Complete noob - How can I make a simple device that upon the removal of a contact beeps?

Discussion in 'The Projects Forum' started by JohnConnor, Jun 18, 2015.

  1. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    My house has two floors, my two toddlers live on the second floor. The stairs going down is closed by a small metal door of around three feet high. The door has a metal rod that is removed to open it. However, people tend to forget to lock the door with the metal rod. I want to make and install a device similar to a walmark card that when the rod makes no contact with the device it will beep as a reminder. I am sorry if I am not painting a perfect picture here. I just would like to learn to do this. However, as stated in the title, I am a complete noob. I can learn though, I know that, hehe. thanks!
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
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    Hi, and welcome.

    I think this is doable with a 555 ic in astable config. Can you post a picture of the locking mechanism?
     
  3. #12

    Expert

    Nov 30, 2010
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    The metal rod and the place it lands are the parts to make a crude switch. The challenge is in making a beeper respond to that lack of connection when the rod is not replaced properly. This might be done with a battery and a relay or an electronic buzzer arranged to start with the absence of a connection. nerdgutta started with the electronic approach. It is electrically much more efficient than a cheap mechanical buzzer and relay, but more complicated.

    Edit: I just noticed your name. Is your mother named Sarah?
    (If you know the reference, you might get a laugh out of that last question.)
     
    Last edited: Jun 18, 2015
  4. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    [​IMG]
     
  5. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    One option would be two micro switches independently operated by the Gate and Rod
    Mounted so that if Gate is in place and the Rod is not the battery operated bleeper sounds.
    Micro switches normally have a change over set of contacts.

    EDIT:
    Switch wiring option
     
    Last edited: Jun 18, 2015
  6. #12

    Expert

    Nov 30, 2010
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    The fact that the frame is metal pretty much wrecks the idea of making the rod be a switch. ericgibbs hit the answer instantly with the micro-switch idea.
     
  7. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    So, how would I go about using two micro switches to do this? sorry for all the noobish questions
     
  8. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    Thanks for the diagram. How do I go about building a "battery operated bleeper"?
     
  9. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    Buy a PP3 9V battery with mating contacts/cable.
    Beeper sounders that operate from 5V thru 12V are available.
    Micro switches have mounting holes that would take a small wood screw.

    Whats your location.?
     
  10. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    NY

    Question, why pp3?
     
  11. ericgibbs

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    Jan 29, 2010
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  12. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    @JohnConnor - do you want the buzzer to sound if the gate is left open? Or only when the gate is closed but not latched?
     
  13. JohnConnor

    Thread Starter New Member

    Jun 18, 2015
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    I want the buzzer to sound when the gate is open
     
  14. Dodgydave

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    Jun 22, 2012
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    Last edited: Jun 18, 2015
  15. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi John,
    This is what you initially said:
    Do you now really mean this.?
    E
     
  16. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Dave beat me to it. I recommend a simple alarm system magnet and switch like you put on a window or a door. 9V battery, piezo beeper, switch. Whenever the gate is open it beeps.

    ak
     
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