Ok so I'm working on a costume. I have fiber optic fabric and hooking LED up to the fiber optics that are woven in the fabric. problem is it isn't very bright. I know it will only manly be in the dark but I'm trying to figure out how to make them brighter. I've never used High Power RGB LEDS (this is only my 3 LED project ever and 2nd complicated one) I want the dress to switch from pink to blue with sound effects when it switches. I'm currently using 5V Power pack, adafruit FX sound board and MEGA PRO 5V microcontroller. I have 2 sets of 3 ultra bright RGB LEDs hooked up to 3 PWM PINS ( 6 lights total hooked up to 6 pins total) and 2 sets of 2 ultrabright RGB LEDs hooked up to 3 PWM pins (2 additional lights total hooked up to 6 pins. For a total of 10 light and 12 PWM Pins)
Is it possible for me to switch to High Power RGB lights. I found some from china that are 3W (1 per color) If it is possible what parts would I need to change or add?
You can't draw more then 40 mA from an ATmega pin. I suspect that brighter LEDs are going to exceed that limit. You can use transistors to switch the power as long as you have separate LEDs or Common Anode RGB LEDs. You will need some way to limit or regulate the current through the LED.
You will need to know the current requirement of each color and the forward voltage drop of each color.
DC Forward Voltage (VF) : Red 2.0-2.6V, Green: 3.0-3.6V. Blue: 3.0-3.6V
DC Forward Currect (IF) : 350mA for each color
Beam Angle: 115 degrees
Lens color: water clear
PCB board: Diameter star 20mm base
Resin (Mold): Silicone Resin
Certificate: CE&ROSH
LifeSpan Time : > 50,000 hours
And my board max out a 50ma per pin... I was afraid of that so then I don't understand how you control them?
The lights are connected to Fiber Optics... No one will be able to see the lights there under the costume, only fiber optics are visible so it needs to be really bright so the light travels though them I think I've figured out how to make this work. To battery packs one runs the board and one connected lights though transistor. I'm using 3.7v 12,000mah single cell lipo batteries. I ordered them factory direct from china and they were made all together so I'm connected to together to make 3.7v 24,000mah battery packs for the project so the costume can stay on for long periods of time. Really not expensive either less than $13 for each battery and free shipping. The batteries have there own individual protection. I've already combined them and charged them. The chargers i'm using is also protected. I've monitored them and they aren't heating up or expanding during charges or usage. (i'll continue to monitor to be safe) it does take almost 2 days to charge these packs though
No one will be able to look at the light directly cause they are connected straight to the Fiber optic bundles. If anyone see's any potential issues please let me know
Here is a video now this is with standard Super Bright 5mm LED... as you can see very dim this is in complete darkness) the fiber optics are woven into the fabric. Its going to be Sleeping beauty and I want to change the costume from Pink to Blue. Like the fairies are trying to fight over what color is should be (like the cartoon) Color Changing Dress
It will be difficult to CC drive a 3.3volt LED from a 3.5volt (loaded/almost flat) battery.
I think lineair circuits like the AL5801 are not suitable because of the 0.6volt drop over the current sense resistor.
And buck types need some dropout voltage to work.
I think the best option is a logic mosfet with a small value current sense source resistor.
And that sense voltage amplified with an IC like the LM324 or LM339, that reduces the current through the mosfet.
Can draw you an example schematic if you want.
Leo..
I am going to get to you just before Grumpy Mike does.
Do not connect the LiPo batteries in parallel. If you are going to use two of them, arrange them so that each drives half of the LEDs.
My concern about your problems with brightness is - what sort of LEDs are you presently using, and how are you coupling them to the fibre optics? There is going to be a major problem there if only because individual fibres are going to be closer to one particular LED colour chip than the others so the colour balance is going to be skewed. And if you do not cover the emitting surface of the LED encapsulation with fibres, you are clearly wasting light.
If you attempt to put some sort of diffuser between the LEDs and the fibres, then you will be losing much of the light in the process. This is the problem you need to address in the first instance before simply throwing more power at it.
TeresaMRoberts:
The lights are connected to Fiber Optics... No one will be able to see the lights there under the costume, only fiber optics are visible so it needs to be really bright so the light travels though them
With
Beam Angle: 115 degrees
you'll waste most of the light, unless you add optical means to re-focus on the fiber.
DrDiettrich:
With Beam Angle: 115 degrees you'll waste most of the light, unless you add optical means to re-focus on the fibre.
This was the crux of my answer. If you use LEDs with a dome, it may be better to carefully slice off the domed section (both to remove the curve and to get closer to the chips) and polish the flat surface, then bond the fibre bunch to that flat surface.
TomGeorge:
Have you calculated the power load, most of it will be heat, so if it is in clothing there will be some ventilation to be considered.
Paul__B:
If you use LEDs with a dome, it may be better to carefully slice off the domed section (both to remove the curve and to get closer to the chips) and polish the flat surface, then bond the fibre bunch to that flat surface.
Did you ever dissect a high power LED.
The ones I took apart had a hard plastic dome, glued on with silicone.
Some of them had some sort of gel inside.
Leo..
I was suggesting potential approaches to problems using the simple 20 mA devices with the implication that using them properly might avoid the need to use ridiculously high power to overcome inefficient coupling.
I think I've figured out how to make this work. To battery packs one runs the board and one connected lights though transistor. 
