NITECORE -- Keep Innovating        
Results 1 to 22 of 22

Thread: 1 watt red,green,blue luxeons used at techno party

  1. #1
    Flashaholic* Lasernerd's Avatar
    Join Date
    Dec 2002
    Location
    The Great Pacific Northwest,home of the Goonies,Short Circuit
    Posts
    724

    Default 1 watt red,green,blue luxeons used at techno party

    Markhanna from the CPF board brought in a handfull of theses cool little led lights with focus optics,
    they placed them like spots at a rotating mirror ball.
    The effects were a brilliant display of freq. centered colors,
    these units had small 3 volt wall wart adapters,
    is 3 volts the max on these 1 watt emitters?

  2. #2
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno party

    max? heck no [img]/ubbthreads/images/graemlins/grin.gif[/img]

    some have run them as hard as 6v!!!

    though the average voltage is somewhere around 3.42v

  3. #3
    Flashaholic* Lasernerd's Avatar
    Join Date
    Dec 2002
    Location
    The Great Pacific Northwest,home of the Goonies,Short Circuit
    Posts
    724

    Default Re: 1 watt red,green,blue luxeons used at techno party

    Wow,,
    so with peltiers these things can really crank it out I am sure.
    They are very impressive at 3 volts!
    what is the max. ma.? are they different per freq.?

  4. #4
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno party

    well...it really depends on the led and the heatsinking.

    if mounted onto a good heatsink, with good thermal contact to the body, most 1w ls' could take over an amp, when lumileds says 350ma is what they want [img]/ubbthreads/images/graemlins/eek.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

  5. #5
    Flashaholic
    Join Date
    Dec 2002
    Location
    Bridgewater, NJ
    Posts
    413

    Default Re: 1 watt red,green,blue luxeons used at techno p

    [ QUOTE ]
    Rothrandir said:
    max? heck no [img]/ubbthreads/images/graemlins/grin.gif[/img]

    some have run them as hard as 6v!!!

    though the average voltage is somewhere around 3.42v

    [/ QUOTE ]
    6V on battery only, I believe, relying on the battery's internal resistance for some current regulation.

    Supplying 6V from a wallwart would be a bad idea.

    Ideally, the Vf is approx. 3.6 volts. This varies from LED to LED. What's more important is the current - Luxeons are nominally rated at 350 mA, and with excellent heatsinking they've been run as high as 1A. With moderate heatsinking (minimag for example) 400 and 500 mA is pretty safe.

    With a wallwart power supply, 5V plus a series resistor for current limiting would be good. A 3 ohm resistor would result in a bit under half an ampere going through the LED if the Vf were 3.6. (5v-3.6 = 1.4v - 1/2 amp would occur with 1.5v drop across the resistor.) ElektroLumens has some excellent heatsinks for Luxeons, you can probably use the disc heatsink alone at under 400 mA or so.

  6. #6
    Flashaholic* Lasernerd's Avatar
    Join Date
    Dec 2002
    Location
    The Great Pacific Northwest,home of the Goonies,Short Circuit
    Posts
    724

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Very interesting,,
    thank you for the info.!

  7. #7
    *Retired* The_LED_Museum's Avatar
    Join Date
    Aug 2000
    Location
    Federal Way WA. USA
    Posts
    19,418

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Most of those wall warts will put out more voltage than it says on the label. But I don't know *how much more* when they're heavily loaded; ie. with Luxeons. Guess that's what a DMM is for. [img]/ubbthreads/images/graemlins/tongue.gif[/img]

    If the Luxeon gets really toasty really fast, it's probably overdriven and it'll kick the bucket pretty quickly. [img]/ubbthreads/images/graemlins/frown.gif[/img]

    If that's the case, take Entropy's advice above. [img]/ubbthreads/images/graemlins/grin.gif[/img]

  8. #8
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno p

    i'm certainly not recommending running a 1w ls off of 6v...but it has been done.

    batteries will often put more than their specified range also. the one i'm refering to used 2 123 batteries, which commonly come with over 3.2 without load. plus the lower internal resistance.
    it was, of course, using a specially selected high vf luxeon.

    i was just saying it could, and has been done [img]/ubbthreads/images/graemlins/grin.gif[/img]

    i've made a lot of mods running dd off of 4.5v with no problem at all.

  9. #9
    Flashaholic
    Join Date
    Dec 2002
    Location
    Bridgewater, NJ
    Posts
    413

    Default Re: 1 watt red,green,blue luxeons used at techno p

    For other voltages, Ohm's Law is your friend.

    V = I*R.
    So if you have a 2v voltage drop between the power supply and Vf of the LED, and you want 500 mA (0.5 amps), you need 4 ohms. 2 = 4 * 0.5

    And yes, direct driving off of 4.5 volts with alkaline batteries is usually pretty safe, because alks have a prety high internal resistance. An alkaline battery can be modeled as a 1.5v source in series with a resistor. (Any battery can, that resistor is a higher value and more significant in alks.)

  10. #10
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    So I see typical flux for a 1W green is 25lm, 1W blue is 11lm, and 1W red is 44lm. Given these levels, if I want to mix these to get white, how many should I use of each? Would 2 green, 4 blue, 1 red be close?

  11. #11
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno p

    there is no way to accurately mix luxeons to get white [img]/ubbthreads/images/graemlins/frown.gif[/img]

    first of all...the wavelengts vary so much, that you would need to hand pic the luxeons, if you could even get luxeons of appropriate wavelength. i don't remember what wavelenghts would be needed, but it's likely luxeons can't supply them.
    then there's the matter of luxeon vf...they would all need to run from seperate power sources and a dimmer to adjust each to the proper power so that they match.
    and then, as the battery goes down, each led will respond differently, some staying brighter longer, some dimmin quicker.
    and of course, as the heatsinks get hot, the output will degrade...especially on the red luxeon.

    even then, it there are other things that would make it next to impossible [img]/ubbthreads/images/graemlins/frown.gif[/img]

    sounds like you need a 5w white [img]/ubbthreads/images/graemlins/grin.gif[/img]

  12. #12
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    It doesn't need to be perfect, and I will be using a dimmer for each anyway. The title of this thread, and my underwhelming experience with the CKSauce LightWasher have me in mind to build a LightWasher that really will color an entire wall.

    I just wanted to get in the ballpark; if I drive 1 red LS at a full 350mA, I expect that 1 green and 1 blue at a full 350mA will not be bright enough to match it, so I'm looking for a guess as to the minimum number of greens and blues I'd need. These guys http://www.tirsys.com/architectural/...mp;productid=1
    are using red/green/blue LSs in a 1:2:2 ratio, so I may try that myself.

    I'm actually building this for a friend's apartment, she wanted to paint the ceiling sky-blue and I suggested - why not get one of these nifty CKSauce things, leave the ceiling white, and use the LEDs to get the sky-blue? You could even mix it a different way for sunset, etc.... But the CKSauce gadgets are too weak to illuminate more than a couple square feet, and they certainly won't have much noticable effect in the daytime.

    In contrast, I can cover my entire living room ceiling in red light using a single red LS. (Well, that's with the LS sitting on a coffee table; the beam can easily spread to cover the whole room.) I plan to mount these light clusters higher up in her place, above eye level and pointed upward so they don't blind anyone. I'm figuring one cluster of LSs in each of the 4 corners of the room should do pretty well. It won't be uniform, but that may not be too important either.
    (I dunno just yet. Without actually seeing it in action, I have no idea how it'll work esthetically. Maybe it will just look tacky, maybe it will look fine.)

    I'm ordering a couple miniature joysticks from CH Products. One will be a panpot to vary the overall brightness in each corner of the room. With the joystick centered I want 350mA going to all LEDs in all 4 corners, subject to the chosen color mix. I was planning to use a second joystick for a color mixer, 1 axis for 0 to full red, and 1 axis for blue to green blending.

    No batteries here. This will use an AC adapter. I'll assemble the LED clusters onto a base and mount RJ45 jacks on each, and run 4-conductor phone cord back to the control unit. (red, green, blue drive, and ground. perfect, and easily installable...)

    So most of the time I expect the output will be something close to sky blue. But I'd like to be able to tweak things to get white if I really wanted it.

  13. #13
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno p

    jeez! that is some crazy stuff in that link!

    red's won't like you if you feed them 350ma..the require less voltage and current thant he white ones do. this hold true for the red/orange and amber leds also.

    sounds like a neat project! sorry, but i don't know how many you would actually need.
    if getting absolute white isn't a priority, you should be alirght with ordering a couple of each color, and mixing the quantities and currents untill you see what you like.
    if you have a couple left over...mod them into flashlights [img]/ubbthreads/images/graemlins/grin.gif[/img]

  14. #14
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Some crazy stuff yes; I think it'd be cool to have one of those around here.

    Red and amber Luxeons are spec'd at 350mA, just like all the other 1W LSs. The difference is they have a lower Vf. Technically, only the red and amber parts are actually 1.0W parts; the other colors are all 1.2W. A 350mA constant current source with a high enough voltage will deliver 350mA to a red LS the same as 350mA to a green or blue, without overdriving it. The trick is building the constant current source in the first place, and that's not hard in this application.

  15. #15
    *Flashaholic* Rothrandir's Avatar
    Join Date
    Aug 2002
    Location
    US
    Posts
    7,796

    Default Re: 1 watt red,green,blue luxeons used at techno p

    didn't know that...thanks! [img]/ubbthreads/images/graemlins/grin.gif[/img]


    i've seen 4.5 700ma adapters at radioshack, which would work very well if you have adaquate heatsinking.
    i wanted to pick one (a couple...) up for myself, but they were $16! [img]/ubbthreads/images/graemlins/eek.gif[/img]

  16. #16
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Found an interesting writeup here http://www.cg.tuwien.ac.at/research/...ic/node24.html
    talking about color measurements, and it also happens to provide wavelengths emitted by CRT phosphors and their relative brightness/weighting factors. Now, one thing I've seen in the Lumileds PR material is that they claim to allow a wider/richer color gamut than CRTs but I'm sure it wouldn't hurt to start there. With red at 610nm, green at 545nm, and blue at 463nm, I think a red-orange Luxeon would be a better choice (~617nm) than a red Luxeon (~627nm). For green you don't have much choice, but the ~530nm green Luxeon is in the right ballpark anyway. For blue it's somewhat of a toss-up between blue and royal blue, since they straddle a 460nm boundary.

    I note that those TirSys guys use arrays of red, green, blue, and amber Luxeons, so that they can generate warmer whites in addition to just a wider color palette. I guess you could use a red and an amber instead of the red-orange, but it might be simpler just to use the red-orange.

    Also from the CRT writeup, the relative weights for R, G, and B were .268, .667, and .065 respectively. I interpret this to mean that we need a red LED that's about 4x brighter than a blue, and a green LED about 10x brighter than the blue, if we want to be able to produce an even white. Given a single red-orange at ~55lm, this means you'd want 2-3 blues at ~5lm each, and 4-5 greens at 25lm each.

    I've also seen some mixes using .3, .6, and .1 for R, G, and B respectively. You could get close to this using single LEDs, and underdrive the red and blue to match the green output.

    Having figured all this out, like I said, I don't care about producing a perfect white. If I just run a R, G, and B trio at full power and get something pinkish, no big deal.

  17. #17
    Flashaholic
    Join Date
    Apr 2003
    Location
    Ulm, Germany
    Posts
    248

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Haven't followed your thread too closely, but have you seen the (presumably Fraen) RGB reflector assembly at diana electronic?

    Bye
    Markus

  18. #18
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    Thanks, I hadn't seen that before. Not quite what I'm looking for though; those reflectors are beam concentrators. What I'd like to build is the opposite, getting as diffuse a beam as possible, to eliminate hotspots and illuminate as wide an area as possible.

  19. #19
    Flashaholic* shankus's Avatar
    Join Date
    Feb 2003
    Location
    Mojave, CA
    Posts
    1,472

    Default Re: 1 watt red,green,blue luxeons used at techno p

    [ QUOTE ]
    highlandsun said:
    I'm ordering a couple miniature joysticks from CH Products. One will be a panpot to vary the overall brightness in each corner of the room. With the joystick centered I want 350mA going to all LEDs in all 4 corners, subject to the chosen color mix. I was planning to use a second joystick for a color mixer, 1 axis for 0 to full red, and 1 axis for blue to green blending.


    [/ QUOTE ]
    Sounds intriguing. You will keep us posted, right? And post pictures of the finished project?

  20. #20
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons used at techno p

    You betcha. I'll post something in the "Homemade..." forum when it's all together. At this point my order from www.luxeonstar.com is a week overdue, which is seriously delaying things...

  21. #21
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons

    Just got my order from www.luxeonstar.com, woohoo!!

    18 lambertian 1W stars:

    6 R4GR - 39.8-51.7lm, 620.5-631nM, 2.79-3.03V
    6 Q1JG - 30.6-39.8lm, 520-525nM, 3.27-3.51V
    6 K3KY - 145-175mW, 440-445nM, 3.51-3.75V

    The reds are about average, the greens are above average, the royal blues are also above average. I'm Stoked!

  22. #22
    Flashaholic*
    Join Date
    Aug 2002
    Location
    Los Angeles, CA
    Posts
    607

    Default Re: 1 watt red,green,blue luxeons

    Hm... With all three running at pretty much dead-on 350mA, the output is definitely bright/light/pastel/pink. The red is just too powerful...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •