200+ led project.

Discussion in 'The Projects Forum' started by M-Nateo, Aug 16, 2009.

  1. M-Nateo

    Thread Starter New Member

    Aug 16, 2009
    2
    0
    Hello,

    This is my first post here, so hello!

    I'm working on an led sign. I have over 200 leds connected in series pairs with a 150Ω resistor. I'm using an Arduino Microcontroller to output to 3 arrays of leds. I'm using an N type mosfet(IRF 510) that uses the logic signal from the arduino to switch the power on and off from the second power source. I have a diagram. the sets of LEDs are representations of much bigger arrays.

    [​IMG]

    The problem is when I output a logic 5+ signal to 1 array they all turn on. I want to be able to activate each of the transistors independently with the 5+ signal from the micro controller. thanks for the help!
     
  2. bertus

    Administrator

    Apr 5, 2008
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  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    You have the Mosfets connected backwards. The source should connect to 0V and the drain should connect to the cathode of the lowest LED.

    Your circuit does not have a common 0V and I don't know why it has two 9V batteries.
     
  4. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    As audioguru has indicated, your circuit is miswired. When you turn on any one of the mosfets, the negative terminal of your battery is tied to ground and therefore all of the leds are illuminated.

    hgmjr
     
  5. M-Nateo

    Thread Starter New Member

    Aug 16, 2009
    2
    0
    Thanks got it!
     
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