Cat Detection Problem

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

 

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.

 

PS. Just remember. Dogs have masters and cats have slaves.

 

I'm sure you could hook up a 555 in monostable mode to do something like that.

 

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

John

 

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?

 

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

 

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.

 

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.