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King Cob Led grow light

Discussion in 'LED and other Lighting' started by VegasWinner, Dec 1, 2017.

    Colo MMJ

    Colo MMJ Well-Known Member

    LOL! That wasn't lost on me. I was like - WTF?

    I guess it works for big Mike of Advanced Nutes with his bimbo girls and his Ferrari.
    VegasWinner and Randomblame like this.

    Dave455 Well-Known Member

    Wonder how much better mirror finish ? Be like mirror reflector ? EC option - priceless.
    Randomblame likes this.

    CobKits Well-Known Member Rollitup Advertiser

    Prawn Connery and Randomblame like this.

    VegasWinner Well-Known Member

    I like the modular concept. The light uses some cob could be any brand.
    Looking at the fixture I was thinking this would be a nice setup for using rigid strips in a modular fashion.
    I am not looking at the diode perse but the concept.
    Moflow and Randomblame like this.

    VegasWinner Well-Known Member

    My GrowGreen 200w pxb has 384 diodes and at 100w slightly warm heat sink using 5.886" x18" with fan much warmer at 200w
    Moflow likes this.

    legalcanada Well-Known Member

    yes the modular design is pretty cool with moveable light rails. i also like the rapid led canopy substrate with 3 and 4 axis rotation. skip to 6:20 as doesn't seem to work on RIU
    Moflow and VegasWinner like this.

    GrowLightResearch Member

    When the DYI guys now have the incredibly inexpensive Samsung F-Series strips, I do not understand why anyone would still be doing CoBs.
    The only appeal CoBs had once upon a time is they were easy to use to build a DIY fixture. LED strips were always superior to CoBs. Better uniformity and much more efficient. The difficulties of fabricating PCBs and assembling them was too much for the DIY guy, The price of these new Samsung strips is so low I, a low volume manufacturer for the past 20 some years, cannot make a similar strip for less than Samsung charges. I have my own pick and Place robot to assemble the boards, still I cannot beat Samsung.

    Bridgelux is the only CoB that can beat Samsung F-Series strips in cost per lumen. Add the cost of thermal management for a 10,000 lumen, 50+ watt CoB and Samsung kicks ass. Then compare uniformity and the increase in PPFD when you lower the strips to within inches of the canopy and the savings in electricity sweetens the deal. Spreading the heat generated over a four foot strip vs. all those watts concentrated in one sq. inch, how can anyone defend using a CoB???

    Then consider the ease of building a DIY fixture with a strip that has poke in power connectors. All you need is about $20 in aluminum right angle brackets (4' x 4') and the power supply drivers. Speaking of drivers, Please do NOT drive CoBs or strips in parallel. LEDs will only have uniform output when driven in series. I do not care how many idiots and morons say you can drive them in parallel, you should NOT do that. The idiots and morons say they have connected them in parallel and say they lit up. When they have not done is measured the current in each strip or CoB. They WILL be unbalanced. No if's and's or but's about it, they will be unbalanced.

    These Samsung strips have taken the price advantage HPS had over LEDs. Dollar for dollar, kW for kW, these strips beat HPS.

    HPS and CoBs are dead. RIP.

    Last edited: Dec 3, 2017
    Prawn Connery and VegasWinner like this.

    nfhiggs Well-Known Member

    Stop tilting at windmills.

    ChaosHunter Well-Known Member

    You do realize the strips and Quantum boards are COBs right ?

    CobKits Well-Known Member Rollitup Advertiser

    because on an efficiency basis the cost is about the same. if you want to build a fixture at a given ppfd/W or lumen/W the costs are comparable

    cobs are also better if you need optics like lenses and reflectors. diffuse light isnt a universal solution for all applications

    CobKits Well-Known Member Rollitup Advertiser

    sure we have. lots of times. the difference is slight and comparable to the difference of wattage and flux between running cobs of variable voltage at constant current in series

    you were actually the one basing all of your experience on a single measurement of an oddly-matched setup nobody here is using. as compared to literally hundreds of actual setups of cobs of appropriate number on drivers of appropriate size that are growing lots of crops as i type this.

    GrowLightResearch Member

    Really? You may want to rethink that.
    A well designed horticulture grow fixture will need not need lenses. And reflectors? Reflectors? CoBs are not isotropic light bulbs. There should be no reason for photons to exit a CoB and be interrupted besides anything other than a leaf.

    Not true. Have have tried similar experiment three times in the past year or so. Each time parallel was problematic. I do have many years of experience in electrical engineering and manufacturing. These things I say are true. Just because they light up does not mean it is being done correctly.

    It's not a big deal. Not going to have a noticeable effect on yield. There are many little things you can do wrong. When you know (or should know) there is a better way to do it, at no additional cost, why keep doing it wrong? Sure, still the same amount of photons will reach the plants. 60% of the photons may come from one CoB or strip and 40% from the other. No one will notice. But all the little stuff adds up. Some day you may understand the difference between right and wrong.

    With the amount of knowledge as you have had on the subject I find it doubtful you would know how to measure the two currents simultaneously or have the tools to do so.

    Fair enough. Can I still keep tipping cows?
    Last edited: Dec 3, 2017
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    CobKits Well-Known Member Rollitup Advertiser

    we know... you tell us every time you post

    i am also an engineer... but dont post about it because people dont really care they judge the posts by their individual merit around here

    busted. i dont own two multimeters to perform this complex measurement. shoulda known you'd see right through me
    Last edited: Dec 3, 2017
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    Randomblame Well-Known Member

    All you say is absolute correct but the voltage and resistance differences are really low in current LED products and when you look at QB/F-strips they are also wired in series/parallel connection and works very well ... and they are unbalanced. Both QB's as well as strips have no on-board CC drivers like some 24v CV strips have but they run very well.

    It really does not matter if one strip provides 1 or 2w more than another, as long as they are cooled properly and there is no thermal runaway. This means it does not matter if you use a QB or a few parallel connected strips.

    Also if you use a 48v CV/CC meanwell driver and use it with a few 46v F-strips in parallel you are still in it's constant current region and you can limit the voltage to say we 48,5v to limit the strips from getting too much current, because a strip would need ~49v when driven at 1,8A(200mA per diode). A voltage limit of 48v for instance would mean the strips could not get more current than 1,4-1,6A and this is well below it's maximum.

    We do not do it because it is right, we do it because in the DIY area it gives more security to work with lower voltages. We know that slight bumps can occur and we accept that, because the differences are so small that they realy do not matter.
    Moflow and nfhiggs like this.

    Shawndeadhead Well-Known Member

    I'm happy with my Veros at 1 cob per sq ft. Why would you say rip cobs ? QB boards are just a bunch of tiny cobs lined up next to each other ???? Crazy what I'm doing with this old technology.... Guezz I'm just old school !!!!! Lol IMG_20171130_193903.jpg IMG_20171201_185905602.jpg IMG_20171201_185030760.jpg IMG_20171126_225232.jpg IMG_20171130_192214.jpg
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    key4 Well-Known Member

    Last edited: Dec 4, 2017
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    Randomblame Well-Known Member

    If you are unsure, measure the vf of each strip at the same current and note it on the strip. Once you've measured them all sort out stripes with more than 0.1v difference. I'm quite sure the most of them are within a smaller difference.

    If at all QB's are arrays from discrete diodes not COB's and also no tiny COB's, LOL! You could compare them with first generation COB's but with a much bigger footprint. The tech behind is the same only the packing is different.
    Moflow likes this.

    Shawndeadhead Well-Known Member

    Hmmmm tells me they are just chip on board diodes that are spread out further, same technology just not as many dies on each chip.....
    "A typical COB has hundreds of individual diodes mounted to its little board, packed very tightly together. There are hundreds of diodes in these QBs as well, but they’re spread much further apart. The principal of harnessing the power of several small lights to produce one powerful source of light is the same, but the QBs just do it on a larger scale."

    VegasWinner Well-Known Member

    COB's have a different cooling technology than LM561C pcb's. pcbs are designed to dissipate heat thru the traces, while cob's have no traces and have one substrate for heat dissipation. The cvircuits are longer in pcb's for the purpose of heat dissipation, cobs are gathered to create a central light effect or a point light versus a distributed light. basic difference in the two dissipation, distribution, and substrate.

    key4 Well-Known Member


    Sounds like you have used every light going, you got any journals to look at?
    ChaosHunter likes this.

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