V when 'stable'.
So just to light all dies (ie ignoring efficiencies and drivers) ...
Running 4S you would need around 13.6V so no go.
Running 2S2P you would need around 6.9V so still short.
Running 4P you would need 3.4V which leaves you with at least 1.4V spare.
On top of the LED you must remember to add (upto) 1V to run a driver and another 10-20% for efficiency of the 'system'.
So you'll be supplying 4.8-6V and using upto 5.2 ish.

To 'do the maths' check out http://pct.cree.com/ as they have a calculator to see the differences between the LEDS. Just remember to add efficiencies and driver Vf in!

Phew ... sorry for the little essay but hope it helps and makes sense ... if it doesn't please correct me!!!!:thumbsup:


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## Dexter (Dec 14, 2009)

Nice work Jonster, your reply has been a big help! thats exactly the information I was hoping for and I have spent ages on google trying to find it. Thanks for your time, I'm off to pick up a 4p and a HIPFLEX Microcontroller to run it (anyone got any comments on the controller)

now, how do I power it? I have a 4D, can anyone suggest a good rechargable alternatvie to alkaline, that will give me enough power and a good run time?

Thanks again Jonster, I'm one step closer


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## Jonster (Dec 14, 2009)

Dexter said:


> Thanks again Jonster, I'm one step closer



No probs - I've had loads of help off friendly people on here so its great to share the love!!!

HPIFLEX is what I'm also going for. Seems a great reliable starter for a newbie!!

On batteries for my application I'm going to use 6 lithium ion ''18650'' batteries from DX ... I'm not sure if 3 of these would fit together in the space of D Cell.
If so you would get 12 in total and could get a phenomenal run time!!!
You could ask around and see if anyone has done a maglite mod with these.
The battery I have plumped for is here ... http://www.dealextreme.com/details.dx/sku.20392
These are ''protected'' and you can also get a charger from DX.
There are lots of precautions to take with Lithium Ions mind. You'll find plenty of stories of overcharging that has caused fires and explosions ... basically I get the feeling that you have to treat these with a lot of TLC!!!


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