wiring question

[SammyLJ]

2 actually 

1 - how can I wire a push button that will properly shut down my pc? I would assume that I can just splice the wires to the power button on the front of the tower for start up but how do i properly shutdown(without visiting windows) by a button?

2 - looking at the wiring diagram for my rgb leds, fairly simple, however when it asks for the voltage drop(V) it is 2.4 max for red and 3.8 for green and blue. What would I put in for white(IE connecting all 3 wires together to achieve white) or purple(red and blue)?

[mgb]

1) The same button thats used for start up, go into your pc settings and set up and set it so that when you press the pc front button, it shuts down.
In xp, its Start
                   -control panel
                               -power options
                                             -advanced
then select shutdown in the drop down box
or
You can set up your frontend (depending on which one, but both Mala and Hyperspin will do it) to shutdown the pc upon exiting.

2) I'm not sure what you're asking here. I understand voltage drops across leds and all that but what is asking for your voltage drop. are you trying to determine what resistor to use in series? if you are using rgb leds from groovy game gear, the resistors are already a part of the unit and they are ready for 5 volts.

[SammyLJ]

here is the voltage for the RGB
RED: Typical: 2 V Max: 2.4V
GREEN: Typical: 3.4 V Max: 3.8V
BLUE: Typical: 3.4 V Max: 3.8V

but what is the voltage when i make white(all three together)?

[MonMotha]

You may find that you have to use three resistors and tweak them a bit to attain the "white" that you want.  Per the numbers you posted, any solution will end up with pronounced red.  It may in fact be impossible to get past the voltage knee on the green and blue LEDs without exceeding the absolute max ratings on the red one.  Do you have a REAL datasheet for this part?  You can overlay all the typical Vf/If curves and find an intersection voltage, then add up the three currents at that voltage to size the LED.

If you happen to have access to both the anode and cathode on all three (this would make it a 6 wire part, which I doubt is the case), you could run them in series using one resistor.  They'd all see the same current, and you'd just add the voltages up.

[SammyLJ]

i bought these off ebay and only have what i posted plus a few other things but I think that the best answer will be for me to just buy white leds.

[MonMotha]

That or use three resistors.  They're not expensive, after all.

[Mysterioii]

True, resistors are cheap.  But if you really truly just want them to always be white, brother I'd just buy some white LEDs rather than triple the wiring work to use the RGB ones.  There are several sellers on ebay that sell lots of LEDs (say 25, 50, 100...) then let you specify what color combination you want.  You get the benefit of the bulk pricing but can pick up a nice variety.

[MonMotha]

You can tie the side of the resistors not connected to the LED together, so you only end up with the same amount of "wiring" for each LED, you just have to deal with all the extra connections right up at the LED.  Obviously buying straight white LEDs would probably be an easier option.