Hey guys,
just wanted to share this great resource with the community, now you dont need an electrical engineering degree [joke] to figure out all the information, it even draws you the schematic diagram.
http://led.linear1.org/led.wiz
sample calculation for 16 LED array:
things you need to know to use the calculator:
source voltage: 5 (red,black), 7 (red,yellow), or 12 (yellow,black) if your using computer power supply
Diode forward voltage: usually 3.2-3.6 volt
diode forward current: usually 20-40 mA
These two specs can be found on the packaging when you buy your LEDs... they are slightly flexible... for instance, for the Antec prize i used 470 resistors with 2 LEDs in series and that resulted in a 10 mA current... so they are not at the brightest setting but they still work just fine. Adding rows of LEDs in parallel has no effect on the LED's, but LEDs in parallel by themselves share current.
pretty much the calculation goes as follows:
[Source V- (diode forward V * #of LED in series)]/resistor <= diode forward mA
OR
have all your resistors in series and diode forward voltage * number of LED = source voltage (eg, 2 LEDs at 3.5V with 7V supply)
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Now that we know the schematic, time to do the work...
I like to use a hot glue gun for computer mods, only costs about 20$ including glue at Canadian tire. I secured all the LEDs to the case using the hot glue, makes it easier to solder when they aren't free to move... Then i did all the soldering and wired it up, making sure all the LEDs polarity was correct.
Pictures from inside the Antec prize from the CS tournament, it has a nice area to work in behind the dust filter:
Picture1
Picture2
Picture3
After
