HELP on building a delay module for a car windscreen wiper motor

Discussion in 'The Projects Forum' started by eiji116, Oct 5, 2008.

  1. eiji116

    Thread Starter New Member

    Oct 14, 2007
    9
    0
    Hello everyone
    I need some hints or advices with my project......
    The lecture gave me an electronic project but i don't have much knowledge in electronics so i'm really need some help or advices.:(

    the project is to desing a delay module will produce a positive going pulse having an on-time of 50 msec duration and an off-time of a duration that can be switched between 16 secs, 8 secs, 4 secs and 2 secs.

    the duration is to be selected by a momentary push button. One push press will give a 16 sec delay, two presses will give an 8 sec delay and so on.

    the ouput will be a enhancement mode MOSFET - a MTP3055E device.

    and i'm only allowed to use the following ICs

    4011 - Quad 2 input NAND gate
    4017 - 5 stage johnson counter with decoded active high outputs
    4020 - 14 stage binary counter
    4093 - Quad 2 input Schmitt trigger.

    after reading the datasheets, and i think i can to use the 4020 for the delay, 4093 for the positive pulse, but whats the difference between 4011 and 4093, and what does 4017 do?

    Thanks in advance for any hints or advices......
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Do you have data sheets for each of the IC's? A CD4017 is a decade counter with decoded outputs. Handy for selecting things like Nixie tube cathodes.

    You need to look into the difference between normal logic inputs and Schmitt inputs.
     
  3. eiji116

    Thread Starter New Member

    Oct 14, 2007
    9
    0
    after reading the datasheets and google around...
    4011 is to give clock pulse
    4020 can be use to set the delay 16sec, 8 sec 4 sec 2 sec
    4093 use for controlling the output
    but still don't know what does 4017 are used for in this project...

    please correct me if i get anything wrong
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Have a closer look at the 4093's datasheet.

    4011 and 4093's are similar.

    However, the 4093 has Schmitt-trigger inputs. This makes them much more suitable for things like oscillators or gated oscillators than non-Schmitt-trigger input components.

    Go to National Semiconductor's site, and download their datasheet for the CD4093B.
    Same thing at TI.com 's website.
    Then go to ONsemi.com and download their MC14093B datasheet.

    Downloading datasheets from multiple vendors will usually yield a good deal of application hints.
     
  5. eiji116

    Thread Starter New Member

    Oct 14, 2007
    9
    0
    after reading and reading and research.... brain exploding
    i can use 4093 to make a 2 secs pulse which feed into the 4017 on output 1, 2, 4 and 8 to give me the 16secs, 8 secs, 4 secs, 2 secs delay
    still not quite sure how to use the 4020 14 stage binary counter
     
  6. darkmorth

    New Member

    Oct 12, 2008
    1
    0
    hey bro did u get urs working? I'm doing the same project and i have no idea how to even start this.
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If you don't need it to do the function, don't use it. That's like the saying we had: 'A good technician always has parts left over'.
     
  8. eiji116

    Thread Starter New Member

    Oct 14, 2007
    9
    0
    after few weeks of hard work.........
    this is the circuit i have come up with
    but can anyone check if my nand gate monostable is right? coz i don't get any output

    thx very much
     
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