LED Q&A thread

Discussion in 'DIY' started by Gomer, Sep 24, 2009.

  1. sfsuphysics

    sfsuphysics Supporting Member

    Yeah that's pretty much the way I wired it up, except their were only 3 LEDs, I have a feeling its simply a matter of these drivers not really being to spec which they say they are. plus the LEDs are all over the map, I had one of the XP-Gs running at 2.95V @ 365mA
     
  2. Marc

    Marc Guest

    Have you had the chance to get them to fire up at all? (the rest of the LEDs)
     
  3. Marc

    Marc Guest

    Their Ultra Premium Kit is weird. They are sold with XP-5 LEDs and lenses for the XR-E which dont fit the XP-5

    "Please note this kit only comes with 12 Lenses for the XR-E LEDs. We currently do not have any lenses for the XP-G LEDs. Also, please only use the LPC-60-1050 driver on the XP-G LEDs, this driver is not recommended for CREE XR-E LEDs. "
     
  4. sfsuphysics

    sfsuphysics Supporting Member

    Yeah all the other ones fire up just fine, when I test it with my wall wart through a decade box (fancy adjustable resistor :D), I haven't had a chance to hook them up and try them with the meanwell again. I haven't yet decided how i want to run them, and how to have them over the tank (i.e. do I just want one huge "light" or a strip. Also haven't figured out what I'm going to do for heat sink material, I was thinking just attaching them to a 1" square aluminum tubing, however I'm not quite sure if that will pull heat away quickly enough, I have been toying with the idea of doing parallel & series connections, so I can reduce the current to each one, maximizing efficiency at the expense of total output from a single LED, and the reduced current means reduced heat stress...

    I've been a tad busy so I haven't had the chance to play around with them in a while.
     
  5. Marc

    Marc Guest

    Those square tubings would look super clean! You could hide and feed the wires all the way down. I wonder how to tell if its enough to pull heat with out damaging the LEDs...
     
  6. newhobby

    newhobby Guest

    I would think they are too thin... Not enough mass
     
  7. Gomer

    Gomer Honorary Member

    Mass isn't important. surface area is :) Arguably, a u channel pointing up would work better for convective cooling than a square tube.
     
  8. sfsuphysics

    sfsuphysics Supporting Member

    Now if I could find a nice small fan to blow air through the square tubing that'd be the beezkneez :D However such a small fan would most likely sound like a farking gnat to move any volume

    I could always attach the c-channel on top of the square tubing too...
     
  9. Marc

    Marc Guest

    Tony, ideally I understand that a U channel has more surface area and would be better...what are your feelings about using a 1" square tube anyways with an LED every 4 to 6" or so? and at what temps do you think would be too hot?

    Edit: just wanted to add this would be over a 4 foot long tank
     
  10. sfsuphysics

    sfsuphysics Supporting Member

    square tubing (of the same size) would have more surface area than a U-channel, however the implication is with the U-channel the inside part's heat can rise and escape where as with a square tube the only place for that heat to go really is either heat the top half, or out the ends.
     
  11. JAR

    JAR Supporting Member

    You could drill some holes on the top of the square tubing for venting.
    I like the idea if concealing the wires inside the tube. H)
     
  12. newhobby

    newhobby Guest

    Sorry is this was already answered, but what is the difference between XR-E and XP-E?
    Why is XP-E cheaper?
    I'm thinking of changing a couple of my LEDs.
    I was going to try replacing a white for a UV and a Royal Blue for a Red.
    Trying to see if that will make my corals not to turn brown. :(
    What are your thoughts?

    Thanks
     
  13. newhobby

    newhobby Guest

    Ok,
    After looking at the spectrum, I think I'm going to try to go higher and lower in the spectrum.
    I'm gonna try replacing one white for green and one royal blue for red on the higher side.
    Then the UV led. Most I've seen are 5mm blacklight UV in the range of 400nm, which looks like emits a purpleish light. Should I try to go lower? I've seen some 365nm on ledsupply.com
    They are all in the 5mm case and run at 20 to 30mA. How many of those should I aim for? Any one has any idea?
     
  14. Gomer

    Gomer Honorary Member

    Robert, if you have the budget, you can try the LEDENGINE UV Leds available at Mouser ( Mouser Part #: 897-LZ110UA05-U7)

    An interesting option I have thought of trying but never did were to use the MCE multi color LEDs and use 4 driver channels to mix and max RBG+W
     
  15. newhobby

    newhobby Guest

    I think that is too powerful... lol
    Datasheet says: "The LZ1-00UA05 UV LED emitter provides superior radiometric power in the wavelength range
    specifically required for sterilization, dental curing lights, and numerous medical applications."
     
  16. Gomer

    Gomer Honorary Member

    400-405 nm does not steralize :p 460nm can cure dental fillings depending on the resin. Ignore the description ;)
    Just think of it as a 5 watt emitter (like a slightly more powerful version of the royal blue, but a bit shorter wavelength)
     
  17. zepplock

    zepplock Guest

    What's the ballpark price of DIY LED system to light 2-4g pico tank with mostly zoa/softies. Not a lot of light but good actinics etc.
    Have anyone tried it (I'm sure someone did) with a better looking fixture. Most DIY fixtures are not wife-compatible.

    Option would be to use PAR38 bulb (9,12,15w I think) which is in $100-$150 range.
     
  18. Gomer

    Gomer Honorary Member

    You could probably use a 3x3 array ($36-40) and a single non dimmable 700mA driver ($25-30), heatsink and fan ($?)
    likewise, you can up the # of LED, run at 350 mA and probably run passive.
     
  19. zepplock

    zepplock Guest

    So around $100 for a whole project. Hmmm, maybe par38 actually makes more sense in this case.
     
  20. yardartist

    yardartist Guest

    Roberto, I am planning to mix 4 white, 6 royal, one red, and one UV to make my 12 per driver. In looking at the bulbs at the last BAR meeting I think I will also saw my heat sink in two and have two lights rather than one to allow me to move them around and over particular corals. I was going to drill and tap, but now think I will glue them on given how everyone had trouble drilling due to the fins.

    I have four additional drivers from the buy last Fall, if anyone wants one, or four.
     

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