Aquarium LED lights

Discussion in 'The Projects Forum' started by BDwarrior52, Nov 12, 2012.

  1. BDwarrior52

    Thread Starter New Member

    Nov 12, 2012
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    I need some help here. I'm designing an aquarium LED light fixture with 75 3W LEDs per 1 foot x 10 inch. I haven't shored up my spectrum choice yet if that matters. I want to be able to control each diode so when they turn on they slowly dim on left to right. Basically my question is how do I design my board so this is possible? I don't know much about PCBs but I'm trying to learn and any help would appreciated. If you feel that I know too little for you to even try and explain this to me I understand but I ask that you post a link to a website that has good info.

    Cheers
    Ben
     
  2. tshuck

    Well-Known Member

    Oct 18, 2012
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    Well, PWM is your control choice and you could try using Charlieplexing to address each LED individually...otherwise, you're gonna need a bigger boat...
     
  3. wayneh

    Expert

    Sep 9, 2010
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    If you can live with controlling a row of 5-10 or so instead of each individual diode, your project becomes much easier.

    Do you have anything purchased yet (power supply, driver, LEDs) or are you starting from scratch?
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    Color matters in the specs of the LEDs vary somewhat accordingly. While this article describes low power LEDs, the basics don't change.

    LEDs, 555s, Flashers, and Light Chasers

    As mentioned, putting LEDs in series is a much more efficient (real efficiency too) way of doing things.

    I helped a lot of people with these kind of projects. What can I say, I like LEDs?

    If you do an advanced search on aquarium LEDs and grow lights you will find quite a bit of material here on the subject. My name will be in there a lot.

    If you have specific questions you can post them publically and PM me to look at the post.

    One last word, look for gadgets like buck pucks, they also increase LED efficiencies enormously. If you are up to building circuitry you can save a pretty penny making them yourself, they are fundamentally a switching power supply current regulator.
     
  5. KJ6EAD

    Senior Member

    Apr 30, 2011
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    Your biggest problem will be heat. 225W of LEDs in 120 square inches is going to require a very substantial heat sink and probably a fan. Are you sure you need that much light, 3000-5000 lumens?
     
  6. takao21203

    Distinguished Member

    Apr 28, 2012
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    A 10W LED needs a heatsink + cooling fan.

    3W LEDs also still need a heatsink + cooling fan (or a very large heatsink).

    So many LEDs will take a lot of effort to mount and to wire.

    By the way I am playing with the idea to build some kind of growlight (10W red LEDs), I want to do something with these Pentium II heatsinks I have here.

    Actually I will consider the risk to run them in voltage mode. This voltage of course needs to be very tightly controlled. I made a large TL494 regulator some while ago, which I could put to some use. Also I have a really very heavy 500VA toroid transformer here! 2x48V I think.

    Or, and this is why I post here, are these buck pucks easier to build than a TL494 regulator (which sits in a drawer, fully working)? I have various IRF MOSFETs here (for instance), and a large number of 700uH inductors.

    Link??

    So, I saw the post, and actually bought the LEDs :)
    And no, it is NOT meant to be to grow M.J. (even if it could be used for that, potentially).
    I have some regular plants here which are not winter-hardy.
     
    Last edited: Nov 12, 2012
  7. tshuck

    Well-Known Member

    Oct 18, 2012
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    You should also use blue LEDs as Chlorophyll A and B both have another peak in the blue region... see here...

    I wish I had my Plant Tender project online somewhere to reference right now... :(

    Also, OP are your fish going to die from all this light!? Some fish are extremely prone to stress and can die from it..
     
  8. takao21203

    Distinguished Member

    Apr 28, 2012
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    See above, I actually bought the LEDs.

    Aquarium LEDs are used to support plant growth, and some weird coralls etc. actually need blue or UV light.

    You don't really need 200W LED, that's a big lot of lumens.
    I use a 10W white LED here, inside my PC case, and my desktop is bright, as well one corner of the room. 200W LED can illuminate a large room, mind that.

    It's about the equivalent of a 1000W halogen lamp, or even more!
     
  9. BDwarrior52

    Thread Starter New Member

    Nov 12, 2012
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    0
    Thanks for all the replys guys.

    Wayneh
    controlling 5-10 would be fine. I haven't bought anything yet but that takes me to another question. How do get power to the PCB? Do I still need a driver?

    Bill Marsden
    When you say more efficient (regarding the buck puck) do you mean each LED will produce more lumens or more efficient as far as watts used?

    KJ6EAD/Takao21203
    My bad I typed that wrong the 75 LEDs wast the amount that i wanted to use for 2 feet. I was thinking 35-40 per foot. Would heat still be as big of a problem. Could I make the fixture wider like 14" or 16" to help with the heat? Do you think that would be enough to make up for the quantity of lights.

    Tshuck
    The light won't be a problem for the fish they are under 1200w of metal halides now not including the T5s.

    I attached a picture of a light unit that I hope to replicate. They use 60 3w leds per ft

    Thanks for the help
    Ben
     
  10. BDwarrior52

    Thread Starter New Member

    Nov 12, 2012
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    I'm confused. Whats PWM and charlieplexing?
     
  11. tshuck

    Well-Known Member

    Oct 18, 2012
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    Last edited: Nov 12, 2012
  12. takao21203

    Distinguished Member

    Apr 28, 2012
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  13. Wendy

    Moderator

    Mar 24, 2008
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    PWM is a way of controlling power to LEDs, it is not mysterious, just a method. You can as easily vary the current, though the efficiencies go down.

    Efficiency from switching regulator comes from the fact it is a convertor. You feed 13W in, you can get 12 W out (losses are always going to be there). So if you have qty 3 3W LEDs and are using a 24 V power supply you may feed 0.55A into the regulator, meanwhile the total chain of LEDs is dropping around 12VDC at 1A, and an added bonus of a cool regulator circuit. With analog regulators (which are much simpler to build and use) you have the same current in as out, the wastage is dissipated as heat (the regulator gets very, very hot).

    Charlieplexing in this application really makes no sense at all. It is a way to control many LEDs from as few pins as possible, typically from a µC (microcomputer). Powering high wattage LEDs is basically a power control application.

    I suspect the brightness comment is very well founded. The power used by LEDs is substantially brighter than a 12W light bulb, LEDs are much, much more efficient that incandescent or fluorescent bulbs.
     
  14. takao21203

    Distinguished Member

    Apr 28, 2012
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    10 W LED (white)!
     
  15. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Just for some info
    In the "reef/aquarium" world its very common to use something like a meanwell ELN-60-48D (or P) and run series strings of 9 to 12 x 3W CREE leds mounted on star PCB's strapped to a large heat sink. Many have used strings of cool white and strings of royal blue as this has been shown to produce a decent spectrum of light for coral growth. Many now are including a few other colors (warm whites/reds/violets/near UV) to try to get a more broad spectrum.


    200W+ of LED's is NOT uncommon at all. My new tank will probably run 200 to 300W of LED's but its a 6 foot long 120G tank with LPS/SPS/soft corals,etc..

    In the aquarium world we don't necessarily go off lumens but rather PAR (photosynthetically active radiation) which is light in the range of 400 to 700nm which is needed for plant/coral growth. You try to use LED's and optics to net desired PAR ratings throughout the tank.. (700 PAR close to the lights and 200 PAR at the sand bed..stuff like that)
    Deeper tanks require tighter optics to get the desired PAR levels deeper into the tank.

    Now having said that.. Dimming each of 75 leds is NOT a simple task. Dimming series strings is MUCH easier as many of the "reef controllers" have PWM outputs to tie directly into the constant current drivers like the meanwell to achieve dimming patters.
    Some actually type in their location and the reef controllers will run the light schedule matching your physical or entered location... including sunrise/sunset/moonlighting,etc.. Some have even gone over the edge and actually have cloud passing and lightning effects going on in their tanks (totally silly if you ask me)

    Fading from left to right as the OP requested is actually ONLY for your own personal "cool factor" and is NOT necessary at all to maintaining a happy coral reef. What most of us do is simply turn on the "blue/actinic" lights first and slowly ramping them up then turning on/ramping up the other "white" lights throughout the day then ramping them all down towards the evening times similar to the rise/fall of the sun.. A parabolic curve mostly of dimming up to noon time then dimming down to sunset. But this is whole strings/fixtures not individual lights.
     
  16. takao21203

    Distinguished Member

    Apr 28, 2012
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    In this case I must apologize for posting incorrect information.

    But really, 1 kW incandescent equivalent illumination is used?
    These must be larger aquariums and/or including decent amount of vegetation.

    I've ordered 10pcs. 10W LEDs, motivated by this thread...
     
  17. Wendy

    Moderator

    Mar 24, 2008
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    Where and how much?

    Something that just occurred, you could add some fader circuits (slowly pulse on/off) for some interesting effects. Not sure how the fish and plants would like it, but it could look cool. Check chapter 12 of the LED link in post #4 I showed.
     
  18. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Yes many of these tanks are lit by multiple 400W metal halide fixtures.. (1, 2, 3 fixtures and up)
    Many with hundreds of gallon tanks full of corals

    The move to LED's is a lot about not having to run a "chiller" to keep the heat from the metal halides from cooking the water and for decreased bulb replacements. Metal halides and similar T5 HO bulbs lose their rated spectrum very quickly and are being replaced every 6 months to a year.

    Some of the "top" tanks here.
    http://reefkeeping.com/joomla/index.php/reefkeeping-blog
     
  19. BDwarrior52

    Thread Starter New Member

    Nov 12, 2012
    6
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    I'm not sure if I stated what I was trying to do on the OP correctly and I'm sorry for the confusion if you guys didn't get what I meant. I want these lights connected to a Circuit Board not the little disk LEDs that are commonly used for DIY LEDs. Thats what all the high end led companies are doing. The only problem with this is I don't know anything about circuit boards or attaching LEDs to them. Below is a light made by aquatic life. This Is what I want to make.

    http://www.3reef.com/forums/3reef-radar/aquaticlife-3w-led-up-close-140887.html

    I know the left to right sunset/rise isn't necessary (especially when you consider that in the wild the sunrise is only 15-30 min) but it looks cool.

    Cheers
    Ben
     
  20. takao21203

    Distinguished Member

    Apr 28, 2012
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    Very likely aluminium PCB is used here.
     
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