Click here for lightsabers
  • Home
  • Help
  • Login
  • Register
Pages: [1]   Go Down
Author Topic: RGB LED's and RESISTORS  (Read 2232 times)
retrothrust
Force Sensitive
*

Force Alignment: 0
Posts: 8


« on: September 15, 2015, 08:51:42 PM »

I have the design for a seven color changing lightsaber running a nano biscotte soundcard.  The leds are running off battery power directly, bypassing the card, to avoid shorting it.  I have a 6 switch dip switch that I plan on controlling all functions with, it's essentially six slide switches glued together in parallel. I'm using this switch because I'm making a lego style hilt and want as small a control as possible in the hole at the base (pommel) below/in front of the speaker.

 Switch 6 acts as the kill switch, sending power to the card, crystal chamber led, and switch 4.  Switch 5 acts as the momentary activation switch on the soundcard, so basically only turns on sound (to simulate a momentary switch I'll just switch it up and down slowly).  Switch 4 powers switches 1, 2 & 3 which power red, green and blue blade lights respectively.

so...
6: kill switch/ card & chamber on (power to 4)
5: activate card (switch powered by card)
4: power to 1, 2 & 3 (the predesignated blade color array)
3: power to red
2: power to green
1: power to blue



My limited knowledge of electronics says I need a risistor on all four led's;  The batteries I have should put out about 7 volts.  I Think I have the correct Resistor for the chamber led but I don't know how to tell which ones I need for the tri rebel star. Should I put the crystal chamber led before, after, or parallel to the nanobiscotte? Here is a link to the one I purchased, http://www.luxeonstar.com/any-3-rebel-leds-mounted-on-a-20mm-tri-star-coolbase  I used lime 313lm, royal blue 1030mw, and red 106lm. ALSO, will cutting power via color selection to one or more leds increase the power flow to the others, changing what resistor they would need?
Logged

Kouri
Knight Commander
*

Force Alignment: 308
Posts: 567


Artisan


« Reply #1 on: September 16, 2015, 02:09:55 AM »

First things that come to mind.

3rd party soundcards aren't really discussed in details around these parts, but I'll save you some heartache; 7v will fry an NB. Always read the manual.

I *seriously* doubt the dip switch setup is rated for the 700-1000mA you'll be pumping through it to run the LEDs. I'd even question whether it's rated for the 7vDC in your battery pack. I'm assuming two lithium cells at 7.4vv?

You realize those three light colors won't mix color the way paint does, yes?

LG + RB = White.
LG + R = Yellow-Orange.
RB + R = Magenta.

I don't remember the three mixed together, but my best guess is a very washed out pink or lavender. If you want color mixing, you'll probably want Red, Green, Royal Blue. Colors mix like the RGB slider on computer software.

If recommend starting more simply. Basic stunt setup. Single lithium setup or 4xAAA. You can tweak the voltage on the AAA setup by choosing between NiMH or Alkaline. Momentary switch. Momentary-to-latching converter. Tri-Cree Rebel or Cree. Resistora for one or two LED.

If you can get that wired up without fault, you'll be able to replace the latching converter with the soundcard of your choice. But mistakes with electronics can get expensive, so it's best to start simple. You won't be color mixing on your first go with that setup, but everything will be there for you to upgrade later on.
Logged

retrothrust
Force Sensitive
*

Force Alignment: 0
Posts: 8


« Reply #2 on: September 21, 2015, 06:12:58 PM »

I'm mostly interested in the lime led, the other colors are just a bonus.  Since the card is still sold out let's leave it and the speaker out of the equation.  These are the batteries I bought;

http://www.ultrasabers.com/Canadian-TrustFire-Protected-37V-900mAh-14500-Lithium-Battery-2-Pack-P1026.aspx

Say I bought better switches, I'm still not sure how to tell what resistors to get, or if turning one led off would burn out the others.
Logged

retrothrust
Force Sensitive
*

Force Alignment: 0
Posts: 8


« Reply #3 on: September 21, 2015, 06:21:39 PM »

I've been trying to figure out how to post pictures but I can't.
Logged

Kouri
Knight Commander
*

Force Alignment: 308
Posts: 567


Artisan


« Reply #4 on: September 22, 2015, 02:25:48 PM »

As far as resistors go, I used this LED resistor calculator for my custom build.

If you put the two Trustfires into a US battery supplying 7.4v. LED voltage and max current will vary by color.

We'll use the Lime as an example, so you would fill the fields as follows:

Source Voltage: 7.4
Diode Forward Voltage: 2.75
Diode Forward Current (mA): 1000

And result is a 4.7ohm resistor that's capable of handling at least 4.7w. You can always go for a higher watt resistor, but it will be physically bigger in size, so you'll have some trouble fitting it into the hilt. A quick search on another shop shows 4.7ohm 5w resistors being readily available.

Alternatively, since you're wanting to use a lower-powered card anywho, you could try to find a parallel battery holder, putting out 3.7v. Then you'd only need a 1ohm, 2w resistor. I did something similar with a hasbro economy board, 18650 battery, and a single Luxeon Lime Green.

As for burning out LEDs, as long as you wire each LED with its own resistor, you wouldn't have to worry about any burning issues when switching.
Logged

retrothrust
Force Sensitive
*

Force Alignment: 0
Posts: 8


« Reply #5 on: September 22, 2015, 07:52:54 PM »

I found a site describing the precise lime led's diode forward voltage, and their Maximum Rated Drive Current (which happens to be 1000 mA) is that the same as diode forward current?
Logged

retrothrust
Force Sensitive
*

Force Alignment: 0
Posts: 8


« Reply #6 on: September 25, 2015, 10:01:34 PM »

Never mind, I bought a driver card.
Logged

Wickedguitarist1
Force Sensitive
*

Force Alignment: 0
Posts: 4


Only two, there are. No more, no less.


« Reply #7 on: August 12, 2017, 01:50:32 PM »

I have a question because I'm new to this and am doing a first build. My question is what about a Deep Red/ Green/ Royal blue Combination? I'm using an NEC Igniter 2 I2-r2. What would color combinations look like and what resistors do I put between led die and board?
Logged

Pages: [1]   Go Up
Send this topic | Print
Jump to: