Need some LED HELP?

[jarhead14]

I need some of everyone's expert help out there..! I have been building my LED bike light, it seems forever. Here are the stats:

2 - 20 mm Triple CREE XP-G R5 boards in series
1 Luxor - Endor Star Triple board
2 - 1000mA 3023 Buckpucks

14.4v 5500 MaH battery pack.

I am using the CopperHead design that I have found on a number of sites.

I have the two CREE boards wired in paralell and the Endor star wired on it's own buck. The problem I am having is that I have full power to the Cree board closest to the buck and only 9.6v to the one farthest away (2").

Can anyone give me some input as to how to remedy my situation? I am getting to the point of chucking everything......However, the wife wouldn't be happy with that.

Any help or advice is greatly appreciated

 

[spencer]

One or both of the following is happening:
- the additional wiring to the far LED is providing extra resistance causing the other to draw more current (almost guaranteed)
- the further dim board has a higher Vf than the other board again causing the bright board to draw more current

So try one of the following:
- switch the two boards so the longer wiring goes to the one that is currently brighter
- make it so that there is an equal amount of wire between each board and the buckpuck

so this                        instead of this
--------------------        + -----------------------
|L1        B      L2|       B         L1          L2|
--------------------        - -----------------------
where B=buckpuck L1and2=LED and ----=wires

I would suggest doing the second point first. More information on how it is currently set up would be helpful.

 

[uk_caver]

I have the two CREE boards wired in paralell and the Endor star wired on it's own buck. The problem I am having is that I have full power to the Cree board closest to the buck and only 9.6v to the one farthest away (2")

Could you expand on that - what do you mean by 'full power' as opposed to 9.6V?