555 timer

Discussion in 'The Projects Forum' started by ol'trusty, Sep 10, 2009.

  1. ol'trusty

    Thread Starter Member

    Sep 9, 2009
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    Hi guys
    I am new to the forum and to electronics I am an electrician so I know my way around . I want to build a timer based on a 555 chip that I can regulate (with potentiometer) between lets say 10-40 sec on/off mode (stays on for the time wanted).
    Any links or help is appreciated .
    Thanks
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Google 555 monostable.
     
  3. bertus

    Administrator

    Apr 5, 2008
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  4. ol'trusty

    Thread Starter Member

    Sep 9, 2009
    48
    0
    Thanks guys.. And that site is great ,just what I was looking for!
     
  5. Wendy

    Moderator

    Mar 24, 2008
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  6. ol'trusty

    Thread Starter Member

    Sep 9, 2009
    48
    0
    I have read the links and thanks alot , but does anyone have a diagram to make a monostable for 10-30 sec with a potentiometer .
    Sorry for being such a novice !
    Thanks in advance
    Trusty
     
  7. Wendy

    Moderator

    Mar 24, 2008
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    From 555 Monostable

    [​IMG]

    Rt should be a 47KΩ resistor in series with a 100KΩ, Ct should be a 580µF. You will have to make the cap value using several capacitors. This was figured using basic algebra.
     
    Last edited: Sep 13, 2009
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