Wiring Led Problem

Discussion in 'The Projects Forum' started by Abrupto, Apr 6, 2009.

  1. Abrupto

    Thread Starter New Member

    Apr 6, 2009
    5
    0
    Hi,

    I'm having a problem with a 5V 20mA led that is wired to two different I/O cards the I/O card A and I/O card B. I want to use the card A and the card B each at a time not both at the same time. So when the card A is connected to the computer and powered the card B is unplugged and vice versa.
    What happens is that if the wires that goes from the led to the card B are connected to the card the led does not light. As soon as I remove them from the card the light comes on. The card B is unplugged .
    What is causing this. Could you please help?

    Best Regards
    Abrupto
     
  2. galal_mounir

    Member

    Apr 5, 2009
    29
    0
    could you attach a circuit diagram to help us understand wat u mean i dont actually get wat u mean
     
  3. Abrupto

    Thread Starter New Member

    Apr 6, 2009
    5
    0
    Tank you for your help. Sorry about my drawing... I'm a newbie...

    Regards
    Abrupto
     
  4. galal_mounir

    Member

    Apr 5, 2009
    29
    0
    where is the led connected in the card ???
     
  5. Abrupto

    Thread Starter New Member

    Apr 6, 2009
    5
    0
    both cards have predifined places to wire the the leds. They are wired there.
    Regards
     
  6. galal_mounir

    Member

    Apr 5, 2009
    29
    0
    i mean u sure u connected the ground to the -ve and the vcc to the +ve or did u invert it
     
  7. Abrupto

    Thread Starter New Member

    Apr 6, 2009
    5
    0
    Tank you
    I'm sure the connections are correct. Double check twice
     
  8. galal_mounir

    Member

    Apr 5, 2009
    29
    0
    when do u want the led to light exactly ?
     
  9. Abrupto

    Thread Starter New Member

    Apr 6, 2009
    5
    0
    as soon as the switch is turned to the on position
     
  10. galal_mounir

    Member

    Apr 5, 2009
    29
    0
    wat switches there are no switches in the schematic u drew
     
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