Electronics Need Ckt recommedations

Discussion in 'Modding' started by BobH, 28 Jul 2003.

  1. BobH

    BobH What's a Dremel?

    Joined:
    28 Jul 2003
    Posts:
    1
    Likes Received:
    0
    Hello,

    I am looking for recommendations for a circuit I am trying to put together. What I am trying to accomplish is a circuit that illuminates 6 groups of 10 LED's (in parallel) in sequence.
    What differs from all the circuits I've come across, like the knight rider display etc is that as this circuit lights a bank of led's I need them to remain on for the next count. Example:
    1
    1+2
    1+2+3
    1+2+3+4
    1+2+3+4+5
    1+2+3+4+5+6
    Full Count all LED's remain on for about 5 seconds and cycle repeats.

    All circuits I've come across sequence the led but drop the previous and only show driving one LED.

    I's appreciate any recommendations. The original circuit I'm trying to duplicate which worked in this fashion contained 555 feeding a 4017 but am unable to discern other components, transistors etc.
    Some suggested 4094 but no recommendation for companion circuitry.

    Thanks all,

    Regards,
    Bob
    Bobhiggins@bellsouth.net
     
    BobH, 28 Jul 2003
    #1
  2. acrimonious

    acrimonious Custom User Title:

    Joined:
    8 Nov 2002
    Posts:
    4,060
    Likes Received:
    3
    Welcome to bit-tech :thumb:

    You could use a thyristor to latch each LED on, working from the output of the 4017B IC. When it gets to output 7 it could trigger a reset sequence.

    I'll see if i can knockup a diagram for you (havign HDD problems ATM)
     
    acrimonious, 28 Jul 2003
    #2
  3. acrimonious

    acrimonious Custom User Title:

    Joined:
    8 Nov 2002
    Posts:
    4,060
    Likes Received:
    3
    As Promised:

    [​IMG]


    This is a ONE LED PER CHANEL version, to get it to drive 10 LED's per channel you may need to add a transistor to each output.

    If you need any help with the niggly little resistor calculations, your welcome to download my program: AcrimELEC.exe (72kb)

    :thumb:

    EDIT: link was broke :blush:
     
    Last edited: 28 Jul 2003
    acrimonious, 28 Jul 2003
    #3
  4. SteveyG

    SteveyG Electromodder

    Joined:
    23 Nov 2002
    Posts:
    3,049
    Likes Received:
    8
    You could also use a network of diodes which would achieve the same effect.

    Acrim: Each SCR should be able to supply at least 100mA to each load (depending on the SCR used), so there's no need to add an additional transistor.


    Connect reset to output ten if you want all the LED's to remain lit for a longer period of time.
     
    SteveyG, 28 Jul 2003
    #4
  5. acrimonious

    acrimonious Custom User Title:

    Joined:
    8 Nov 2002
    Posts:
    4,060
    Likes Received:
    3
    i shall remember that.

    You'll need the reset on output 9 along with the trasistor/relay on output 8 though for a longer all-lit period
     
    acrimonious, 28 Jul 2003
    #5
  6. cpemma

    cpemma Ecky thump

    Joined:
    27 Nov 2001
    Posts:
    12,328
    Likes Received:
    55
    You can also do it with a LM3914 bargraph chip fed from a dual-op-amp triangle wave generator, a la macroman's KR circuit.

    And I think zapwizard has an inverse 4017 method on his site, using transistor switches so the "on" dot is off and vice-versa. That would be cheapest for a lot of leds.
     
    cpemma, 28 Jul 2003
    #6

Share This Page