Not bright enough is cree the answer

[johnny5.5]

I Have just started building some new bike lights following a website using 3 Luxion3 LED.s and 2 2009 micopuck drivers using 4s AA, wiring in parellel buckboost, switching 1 or 3 on, I have found that when only 1 Led is on it is much brighter than when all 3 are on. It dims down to the same as the others, Does this mean with more power I can have all 3 this bright or by adding another driver please advise??

Would batterys with higher amh Give more light or just go in for longer.

Or is this all i can get with these LED,s, What about Cree XR-E star boasting 107 lm are these the answer and what drivers would i need to make them work.

 

[csshih]

Micropucks are 1 watt led drivers.. Lux IIIs are 3 Watt LEDs. -- and also pretty much obsolete. You should upgrade to either the Cree XR-E, XP-E, XP-G (XP series is much smaller.. got soldering skills?) or Luxeon K2s

You need a different driver, but then, 4AAAs will not supply enough current to drive 3 LEDs well..you'll also need a better power source.

 

[johnny5.5]

I am using 4 AA not AAA, If I need more power please be more specific do i run 4 more in parellel for more amperage will that help?

What about cree MC-E? These look very bright

 

[Hack On Wheels]

Lets see... if you want to use NiMH AAs... 6 in series will give you a nominal 7.2V, or about 8.4V when freshly charged. Then you could use a boost driver like the maxflex from taskled.com to drive 3 single-die LEDs in series from this. You could use some SSC-P4 emitters in U bin or U2 bin for (not class-leading) respectable brightness, these would probably allow you to use your current optics if you wanted as the emitting pattern is similar to that of the Luxeons. Other options would be the XR-E line, R2 is the brightest bin, and these are a reasonable size to work with; or if you are getting them on a fairly big star (thats the board you can buy them pre-mounted on) then XP-E or XP-G emitters are also easy enough to work with. XP-G being the brighter of the two, but the increase in brightness over the XP-E won't be in the middle spot, it will be in the spill/flood. You can also get XP-G and XP-E as bare emitters or on small 10mm round or square boards for making very compact lights.

Of course, there are far more options for battery, driver/regulator, and LED configurations, but something like what I listed should be much much brighter than what you currently have. MC-Es can be used to get a lot of lumens, but anything will be a good step up and you probably don't want the power consumption to be too high if you are using AAs.

 

[herulach]

If you want to run 3 LEDS in parallel (presumably how you have yours set up) from 4AAs you need cells that can sustain a 3A load, pretty much limits you to Sanyo NiMh 2700s, and even then you're pushing it. A more realistic option is to use a quad AMC7135 based driver, this will drive each LED @500ma, and will be much easier on the batteries. Of course run time will probably only be about an hour.

All that being said, swap the Lux3 out for a new cree xpg LED and it'll comfortably output 2-3x the light. so you only need one emitter

 

[johnny5.5]

Not fixed on 4AAs just want maximum light possible, Will bigger batts give more lumens?/

 

[yellow]

not "bigger batteries" only.
The driver that gives the led power gives more lumens, but that driver needs the according batteries


change to a 7.2 V Li-Ion Camcoder pack, that is the cheapest, but best, battery option at the moment.
These can drive Your three led wired in series with ease.

Now You need a step-up driver that gives POWER to the led, some 800-1000 mAh.
With that power even Luxes are very bright, but actual led give nearly double the output - at the same power!
.. so no way anyone could recommend You to use the Luxes NOW.

Get Cree XR-E or Seoul P4, or try to get Cree XP-G (but there are only very cold (=blue) ones available by now. And there are no focusing devices available, afaik)

 

[TorchBoy]

Re: Not bright enough; is Cree the answer?

Cree is part of the answer. The MicroPuck isn't particularly efficient in the buck/boost arrangement, and for "maximum light possible" there are better drivers you could use. If your budget isn't too tight then buy a pre-fabricated multi Cree XP-G board and optic and drive each LED at 1 amp. Just make sure you deal with the heat generated.

If you want to run 3 LEDS in parallel (presumably how you have yours set up) from 4AAs you need cells that can sustain a 3A load, pretty much limits you to Sanyo NiMh 2700s, and even then you're pushing it.

For NiMH, Sanyo Eneloop can quite easily cope with a 3 A load. SilverFox's testing showed almost 1.8 Ah and just over 2 Wh per cell for the Eneloops and 2.4 Ah and 2.666 Wh for the 2700 mAh cell. The Eneloops have less capacity but will have a much better cycle life (ha ha) than the 2700 mAh cells. It's a simple trade-off: Capacity vs lifetime (and knowing you don't have to charge them right before you start cycling).

A more realistic option is to use a quad AMC7135 based driver, this will drive each LED @500ma, and will be much easier on the batteries.

A 4x AMC7135 driver normally gives a little over 1.3 A. You can occasionally find AMC7135 chips that do 380 mA instead of 330 mA though.

... Cree XP-G ... And there are no focusing devices available, afaik)

Remember the 10 mm square ones? And there are dedicated optics for 3, 4 or 7 LED boards.

 

[herulach]

Re: Not bright enough; is Cree the answer?

much[/B] better cycle life (ha ha) than the 2700 mAh cells. It's a simple trade-off: Capacity vs lifetime (and knowing you don't have to charge them right before you start cycling).

Not seen that thread, still, dare say even eneloops will struggle to sustain many cycles like that.

A 4x AMC7135 driver normally gives a little over 1.3 A. You can occasionally find AMC7135 chips that do 380 mA instead of 330 mA though.

440/500 who's splitting hairs?

As far as the OP goes, looking at the datasheet I think you have them wired to supply 700ma to the LED. When you're switching the extra leds in this drops it to c. 200ma.

Using what you have you can get 800ma to two of the leds. Move the batteries to a 2s2p configuration (2.4v nominal if you're using nimh - which you should be) and then wire the drivers as on page 5 of the application notes here

That being said, long run you're still going to be better starting from scratch rather than trying to make that kit work.

 

[TorchBoy]

Re: Not bright enough; is Cree the answer?

Not seen that thread, still, dare say even eneloops will struggle to sustain many cycles like that.

Literally hundreds (there are threads on that sort of things too). There are many reasons they're so popular around here.

That being said, long run you're still going to be better starting from scratch rather than trying to make that kit work.

Agreed. Just changing the LEDs will give two or three times as many lumens, even without changing the drivers.

 

[johnny5.5]

Re: Not bright enough; is Cree the answer?

As far as the OP goes, looking at the datasheet I think you have them wired to supply 700ma to the LED. When you're switching the extra leds in this drops it to c. 200ma.

Using what you have you can get 800ma to two of the leds. Move the batteries to a 2s2p configuration (2.4v nominal if you're using nimh - which you should be) and then wire the drivers as on page 5 of the application notes here

Will try wiring 2 lux,s 2s2p do I run them series or parallel?


That being said, long run you're still going to be better starting from scratch rather than trying to make that kit work.[/QUOTE]

Think I will try and get these lights working as best I can (as I am in the uk and have to pay arrage/tax orders) and use them for a helmet cam, Then I will start again using 3 x Cree Xre w107 with a Wired BuckPuck but what size do I need, Or will a Pre made boardgive me more light?
Please advise