Pressing the button twice quickly to activate power

Discussion in 'The Projects Forum' started by rokz_2005, May 15, 2011.

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  1. rokz_2005

    Thread Starter Member

    May 14, 2011
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    Hi guys im a total newbie,
    How can I make a switch where I can press it twice in say half a second to activate instead of pressing it once?

    I would appreciate any diagrams and list of components, thanks :):)
     
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    [​IMG]

    would be one way to do it.
     
  3. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    A string of several buffers may be needed in the line from the switch to the AND gate to delay the switch signals arrival at the AND gate. If not, the switch may stay 'closed' long enough to still be present when the one shot triggers.

    Probably easiest to do this with a simple 8 pin micro and a few lines of code.
     
  4. rokz_2005

    Thread Starter Member

    May 14, 2011
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    Thanks a lot for that.

    My Dilemma is that i'm going to be using a 555 Chip to have the switch stay on for 1min, but in order to activate the power , the button needs to be pressed twice. would i need to 555 timer chips, one for the double tap and one for the delay?
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
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    Or one 556 IC.
     
  6. John P

    AAC Fanatic!

    Oct 14, 2008
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    I don't see how the 555 chips, or whatever it is that you use, will get power until the double-click action occurs. Or is this not actually about a device to "activate power"?

    Also, remember that switches tend to be electrically noisy, in the sense that pressing the switch once will most likely involve several contact closures. Switch debouncing is a common issue in digital circuits.
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
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    If the first 555 or 1/2 556 is connected as a one-shot, multiple triggers won't be a problem as long as they occur during the timing period.
     
  8. rokz_2005

    Thread Starter Member

    May 14, 2011
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    I feel so useless. I almost have no clue what you guys are on about (way too complex for me)
    Can you guys maybe state the components i need?
     
  9. rokz_2005

    Thread Starter Member

    May 14, 2011
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    Would it better if i used a 556 ic?
     
  10. rokz_2005

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    May 14, 2011
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  11. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Lets continue in the other thread and stop scattering with all the threads.

    Bertus
     
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