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Thread: New to DIY LED Lighting...please help!

  1. #1
    Fresh Paint
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    Default New to DIY LED Lighting...please help!

    I was thinking about picking a few of these up as my first project.
    https://www.goldmine-elec-products.c...p?number=G9987

    I figure they are cheap and if I can pull it off they will make a great addition to my basement as DIY LED pars.

    Alas, as I mentioned I am very new to all this, and as technically inclined as I feel I am, after doing a ton of research, I've realized I don't even know where to start.

    Any pointers? What am I going to need to power these things up? Will I be able to make them run through a 110v wall socket? If so, what parts do I need to pick up?

    Any push in the right direction would be greatly appreciated.

    Thanks in advance.

  2. #2
    Ceann na Drochaide Bige! XcOM's Avatar
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    Default Re: New to DIY LED Lighting...please help!

    buy best guess (As the site provides no info on that item at all) i would guess it would run on about 35-40 volts as it says 19v for green and 13 for red which is 32v, plus some for conversion.

    I would assume you would need a control board for it as from the looks its software controled, either that or there a 3 pole switch on the back of every LED (Yea rite)

    Your best bet would be to e-mail them and ask for a model number or link to the manufactures site so you can get more info on it.

    But im prity sure you will need a control board of some description, Will be cool though if you get it working


    Mary had a little lamb. It bumped into a pylon. Ten thousand volts went up its arse and turned its wool to nylon!

  3. #3
    Fresh Paint
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    Default Re: New to DIY LED Lighting...please help!

    Quote Originally Posted by XcOM View Post
    buy best guess (As the site provides no info on that item at all) i would guess it would run on about 35-40 volts as it says 19v for green and 13 for red which is 32v, plus some for conversion.

    I would assume you would need a control board for it as from the looks its software controled, either that or there a 3 pole switch on the back of every LED (Yea rite)

    Your best bet would be to e-mail them and ask for a model number or link to the manufactures site so you can get more info on it.

    But im prity sure you will need a control board of some description, Will be cool though if you get it working

    Thanks XcOM...I figured out that it is the Sharp LT6750 and the datasheet is here:
    http://chipmanuals.com/datasheets/download/170251.html

    Any other tips now that I've found this?

  4. #4
    SOB Fettler xmastree's Avatar
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    Default Re: New to DIY LED Lighting...please help!

    Quote Originally Posted by XcOM View Post
    buy best guess (As the site provides no info on that item at all) i would guess it would run on about 35-40 volts as it says 19v for green and 13 for red which is 32v, plus some for conversion.
    That's not how I interpret it. I would guess there are two strings in there, green and red, individually wired.


    This datasheet from here shows the internal wiring, last item on page 3. Notice there's no current limiting device there, so you shouldn't just connect them up to a voltage. You need a resistor in there too.

    Running all requires 180mA, which isn't much at all.

    I would use a 24V wall wart, since they're readily available.

    So, time for the maths.
    Forward currents are: Green 120mA red 60mA.

    So for the green, 24V - 19V = 5V.
    Ohm's law: R=V/I = 5/.12 = 41.67 Ohms. 39 is probably the nearest.
    P=VI = 5*.12 = 0.6 Watt. Use 1 Watt

    Red, 24V - 13.2V = 10.8V
    R=V/I = 10.8/.06 = 180 Ohms
    P = VI = 10.8*.06 = .648 Watt. Use 1 Watt


    So to run off a 24V supply, the Green needs a 39 Ohm 1 watt resistor and the Red needs a 180 Ohm 1 Watt resistor.



    Edit: I just thought of something. If you go for 24V, you could put a couple of 12V batteries in there too and end up with some pretty cool emergency lighting.

    Quote Originally Posted by aintnothang View Post
    Think of a way to simulate a real bullet hole, like shooting it.

  5. #5
    High-tech Redneck crazybillybob's Avatar
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    Default Re: New to DIY LED Lighting...please help!

    You could use one of the Flashing circuits that have been posted here at TBCS to make the Red and Green LEDS flash at different times, just replace the led in the circuit with a 5V Relay or a FET.... If you not sure just ask one of us will guide you to the proper ends

    Nice find by the way!

    Xmas I read it the same way (white lead is ground Red is + for Red LEDs, Green is + for Green LEDS)

  6. #6
    SOB Fettler xmastree's Avatar
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    Default Re: New to DIY LED Lighting...please help!

    Quote Originally Posted by crazybillybob View Post
    Xmas I read it the same way (white lead is ground Red is + for Red LEDs, Green is + for Green LEDS)
    So we were both wrong then... Looking at the spec sheet, white is +ve and the colours are -ve for each colour.

    Quote Originally Posted by aintnothang View Post
    Think of a way to simulate a real bullet hole, like shooting it.

  7. #7
    Practice random acts of generosity Omega's Avatar
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    Default Re: New to DIY LED Lighting...please help!

    Any teasers as to what the project will be? If It's something that needs that particular assembly, then go for it, but if you just want to cannibalize it for the LEDs, I say find a LED dealer that you can get LEDs with known specs for and build the custom assembly yourself.



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