Wiring 5 blinking LEDs over 100 foot distance

Discussion in 'General Electronics Chat' started by kaushika, Dec 22, 2013.

  1. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    I want to wire 5 blinking LEDs over a distance about 100 foot.

    A few design goals:
    Should be able to run continuously 24/7.
    Power consumption should be minimum.

    Looking for design ideas for power supply, type of wire and blinking mechanism.
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    What do you mean, a 100 foot distance.

    Do you want the light to be visible 100 feet away, do you want to trigger it to flash from 100 feet away (wired, wireless)...? Other?
     
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
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    A little more info.
    What blink rate?
    Are they just standard 20 ma leds?
    What color?
    Do they all blink at the same time?
    If they are standard red ones and all blink at the same time you could hook them in series and drive them with a simple 555 timer and a 15 volt supply.
     
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  4. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    By "over 100 foot" I mean that LEDs are placed at about 20 foot distance (20 foot of wire in between them). I just want to use standard LEDs.
     
  5. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    No need to blink at the same time. Any color (red would be better) would do.
     
  6. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    Do you mean 15 Volt DC? I have a transformer of 12 Volt DC, would that do?
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    12V should do.
    If you want to minimise the amount of wire needed (200 ft) you have two choices:
    1) build a timer circuit and wire standard LEDs in series (they will then blink at the same time),
    2) use LEDs with a built-in blink function (they will then blink at different times and no timer circuit would be necessary).
     
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  8. Brownout

    Well-Known Member

    Jan 10, 2012
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    I recommend #2 in the post above. Those LED's should have integrted current limiting, and so all you need is you 12v power supply and a linear reagulator for the operating voltage, probably 5v.
     
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  9. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    What kind of wire would you recommend? Thickness etc.
     
  10. kaushika

    Thread Starter New Member

    Dec 22, 2013
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    How much amperage is needed with 5 V (or 12 V) supply?
     
  11. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Option 1
    Assume 25 mA if you wire 5 red LEDs in series with 68 or 82 ohm resistor in series with 12 volt supply (5 volt supply does not work here). You can use something as low as 30 guage wire here.

    Option 2
    Assume 25 mA x 5 LEDs is 125 mA for a parallel connection.
    You will need a resistor in series with each LED as you connect them across the two 12 v or 5 v main wires.

    For Option 2 and 5 volt supply, use 120 ohm resistor with EACH LED

    For Option 2 and 12 volt supply, use a 390 or 470 ohm resistor with EACH LED.

    Use a bit thicker wire here because you are carrying slightly more current AND the LEDs further from the source wil see more resistance in the wire than those close to the power supply (not a problem for option 1 (all will automatically be the same briteness)). Use something between 18 and 30 guage (what ever is cheapest).

    Option 3
    You can buy hobby LEDs with a built-in resistor. In that case, do things the same as option 2 with 12 volt supply and skip the resistor.


    Remember that LEDs are very directional. You may want several LEDs at each node to improve visibility.
     
    Last edited: Dec 23, 2013
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