Connect with us

How to wire LED

Discussion in 'LEDs and Optoelectronics' started by z7master167, May 9, 2013.

Scroll to continue with content
  1. z7master167

    z7master167

    5
    0
    May 9, 2013
    I am trying to wire some uv leds up to a 12v deep cycle marine battery heres what i have done, i bought 4 uv lights at walmart they have 9 uv leds. I soldered one wire to positive and one wire to negeative on all 4 lights. I then took the positive wire from all 4 lights and soldered them together then i took a 10ohm resistor and soldered it on the 4 wires , then i took all the negative wires and soldered them together then i hooked them up to the battery, after a minute or so my resistor turned black and started smoking pretty bad, i on hooked if from the battery and now i dont know what to do i dont wanna burn up the lights
     
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
  3. glewis721

    glewis721

    49
    1
    Apr 30, 2013
    What's your powering situation like? Mabey the resistor couldn't take that much power.
     
  4. z7master167

    z7master167

    5
    0
    May 9, 2013
    Im using a 12v deep cycle marine battery , from everything ive read, the lights are on parallel theres 9 of them on each circuit board im assiming they are 3.5v amd 25ma so would i multiplt my milliamps 9x25 and use 4 resistors or would i multiply 36x25 and use one resistor im totally dumbfounded when it comes to this
     
  5. z7master167

    z7master167

    5
    0
    May 9, 2013
    No the resistor was brand new but it was 10ohm and 1/2 watt, on the online calculator it tells me to use a 7.8 watt 15 ohm resistor and thats hooking all 36 lights up to one resistor
     
  6. glewis721

    glewis721

    49
    1
    Apr 30, 2013
    WELL THAT'S YOUR PROBLEM!!! =)
    Get a resistor that can handle more power.
     
  7. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
    7.8W is a lot higher than 1/2 watt.

    Also choosing a 10 ohm resistor instead of a 15 ohm resistor made things worse (for the resistor AND the LEDs).

    It would be far more preferable to place a resistor in series with each LED, and even better again to arrange them in strings.

    If you can't do this, get a 15 ohm resistor rated at (at least) 10W and use that.

    A single resistor like this for LEDs in parallel is likely to result in the individual LEDs having a much shortened life.
     
  8. z7master167

    z7master167

    5
    0
    May 9, 2013
    Can i wire the led lights up in series even though the lights are wired in parallel? I can run one positive to the + on my battery then the - to the + on the other light and so on to all 4 lights then run the - to my battery from the 4 th light? And if so what kind of resistor do i need then? Anybody have a diagram?
     
  9. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,497
    2,838
    Jan 21, 2010
    You need to re-wire them.

    The alternatives are shown in the link I gave you in the second post.

    LEDs in parallel are only ever OK if they are both matched and in close thermal contact.
     
  10. z7master167

    z7master167

    5
    0
    May 9, 2013
    But i wont be able to rewire them they are already on there on circuit board wired in parallel from factory can i not wire in each 9 led light in series to one another?
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-