Unexpected Results with NAND Gate

Discussion in 'Homework Help' started by User1.0, Aug 10, 2011.

  1. User1.0

    Thread Starter New Member

    Aug 10, 2011
    13
    1
    I have only just begun with any circuitry whatsoever, and have already fallen into an issue. I'm reading "Electronic Circuits for the Evil Genius 2nd Edition" On the introduction to the NAND Gate, I was to build the circuit shown below (including key.)

    [​IMG]



    My issue is that when built, I have the exact opposite results than what the book shows. I've checked my wiring several times against both my interpretation of the schematic, and an actual picture of the breadboard in the book.

    The book states that when the switch is off (open circuit) the light should be off, and when the switch is on, the light should come on. It should remain on for some time after the switch has been released.

    My results:
    Switch off (again, open circuit) - LED on
    Switch on (closed circuit) - LED off, and remains off for some time after switch is released.

    I am using the 4011. hooked up correctly from my numerous checks.
    From my calculations as well, I see that my results are right. As far as I can see the book is incorrect, but that is a hefty assumption on my part being so early in my electronic development.
     
  2. User1.0

    Thread Starter New Member

    Aug 10, 2011
    13
    1
    Wow! After leaving and coming back to it, I found the issue. My LED was misplaced.
    I misunderstood the full ability of the 4011, I suppose. I thought it would put either positive signal out or no signal. I had no idea it was actually putting out ground over leg 3 when power was withheld from 1 and 2. I had the LED hooked up to the 3 leg and the ground, but in the correct direction, so it worked, just not when it was supposed to.

    Thanks for looking! Maybe this can help someone else later on!
     
  3. Jony130

    AAC Fanatic!

    Feb 17, 2009
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  4. User1.0

    Thread Starter New Member

    Aug 10, 2011
    13
    1
    Yeah, it all makes since now.
     
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