10 led, 2 ic circuit explanation

Discussion in 'The Projects Forum' started by sonubkk, Aug 8, 2006.

  1. sonubkk

    Thread Starter New Member

    Jun 13, 2006
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    0
    hey can anybody explain how this circuit works, i have attached it, i hope u guys will be avle to dwnload it, its quite simple really but i am not familiar with ics. a detail explanation on how the ics are being controlled will be extremely helpful.
    thank u guys very much,
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Without the type number of the ic's, it's a bit difficult.

    IC1 looks like it is a 555 timer, set up to free run. IC2 is probably a light bar function. The led's will illuminate in succession as the voltage input increases.

    I think that all this circuit will do is to flash some or all of the leds as the 555 runs. The 555 output is either on or off, so there won't be any change in level slow enough to have the light bar come on one at a time.
     
  3. efox

    Member

    Aug 8, 2006
    11
    0
    I think it may be different. I do believe that one of the IC's is the 555 timer. I would say that the next IC is a shift register with an enable pin connected to the ouput from the 555 timer.

    So what is basically going to happen is that you can adjust how fast or slow the leds count up or down ( i dont know) to whatever. Don't know if it would count to 10 or count to 1024.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    If IC2 is a shift register, then it won't count. Every pulse out of the 555 will turn on an additional led. It will just go until the last led is lit, and than will not change further. Having the device number for IC2 would help solve the mystery.
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    655
    It's an LM555 and a CD4017 decade counter. Google "LED chaser".
    The 555 is the clock for the 4017, which is a 5 stage Johnson (twisted ring) counter (Google) with all ten states decoded. The outputs are mutually exclusive, so it only needs one current limiting resistor for all ten LEDs.
     
  6. sonubkk

    Thread Starter New Member

    Jun 13, 2006
    7
    0
    Ron H is right, sorry i forgot to show the ic number, its an led chaser. i dont understand wat is 4017 doin there and wat output does it produce.
    thnx for all the answers, pls answer this also :)
     
  7. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    655
    I explained the 4017 operation briefly in my previous post. If that was insufficient, do you understand electronics well enough to understand a datasheet?
     
  8. eng_mostafa.bakry

    New Member

    Nov 20, 2006
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