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DiY LEDs - How to Power Them

Discussion in 'LED and other Lighting' started by SupraSPL, Feb 22, 2014.

  1.  
    BobCajun

    BobCajun Well-Known Member

    It says it requires 50v though.
     
  2.  
    sunny747

    sunny747 Well-Known Member

    Yea, I thought of that after I posted.. I made the assumption that it was a 36v, but it's not.

    For the sake of argument lets say it was a 50v driver running at 3 amps. What's wrong with running these cobs at higher wattage's? I believe you lose efficiency,.

    If that's the case, then will there be a day when we have single cobs that can run at higher wattages and still be efficient?

    I only ask because it's nice to have a powerful single COB light source. It cuts down on cost and complexity of build etc.. think of a 600w HID. You just buy it for $150 bucks and in 10 minutes your lights are rigged and on. Then you spend the rest of the summer worrying about heat and your AC bill etc :)
     
  3.  
    BobCajun

    BobCajun Well-Known Member

    Yeah you just lose efficiency. At 25 C and 3000 ma it runs at 55v though so you'd need even higher driver voltage. Most of them only go up to 54v which may not be enough. Most don't go up to 3 amps either. Probably better off to use more COBs at lower power, just from a driver availability standpoint.
     
  4.  
    sunny747

    sunny747 Well-Known Member

    Thank you..

    Here s a 60v at 2.6 amps.
    http://www.mouser.com/ProductDetail...5PRBMPTWcaTdz0ax3t15k5ED5DVE8TEzmVYkWsCYhDA==

    I'm just stuck on this thought because there is a producer putting together nice 55w units using 1812's I believe... I just like the single light design. I'd just like more watts. I guess there is no free lunch :)

    autocob.jpg
     
  5.  
    BobCajun

    BobCajun Well-Known Member

    There's a problem with that driver too, because it's constant voltage and constant current, which means it puts out exactly 60v all the time, which is too high. The voltage of COBs changes from when they're first turned on to when they get to the highest temperature. That's why I don't think constant voltage is appropriate for COBs. I don't know the exact details of what happens when you try to drive a COB with CV but it looks problematic to me. Maybe there's enough safety factor in the COB voltage requirements that it would work, but maybe there's not. I recommend finding a CC only driver with a voltage range considerably beyond the COB's requirements in both directions. I wouldn't try to max out the driver's voltage range, I'd leave a safety factor of probably at least 5v.
     
    sunny747 likes this.
  6.  
    vahpor

    vahpor Well-Known Member

    @sunny747 Efficiency, driver options, and light spread are limiting factors to a single LES design. There are some large cobs (Opto Luna's for ex, check out the thread about them here on RIU) that are designed to be driven hard. They are less efficient, but would probably handle a 4x4 tent by itself. You will need some serious cooling. So, with a larger driver and larger heatsink, you lose some of your 'savings'. It is simpler, but you have a lack of redundancy.

    imo/e, cobs advantage is more pronounced when using many les. you get far less heat, far better coverage, w/o that single intense/hot spot. potentially allowing your plants grow more uniform and consistently.

    The less efficient, the more heat you have to manage. Efficiency is how much power is converted to light. What isn't converted to light is turned into waste-heat.

    Some chips are more efficient than others when driven hard, generally the large chips. ~45% efficiency would be my personal minimum from a modern chip.

    Another thing to keep in mind, the cooler the chip, the more efficient it is as well.

    Bring on the 1 cob revolution! Even 1 cob is better than throwing away more HID bulbs. And hopefully will get you to build some more LED devices. :)
     
    Last edited: Jan 8, 2017
    sunny747 likes this.
  7.  
    nevergoodenuf

    nevergoodenuf Well-Known Member

    @BobCajun The CV drivers are not like a computers 12v source. If you go into the data sheets, you will see they act as a CC driver until they hit that voltage wall (48v, 60v) then the driver reverts to a CV. The COB only draws the voltage it requires. The only difference for us, is we call only run one COB on it, unless they are ran in parallel (minimum voltage change). This method has not given me any issues as long as we are cool properly and thermal paste application is consistent. I prefer the CC+CV drivers for the flexibility, if I want more C's, I add COB's. It only requires a Y.
    Even on CC drivers, I have ran both parallel and series and sometimes both. No issues yet. So my thinking is if you already built some fixtures, but you want to upgrade cheaply, you can put 2 old fixture in parallel and put it on one driver. Now all your old lights are running more efficient and you have a driver free to start the next build.
    @vahpor I like my COB's running over 150w each. Here's 4 COB's for a total of a thousand watts in a 4'x8' tent, kill it. 2487.jpeg
     
    momo2015, sunny747 and vahpor like this.
  8.  
    topcat

    topcat Well-Known Member

    You might like this combination: HBG-160-60B, HBG-160 Connector Set, ModuLED Giga 152100-B-HBG. With the 1825, it would be about 140W, if I'm not mistaken. Maybe need the 152150 heat sink. I need verification from someone who knows for certain, I'm making an educated guess.
     
    sunny747 likes this.
  9.  
    BobCajun

    BobCajun Well-Known Member

    Maybe it's the reverse of constant current, where it supplies whatever voltage is required to maintain that current. Maybe with CV it supplies a steady voltage and only puts out as much current as required at that voltage.
     
    sunny747 likes this.
  10.  
    Godfather420

    Godfather420 Well-Known Member

    ?... I'm building a configuration running 9 vero29 bxrc-30g10k0-d-73 38v

    Stumped as to whether or not go hlg 185h-c1400b or hlg 240h-c2100b.....The 240 gives me some room for flower power...but its ability to only dim to 1050 kinda sucks if I'm reading right? 1050ma x 37.2v=39.06 watts. the 185 allows me to get to 1400ma x 37.2=52.08 watts

    I'd like to flower early under 40-50w per cob and be able to crank it up a lil towards the end.... I really wanna see these things can do. Any suggestions? These will be water cooled.
     
  11.  
    SomeGuy

    SomeGuy Well-Known Member

    It's been a while for me but checking in. Some really cool stuff being built. My vero18 bars are still pumping out bud and have more than paid for themselves.

    I have a question. If you had a driver sitting around (pictured). What would you choose to drive w it? :-). I also have three actively cooled CPU heatsinks sitting around.
    IMG_20170106_084936638.jpg
     
  12.  
    BobCajun

    BobCajun Well-Known Member

    Any COB between 21 and 42v that can take 3.9 amps, or a few lower current ones wired in parallel. I think most Crees have a 3 amp maximum. Could put two in parallel running at just under 2 amps each. If one of them malfunctioned the other one would probably burn out though. For parallel it's probably best to use COBs that could take the full current each if required.
     
    SomeGuy likes this.
  13.  
    SomeGuy

    SomeGuy Well-Known Member

    Single chip option is best. Just need to find a big chip and chunky heatsink
     
  14.  
    Darkfurion

    Darkfurion Member

    Hi guys and girls.
    I have one question for you: I would like to connect 2 COBs Cree CXB3590 36V in series to this driver: ELG-150-C2100BE
    Details about the driver:
    Wattage: 150
    Output Voltage: 36-72V
    Current: 2100mA

    Is this a good choice or should I search for another driver? Is it too hard for the LEDs to run them at 2100mA?
     
    Last edited: Jan 11, 2017
  15.  
    Godfather420

    Godfather420 Well-Known Member

    What about 3 at 1300ma? Just making sure i'm rolling along correctly
     
  16.  
    Darkfurion

    Darkfurion Member

  17.  
    Godfather420

    Godfather420 Well-Known Member

  18.  
    BobCajun

    BobCajun Well-Known Member

    Yeah, you got it. But as mentioned by another poster, parallel wiring of COBs is not recommended. If you can afford to lose the COBs then it might be worth trying.
     
  19.  
    rth

    rth Member

    Last edited: Jan 16, 2017
  20.  
    visajoe1

    visajoe1 Well-Known Member

    I run (2) CLU048 1818 90CRI on the A version on this driver at 100%. It pumps
     
    SomeGuy likes this.

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