buck driver and optics advice required

[Babas]

I'm really amaized by all of DIY lights posted and menioned here. It actually inspired me to do it myself So here goes my first post with few questions already. I would appreciate if somebody could advice me.

I'm planning to build simple "tube" (aka dinote) design, but with 3 LEDs (preferably Cree XR-E Q5's):

1. Buck driver: I do not require "fancy features", which I find in some advanced drivers. What I want is simple operation by switch in 3 modes (OFF/750mA/1000mA) and preferably some heat protection (could be fixed to i.e. 70 degrees C). However I have difficulties finding such drivers: it's either "fixed current" (like 3023/3022) or advanced and programmable (i.e. bFlex, nFlex). Is there any place where I can find such semi-simple drivers, or it is too much I ask for?

2. Triple LED on MCPCB and tripple optics combo: is it really only cutter (AU), where I can find three Cree FR-E Q5's LED's mounted on MCPCB with matching triple optics (from Khatod)? What is the compatibility between different optic vendors: do they have any standard for layout (i.e. distance between LED's)? Can I buy three mounted Cree Q5 LED's MCPCB in one pleace and then easily choose any triple optics from any vendor? There is a chance, that I could buy some triple optics in advance (i.e. Ledil) and then try to solder/mount emitters on MCPCB myself to match optics layout. However, I'm not very experienced with soldering (done it ~15 years ago), so considering size of emitters and MCPCB (I want MR11=35mm, in worst case MR16), it would be "very expensive challenge". Thus never seen bare triple MCPCB's either.

Thanks a lot in advance for your patience and advices.

 

[Tidra]

You need a small amount of time to figure out TaskLed /nflex, Bflex) drivers and then it is pure joy to use,... so why bother,... program it once and leave it alone,...

LP
I.

 

[TorchBoy]

0. :welcome:

1a. Do you know about the driver board list?

1b. Why 750mA and 1000mA modes? There's not going to be much brightness difference between them.

2. Why not buy something like this optic, buy your three Crees on stars, and glue the stars onto a large heatsink in the appropriate places for the optic? You'll have plenty of wiggle time while the glue dries, and you'll only have to do ordinary soldering.

FWIW this this four-way is said to clip on to Crees nicely, but you'll have to trim stars (@ 20mm) or get Crees on 16mm round boards.

 

[Babas]

thanks a lot, TorchBoy

0. :welcome:

1a. Do you know about the driver board list?

1b. Why 750mA and 1000mA modes? There's not going to be much brightness difference between them.

Great list of drivers - nice and valuable work. I will definatelly use it as reference. And you are probably right regarding 750mA vs 1000mA - I just didn't think about it. So most probably I'll stick with 750mA fixed buckpuck or similiar, and that should be enough for light power of 3 Q5 Cree's (~600 lumens).

2. Why not buy something like this optic, buy your three Crees on stars, and glue the stars onto a large heatsink in the appropriate places for the optic? You'll have plenty of wiggle time while the glue dries, and you'll only have to do ordinary soldering.

FWIW this this four-way is said to clip on to Crees nicely, but you'll have to trim stars (@ 20mm) or get Crees on 16mm round boards.

I saw both of your sugested optics, but both of them are 50mm and quite narrow. In best case, I would like to have 30mm and somewhere between 12-15 degrees. However your idea about round boards sounds very good, and most probably I'll take that option with triple 50mm optics (4 seems too much for me), if I fail to find something else to fit into 30mm.

Thanks once more for valuable input!

 

[TorchBoy]

Do post pics of your finished light.

 

[sfCyclotourist]

0. :welcome:

1b. Why 750mA and 1000mA modes? There's not going to be much brightness difference between them.

I disagree...there is a noticeable change in brightness/output between 700 and 1000mA on my dual-Cree bike light.

I'll add another vote for the bFlex -- it sounds complicated to use, but it's really much simpler than it seems. Once you set it (which takes all of about 10 minutes), you forget it, and everything is controlled via ONE BUTTON. And if you ever change your mind (or change LEDs) and want a different max current, you can just reprogram the bFlex without even having to open up your light.

 

[TorchBoy]

Yeah, yeah, I didn't say it wasn't noticeable - a Cree Q5 (as per OP) has probably another 40-45 lumens from 750 mA to 1,000 mA, after all. But with one mode at 80% or more of the brightness of the other, 90% of the range to the same brightness (inverse square law), and considering the logarithmic way our eyes work, what would be the point in having those two modes only? :shrug:

Cheers.

 

[znomit]

+1
The isn't really any situation where you want "just a little less light" which is what going from 1A to 750mA does. Your triple Q5 drops from 700lm to 580lm at these settings. Yes you can notice this when switching between but you could easily go out for a ride on low thinking it was on high.

For a light typically you will use high for downhills and medium for flats and a low setting for climbing(and fixing punctures etc). 1A, 500mA and 250mA works well in these situations (I use the old 3 level bflex set to about this). This is about 240, 420, 700lm for your triple Q5. Big gains in runtimes by using the appropriate current levels.

For a dual level light maybe 1A and 400mA(350lm) would be a good compromise.

 

[ifor powell]

Here is what I am comfortable level wise with my setup I have been experimenting and thinking about it to see what batery setup I need to for an all night mountain bike jaunt I plan to do sometime in April (40th birthday during the month).

My setup is 6 leds on the bars and 4 for a helmet, driver is a maxflex for the 6 set to 1200mA and a nflex for the 4 set to 1000mA with my curent bateries flat out I have 55 mins for the 4 and 2.5 hours for the 6. With the nflex and the maxflex at these curent settings you basicaly half the curent each level down although the bottom level is a fixed minimum so there is a biger jump there.

stationary helmet L1, bar off.
tarmac up and flat helmet off, bar L1
tarmac down helment L1 bar L2-L3
double track up helmet L1 bar L1
double track flat helmet L1 bar L2
double track down helment L2-L3 bar L3
Single track up helment L2 bar L2
single track flat - flowing helment L2 bar L3
single track down helment L3-4 bar L3-L4
Full on flat out down hill single track L5, L5

As you can see I use all 5 levels sencibly so I am a big fan of the nflex/maxflex. For the long ride I am contemplating I think I am OK batery wise for the 6 L3 should be capable of 10 hours and as I will be spending more time on the ups than the downs I should be OK. For the Helment I will need more, I have more cells on order and will probobly end up with a pack thats good for 3 hours with my curent pack as a spair...

Ifor

 

[StevelKnievel]

I also think that the five level bflex/maxflex UIB2 is awesome. On my 13 emitter maxflex driven handlebar light I run the 1200mA scale, although I'm probably going to reduce that to 1A as I never feel like I need more light than my current L4 produces. I ride L1 for all tarmac and L2 or L3 for singletrack. L5 is reserved for giving riders ahead of me a hard time :devil:. The dimming steps are well spaced, and actively using them really helps extend runtime. If you want less complexity you can configure the bflex with 2 levels instead of 5. Taskled drivers have proven to be very reliable and versatile for me...another vote for bflex!