Cat Detection Problem

Discussion in 'The Projects Forum' started by Blainus, Sep 29, 2010.

  1. Blainus

    Thread Starter New Member

    Sep 29, 2010
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    Hi everyone!

    I'm a complete beginner with electronics but I have an interesting project because my wife refuses to get a cat flap!

    I've got a simple Infra Red detector outside which signals a wireless doorbell indoors when the cat triggers it. That works fine, except she constantly sets it off the whole time she's sat there and the <snip> thing keeps ringing, very annoying and the batteries only last about a fortnight, so...

    Q: Is there some kind of switch or relay I can incorporate into the transmitter so that once it's triggered it turns off for X minutes?

    Gratefull for any pointers or solutions,
    THANKS
     
    Last edited by a moderator: Sep 29, 2010
  2. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    Due to my love of cats I would hook it up to a solenoid triggered shotgun. Problem solved. Guess you can close this thread now.:D;)
     
  3. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    PS. Just remember. Dogs have masters and cats have slaves.
     
  4. campeck

    Active Member

    Sep 5, 2009
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    I'm sure you could hook up a 555 in monostable mode to do something like that.
     
  5. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    In my neighborhood, the coyotes take care of house cats every night. Without a trace.

    John
     
  6. Blainus

    Thread Starter New Member

    Sep 29, 2010
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    Yeah thanks a bunch guys, that's a great help!!! Thing is I've got no shotgun and no coyotes. How many volts would I need to fry it?
     
  7. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Perhaps a monostable multivibrator between the sensor and transmitter will help.
    Our member Bill_Marsden wrote a thread about it:
    Next Submission, 555 Monostable

    Bertus
     
  8. t06afre

    AAC Fanatic!

    May 11, 2009
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    New wife perhaps....... But joking aside some sort of silent alarm. You could also lure it in more easy by changing the feeding times.
     
  9. Wendy

    Moderator

    Mar 24, 2008
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    If you could come with some way of detecting which way the cat was pointing it would help. A cat sitting down looking out is not wanting in, but a cat with its nose to the door is. Seems like a proximity sensor on the collar might be an answer, maybe along with a pressure pad switch to be sure they are actually in front of the door. Only if the collar is really close to the door by a precision distance (a specific location) would you want to trigger it.

    Thing to remember though, the cat wants the door open on general principal, and is probably willing to go through contortions to make it so. Ornery animals, cats, gotta love them.

    I used to have a cat who was too cool to come in when the garage door button was pushed. It would look at the door, then casually look away. Repeat. Repeat. Then came the mad dash. Fortunately for him my door sensitivity was adjusted properly, though his ribs still had to hurt the last time he did this, as the door quite comically splatted my cat cause he cut it too fine.

    One of my favorite authors (Robert A. Heinlein) once said something about cats being natural comics. You just couldn't laugh at them. This is a truth.
     
    Last edited: Oct 2, 2010
  10. DaedalusYoung

    New Member

    Sep 29, 2010
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    Our first cat used to do something similar, with a sliding door. He would meow when he wanted to go outside, but when you opened the door, he'd just sit there. So after a while we'd close the door again and of course just at that moment, he'd run through. Luckily never hit his tail or anything, though he did get stuck at the waist once, but again luckily no damage.

    And it's just typical of cats, when you hang up an IR to see if they're in front of the door, they'll flawlessly find the exact spot to go to sleep so that the IR keeps triggering.
     
  11. Wendy

    Moderator

    Mar 24, 2008
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    All my cats can count down. I start at 5 and at 0 I close the door, ready or not.
     
  12. wayneh

    Expert

    Sep 9, 2010
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    I agree this is the likely best approach. But depending on the existing circuitry, you might be able to accomplish the same thing even more simply with just an RC tank. I'm thinking you could drive it low (or high) when the cat is near, and after a few seconds - adjustable with RC - the low (or high) signal shuts off the transmit to the indoor receiver. If the transmitter is strictly on or off, and you don't have a spare op-amp or comparator already as part of the IR detector, then you might as well go ahead and add the 555.
     
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