Curious LED question

Discussion in 'General Electronics Chat' started by musicalavtech, Oct 4, 2013.

  1. musicalavtech

    Thread Starter Member

    Mar 23, 2012
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    If a 3 lead, red/green LED was switched between leads/colors at a rapid rate, would/could a brown color appear to be emitted?
     
  2. nigelwright7557

    Senior Member

    May 10, 2008
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    Yes, you can vary the colour between the two extremes.
     
  3. #12

    Expert

    Nov 30, 2010
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    Red light plus green light appears to be yellow. Switch them fast enough and persistence of vision will make them both appear to be on all the time, so theoretically, you will see yellow. A very dull yellow might be interpreted as brown, but I don't think so. There is also the consideration that some very poor quality LEDs exist. Some of them are hard to tell whether it's green or yellow in the first place.
     
  4. MrChips

    Moderator

    Oct 2, 2009
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    You are thinking of red and green subtractive colors.
    If you mix red and green paint you get brown.
    However if you add red light to green light you will get yellow.
     
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  5. #12

    Expert

    Nov 30, 2010
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    Thanks. I couldn't place the reference to brown so I didn't make the required connection.
     
  6. shteii01

    AAC Fanatic!

    Feb 19, 2010
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  7. musicalavtech

    Thread Starter Member

    Mar 23, 2012
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    Ok then. My curiosity is cured...for now. Thanks.
     
  8. ErnieM

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    Apr 24, 2011
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    Last time I did this with a red & green LED it appeared as orange with both alternating on: you need the proper mix of red & green to get yellow.
     
  9. MrChips

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    Oct 2, 2009
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    Orange...yellow, close enough. Men don't know the difference!
    I'm sure if you increase the current it will look more yellow.
     
  10. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    That is true. On our unit it was orange when I looked down when the unit was sitting on the table, so I was looking at the led sort of from the side. But when you looked straight at it, head on, then it is more yellow.
     
  11. mcgyvr

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    Oct 15, 2009
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    real men know the difference.. Its orange.. ;)
     
  12. ian field

    Distinguished Member

    Oct 27, 2012
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    True - but if you dim it down to low current, the yellow will start to look brown.
     
  13. MrChips

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    Oct 2, 2009
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    So what color is it, yellow, orange or brown?
    If you dim it low enough it will appear black.:rolleyes:
     
  14. ian field

    Distinguished Member

    Oct 27, 2012
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    Orange is about midway between yellow & brown.
     
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