Help With Wiring 10w RGB Chips

Discussion in 'The Projects Forum' started by berry1, Oct 17, 2013.

  1. berry1

    Thread Starter New Member

    Oct 17, 2013
    Hi everyone i could really do with some help wiring up my aquarium light. Building a small led panel for my fluval edge nano reef aquarium and still really new when it comes to leds and wiring so if someone could help assist me with this it would be appreciated.

    I picked up 5 10w RGB leds unfortunately in the wrong colour spectrum so im waiting on some more to be delivered. Why im waiting on that im going to try and make a panel up from these 5 10w red RGB leds.

    Want to power the 5 10w leds using a 19v laptop power supply and wire them in series.

    So my main question is do i need a resistor? im guessing the answer to this would be yes so what resistor would i need? and could i use one large resistor on the positive wire before it goes to the leds instead of wiring a resistor after each led chip?

    Heres the specs from the led vendors page on ebay

    Forward Voltage (VF): DC 10-12V
    Forward current (IF): 1050MA
    Out put Lumens: 800-900LM
    Beam Angel: 140 degrees

    Link to the led chips im using

    Quick overview

    5 10w RGB leds
    Wired in series
    Run off a 19v power supply

    Also i dont currently have star heatsinks for the leds ? anyone know if this could be a problem? i was thinking of possibly using thermal adhesive to stick a piece of thermal pad to the heatsinks im using then use a small amount of thermal glue to attach the led chip to the thermal pad? so the led sits between the thermal pad and the main heatsink.

    Thanks for any help in advance and apologies if some of these questions are ridiculous lol.
  2. Shagas

    Active Member

    May 13, 2013
    Found a vid on youtube :

    You will probably have all your questions+ more questions answered there , if not I suggest searching youtube for more similar videos "Led aquarium Lighting' " aquarium Led" etc.

    Led's almost always need a resistor in series but I think these are actually led "chips" with an inbuilt resistor (or maybe even without) so You can just connect 10-12 volts dc and you are good to go but don't quote me on that , make sure first !

    As far as wiring them up in series goes .. well you won't be able to .Each Led needs 10-12 volts so you will need to hook them up in parallel .
    Looking at the data , they take a maximum of 1 amp current so if you want 5 of them in parallel then that would be 5 amps which your laptop power supply won't provide . (I think it gives a max of 3 or 4 amps ) .

    What I suggest is getting a cheap computer power supply.
    It's perfect for what you want, it gives 12 volts DC and plenty of current output .
    Cheap computer PSU cost about 20 bucks

    Good luck
  3. Melvang

    New Member

    Oct 17, 2013
    If you do some digging online you can find a power brick that plugs into the wall with a 4 pin molex connector on the other end. I know this really isn't what you are needing but it gives you a standardized plug. I have one behind my entertainment center running my pair of 12" CCFLs and the PC case fan I put in the back for helping cool my PS3.

    The reason I suggest this instead of the PC power supply is because you will have a bunch of extra wires hanging around doing nothing unless you buy one that is modular. Those you probably aren't going to find for $20. Plus there you would have to wire up your own switch to actually turn it on and off.

    For this you would need to install a momentary switch between the one green wire and any black wire on the 12+ pin plug that normally plugs into the motherboard.
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    Those aren't "RGB" leds.. Thats a misleading title on the ebay ad to attract more viewers..
    You simply have multiple 10W high power LED's of one color I suspect..

    The "smart" way to power these is not with a current limiting resistor but by using "constant current" drivers (power supplies)
    You have a few "common" choices now that most people are doing now with them.
    #1-Using a regular constant voltage power supply and then something like meanwell LDD drivers to provide the "constant current" portion.
    #2-A "complete" constant current driver like meanwell LPF series (my personal favorite) that you simply attach to the LED's and then slap on a wall plug and plug it right no need for a regular power supply with that choice. Plus you can do "dimming" with a manual potentiometer or pwm and analog signal if you might have a "aquarium controller" (Reef Angel for me)

    A good place to start is by doing a small series string.. Your power supply needs to be more than the sum of the max forward voltage ratings of the LEDs. A 19V supply isn't a good choice because of that..

    Personally I would get a meanwell LPF-40D-54 (and a 100K potentiometer if you want dimming) and put all 5 LED's in "series" (4 would/might be better if the vf is too high).. Slap them on a good chunk of aluminum (heatsink) and never look directly at the LED's when on.. They are BLINDING..

    Please don't forget about heatsinking and thermal grease.. They will be destroyed rather quickly without a good heatsink on them.
    Shagas likes this.