# Anything other than an XM-L for a flood light?



## Mattaus (Apr 12, 2011)

Hi all,


I'm new to this whole game so please be patient.


I'll cut to the chase and just ask those in the know: are there any alternatives to the XM-L LEDs for use in flood lights? I realise that XM-L LEDs appear to be the 'best' at the moment, but there are so many LEDs out there floating around at half the price that surely one of them will be a decent 2nd choice?


I'm building a 4 emitter flood light. The brighter the better obviously. I'm using the following driver (http://www.dealextreme.com/p/18v-5w-cree-circuit-board-for-flashlights-16-8mm-5-5mm-26110) to run 2 LEDs in series, with two of these setups in parallel forming one flood light. The setup will then be connected to a deep cycle battery.


If a different driver is required as a result of using a different LED that is fine, but a total current draw up 3A or less is desirable.


If nothing is even close to being suitable I'll go with the XM-Ls.


Any guidance or insight would be greatly appreciated.


Cheers,


- Matt.


----------



## calipsoii (Apr 12, 2011)

Cree's not the only game in town. Check out the Luminus SST-90. With proper heatsinking they're rated to 2200lm. The die on these LED's is larger than the XM-L (giving it much more flood) and since they've been out for a few years now, they're available in pretty much any tint you could want. Nailbender made me a dropin with an SST-90 3000k color temperature that does about 550 lumens out-the-front driven at 2.8 amps.


----------



## Mattaus (Apr 13, 2011)

The SST-90 seem expensive ($30+) and at 2.8A I can run several smaller LED's and get over 1000Lumen. If my understanding of how it all works is correct?

How about 4 of these: http://www.dealextreme.com/p/cree-xp-g-r51b-7000k-350lm-emitter-with-16mm-base-44306. Driven at 1.2A they could put out around 380Lumen each.

Or alternatively 6 of these (http://www.dealextreme.com/p/cree-xr-e-q5-emitter-on-premium-star-228lm-at-1a-2394) driven at 1A would give me around 1400 Lumen total?

Either of these 'solutions' appear to still give approximately the same output strength as the 4 XM-Ls but at close to half the cost. What am I missing here?!?!


----------



## hellokitty[hk] (Apr 13, 2011)

Those XR-E's are Q5 binned, they're about 28% less efficient than R5s and T6s. Also, they are most certainly not flood lights.
Your not driving the XM-L's hard enough; if they were driven at 3A each, there is no way an array of less than 6+ XP-G's are going to be able to keep up.
If you modify DX SKU 20330, you can get 3A output and four XM-L's in series.
Though since your saying 3A or less, then there is no point in using four XM-L's.


----------



## Mattaus (Apr 13, 2011)

Ok but what about the XP-G's I have listed above? Same story I guess?

Maybe one option would be to run that driver you have listed with 2 XML-T6 in series with the driver providing 2.4A. This should give about 1600 Lumens output apparently...though I should point out this light needs to run on a 12V deep cycle battery. For that to work I'd have to hook a diode (or 2) up in series with the battery to drop the voltage down to the required 8.4V. My understanding of this concept is loose so I may have to ask around to confirm :-/


----------



## sn0wBLiND (Apr 13, 2011)

XR-E and XP-G would be easier to drive than XM-Ls but I don't think you will save any money by using them.
LCK-led has a sale on T6 flux 1A tint XM-Ls, $6 each.
Also have you considered using bridgelux leds?


----------



## Mattaus (Apr 13, 2011)

sn0wBLiND said:


> Also have you considered using bridgelux leds?



Totally. What are bridgelux leds lol? Seriously is it a brand or a type?

I signed up with LCK-led and just bought several T6's. Damn sales...so I guess that's that sorted haha! Just need to decide how I best drive them. I'll probably go with 2 in series with the driver hellokitty suggested (with a diode on the battery line to drop the voltage below 8.4V), and if that is not bright enough I can hook 2 sets in series and they'll share the 12V input so won't go over the 8.4V input limit.

If that is even the right way to think about it.


----------



## evilc66 (Apr 13, 2011)

www.bridgelux.com

Great LEDs, with good color rendering, and high quality, although not as efficient as the latest and greatest Crees. But, you can get a single emitter (multi-die) 8800lm cool white LED from them


----------



## Mattaus (Apr 13, 2011)

Having just bought the T6's I'll have to keep bridgelux LEDs in mind for next time :-(


----------



## videoman (Apr 13, 2011)

The DX 26110 driver puts out 1.2A , 2 leds in series will still have 1.2 A going through them, really underdriving the Xm-l's by a wide margin. Like driving a ferrari under 65. You really want lots of output from 4 leds with a floody beam ? Try using 4 XM-L's 2S2P driven by taskled's 6A driver H6CC I beleive, put carclo 70 degree reflectors ( 10170 I think) on them, Made for the MC-E but works fine with the XM-L, and whoa, you're looking at somewhere like 6K luxes to brighten things up a lot. I would drive them at around 75% full throttle for better heat management/efficiency and drawing around 3-4 A from the batt. Nice thing about that driver is that it is dimmible ready.


----------



## hellokitty[hk] (Apr 13, 2011)

I do not think diodes reduce voltage.
The vin of the driver I mentioned can be increased by replacing the capacitor.


----------



## Mattaus (Apr 13, 2011)

I shied away from the H6CC driver in my flood light thread already because I couldnt bring myself to spend $32 on one driver. I still feel much the same way despite getting the XM-Ls for $6 each. Surely Task-LED are not the only mod who make high power drivers?


----------



## Mattaus (Apr 13, 2011)

hellokitty[hk] said:


> I do not think diodes reduce voltage.
> The vin of the driver I mentioned can be increased by replacing the capacitor.


 
Yeah I saw that in one of the reviews but I can't quite follow the maths he's used to determine it. It's probably not complicated but I can't understand it the way he's written it :-(

Be good to clarify though because if that is easy enough to do (my sodlering skills are better than average) then that's the ticket for sure.

EDIT: Sorry...the guy's maths just clicked. Replace the capacitor with a 10mF one and the unit will work with any Vin up to 16V. That cap is nice and big as well so it'll be a piece of cake top replace.


----------



## Mattaus (Apr 14, 2011)

This is possibly a stupid question, but what's the limit on the number of LEDs I can run off one of these drivers? Is it dependent on the voltage of the system? In my mind duh2 a 12V system would mean I should be able to run 4 XM-L LEDs (3V each) off the one driver while a 9V system could only run 3 and so on. Or is this a fundamentally flawed idea?

:thinking:

The reason I ask is because it would seem doing this would allow me to run 4 XM-Ls at 2.8A at 12V. However, if I can only run 2 XM-Ls off 1 driver, then 4 LEDs would require 2 drivers and thus pull 4.8A at 12V. Obviously less current draw is better...

I'm thinking about this too much today. Might be a good time for a break!


----------



## hellokitty[hk] (Apr 14, 2011)

The vf is not <3v except at very low levels, so no it won't work.



Mattaus said:


> The reason I ask is because it would seem doing this would allow me to run 4 XM-Ls at 2.8A at 12V. However, if I can only run 2 XM-Ls off 1 driver, then 4 LEDs would require 2 drivers and thus pull 4.8A at 12V. Obviously less current draw is better...


If you're saying that 4 XM-Ls2s2p @4.8a per series circuit (2.8a each) at 12v is equivalent to 4 XM-Ls in series @2.8a and 12v, then you're doing it wrong. It sounds like you're saying that you can get the same output for half the power just by using one driver instead of two, which is not true. 
Now firstly, 2.8*2 is 5.6. 

If you use two drivers in parallel with your power source, powering two XM-L's in series each, then you'll be drawing 2.8a per driver and 2*vf, so each XM-L will receive 2.8a and will consume ≈ 6.2v - 7v per pair.
If you use one driver and 4 XM-Ls in parallel, then each LED will also be getting 2.8a and the proper vf, but the driver will be outputting ≈12.4v - 14v. 
Both scenarios multiply to the same wattage, so now we're not randomly pulling half as much energy for the same output.

That driver is a buck, so you vin will need to be at least a couple volts higher than the output voltage, and it will most likely run more efficiently with a higher vin. 

Remember that in both of these calculations we are not factoring in the temperature coefficient of the XM-L, which is -3mv/°C, or resistance in wires ect...careful with battery vdroop too if you're using a battery.


----------



## Mattaus (Apr 14, 2011)

hellokitty[hk] said:


> Now firstly, 2.8*2 is 5.6.



Haha! Fail.  

In my defense I have been looking at a few drivers today all with different voltages/currents etc so probably got them mixed up. I can multiply that is for sure...at least in my line of work I'd hope so.

Most of everything else you've written makes total sense. 3 XM-Ls in parallel with 1 driver could be a good compromise - 2.8A at 9.3-10.5 volts gives a 26-30W system and sits nicely between the two solutions. Leaves some room in the battery/other losses etc - though is it enough or too close?

Voltage drop shouldn't be too much of a concern as the deep cycle battery I need to use indicates when it is at 50% capacity and needs a recharge. Not totally sure how the temp coeff changes things but I'd imagine that it's to do with an increase in voltage as the LED gets hotter. I'll google that.


----------



## videoman (Apr 14, 2011)

A little bit of basic electronics here would help you understand 3 most important formulas. The good ol' ohm's law that V=IR and P = VI . Now you can interpolate them as you will like I=V/R or I=P/V. Also to remember is that when resistances (or leds for that matter) are paralelled, each led gets 50% of the total current applied. ( considering that the leds are the same spec'd resistance values). When leds are series connected, each gets the SAME current through them (again considering all the leds used are theoretically identical). Now, when one is using 4 identical leds of 2 series strings connected in parallel, say you have 3 amps as the feed, that 3 amps gets split in two for 1.5 amps for each series string so that each led gets fed 1.5 amps. If you are using a battery of 12 Volts DC, (car battery, deep cycle, motorcycle battery, or any good 12 Volt dc source that can give out a healthy 4 amps of current without droop ( voltage drop when applied to load), then you can easily string 3 leds in series ( if the leds are around 3 volt rated, usually 3.2-3.4) or 2 leds in series so that the driver ( if it is a buck design) will 
be able to buck that 12 volt to the voltage level that the leds require WITHOUT going over their max rated voltage. It does so by having a constant current going through each led as specified by the driver design. If your driver is rated at 6 amps out, then you cannot just put 3 leds in series that only accept a maximum of 1.5 amps each. That will let each led take in 6 amps and in no time will burn them out.If you have a 3 amp driver, even that will burn out the series string UNLESS 1- you put 2 SERIES STRINGS IN PARALLEL to HALVE that 3 amps to 1.5 so that each led will receive the maximum without burning up. If you have a 6 amp driver, now you can put 4 series strings and have each string with 1.5 amps OR take the XM-L led that can handle 3 amps and connect 2 strings with 3 amps each. Reducing the amount of leds has advantages. Fewer leds mean fewer lenses/reflectors, less soldering, less adhesive potting, less overall cost. I heard it before that 2 XP-G's are equal to 1 XL-M , or very close. So let's take an example of using 4 XM-l's ( 2S2P configuration) with a 3 amp driver, you have 1.5 a through each led (underdriving them) Nice and cool running at that, with around 450 lumens each ( I could be a little off on this one) depending on the bin. You could also get that kind of figure using 4 XP-G's instead, but you will be maxing them out. Not a problem . Let's say you have a large enclosure with excellent heatsinking and ou really want to up the lumens.Then you go for the big guns (XM-L's and feed them a steady diet of 3A each with a 6 A driver.) Put 2 series strings of 3 each paralelled. Now look at that figure of around 750 lumens X 6 = 4500. Add reflectors on those and you get what I'm talkin' about.


----------



## videoman (Apr 14, 2011)

Mattaus said:


> Haha! Fail.
> 
> In my defense I have been looking at a few drivers today all with different voltages/currents etc so probably got them mixed up. I can multiply that is for sure...at least in my line of work I'd hope so.
> 
> ...



Driving 3 XM-L's in parallel at 2.8A to them really means you are driving each at 933 milliamp if your driver Iout is 2.8A. Not really the best solution as you can just drive 1 let at full pop (2.8 A)for around the same lumens. To drive 3 XM-L's in parallel at 2.8A each is only possible if your driver is 2.8 X 3 = 8.4A. Perhaps you meant 3 leds IN SERIES, now that would make sense.


----------



## Mattaus (Apr 14, 2011)

videoman said:


> Perhaps you meant 3 leds IN SERIES, now that would make sense.


 
That's exactly what I meant...I just described it very poorly. I'm losing my way it seems lol. Assuming I said 'series', arethe 3 XM-Ls in series with 1 driver an OK bet? Lets imagine I have not done anything dumb (again) this would provide each LED with 2.8A and require 9.3-10.5 volts from the driver.

Maybe I should just stick with 2 LEDs to keep it simple...

For the record I'm still digesting your last post. I have seriously copied it to a word file and am in the process of putting in my own terms (ie// dumbing it down), though this pesky thing called 'work' is slowing my progress.


----------



## Starlight (Apr 15, 2011)

You really need to look at this thread. You can run 3 XM-L's with 12v input and a cheap driver. http://www.candlepowerforums.com/vb/showthread.php?201392-Poorman-Mutli-Lux-setup-method


----------



## Mattaus (Apr 15, 2011)

Starlight said:


> You really need to look at this thread. You can run 3 XM-L's with 12v input and a cheap driver. http://www.candlepowerforums.com/vb/showthread.php?201392-Poorman-Mutli-Lux-setup-method


 
I could be wrong but this seems more complicated than what I was going to try with the DX SKU 20330 drivers....even after replacing the capacitors. And no one has been able to confirm it but I can't see why 3 XM-Ls in series with this modified driver would _not _work. Guess I'll have to experiment and hope I don't destroy anything.


----------



## Starlight (Apr 15, 2011)

Read the whole thread and you will see why it works. Basically you are using two LEDs as resistors to drop the voltage to the regulator. The regulator then works as a linear current limiter for the last LED. Since current is constant in the circuit, all the LEDs see the same current. Viola, 3 XM-Ls run off 12v and an under $10 2.8A driver. Mr Happy vouches for the schematic, and that should be good enough for anyone on CPF.


----------



## Mattaus (Apr 15, 2011)

Oh I see it now...thanks for the quick explanation. I'm a little lost though in that all the 7135 drivers on DX (haven't had a chance to look elsewhere yet) are 1000mA max. Is this what he is referring to when he stats 8x7135 - as in 8 of these little drivers? So if I wanted a 3A circuit I'd need 3x7135?

Forgive my ignorance but it really seems like using the 20330 driver is the simpler solution - even after having to replace the capacitor?? Please remember I'm new here so things that appear to be second nature to you I am struggling with :-\ (though catching on quickly I hope lol)


----------



## Starlight (Apr 15, 2011)

Shingbeam at http://www.shiningbeam.com/servlet/StoreFront

This driver http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail 

$6.75


----------



## Mattaus (Apr 15, 2011)

Starlight said:


> Shingbeam at http://www.shiningbeam.com/servlet/StoreFront
> 
> This driver http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail
> 
> $6.75



Bugger....could have used this as per the diagrams you mentioned earlier. One in series with 2 XM-Ls and then 1 XM-L off the driver itself (as this would drop the Vin down to 6V for the driver. Might buy one anyway to see how it runs.


----------



## Starlight (Apr 15, 2011)

One caveat; read the part of the thread about possibly needing an additional resistor inline with the 2 LEDs. It will depend on the vf's of the LEDs that you use. You would like to keep input voltage to the driver at the low end of it's stated voltage range.


----------



## Mattaus (Apr 15, 2011)

Starlight said:


> One caveat; read the part of the thread about possibly needing an additional resistor inline with the 2 LEDs. It will depend on the vf's of the LEDs that you use. You would like to keep input voltage to the driver at the low end of it's stated voltage range.


 
Duly noted. I will read through the thread when I get a chance. I'm on the road at the moment and only have my phone for internet access. Replying to threads is easy but reading large amounts of text with nice big diagrams is still sadly hard to do on anything smaller than 11" IMO.


----------



## videoman (Apr 15, 2011)

I'm getting a little confused myself. What is your target lumen output that you are looking for ? That way I or others can suggest the best possible way to achieve it. Also, what kind/size/material will the enclosure be, and how many leds are you looking to use. On your original post you said 4 emitters, so I am imagining that would be a good starting point. You also asked "anything other than an XM-L". Yes, definitely there are many others than XM-L's. The XM-L being what it is, is a tough act to beat. Just look at the specs. You will not find anything more efficient for lumens per watt BUT many others are close but no cigar. The XP-G runs a very close 2nd, but you will need 2 of them to be equivalent to an XL-M. Let us assume using 4 leds for the project as you wished. Either 4 XP-G's or 4 XL-M's. XP-G's max out at 1.5 amps through each whereas XL-M's are 3 amps. OK, OK, you can feed more but there is a point of diminishing returns so let's stick with the given specs or else this will never end. On the cheap, go with 4 xp-g's and 2 DX 1.99 drivers (26110) each driver puts out 1.2 A . with 2 seried XP-G's. You also have a nice 5 ish volt headroom to boot. You can easily add another XP-G to each string and still be able to drive it with 12V in. Using 4 XM-L's with the same setup is really underpowering them and will add to the overall cost , unless you wish to drive them with 2- 2.8 A drivers, then so be it and up goes the lumens along with the heat. Can your heat sinked enclosure handle 4 XM-L's at 2.8 A each ? That's around 40 watts. If your enclosure can handle that, then you will have a very bright light.


----------



## Mattaus (Apr 16, 2011)

OK...let's clarify shall we?

This heat sink is being used: http://cgi.ebay.com.au/ws/eBayISAPI...31595&ssPageName=STRK:MEWAX:IT#ht_2212wt_1139.

The LEDs and driver MUST all fit on the flat face of the heat sink. This way I can add a simple aluminium enclosure (bolted top and bottom, with the bulk of the heat sink fins exposed) with a nice plexi-glass or similar face.

The whole purpose of this light is to run off a deep cycle battery. Overall current draw is to be as small as possible. I have NO desired light output other than "as bright as possible". 3A MAX seems to be the sweet spot in terms of current draw but lower is obviously more preferable. See this post for the whole reason behind this: http://www.candlepowerforums.com/vb/showthread.php?312129-Snowboarding-at-night...

I have already purchased 4 XM-L T6's and 2 of the 20330 drivers, so it is preferable that I do something with these first. I was going to replace the capacitors on the 20330 drivers with 10mF caps (which I have also already purchased) so that I could run the driver off a 12V battery. Further more I have some reflectors to help narrow the beams a little (still floody) and increase out put.

HOWEVER I am now wondering why I can't use the 20330 drivers as per the diagrams that Starlight pointed to earlier (thus negating the need to replace the caps). An example circuit would be:

Battery(+) *>* Switch *>* XML *>* XML *>* 20330(in) *>* XML *>* 20330(out) *>* battery(-)

Seen as the 2 XMLs between the battery and Driver will drop the 12V down to approx. 6V, this would drop the circuit voltage at the driver below the drivers required input (8.4V). The Driver then dictates the circuit current. No resistor would be required anywhere as the voltage drop before the driver is already over 2V lower than the maximum allowed voltage. Therefore I have a 3 XM-L circuit running at 2.8A and approx. 9V.

Someone please tell me this would work because I keep thinking I've got it and then I get told otherwise :fail:

EDIT: Checking with Visio I can easily fit 2 XM-Ls and one 20330 driver on the face of the heat sink. 3 XM-Ls and one 20330 will also fit but not symmetrically. I guess if it's bright enough 2 XM-Ls would be preferable because then I can make 2 separate lights from the materials I already have.


----------



## videoman (Apr 16, 2011)

Now I see what you are after. Night time LARGE AREA illumination. Now that should have been mentioned on your original post. Anyway for what you have on hand and intend to do:
That heat sink is way too small for 2 XM-L-s. Unless there is a steady wind and the fins are exposed to it, it will get mighty hot and the driver will most likely shut down if it has thermal protection in it. However, I may be wrong if the ambient temperature is low enough. Them leds are very bright but I really don't think they will light up adequately for your intended purpose of a large area illumination. Also the driver you have is really not practical with the modifications to run it off a 12 v source .I videotape weddings and the dance areas are large and dim. As an example, the area measures 75 feet long X 40 feet wide ( big party wedding). I had to use 2- 500 halogens on AC on both ends, and that was the bare minimum for adequate visual recognition. My honest suggestion will cost you a bit more. I really see 4 units with a larger heat sink, at least 6 XM-L's per unit with 2 proper drivers per unit. Even if your driver is used with the 4 XM-L's you have,you'll get only around 3500 lumens at best an can only hope to gain more at the expense of reflectors and narrowed down beam angle. With a single light you will get a directional source that is bright near the unit and will gradually get darker (very dark) at the far end of 30 meters . Not the best idea.You're talking 30 meters long, that's like 100 feet, WOW.Lighting that will need at least 4 big units drawing around 50 watts each. On a single battery ? That ain't gonna happen. What you are trying to do is make a silk purse with a pig's ear.


----------



## srfreddy (Apr 16, 2011)

You want optics, maybe frosted medium? But yeah, there's no way you're gonna be able to put 2 XML's on one of those heatsinks- you are going to want to use one per, and lap both the heatsink and the stars, and screw the stars down. One driver per LED, 4 sets in an enclosure, and maybe 3 enclosures, with 2 batteries per?


----------



## MikeAusC (Apr 16, 2011)

Mattaus said:


> This is possibly a stupid question, but what's the limit on the number of LEDs I can run off one of these drivers? Is it dependent on the voltage of the system? In my mind duh2 a 12V system would mean I should be able to run 4 XM-L LEDs (3V each) off the one driver while a 9V system could only run 3 and so on. Or is this a fundamentally flawed idea?
> 
> :thinking:
> 
> ...


 
Hi Matt

At 2.8 amp my XM-L drops 3.3 volts, so 3 of them would need 9.9 volts. 

If you're going to run the battery until it's output and wiring voltage drop is 11.5 volts, you need a driver that can work with 1.6 volts.


----------



## MikeAusC (Apr 16, 2011)

Mattaus said:


> HOWEVER I am now wondering why I can't use the 20330 drivers as per the diagrams that Starlight pointed to earlier (thus negating the need to replace the caps). An example circuit would be:
> 
> Battery(+) *>* Switch *>* XML *>* XML *>* 20330(in) *>* XML *>* 20330(out) *>* battery(-)
> 
> ...



Because the 20330 is a switchmode driver - power out = power in x efficiency. Input current might be HALF the output current.

7135 is a Linear Driver - input current ALWAYS equals output current.

If you're going to drive 3 XM-Ls from a 12 volt battery not on charge, a Linear driver will be better because it can cope with the low voltage drop needed. The efficiency here won't be much different to using Switchmode Regulator.


----------



## srfreddy (Apr 16, 2011)

MikeAusC said:


> Because the 20330 is a switchmode driver - power out = power in x efficiency. Input current might be HALF the output current.
> 
> 7135 is a Linear Driver - input current ALWAYS equals output current.
> 
> If you're going to drive 3 XM-Ls from a 12 volt battery not on charge, a Linear driver will be better because it can cope with the low voltage drop needed. The efficiency here won't be much different to using Switchmode Regulator.


 
Eh....no....because than you would be inputing 12v and say 9 amps, and outputing 3.3 volts and 9 amps......with the linear regulator. That driver will buck the voltage down, so use the voltage to increase current.


----------



## MikeAusC (Apr 16, 2011)

Mattaus said:


> . . . . . are there any alternatives to the XM-L LEDs for use in flood lights? I realise that XM-L LEDs appear to be the 'best' at the moment, but there are so many LEDs out there floating around at half the price that surely one of them will be a decent 2nd choice? . . . .


 
ANY of the modern power LEDs will work well for flloodlights - MC-E, SSC-P7, SST90, SST50, XP-G, etc - they all have virtually identical illumination angle. 

The XR-E has a narrower angle - but it still works well as Flood - it depends on what your idea is of flood angle !

The latest LEDS - XP-G, XM-L - are more efficient than the others.


----------



## videoman (Apr 16, 2011)

A quick and rough calculation. For 100 feet length area to illuminate, considering total darkness, 4 units placed at 25 ft. intervals ( 0-25-50-75-100) each with around 5000 lumens and take up approximately 60 watts of power from the batt. and be equivalent to around a 300 watt incandescent bulb. ( that figure is based on my calculation of minimal illumination needed). Now 60 watts X 4 units = 240 watts draw. 240 watts divide by 12 volts = 20 amp draw per hour from battery. If your battery is rated at say 100 amp/hour, then you can run them for 5 hours. You need to run them for 6 days at 3 hours a day, or 18 hours, so you will need 360 amp hours total. (18 hours X 20 amps)
You will need either to recharge battery after each session ( considering you have a 100 amp/hr battery).Or have multiple batteries pre-charged.
There are also other factors to consider such as power losses from wiring distances which dictates thick gauge wiring for minimal DC voltage loss to the drivers from the battery. You will be stringing considerable wiring.That voltage from the battery may not be quite 12 volts when it hits the drivers. 
One quick question, perhaps silly, Why don't you snowboard during daylight hours ?


----------



## Mattaus (Apr 16, 2011)

:sigh: I feel like I'm getting no where and it's my fault because for some reason or another I can't make use of, or can't afford, everyone's perfectly reasonable solutions.

I replied to the last post on page one before I realised there was a second page now...



> One quick question, perhaps silly, Why don't you snowboard during daylight hours ?



We are - in the resort bounds. After we get back to our site at night the urge to ride won't have died down (we get to go rarely), and it's something to do. Night riding in and around our tent, and indeed camping above the snow line, is a pretty attractive prospect to us for some reason. However I'm getting to the point where I'm thinking I should just admit defeat. Except now I have 4 XM-L T6's, 2 20330 drivers, a large pot of thermal glue, 4 reflectors, a heat sink and a few pieces of aluminium - and nothing to make.

Maybe I should go back to basics. Not sure if I should start a new thread or not because this has become very convoluted. 

I feel, and I could be wrong, that 3 or 4 lights like these would be sufficient to illuminate the area we desire: http://www.litestorm.com.au/xtreme/ls24x.htm (24W @ 12V producing 1600 Lumens)


How would I go about reproducing that performance (light and power draw) for less than they sell for?
Is anything I have bought even remotely useful?
How big a heat sink should I use for 2 XM-Ls? 
Would a CPU heatsink and fan combo be large enough?
Would the small heat sink I've already ordered even be useful for one 20330/XM-L combo?
Why are the 20330 drivers, modified with the new Capacitor, not practical off a 12V source?

We will have some way to recharge the battery, I will keep cable lengths down (the battery will be attached to the light mast), and we will probably not run it 3hrs a night 6 nights straight - that is hopefully a worst case scenario. Always over spec!

Opinion time: should I just give up on this idea because it appears to be not really practical?

:mecry:

P.S: We only need to light the jump and landing area. The area surrounding these will not get full light, but I'm sure enough light would leak so as to allow us to see a tree...


----------



## videoman (Apr 17, 2011)

1600 lumens and $250 each ? ouch !! looks mighty bright in the photo but photos are deceiving at times. I know what 1600 lumens are like and even 4 of them still won't light up the intended area coverage quite well. Hate to sound negative here, but hey, I would really try one out firsthand before shelling out a grand for 4 units. I thought you guys are on a tight budget for this. To build something of it's equal is easy. Just use 2 XM-L's on 20mm stars with medium beam reflectors like 40 degrees and string them in series for 2.8a each. With the reflectors you will get over 1600 lumens, perhaps 2200 or more. If getting a driver for that is difficult, you can always use 4 XP-G's with 2 DX's 26110 per enclosure and get just about the same output. Make sure you get a proper heat sink. Just goes to prove what only 2 XL-M's can do. That pictured unit has to use 8 leds Ha ! Ha !


----------



## Mattaus (Apr 17, 2011)

I might have updated my post since you replied. I should stress we WILL NOT be purchasing those lights - we are indeed on a tight budget. All I'm saying is that they are what we would like to replicate.

I have the XMLs (although on 16mm boards) and the 20330 drivers and I'd like to use these if _*at all*_ possible.

Can you expand on why you feel the 20330 driver modified with a larger capacitor is not appropriate for a 12V system? Because if I can use them then all I need is a decent heat sink!


----------



## videoman (Apr 17, 2011)

http://www.dealextreme.com/p/6-18v-3000ma-3-mode-circuit-board-for-xm-lt60-emitters-57779?r=85749907

Have you seen this one ?? Perhaps anyone has had experiences with this driver, Seems good !


----------



## MikeAusC (Apr 17, 2011)

srfreddy said:


> Eh....no....because than you would be inputing 12v and say 9 amps, and outputing 3.3 volts and 9 amps......with the linear regulator. That driver will buck the voltage down, so use the voltage to increase current.



If you have 12 volts available, why would you put three LEDs in PARALLEL ??? You're just going to have problems with current-sharing.

You're going to need a 9 amp driver instead of a 3 amp driver ! 

Using the stacking technique mentioned, you can drive 3 LEDs from 12 volts using the 7135 Linear Regulator, even though it's only rated at 6 volts.


----------



## Mattaus (Apr 17, 2011)

> http://www.dealextreme.com/p/6-18v-3...779?r=85749907
> 
> Have you seen this one ?? Perhaps anyone has had experiences with this driver, Seems good !



I'll be more than happy to be the first to try this. I guess I'd be able to hook 2 or even 3 XMLs in series with that driver?



> Using the stacking technique mentioned, you can drive 3 LEDs from 12 volts using the 7135 Linear Regulator, even though it's only rated at 6 volts.



Is that this: Battery(+) > Switch > XML > XML > 7135(in) > XML > 7135(out) > battery(-)? And if so is it ONE 7135 or 3 of them stacked in order to achieve 3A?

Although if the driver videoman found above is the goods I'm going with it. No point screwing around if it's not needed.


----------



## deadrx7conv (Apr 17, 2011)

http://www.candlepowerforums.com/vb...8-My-First-LED-project-outdoor-security-light
The above thread is a good read on homebuilt LED floodlight for driveway. 
Search egghead's other threads as he has built some other projects too. 

Shorelineimports(in Australia) has LED lights. I believe that their flood lights are about $105-$180 for 15w-24w LED, as does jagtrading(ebay store)... Too many 'brands' are marking up garbage chinasourced LED lights by 100-300% with fancy marketing, when you can get the same cheaper from other sources. 

Whats the budget? and is home-built needed or are you just wanting a project? 

Having a high-K low-CRI cool-white LED will light up an area. But, if you want to be able to see at night, you want the highest CRI LEDs available. I think that the bridgelux are 80+. I wouldn't consider any of those <70cri LEDs for 'playing' or 'working' at night. Don't want to be blinded by the light. HighCRI is the way to go. WarmWhite is next. Bridgelux, Sharp Zenigata, Edison Edistar/Edipower, Citizen CL... if available, should be considered.

You can also retrofit 300w or 500w halogen department store bought outdoor flood lights. Usually they are cast in aluminum and once you take it apart, you have room for the heatsink(which will assist the cast aluminum housing), drivers,....... and they come with reflector/glass/seals...

I'm using a simple 12v-50v 120w DC adjustable step-up power supply for one of my outdoor lights. It works great for the LED arrays that require >12v powered by deep cycle marine/RV batteries. I simple use my DMM's to set voltage and current to get the wattage that I need. For example:
http://cgi.ebay.com/120W-Adjustable...584?pt=LH_DefaultDomain_0&hash=item3366f352d8 

Also check out this forums other fixed lighting, bicycle, and automotive sections. 

This will give you some dimensions for a 30w light, and there are multiple ebayers selling equivalent in 30w and the bigger 50w sizes. Most are identical to what is available from alibaba.com or aliexpress.com or other internationally type of store/importer: 
http://www.satisled.com/30w-led-floodlight-purewarm-whiteredgreenblueyellow-wide-angle_p7.html

For power, if you don't want the lights to dim over the 3hrs of usage, and if you want the batteries to last, you'll want to multiple the wattage by 2x+ for the battery amphr capability. My 50w light uses 250ah battery for my abusive 12hr dusk/dawn habits. Your 3hr habit every day should be fine with a single 90-125ah battery for EACH 50w light. The bigger the battery, the more reserve you have in case of emergency and the less stress on the battery. Generator, wind, or solar charging ... are some choices.


----------



## videoman (Apr 17, 2011)

I mentioned that the 20330 driver is not PRACTICAL as you have to be sure that you can do that sort of modification and you have to be very good at soldering small areas and you have to be sure that the value of the capacitor is right. Or else you may render the driver useless or inoperable. As you are on tight budget, there is no room for experimentation that may cause you to purchase replacements. Where did you get info that changing to a higher value cap will do the trick ? I really don't mess around with drivers as I purchase what is on hand and tested good. Drivers in the 1 to 1.5A range are more easily found and available than drivers in the 2.8 to 5 A ones. I had a hard time myself locating a reliable 2.8A single mode buck that has a wide input dc voltage range. Only very few are available under $10 and extremely few with dimming option at around $30. If the driver I mentioned #57779 is proven good at $5, then it may not be worth your while with the modification. At that price, I would purchase a few spares. Also to take note is the underside of many drivers have contacts that can easily short out if touching directly to the heat sink.


----------



## hellokitty[hk] (Apr 17, 2011)

Firstly I'd like to say that you should continue with this project if you feel up to it! I think it's a great project and you'll be quite pleased if you get it to work.

We don't know anything about the capabilities of that new buck driver; I've heard that several members are currently awaiting their orders to arrive.

I hope you're learning that value of planning beforehand...I know you did sort of plan it out, but not that solidly.

Anyway, there are several different kinds of drivers.
The 8x7135 2.8A driver is a _linear driver_. That driver outputs constant, and gives a variable voltage that the LED is drawing at the current (which we can estimate to be ≈3.3v ish). Any excess voltage will be burned off as heat, and if that voltage is higher than 5v+, than your driver will get warm, higher than 6v and it will burn.

Let's explain the "poor man's setup" with this in mind.
In series, the amperage is always the same, so any current regulation that goes on will apply to all LEDs.
So first we have 12v into two LEDs, since the amperage will be 2.8, their vf will be about the aforementioned 3.3v. 12v in - 6.6v from the LEDs = 5.4, which is now an acceptable value to go into the driver. One you thing you must remember is that although batteries have a given nominal voltage rating, when fully charged, they may be higher.

The other driver that you got capacitors for is a _buck driver_.
What that does is "bucks" down the input voltage to something acceptable, and the usually have their highest efficiency when voltage in is much (like double maybe) higher than voltage out. They too are constant current, and will supply whatever variable voltage the LED needs. Since it bucks down the input voltage, the input voltage needs to be a good bit higher than the output voltage, and that's probably why people are saying it won't work; I actually haven't read through all of it.

Depending on the CPU cooler, it would be able to dissipate power from three XM-L's, but I don't think you can fit three?
Here is a picture of an XM-L on a 20mm star mounted on a rosewill low profile CPU cooler; ignore the white plate it won't be there if you happen to do this.
https://picasaweb.google.com/hfhfdjsk/ScienceFair#5576382568474715138
And here is one without the white plate, but it's on so it's hard to see.
https://picasaweb.google.com/hfhfdjsk/ScienceFair#5576386518803355586

Now if you want to use three CPU coolers, that would provide ample cooling assuming that you stick them on well with thermal epoxy, or drill screw holes even.


----------



## Mattaus (Apr 17, 2011)

> Whats the budget? and is home-built needed or are you just wanting a project?



No set budget (typical:ironic but basically the same power at a drastically lower price than the lights here: http://www.litestorm.com.au/xtreme/ls24x.htm

If I had to pick a number I'd say $80 or less. Home built is not needed but I'm a "tinkerer". I Love DIY.



> For power, if you don't want the lights to dim over the 3hrs of usage, and if you want the batteries to last, you'll want to multiple the wattage by 2x+ for the battery amphr capability. My 50w light uses 250ah battery for my abusive 12hr dusk/dawn habits. Your 3hr habit every day should be fine with a single 90-125ah battery for EACH 50w light. The bigger the battery, the more reserve you have in case of emergency and the less stress on the battery. Generator, wind, or solar charging ... are some choices.



Deep cycle batteries are so expensive. I might be curtailing our desired running time purely to keep the cost of the batteries down. This would all be so simple if we were allowed to use our d*mn generators.



> Firstly I'd like to say that you should continue with this project if you feel up to it! I think it's a great project and you'll be quite pleased if you get it to work.



I'm busy building a 3-phase axial flux electric motor from scratch. I am reasonably confident I can build a big flash light. I just seem to be getting very lost because there appears to be so many different ways to do the same thing!



> Let's explain the "poor man's setup" with this in mind.
> In series, the amperage is always the same, so any current regulation that goes on will apply to all LEDs.
> So first we have 12v into two LEDs, since the amperage will be 2.8, their vf will be about the aforementioned 3.3v. 12v in - 6.6v from the LEDs = 5.4, which is now an acceptable value to go into the driver. One you thing you must remember is that although batteries have a given nominal voltage rating, when fully charged, they may be higher.



I'm still lost as to *how many* of these linear drivers I need. Is my assumption that they get 'stacked' (placed in parallel to each other) to increase the output current correct? Come to think of it how would you physically do this? The leads from 3 1A drivers running to the same contacts on a single XML? Must read more...



> The other driver that you got capacitors for is a buck driver.
> What that does is "bucks" down the input voltage to something acceptable, and the usually have their highest efficiency when voltage in is much (like double maybe) higher than voltage out. They too are constant current, and will supply whatever variable voltage the LED needs. Since it bucks down the input voltage, the input voltage needs to be a good bit higher than the output voltage, and that's probably why people are saying it won't work; I actually haven't read through all of it.



If i'm feeding the buck driver 12V+, and it has two 3.5V XMLs hanging off it, the Vdiff (Vin - Vout) is 5V+. Is that not enough of a difference? Genuine question...I have no idea!



> Depending on the CPU cooler, it would be able to dissipate power from three XM-L's, but I don't think you can fit three?
> Here is a picture of an XM-L on a 20mm star mounted on a rosewill low profile CPU cooler; ignore the white plate it won't be there if you happen to do this.



A peltier module...burnt myself a few times mucking around with those a few years back. Does that surprise anyone!? I'm assuming you were trying to regain some power lost as heat - wonder if it could run a fan attached to the heat sink?

I'm going around in circles at the moment. I don't know which direction to take. It's clear to me now that I need a bigger heat sink. But what driver, and what type of set up? I'm leaning towards the linear drivers now but I need to be 100% confident with how they should be setup before I buy any. Then again the t60 specific driver videoman found seems the easiest of the lot. How many XMLs could I reasonably string together on that one? I'm assuming 2 will not be an issue.

I think I'll be going for a single driver, 2 XML (because they are already purchased) flood light with reflectors to focus the light a bit better. 3A and 2000+ lumen should SURELY be a decent flood light???


----------



## MikeAusC (Apr 17, 2011)

Mattaus said:


> . . . I'm still lost as to *how many* of these linear drivers I need. Is my assumption that they get 'stacked' (placed in parallel to each other) to increase the output current correct? Come to think of it how would you physically do this? The leads from 3 1A drivers running to the same contacts on a single XML? Must read more...
> 
> If i'm feeding the buck driver 12V+, and it has two 3.5V XMLs hanging off it, the Vdiff (Vin - Vout) is 5V+. Is that not enough of a difference? Genuine question...I have no idea!


 
Each 3-pin 7135 chip will pass 350mA as long as there is more than 0.6 volt across it. If you have a Driver board with 4 chips on it (all wired in parallel, pin for pin), it will drive 1.4 amp. Wire two boards in parallel and you have 2.8 amps drive.

With Buck drivers you may need as much as 2 volts across them, so for two LEDs in series you need at least 3.3 + 3.3 + 2 = 8.6 volts, so 12 volts is great.


----------



## MikeAusC (Apr 17, 2011)

duplicate ???


----------



## Mattaus (Apr 17, 2011)

> Each 3-pin 7135 chip will pass 350mA as long as there is more than 0.6 volt across it. If you have a Driver board with 4 chips on it (all wired in parallel, pin for pin), it will drive 1.4 amp. Wire two boards in parallel and you have 2.8 amps drive.



Seems like an awful lot of soldering, work and potential failure points for 2.8A when there appears to be simpler methods out there, linear or not...



> With Buck drivers you may need as much as 2 volts across them, so for two LEDs in series you need at least 3.3 + 3.3 + 2 = 8.6 volts, so 12 volts is great



So provided I don't screw up the soldering job, and the replacement capacitors I have are the right ones (16V 10uF from Jaycar), the buck drivers I have and 2 XM-Ls should be fine with appropriate cooling.

I'm going to find out one way or another!!!


----------



## Starlight (Apr 17, 2011)

You are missing the point. The 7135 is a chip that is contained on the driver boards that we are talking about. When you purchase a 1.4A driver, or a 2.8A driver, it has the required number of 7135 chips installed, i.e. the chips are already mounted on the boards. When we say a 7135 driver, we mean one of the boards with that type chip installed. The only soldering you do is battery and LED. The reason we have recommended the 7135 DRIVERS is that they are linear, constant current drivers.


----------



## MikeAusC (Apr 17, 2011)

Mattaus said:


> Seems like an awful lot of soldering, work and potential failure points for 2.8A when there appears to be simpler methods out there, linear or not...
> . . . .


 
You can buy Driver boards which already have 4 or 8 7135 chips on them.


----------



## videoman (Apr 17, 2011)

" 3A and 2000+ lumen should surely be a decent flood light ??? "

If your playing field is reduced in size from 100' to 25' perhaps so.
A 100W incandescent kitchen light bulb is around the equivalent to 1700 lumens http://en.wikipedia.org/wiki/Incandescent_light_bulb
You will see the lumen value chart near the bottom of the page.


----------



## Mattaus (Apr 17, 2011)

> You are missing the point. The 7135 is a chip that is contained on the driver boards that we are talking about. When you purchase a 1.4A driver, or a 2.8A driver, it has the required number of 7135 chips installed, i.e. the chips are already mounted on the boards. When we say a 7135 driver, we mean one of the boards with that type chip installed. The only soldering you do is battery and LED. The reason we have recommended the 7135 DRIVERS is that they are linear, constant current drivers.


 
That makes sooooo much sense now!

:bow:



> You can buy Driver boards which already have 4 or 8 7135 chips on them.


 
Maybe it's because my 'search catalogue' is currently limited to DX and cutter (due to my noobness) but I seem to be unable to find any single board 7135 drivers with any max current rating over 1000mA. I'll keep looking though. Google is my friend. Apparently.


----------



## hellokitty[hk] (Apr 17, 2011)

Mattaus said:


> A peltier module...burnt myself a few times mucking around with those a few years back. Does that surprise anyone!? I'm assuming you were trying to regain some power lost as heat - wonder if it could run a fan attached to the heat sink?


Glad you recognize it . at 3.0A, I'm getting only a small amount...≈.6v and .15a. I attached a tamiya low voltage motor (high torque to break the startup barrier) and it starts spinning the fan that came with the CPU cooler within 20 secs.

For the "poor man's setup", you only need ONE 8x7135 AMC driver.
A single AMC 7135 chip regulates current at 350mAh (burning excess voltage as heat), so the 8x7125 driver is eight of those in parallel to boost the current to 2.8A.
Since they should be in series, the current will remain at 2.8A per LED, which I assume is about what you're looking for.
Kaidomain, Dealextreme, Shinningbeam, and Illumination supply all carry the 2.8A driver.



Mattaus said:


> If i'm feeding the buck driver 12V+, and it has two 3.5V XMLs hanging off it, the Vdiff (Vin - Vout) is 5V+. Is that not enough of a difference? Genuine question...I have no idea!


Sounds fine actually, preferably you have a high input voltage, but that's not necessary, the different in efficiency won't be too bad until you get quite close to the input voltage, within a few volts. At that point you should just switch to direct drive or change a battery.

Here's a thought: you already have some XM-Ls and some drivers, if you want you can try to power up one XM-L for a second to test how bright it will be. Should be similar to a 60w incandescent, maybe a little brighter. If the star is too hot to hold, then you should probably stop soon.


----------



## Starlight (Apr 18, 2011)

Go back and look at the DRIVER that I gave you the link for in post #24. It is the 2.8A DRIVER that has 8 x 7135 chips on it. $6.75 and you are in business. Connect it up the way they did it in the post I quoted. It will run a few seconds without heatsinks so that you can see how bright it will be. Then, heatsink, heatsink.


----------



## Argon (Apr 18, 2011)

I’ve seen several Cree drop in’s for flashlights, what are peoples thoughts on putting several of these into a custom housing?

http://www.dealextreme.com/p/cree-q5-led-drop-in-module-3-7v-18v-input-11621

Also I’m going to be using these lights as well so I have some interest in the project.


Cheers,
Adrian


----------



## Mattaus (Apr 18, 2011)

Starlight said:


> Go back and look at the DRIVER that I gave you the link for in post #24. It is the 2.8A DRIVER that has 8 x 7135 chips on it. $6.75 and you are in business. Connect it up the way they did it in the post I quoted. It will run a few seconds without heatsinks so that you can see how bright it will be. Then, heatsink, heatsink.



Apologies....bit hard to keep track of where everything is going in this thread now. I ordered 2 of the drivers that videoman found (3A XM-LT60) this morning so I now have 4 2.8A+ drivers for 4 XM-Ls lol. Might wait and see if none of them do what I'm after. Though I'd be very surprised if they didn't!!!


----------



## Mattaus (May 14, 2011)

For anyone who cares (and to close this thread up nicely) here is what I ended up with.

Peace!


----------

