Flashlights that create white from 3 colors?

[ikendu]

It seems to me that I've seen a LED flashlight that uses 1 red + 1 blue + 1 green LED to make a "white" output. But I can't remember which or where.

Anyone seen such a light? Thanks!

 

[VidPro]

i have seen one
i made it, using 3 then 4 rotated 3W RGB emitters in a mag mod format.
it was not easy, and barely makes "white" its just a bit blotchey, and rather wide beam pattern.

 

[TigerhawkT3]

Yeah, that's an awesome light! It's cool to watch the emitters just change color like that...

Say hi to Choco for me.

 

[LEDninja]

Newbie *Retired* built one.
Tri-Lobe reflector concept for CREE LEDs
http://candlepowerforums.com/vb/showthread.php?t=138999
McGizmo too (post 2)

 

[ikendu]

Thanks for the posts!

The unit I was thinking about was a commercial unit. I can't remember it though...

 

[LEDninja]

The unit I was thinking about was a commercial unit. I can't remember it though...

Something like this?
eternaLight(tm) Model X2 - "Rave'n2"
http://www.techass.com/el/raven2/raven2.php

Battery life up to 500 hours! Uses 3 regular AA alkaline batteries.
Up to 100,000 hour lamp life!
Water resistant up to 100 feet!
Concrete drop/shock resistant up to 10 feet!
Ergonomic shape - comfortable to hold!
Large strong lanyard hole - easily attaches to strings, ropes, clips, etc.!
Battery saving Timer!
Dimmable!
Visible from over 2 miles!
Special effects!
Colors combine to make a near white light flashlight!
Glow-in-the-dark keypad!
Mind BLOWING multi-color visual effects!
Plays games! 12 modes of FUN functions:
**Timer - helps save batteries or lets you fall asleep in light without worry.
**On/Dim mode - 9 levels of brightness! Lasts up to 500 hours on one set of alkaline batteries!
**"Dice" game mode - pick a color, Rave'n(2) SPINS and picks one! Great for chance games and other amusements.
**"DragRace" mode - imitates a Drag Race Signal Tree with 1/2 second intervals for starting race events.
**"StopLight" mode imitates a stop light for Red light/Green light type games and traffic control uses.
**"Cops" mode imitates the blinking sequences of many police car lights. Great for in-house type security uses, kids pretend games.
**"Flasher" mode flashes all lights, rate is controllable - great for mode setting or dancing.
**"Strobe" mode flashes all lights like flasher but much quicker, creating a stroboscopic effect. Great for danincing or creating special effects.
**"Blaster" mode - lies dormant with a quick but dim sequencer running. When the adjust button is pressed, all lamps come on full power until the button is released. Great for kids games!
**"Sequence" mode - runs each LED sequentially and repeats. Rate is adjustable. Great for dancing or special effects.
**"Chase" mode - turns off each LED sequentially and repeats. Rate is adjustable. Great for dancing or special effects!
**"UFO" mode - gradually brightens and dims all lamps in a smooth action. Great for special effects or dancing!


And I was complaining about the complicated UI of the new breed of Chinese lights! This thing is worse!! And it (or its predecessor) has been around for ages!!!


EDIT
To find threads about this or similar lights do a Google search for eternaLight. CPF search won't find them as most of the threads are over a year old.

 

[ikendu]

I had forgotten about this light!

Although, I still don't think this is the "multi-color to white light" that I remember. It might be. Thanks for the post!

 

[ikendu]

I did find an interesting tidbit about signs using LEDs here:

http://resource.controleng.com/article/CA6358275.html

"White-light LEDs

Two methods are used to produce white light from LEDs:

Combining red, green, and blue LED chips in one discrete package or cluster LED lamp. The technique of mixing red, green, and blue (RGB) LED chips is typically used in signage because RGB LEDs can be combined to create 256 colors cost-effectively and efficiently.

Coating blue InGaN (indium-gallium-nitride) LED chips with phosphorus. Blue light from an InGaN LED chip filters through the phosphorus and generates a cool-white or fluorescent-light appearance. InGaN technology offers high reliability and color integrity. Brightness and color purity depend on the amount of phosphorus coating. Three shades of InGaN-white LEDs exist: cool white, pale white, and incandescent white. Cool white has the least amount of phosphorus and is the brightest.

At one time, lack of white-light LEDs limited integration of LEDs into some applications. However, it is a misconception that InGaN-white LEDs can illuminate a lens of any color, and simplify lighting requirements and designs. Because red is not represented in white LEDs, they can only be used behind a clear or milky white lens or panel. Placing a white LED behind a red lens produces pink, a green lens shifts to aqua, and so on. To maintain accurate and brilliant colors, LED color must match lens color. Therefore, white LEDs made from a blue chip cannot be used as a general backlighting light source for different-colored lenses and panels."

 

[ikendu]

I also found an interesting article about using 4 colors of LEDs (red, green, blue and AMBER) to create "high color rendition" white light. Here is a graph that shows the concept:

The "white paper" can be found here:

http://www.ledcentral.com/whitepapers/26_intertech_final.pdf

 

[Flying Turtle]

Not exactly a flashlight, but the CK Sauce Lightwand, Lightsaucer, and related products do this. Actually, I just found a Lightwand in a clearance bin at REI for $4.88.

Geoff

 

[ikendu]

Very neat! I wasn't aware of these CK Sauce color lights.

The keychain MicroLightWand item is pretty cool. Too bad it runs on 4 of the tiny button batteries. It'd be nice just to have one of the single AA light wands "just for fun" ...especially for less than $5!

 

[Cydonia]

I have always thought this was a good concept. Imagine an Inova X5, with these color LED's.

• Blue
• Turquoise
• Green
• Orange
• Red (and please, make it 660nm or higher! Not these 620nm "nearly orange" ones!)

And combined they are a very good white. But best of all, you could select to run just 1 LED at a time for 5 colors. And adjustable output. Red or Orange alone would last anywhere up to 1000 hours or more on one set of CR123A cells, depending on user selected brightness.

Now that would be a light I would buy and not care about CR123A costs. Surefire Kroma comes closest I've seen. Close but no cigar...
If it had all those other colors I woud be irresistibly drawn into buying one I think.

 

[roverjohn]

Wasn't there a drop in for the mini mag that had three colored leds that sort of made white light about ten years ago? I thought it used three Ns and some sort of reducer tube. If I rememeber right it was before the first white Nichias and kind of looked like the NI drop in.
John...

 

[Martini]

Polymer Optics makes a range of color-mixing optics for Lux, Osram, Cree, and Seoul LEDs. These looks like they could do a decent job of mixing RGB. Check out the data sheets.

 

[2xTrinity]

Honestly, what I think would work out the best for color rendering would be a cool white phosphor LED plus a little bit of deep red -- the red is usually the only thing lacking from the output on my Cree LEDs that have the best color rendering -- that is why they will generally appear "greenish" as they have the blue and green already in proper proportion, but are too low in red. (The ones that look bluish are the worst -- those are too low in green AND red)

Something like a Cree Emitter though, with both cool white and red in the same package with three leads woudl be interesting -- both could be used together for lightly improved color rendering, or red could be used alone for night vision.

* Blue
* Turquoise
* Green
* Orange
* Red (and please, make it 660nm or higher! Not these 620nm "nearly orange" ones!)

This is a good idea. However, "cool white" LED -- particularly the ones with the nasty blue tint, may be more efficient than using the blue + cyan + green combo. Having separate amber/orange/red emitters though would still "warm up" the output and improve the color rendering. Honestly, the only single-color I really ever want in most cases is red -- as it's the least apt to cause glare/disturb others, and has minimal effect on night vision. UV might also be interesting, for checking money, or lighting up fluorescent paint etc.

Having the deep red and orange separate is also a good idea -- 620nm "red" LEDs sort of split the difference, which makes them appear very bright, but they can still wipe out night vision. 660nm would be able to be useful in the dark without risk of affecting night vision.

 

[LEDninja]

Honestly, what I think would work out the best for color rendering would be a cool white phosphor LED plus a little bit of deep red

I remember LRI pointing out the Proton can be run with all LEDs on -6 white, 1 red to create a more pleasing colour.