Help with a tilt circuit

Discussion in 'The Projects Forum' started by medic265, Mar 13, 2009.

  1. medic265

    Thread Starter New Member

    Mar 13, 2009
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    Hello everyone,

    I am need a little help. I'm a little new to electronics...

    I need a tilt circuit that will activate after an object has been tilted for at least 5 seconds.

    I was going to use a mercury switch for the tilt part, put I have now idea how to make the circuit activate after being tilted for 5 seconds.

    Any help would be great.
     
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    287

    How do we do this....let me count the ways.

    Well, probably the most ELEGANT means is with a simple RC time constant and a comparator. When the switch closes, the capacitor charges for X period of time. If the voltage exceeds the threshold for the comparator, voila!

    You do want to be sure you have some means of DISCHARGING the network between tilts...otherwise the comparator will ADD the time constants of all your "short tilts" together.

    Eric
     
  3. medic265

    Thread Starter New Member

    Mar 13, 2009
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    0
    Eric, Thanks for your quick reply. I appreciate your help. But I'm a bit new to this stuff. If you have the time could you attach a sketch of something?

    And elegance is great....but I really like simple better...lol

    Thanks a bunch
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287

    They're one and the same!
    ( I'll try to get something to you this weekend ifn I don't forget. :)

    eric
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Do you already have a tilt sensor? Lots of EASY fun things went away with the Hg/Mercury ban.

    I have a couple of these that work OK They are very sensitive to vibration in addition to tilt, a heavier ball/switch reduces the vibration sensitivity.

    For the one linked above, the travel of the ball inside is very short, and it is easier to detect tilt from contacts going open rather than closed. I use ~10mS multi-sample "Open" as "tilted". Like an inverse ~10mS switch debounce.
     
  6. medic265

    Thread Starter New Member

    Mar 13, 2009
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    0
    Eric, I certainly do appreciate your help....I am looking forward to anything you can offer.

    After a little more thought, I came up with the idea of actually using two tilt devices.

    The first would possibly initiate a 555 timer circuit. Then at the end of the 5 seconds, if the second tilt device was at the same angle, it would allow the circuit to complete.

    thatoneguy,
    Thanks for the link to that sensor. That will probably be perfect for what I need.

    Thanks everyone
     
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