Leds not working when Soldering them (pics)
Posted: 06 October 2011 08:49 AM   [ Ignore ]
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HI again
straight to point

I joined 3LEDs with the help of a thin wire(got after peeling a wire apart) they worked fine
But when i soldered them they don’t glow

both time powered with 3AA size cell 1.5v

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Posted: 06 October 2011 12:42 PM   [ Ignore ]   [ # 1 ]
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I’m no expert on soldering, but I do believe LED’s are very delicate when it comes to heat.  I’d try putting your power to each LED individually in the chain and see if they still work singularly.  It is possible that A) you don’t have enough power! B) one or more of the LED’s took heat damage during soldering and will need to be replaced.

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Posted: 06 October 2011 04:03 PM   [ Ignore ]   [ # 2 ]
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hey
1-Make sure you respect the polarity.
2-1.5v on 3 led in parallel ... not sure you got enough voltage…
try 8 in parallel on a 12 volt dc source.

good luck
js

ps:  if they work you won t see it with your eyes, try to use a cell phone camera to verify they are working

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Posted: 06 October 2011 04:22 PM   [ Ignore ]   [ # 3 ]
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Looks like the polarity is wrong on one of the LEDs, the on the left (from what I can see from the image).

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Posted: 07 October 2011 05:51 AM   [ Ignore ]   [ # 4 ]
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Thank all smile

Though I tried best to keep polarities in position but the last one was placed wrong

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Posted: 07 October 2011 05:58 AM   [ Ignore ]   [ # 5 ]
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I have made holes on all four sides

2 side 33 holes (will make 11 groups)
2 sides 39 holes(will make 13 groups)

I’m thinking of making group of 3 LEDS .That’s fine rite? It’s just matter they glow

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Posted: 07 October 2011 06:17 AM   [ Ignore ]   [ # 6 ]
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That will work fine but it would get messy with wires and getting a proper power supply. Using 8 LEDs in series with a 12V supply would probably be a cleaner solution, you can just use resistors for the remaining LEDs that are not in a group of 8. Also 12V power supplies are usually easier to find than 4.5V. I know that you tested the LEDs with batteries but batteries might not be the best solution to run all the LEDs in your multitouch table with.

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Posted: 07 October 2011 06:30 AM   [ Ignore ]   [ # 7 ]
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Actually I’m a student in foreign country
Don’t know Arabic so its hard to tell the shopkeepers around what I want
Since I m doing it all alone (physically ,though Whole NUI group is with me smile)
So, in short all that matters is that they should glow
and today I’ll look for DC power supply
Now busy soldering LEDs

Thanks NUI members smile

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Posted: 08 October 2011 01:42 AM   [ Ignore ]   [ # 8 ]
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I suggest that you get an led in the visible spectrum and hook it in the string temporarily. That way you can see right away if your string is working. Also, you should do a google search for LED Wizard. This app will help you set up your array of leds and the resistors needed.

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