Up counter with 74LS192N and 74LS47 decoder

Discussion in 'General Electronics Chat' started by pentanol, Dec 29, 2016.

  1. pentanol

    Thread Starter New Member

    Dec 29, 2016
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    Hi
    I am trying to make an up down counter using 74LS192N and 74LS47 decoder in Multism
    This doesent work for the configuration I made. Where is the mistake in the attached picture.
     
  2. ericgibbs

    Moderator

    Jan 29, 2010
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    hi p,

    1Watt/5Volt = 0.2Amp , A 74192 cannot supply 0.2Amp.

    E
     
  3. pentanol

    Thread Starter New Member

    Dec 29, 2016
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    When I make on if the inputs high the lamps work fine. There is no problem in the electrical configuration
     
  4. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Are you going to define the problem you are seeing? Or do you expect people to look at every single possibility of what might be wron?
     
  5. MrChips

    Moderator

    Oct 2, 2009
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    Connect DOWN to Vcc.
    Read the data sheet.
     
  6. dl324

    AAC Fanatic!

    Mar 30, 2015
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    Welcome to AAC!
    When counting up or down, the other clock input needs to be HIGH.

    Is this homework?
     
    pentanol likes this.
  7. Reloadron

    Distinguished Member

    Jan 15, 2015
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    You are showing a 50 Hz input frequency. Your display will likely appear as a blur. 50 Hz is .020 second which is sort of fast if you are expecting to see an incremental count on the display. Also your X1 through X4 reflect incandescent lamps which as mentioned, if that is the case the chip won't drive and again, at a 50 Hz rate you will never see them change on or off.

    Ron
     
  8. pentanol

    Thread Starter New Member

    Dec 29, 2016
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    Thank you that's the corect answer. This is not a homework.
     
  9. dl324

    AAC Fanatic!

    Mar 30, 2015
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    Multisim won't simulate anywhere near 50 Hz. I've used a fast clock many times to get a reasonable actual frequency...
     
  10. EM Fields

    Active Member

    Jun 8, 2016
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    The incandescent lamps loading the counter will load its outputs to the point where the inputs to the 74LS47 will be out of bounds.
     
    Last edited: Dec 29, 2016
  11. dl324

    AAC Fanatic!

    Mar 30, 2015
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    Not in Multisim.:eek:
     
  12. Reloadron

    Distinguished Member

    Jan 15, 2015
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    Yes, unfortunately.

    Ron
     
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