4017 chaser leds

Discussion in 'General Electronics Chat' started by mostaghfir, Jul 10, 2012.

  1. mostaghfir

    Thread Starter Member

    Dec 29, 2010
    10
    0
    pleas said me if is there a mistakes in this circuit shematic because if i select the position n° 1 for exemple some leds ordered by 2n2222 n°2 turn on despite their vcc is isolated ....I can't understand:confused: below the schematic:

    Untitled - 2.jpg
     
  2. mostaghfir

    Thread Starter Member

    Dec 29, 2010
    10
    0
    the complet schematic (the first is incomplet)
    Untitled - 2.jpg
     
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    The transistor collectors should be connected to the cathode ends of their respective LEDs. All LEDs should have their own individual current limiting resistors. The outputs of the 4017 are numbered 0-9 coresponding to a 1-10 sequence. There may be other errors, but those are the most obvious.
     
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,962
    743

    The second and third set of Black leds look like they are reversed, the leds need to be connected with the cathodes to the transistors, each led needs its own resistor,also if your only using 3 outputs, pin 15(reset) needs to be connedted to to the forth output (pin 7) to give a better display.

    try this first
    http://www.qrp.pops.net/LEDs.asp
     
    Last edited: Jul 10, 2012
  5. Wendy

    Moderator

    Mar 24, 2008
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