COB LED

Discussion in 'Anything DIY related' started by f-fish, May 11, 2018.

  1. f-fish

    f-fish #unspecified

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  3. Barry Roux

    Barry Roux

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    Hi Ferdi is the led place on the metal part off the heatsink? You should be able to run without an fan if the heating isnt in an closed up area
     
  4. OP
    f-fish

    f-fish #unspecified

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    Morning Barry
    Yeah figure I can flip the CPU mount .. that gives me 5mm closer to the heatsink then just clamp it down. Busy warming up the soldering iron to give it a spin.

    Later Ferdie
     
  5. Innocent159

    Innocent159

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    I like your projects @f-fish always nice to see something used for something different to its intended purpose
     
  6. OP
    f-fish

    f-fish #unspecified

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    Part of the fun I suppose.
    Yw4f-E9G5ZuWC7C_Px09RJrFmg7GU6ywHFKNAGB6-NlfpbwOHyobko8IdLFUFvrXWTwxpPtSjKaR56yjw=w2200-h1241-no.jpg
    So that is a no ... to run the 30Watt COB without running the fan ... man these cobs are inefficient. Good thing it is winter I an do not min a bit of extra heat in the room. 15 minutes in and I can not touch the heat sink.

    cBRiX2mmYGT405ahiVqDMUBOoxWEiFpNyozsGWsYKpKw6UhVncBlc4naH_hLYQeC5zTR7ZP41aP-UR0yg=w2200-h1241-no.jpg
    Trick is to mount this as flat as possible ... had to do a bit more adjusting after this pic.

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    Light int he tank seems less blue than the other panels, not 100# sure this is going to be a successful solution yet.

    Later Ferdie
     
  7. OP
    f-fish

    f-fish #unspecified

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    with lights on the difference is huge ...

    Bo1AR0mY0I0UM-SyRN23zUWvMjXiKYElimcyG2mTm29_FUK6Pexgrba6MrHbWgEMCvnB6F18Hab0aKRhQ=w2200-h1241-no.jpg

    Back light normal t5 tube, left panel grow light and right the COB grow light.
    72aMLz2pLrFVCFUnlSMp0V5tMY1Ht_Dzjn0GvXCRbTekP7iZAqr9kxFJU0Ida-rutDG92Eq9pjja19FCQ=w2200-h1241-no.jpg
    With just the back off you can really see the difference ...

    Later Ferdie
     
  8. OP
    f-fish

    f-fish #unspecified

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    With the fan on it stays very cool - almost cold to the touch.
    and stays at a constant power consumption of 34 watts.

    f47_h9zlYdcI9Zl7668uolOkx8i3hF_wpQTdlEE2K_bYSTiBQ7-Z6lgbPwULPxwtcOUfpRSPxhEoqW6XQ=w2010-h1265-no.jpg

    but
     
    Last edited: May 12, 2018
  9. OP
    f-fish

    f-fish #unspecified

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    With in 13 minutes .. I can not touch the heatsink when the fan is off and the power draw has decreased - I assume the preotection circuit on the device is causing this or it is getting ready to burnout.

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    less than a minute later is stabilizes on 33 Watt draw and the unit is cool to the touch once the fan is switched back on.

    So clearly the fan is the way to go here. Wonder if the this will work form usb 5 volt ... less flow but maybe one does not need all the draw

    Later Ferdie
     
    Last edited: May 12, 2018
  10. OP
    f-fish

    f-fish #unspecified

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    It did take a while for the consumption to get back to the original values ...
    yTHKMaXw4xae5RRnXizb-lcnCPFaGaXYvolqWyvttCpSsJuyROZ1pPQlEcgh8AVRSE1pYe8xFzFmfUHig=w2200-h1241-no.jpg
    timeline below

    upload_2018-5-12_13-23-24.png

    Later Ferdie
     
  11. Barry Roux

    Barry Roux

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    If you add some heatsink paste between the led and the heatsink your heat transfer will be better also an longer contact area with the flat surface off the heatsink will help to disperse the heat better
     
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  12. OP
    f-fish

    f-fish #unspecified

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    100% .. got the thermal paste ... heatsink gets too warm to touch ... but good thing it comes with a fan ;-)

    I think these full spectrum COB's generate way more heat than say a 4000k one , have seen it with LED strips also RED runs way hotter than a white LED.

    Once thing is nice ... this spectrum is way more photo friendly.

    oFtOIU4q91ZGCs1mUANLIV6LZH-DEuE0SLi1NUQwVD_VqxPkRz4_hzRNvcZYCP_GBcMi2yAao12DNWeWg=w2200-h1241-no.jpg

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    Should probably clean up the cables and wire it all in, seems like it is here to stay

    Later Ferdie
     
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  13. Beachless

    Beachless

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    Its a pity its harder to drop the voltage on AC would love to see how much cooler it runs off say 200v. My cob led's haven't even registered on the SA side yet :(

    I think watercooling would also be a interesting thing to try especially during winter.
     
  14. OP
    f-fish

    f-fish #unspecified

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    Yeah just ordered some other form bang good, not expecting them for 50 days or so.

    contemplated water cooling before .. but that was on 12 volt kit, would not dream of it with 220 in the open.

    later Ferdie
     
  15. Barry Roux

    Barry Roux

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    Maybe an stupid q but cant you add an light dimmer and drop the voltage that way ?
     
  16. Beachless

    Beachless

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    With the 220v you would have to be careful but using pc water-cooling heater blocks and sealing the cob in a glass covered case it should be ok. Some fuses are also a good idea. If you look at the cob security lights that are meant to go outside that could also do as a waterproof casing.
     
  17. Beachless

    Beachless

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    Not a stupid question at all. The short answer is it depends. AC LED's are more finicky about being dimmed and the older dimmers need a big load to dim the lights properly. You end up having strobing and other issues. I have ordered a few dimmers both AC and DC with my cobs but it can be a bit of a hit or miss with the AC ones and they are more pricey.
     
  18. OP
    f-fish

    f-fish #unspecified

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    Using dimmers all depends on what these AC all in one COB block does. The heat with the fan is actually perfectly OK. If one wanted to be safe then a temp probe on each heat sink that kicks off the power if it gets to hot is the way to got.

    Just checked - I am already using a sonoff Th16 to switch this power line for this bank .. got a temp/humidity probe connected to it at the moment.

    upload_2018-5-13_12-10-36.png

    But one can easily add several ds18b20 and add a safeguard rule around heatsink temp on these lights. The AM2301 and the DS18B20 should be just fine on the same 1-wire bus ... but for the Si7201 I need to make a note for myself that I will need to upgrade to a newer version of espeasy .. https://github.com/letscontrolit/ESPEasy/issues/691 so I will leave those in the draw for now.

    Later Ferdie
     
  19. OP
    f-fish

    f-fish #unspecified

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    Hmm should have done this before ... get a pic of the COB and what is actually working and what not. Not 100% sure but might have lost a chip already or maybe never had one working in the first place ?

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    oh well ..
    Later Ferdie
     
  20. OP
    f-fish

    f-fish #unspecified

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    Ok had to look if I had burned a COB or not ...
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    Looks the same as when I got it .. so maybe that is why they are being sold a singles? Nice thing it is cold to the touch when you switch it off - yes even after running the entire day. Finger print shows where I touched it.


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    While I had it flipped I added some of these thing for virbation damping - no I idea how they will survive in the fishroom.

    Later Ferdie
     
  21. OP
    f-fish

    f-fish #unspecified

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    Ah yes the other thing I forgot to measure lux

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    Now this mean little to nothing - since the UT383 is not really that great a lux meter - one can not calibrate it to the different spectrum etc

    What this will tell me is COB degradation over time. But WOW ... look at the math 16240/34 = 477lux/Watt

    Compare that to the previous grow panel

    uDdtH_782Sm18ZmDdK3DxerByi2mC5ExgvsG6J7JxQxPmMl2Cq7llpf4x1y-tKf8bH6e8pWzp8kLcEhIw=w2200-h1241-no.jpg

    3526/13 = 271 lux/Watt

    Later Ferdie

    PS a side note edit ...

    meter measures flux not lm ... your light bulbs might report lm/watt - 1 lux - 1lm.m2
     
    Last edited: May 13, 2018

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