4D ls mod question

[caver]

I searched around for an answer to my question but couldn't find it, so hopfully someone will help me.

I am thinking about doing a mod to a 4D cell light with a ls...

I don't know much about electicity and resistors, etc, so speak slowly and use small words

What do I need to do so the ls doesn't blow? I know that 2 cells are ideal, but can I run 4 parrallel, or should I put in resistors or something like that?

My goal is long battery life but still plenty bright. I did a nice mod to the sportsman headlamp (2AA) but I need brighter and longer life. Anyone have any data or guess on what the runtime for such a light would be?

Thanks for helping out a wanna be EE

 

[lambda]

Check this thread for Mag mod details:
http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=001634

 

[ElektroLumens]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by caver:


I am thinking about doing a mod to a 4D cell light with a ls...
<HR></BLOCKQUOTE>


I did a 4 'D' cell Mag Lite conversion. I used 3.3 ohms resistance. Works great. You might want to go with 5 ohms to be on the save side? You can get 2 10 ohm resistors, and run then parallel. You must have good heat sink, or you'll fry the Luxeon!

Wayne www.elektrolumens.com

 

[papasan]

depends what LED you are using to some extent...

if you want to use a red/orange/amber chemistry LS it has forward voltage of 2.95V, for efficiencey's sake i would put your 4D cells into seriesed pairs and run these in parallel...so you would have 3V output from 4 cells...these would probably last days and be nice and bright for awhile (the amber lambertian LS has a lux output of 36 when driven to specs, over twice that of the white, and is a descently usable color although monochrome)...

with the cyan/blue/white chemestry LS that has a forward voltage of 3.42 you would take an output hit with only a 3V source, so you may want to use a droppign resistor...

depends what you plan on using the light for...

if you wanted to use a resistor to get maximum brightness or to overdrive the LS then you may want to think about using 3D cells instead of 4, as the last cell will mostly be wasted away as heat in the resistor...