10 stage LED sequencer

Discussion in 'The Projects Forum' started by ale2121, Aug 23, 2009.

  1. ale2121

    Thread Starter Active Member

    Mar 20, 2009
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    0
    Hi,
    I'm building this circuit . If you scroll down to the 10 Channel LED sequencer, you will find the schematic I'm using. I've got this built exactly the way it's set up in the schematic, only I'm using 9volts of electricity instead of 6. It's going all haywire, lighting up one random LED then all of them, then another random LED, then all of them. What's wrong? Do I need a pulldown resistor somewhere?

    I have a few other questions too. If I want to be able to change the speed of the LEDs, do I just replace the 47k resistor with a potentiometer?

    AND if I want this to be only 8 channels, how do I eliminate the last two LEDs?

    I saw this thread, and tried adding a few bypass capacitors, but I don't know how to do that? or where to put them? I added a few ceramic disk capacitors, one from pin4 on the 555 to ground, and one from pin 16 on the 4017 to ground. Nothing changed.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,534
    Have you seen my series of articles?

    Introduction to the 555
    555 Schmitt Trigger
    555 Monostable
    555 Hysteretic Oscillator
    555 PWM Oscillator
    CMOS 555 Long Duration Minimum Parts LED Flasher
    CMOS 555 Long Duration Red LED Flasher
    CMOS 555 Long Duration Blue LED Flasher
    CMOS 555 Long Duration LED Flyback Flasher

    The long duration series is my answer to the LM3909 chip, which is now obsolete (which means they don't make em any more).

    BTW, the guy whose circuits they are still has a web site, those are copies from his site.

    http://www.bowdenshobbycircuits.info/

    I have a version of the 10 LED sequencer here...

    LEDs, 555s, Flashers, and Light Chasers

    Bill's Index
     
    Last edited: Aug 23, 2009
  3. ale2121

    Thread Starter Active Member

    Mar 20, 2009
    71
    0
    I'm sorry, I have seen your articles. Thank you, but they don't really help me with the schematic I'm working on.
     
  4. Wendy

    Moderator

    Mar 24, 2008
    20,764
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    OK, but the article does answer your question. Basically you use the reset line, and tie it to the 9th output, to reset to 0 when the circuit has counted to 9.
     
  5. ale2121

    Thread Starter Active Member

    Mar 20, 2009
    71
    0
    I realized that after I posted. Getting it to work in the first place however is my bigger problem.
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
    395
    I did not see a LED color, if red, increase 120 to 300 with 9V. You can use a pot, about 1 meg for about 1 sec/step on slow end. Have you found the trouble yet? If not give us a schematic as constructed, not origional print.
    Again you may have a bad chip.
     
  7. ale2121

    Thread Starter Active Member

    Mar 20, 2009
    71
    0
    I did find it. my 555 was bad. thank you :)
     
  8. VooDooCC

    New Member

    Aug 28, 2009
    6
    0
    I looked at that a few times, but the main thing that turned me off is the cost, but it looks like it might be a better quality piece. My options are wide open, but I'm trying to keep this budget friendly as well.
     
  9. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Cost?
    If you are in a civilized country then the NE555 and CD4017 cost almost nothing. 10 LEDs also cost almost nothing today. The 9V battery costs much more and is soon is discharged.
     
  10. ale2121

    Thread Starter Active Member

    Mar 20, 2009
    71
    0
    ^^I think this post was made accidentally? or drunkenly?
     
  11. wdkh68

    New Member

    Jan 12, 2010
    29
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    LED Sequencer - how can I continue on with the sequencing with more leds and 4017's ? Thanks!
    [​IMG]
     
  12. Audioguru

    New Member

    Dec 20, 2007
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    You should use the Cmos 555 instead of the ordinary 555 because the ordinary one causes a 400mA supply current spike that upsets the CD4017 counter.

    Bill Bowden (see earlier in this thread) and 4017 datasheets show how to cascade numerous 4017 ICs.
     
  13. wdkh68

    New Member

    Jan 12, 2010
    29
    0
    Thanks for the info for the Cmos 555!
     
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