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HELP to make a hanging cluster of LEDs. I would like the LEDs in groups and one group at a time fading in and out. Answered

Hi Everyone,
I am new to Electronics (well I did the basic electronic circuits in Highschool but that was many moons ago!) and am needing some advice. 

I am wanting to set up a hanging cluster of approx 300 LED lights.  Each LED will be hanging off its own individual wiring.  In the cluster there will be certain lights creating groups.  I would like all LEDS to come on at the start and then fade out. Then one group at a time to fade in and fade out. I have attached a VERY BASIC colour-coded drawing to show what I mean by the cluster and the groups.

I am wanting to use LEDS that are smaller that 1cm in diameter.  I would like the warm white look instead of the cool blue white and each LEDs need to be quite bright.  I like the look of the Dome LEDS but am open to suggestions!  This set up would need to be battery powder.

I have been trying to research how to set it up but am a bit lost.  I am stubborn and driven so my lack of experience will not stand in my way.  Any help, advice or pointing in the right direction would be awesome.

Thanks Team!
 

Discussions

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Wired_Mist

4 years ago

Wow, you really want to open a can of worms there eh? Right on!

Let me break it to you right now, you'll be working on this for a couple of months. The Logistics of soldering the 300 LED's alone means a minimum of 1200 solders, Ouch!

Start with what Rick-Harris posted, that will give you an Idea of what you need to do.

(A:) You said you wanted to turn them on and off in groups, So run groups of 3 LED's in series with a 100-120 Ohm resistor, that will allow you can run them off 12V. The Higher source voltage will bring your power consumption down to something more reasonable. (12v @20ma VS 5v @60ma) You could get away with a 2.5 Amp-12V power adapter, Barely.

(B:)You will also need to control them Using a Micro controller (I Prefer Arduino but PICAXE would work just as well. I only suggest Arduino because there is more of a community for help)

Even if you fallow my advice buy running them on series, that still leaves 100 strings to drive (Not going to Reasonably happen) Check This Out The TLC5940 will be able to supply a safe 100ma of current per Channel; meaning you can fit up to 5 of the strings I mentioned earlyer per channel. So set up two TLC-5940 in Parallel (See Picture attached) then wire 3-5 strings per pin of the Chip as you see fit.

As you need more help to get this rolling, and eventually finished, feel free to send me a Private Message and I'll offer what Help I Can :)

Good Luck; You'll need it :D

breadboard-arduino-tlc5940.png
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ahartitzschWired_Mist

Answer 4 years ago

WOW! I will be honest this is a lot harder that i thought it would be! It is like a complete different language! I will be having a look into all the replies I get so firstly I can understand what is being said and secondly be able to start!
Thank you for all your info and offer to help in the future! No Doubt I will message you!

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-max-

4 years ago

Build up a simple a simple arduino with a ATmega328 (get the one w/ the bootloader on it) and use all the analog output to drive a small MOSFET like the 2N7000 which will drive the LEDs (assuming you are using 30mA 5mm LEDs). There is a LOT of info on the web about making a custom arduino, and it is much cheaper than an arduino board itself.

You will need a $8 FTDI adapter (which is a simple USB to UART serial converter basicly) to program it and get a 'sketch'. It should be very easy to program just a simple looped outputs, that was the first thing I learned on arduino, and it took less than 10 minutes to figure the basics out (like making LEDs blink, anyway!).

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ahartitzsch-max-

Answer 4 years ago

Thank you for your help. Will be busy research for the next wee while!

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rickharris

4 years ago

1. If you want your LEDS to fade up and down then your going to need to use some kind of microprocessor (computer)

http://www.picaxe.com

(See their manuals to see how microprocessors work.)

To fade an LED you need to turn it on and off very quickly. In principle you could do this with a simple timer cct such as a 555 timer chip. However to automatically fade up and down would be hard with just a timer and no electronic experience.

2. To understand how LEDs work and how to drive then try looking here

http://led.linear1.org/category/led-basics/

3. As a generality a normal LED draws about 10 to 20 Ma of current. 300 will need 300 times that so up to 6 amps. (6000ma.) That's quite a lot.

If you want very bright LEDs then they need more current.

4. To successfully drive leds you really need a constant current source.

That should give you some things to look up and read about

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ahartitzschrickharris

Answer 4 years ago

Thank you very much for your advice! You have given me lots to research and look into- I now know what I will be doing on the stat holidays! It is like another language! Exciting and terrifying all at once!

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Wired_Mistrickharris

Answer 4 years ago

+1

Start by reading ALL of this before you even pick up a soldering iron !