Some Electronics Help

[GarrHyde]

So, I've only ever built one saber before, and it was a super basic setup. Turned out well enough, I suppose, but now I'm kicking things up a notch.

Working on the initial stages of a birthday gift for my fiancee. She's only recently taken any interest in this silly hobby (thank you, TFA!), and I thought it was a good time to give the grand old gift of her very own lightsaber. She's fairly set on purple.

Now, I come to realize that purple LEDs don't exist (duh). No problem. I'm planning on using a Tri-Cree, Royal Blue-Red-Blue. I've done some research, and I've learned that you need to wire them parallel in terms of the resistors. Now, I'm gonna be honest: I have no clue what that means. Would someone mind explaining to a total electronics dolt what it means to wire them parallel, and maybe explain how to do it? Thanks a ton (sorry if I missed a thread that explains this).

[FenixFire]

+ to + and - to -. You'll need to buy several resistor values of resistors to dial it in. Check out the videos.

The wiring will depend of what sound card you will use.

[GarrHyde]

I don't intend to use a soundcard; shoulda mentioned that this was a stunt saber. Will that actually have much effect on this?

[Silver Serpent]

Parallel wiring means you attach a resistor to each LED die (either the + or the - pad, doesn't matter). Then you connect all the (+) together and connect all the (-) together. Then you hook the combined (+) and (-) to the battery and switch.

Series is the other method of wiring (not particularly useful for color mixing). In series, you connect the (+) of one LED to the (-) of the next LED, making a chain of them. You hook up the unconnected (+) and (-) on the ends of the chain to the battery and switch.

[FenixFire]

Just on the switch you use, wiring the LEDs would be the same if using resistors. For my purple saber using the hasbro/mosfets wiring I wired the rB and Red die. I had to resistor both slightly down from their max brightness to get the color I wanted. Using a 3.7v I used somewhere around a 1ohm on the rB and a 3 ohm on the red. I had several for testing and swapped them in and out using alligator clips until it was where I wanted it.

[GarrHyde]

Okay, so at present I'm planning to use a 3.9 ohm 5w resistor for the red and a 2.7 ohm 10w for royal blue and blue each. Does that sound about right, or am I doing something wrong?

Edit: Also, would I just use a single 2.7 ohm 10w resistor for both rB and B? Sorry I'm so hopeless with these things.

[FenixFire]

What battery setup? The wattage sounds fairly high. I did not exceed 2 watts on initially a 4.5v (3 AAA) setup. The 5w and 10w resistors wont hurt anything but they are large. You will want to get several different resistor values to mix to the desired color. I assume you are planning either a 3 or 4 AA/AAA setup or a 3.7 since a 7.4v in this case would be a waist of electricity.

Running the math for a Red Cree 2.65 fv on a 3.7v input the 3.9 ohm gives 270 mA and only needs a minimum 1/2 W resistor. I would get several resistors ranging from 1.5 ohm to 3.9 ohm in a 1W rating.
For the Blue the 2.7 ohm would only drive the LED at 111mA and would only need to be 1/8W. To be honest I don't think a Cree would even light at that low of current if it did it would be very dim. On a 3.7v battery the blues are safe on anything above a .5 ohm I would get several that range from .5 ohm to 1.5 ohm also in a 1/2W or 1W rating since you are not trying to fit a sound card and such into the hilt.