Help With School Project!!

Discussion in 'The Projects Forum' started by compnerd4, May 21, 2008.

  1. compnerd4

    Thread Starter New Member

    May 21, 2008
    4
    0
    Ok so im working on a project for class and now im stuck and am now seeking your help!

    I have a circuit with 6 LED's and 1 Switch what i need help with is i want to be able to push the switch and only LED 1 comes on then i let go and it goes off then i push the same switch again and only LED 2 comes one then off once i release the switch... and so on.

    Any help is help and i need it so thanks!!

    Matt

    **image attached of what i have already**
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    You can use a cmos 4017 decade counter. This device, every time you give it a pulse, activates the next output and turns off the previous output which was activated. The outputs are numbered from Q0 to Q9.

    http://www.kpsec.freeuk.com/components/cmos.htm
     
  3. compnerd4

    Thread Starter New Member

    May 21, 2008
    4
    0
    thanks for the help! but i don't really understand how it will work any chance of a schematic?
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The circuit will not need the regulated power supply that you have sketched. It will work directly from a 9V battery.
     
  6. compnerd4

    Thread Starter New Member

    May 21, 2008
    4
    0
    heres a bit of an update but the program im using (Tina Pro 6) shows the IC Pins differently so heres the new pic
     
  7. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Your answers are in this document: http://www.datasheetcatalog.org/datasheets/166/108736_DS.pdf

    Don't forget to put in some current-limiting resistors in series with those LEDs!

    Now for the extra credit, can you determine from the datasheet which output gets routed back to "reset" in order to count to only six?:cool:
     
    Last edited: May 22, 2008
  8. compnerd4

    Thread Starter New Member

    May 21, 2008
    4
    0
    this is the best i can do...

    sorry its a bit messy

    opps forgot pin 8 is my ground?
     
  9. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    You forgot to connect pin 8 to ground and you forgot to put current limiting resistors for the diodes as Audioguru said. Also you have to connect pin 13 (clock enable) to ground and your reset to Q6 (pin 5) and not Q5 (pin 1) because your last led wont light. The chip will reset instantlly.
     
  10. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I've seen lots messier! ;)

    What is the current @ voltage rating of your LEDs?

    Have you looked at the "electrical characteristics" in the 4017 datasheet, in particular the "output drive current" portion?

    Have a look, and tell us how much current your 4017 will be able to source (output) running at the voltage that you're considering operating with.
     
  11. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Have you looked at the timing diagrams in the datasheet?

    When you use TINA, the pin numbers will be on the lower left of your screen as your mouse hovers over the connection.

    See attachment:
     
Loading...