Gomer's LED array

Discussion in 'DIY' started by Gomer, Dec 30, 2009.

  1. Gomer

    Gomer Honorary Member

    still have some more to do, but for now:

    3 strings of 12 crees. Decided to just go 50/50 with white/royal blue. Didn't feel like wiring up for "color" control.
    Will be driving at 1amp max controlled by an APEX. Drivers powered by Meanwell ELN-60-48-D (anyone want some Ps? lol)

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    Top Radium (on icecap ballast) ~250watts
    Bottom LED (@ 1amp or ~ 130watts)
    Exposure settings are identical.

    (please ignore the algae..I was so good about keeping it in check, then I got lazy and went on vacation :p)

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  2. GreshamH

    GreshamH Guest

    What's the projects over all cost?
     
  3. Gomer

    Gomer Honorary Member

    Drivers + LEDs + heatsink = ~$300
    Molex connectors $4

    PSU cable +CPU fans + wire + heatshrink + solder + thermal compound = free (already had)


    This guy should pull about 130watts @ 1amp. The goal is to replace my 250 MH. I'll soon see if it will :-D
     
  4. GreshamH

    GreshamH Guest

    If you didn't get a deal on the drivers, LEDS & heat sink how much more do you think it would cost???
     
  5. Gomer

    Gomer Honorary Member

    Not a whole lot more. Maybe another 10-15%.
     
  6. GreshamH

    GreshamH Guest

    Wow not bad. Makes me want to build one now :lol:
     
  7. Gomer

    Gomer Honorary Member

    Lets see how this guy does first :-D
     
  8. dswong01

    dswong01 Supporting Member

    Tony
    what are you using to hold the crees to the heat sink? Nylon hardware?
     
  9. Gomer

    Gomer Honorary Member

    4-40 nylon screws.
     
  10. Gomer

    Gomer Honorary Member

    ok, that's enough work for now. I'll hook up power tomorrow :)
     
  11. JAR

    JAR Supporting Member

    nice work!!!!!
     
  12. sfsuphysics

    sfsuphysics Supporting Member

    Sweet Tony, now fire that sucker up!
     
  13. Gomer

    Gomer Honorary Member

    It's alive!!! Got it all running from 0.1 to 1 amp. I had one blue led which was a dud from the very beginning (I'll see if I can get a new one to replace). Luckily, I ordered 2 extra whites and 2 extra blues so I can run at full capacity.

    Sorry, no pics. Camera is charging :p

    Tonight when it is dark and my MH turn on, I'll do a side by side comparison of a Radium (250watts) to my LED (130watts max).
    I do know for sure, that I'll need to keep the fixture fairly elevated with the 60deg optics. Luckily, I have that as an adjustment parameter on my setup :p Most people will probably find 80deg or no optics satisfactory depending on their application. I personally like a fixture off the water. In fact, way in the future, I'll have a fixture that projects down from ceiling level almost as if it were a sky light.


    ..and eventually, I'll pretty it up with a little decorative wood frame
     
  14. dswong01

    dswong01 Supporting Member

    Where did you buy them?
     
  15. Gomer

    Gomer Honorary Member

    The optics? In the group buy here.
     
  16. dswong01

    dswong01 Supporting Member

    Nylon screws
     
  17. JAR

    JAR Supporting Member

    Why nylon screws?
    SS screws would transfer more heat wouldn't they? Would they short out the LED?
    Are you going to construct a cover for the exposed wiring?
    I'm not being critical as my LED's are still in the ziploc baggie...
     
  18. Gomer

    Gomer Honorary Member

    Nylon because the screw heads touch the unused contacts a tad. They also (even if copper) are a trivial heatsink pathway. The heat path is from the MCPCB through the thermal paste to the heatsink.
    Eventually, I'll do some sort of wood frame. I just wanted to get it up and running while I am on vacation so that I can monitor it.

    (new pics in OP)
     
  19. sfsuphysics

    sfsuphysics Supporting Member

    Fire that cameraman and get someone with a camera waiting to go!!! I like the side by side, while it can be deceptive (our eyes pick up more favorable colors, yellows/greens, rather than blues/purples/reds) it should be interesting to see the side by side, even if its not EXACTLY the same. I remember building my 100'odd LED array back in the day (5mm LEDs... 5000mcd or something insanely small) and when no lights were on in the house it looked intensely bright... however when I fired up 4 - 55w PC bulbs (this was over a 6 foot wide tank so the bulbs were spread out quite a bit) you could hardly tell if the LEDs were on or off.

    Out of curiosity though, did you test each one with a 3V source before you hooked them up? Or hooked them up, put the current source across them, and then just replaced which ever ones didn't light up?

    Also 60°? Is that the angle measured from dead center? So 120° side to side. Or 60° is the side to side full width half mast (or whatever they use to measure) angle? I think it'd be neat to mount these on the ceiling or something if you had a nice open top tank.
     
  20. Gomer

    Gomer Honorary Member

    Mike, check the original post with side by sides. The radium in person is a tad more purple and the LED in person is a tad more blue.

    I tested each LED first with a DMM in diode mode (this barely turns on the LEDs) then I did it with ~ 100mA from the drivers, then 350 then 700 then 1000mA. When all checked out, I was happy. there was just one that didn't light up and I replaced it.

    60deg is 50% intensity full angle.

    In the comparison, the radium is about 12" from the water and the LED is about 18". I think I can bring the LED up a few more inches.
     

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