Add LED to 7447 BCD to 7 Segment Display Decoder

Discussion in 'Digital Circuit Design' started by christw16, Jun 13, 2018.

  1. christw16

    Thread Starter New Member

    May 31, 2018
    12
    0
    The first picture below is my circuit diagram
    It consists of dip switch 4 bits, ic 7447 and seven segment
    However
    I want to add LED. When I input 0001, the seven segment will show "1", and i want to have 0001 LED just like the second picture
    How can I do?
    Thank you guys so much!

    upload_2018-6-13_21-57-51.png
    ---------------------------------------------------------------------------------------------------------------------------------
    upload_2018-6-13_22-4-34.png to upload_2018-6-13_22-4-50.png
     
  2. dl324

    AAC Fanatic!

    Mar 30, 2015
    6,492
    1,464
    What do you want that LED to do for other numbers? Specifically, 3, 5, 7, and 9.
     
    christw16 likes this.
  3. christw16

    Thread Starter New Member

    May 31, 2018
    12
    0
    i only take 0001 as example
    yes other numbers are counted

    The purpose is I want to add 4 LED.
    I should explain in detail sorry
    if I have my dip switch to 0000, I want to let my LED turn light to be 0000 as well, the seven segment will be 0
    if I have my dip switch to 0001, I want to let my LED turn light to be 0001 as well, the seven segment will be 1
    if I have my dip switch to 0010, I want to let my LED turn light to be 0010 as well, the seven segment will be 2
    if I have my dip switch to 0011, I want to let my LED turn light to be 0011 as well, the seven segment will be 3
    if I have my dip switch to 0100, I want to let my LED turn light to be 0100 as well, the seven segment will be 4
    .
    ..
    ...
    ....etc
     
  4. dl324

    AAC Fanatic!

    Mar 30, 2015
    6,492
    1,464
    You want to display the switch setting as a binary number using 4 LEDs.

    You can add an LED with current limiting resistor in parallel with each of the 1k resistors.
     
    christw16 likes this.
  5. MrChips

    Moderator

    Oct 2, 2009
    16,153
    4,957
    What is wrong with what you have shown on your breadboard?
    It looks correct to me.
     
  6. christw16

    Thread Starter New Member

    May 31, 2018
    12
    0
    it is correct.
    I just want to add 4 addition LEDS like this
     
  7. ericgibbs

    Moderator

    Jan 29, 2010
    4,689
    905
    hi chris,
    Unless I am missing something, isn't that already doing what you ask.?
    E
     
  8. MrChips

    Moderator

    Oct 2, 2009
    16,153
    4,957
    Are you saying that the photos are not your own and you just want to duplicate what someone else has shown?

    Put the LED between the DIP switch and the pull-down resistor.
    Note that in the photographs shown, the pull-down resistors are 330Ω.
     
Loading...