Chunga, as the site shows, you could use a 3 x 20 array of LEDs with a 120ohm resistor in series with the 3 LEDs and simply have 12v powering them.
And as I told you before, the amperes will kill the LEDs more likely than the voltage would. I should know xD I ran a $2 LED (RGB T_T) at 12v and forget to add a resistor and poof it burned to a crisp with like 200mA running through it =/
lol, thanks robodude, anyway, so theres the information, and i plugged it into the link Beth gave me and it came up with 5 rows of 3 LEDs each, with a 100 ohm resistor at the end of each one (running at 25 mA)
well, off to the mall to fill my Simon mall gift card that doubles as a Visa , cya later
i am not getting the IR LEDs for right now, just normal white 18,000 mcd LEDs and thank for the advice about the IR LEDs, i iwll be sure not to have too many and i will try and keep them sub 8-10 thousand mcd
well, guys, quick update on the LEDs, got a breaboard today and set up wat 1 of the turrents/bar lights will look like on my rover, took some before and after pictures in the dark, its not too impressive, but i think it will be ok
LEDs function quite differently from most other components we encounter in the robot electronics world. Instead of being fed with a constant voltage, they need to be fed with a constant current. When your getting started with electronics (and I say that without any sense that I really have any meaningful handle on it all yet) its easy to see these things as being fundamentally different. But they are not necessarily. The resistor driving the LED technique is about taking a known constant voltage and dividing it down to a known constant current.
How all this answers your original question, well… it doesn’t at all. It just seemed that you were struggling with a concept that took me longer than it should have to learn and I wanted to share
(running at 25 mA)
, cya later
He wants 15 LEDs per PCB! I didn’t notice that. sorry! 
