I’ve had this irritating problem next door for a while. Actually at both next doors. I can’t go into my own carport without the dogs on both sides of me barking like crazy. I understand if I was going into their yard, but I’m coming and going from my OWN HOUSE no where near them. They also bark at other things, like squirrels, feral cats, whenever any dog in a five mile radius barks, or when the molecules of the air actually move. Their favorite time to bark used to be from 1am until 4am, on and off for hours. I even had to go so far as to write the neighbors a letter and call the police one night at 2am.
Amazon to the rescue! After searching online for various ways to kill my neighbors’ dogs, and also searching for the penalties for killing my neighbors’ dogs, I decided on a more humane approach. The ultrasonic dog bark eliminator. Basically its the ultrasonic equivalent of nails on a chalkboard. Not particularly painful, but irritating enough that after a while, dogs learn if they don’t want to hear the sound, they don’t bark.
Now instead of constant barking when I get near the fence to work on my grape vines, the dogs sort of chuff and growl at me under their breath, and if a cat or squirrel wanders by, they don’t have to bark at the empty air for 90 minutes. I have two of these on posts pointing at the neighbor’s yard on one side of the house.
Unfortunately, after a year, the dogs have learned that if they go all the way to the other side of their yard, they can bark until their hearts are content, and the little birdhouses either don’t pick up the sound, or the speakers just aren’t powerful enough. Also, the dogs on my other side are across a road, and the little birdhouses can’t reach them either.
So, what to do? So I looked at a more powerful unit, because why not more power? If a little birdhouse works, then obviously a more powerful device would work better… This unit is advertised to work up to 150feet away, and even comes with a remote in case the microphone doesn’t quite pick up the annoying canine. There’s even a $100 big brother to this thing that’s supposed to work slightly farther. But still, how much volume can it really put out with another 9volt battery, and the biggest complaint is it eats batteries inside of a week. So again, We need more power.
What ARE these things anyway? Basically they are ultrasonic generators. They generate a beeping sound above the range of human hearing. So all you would really need to make a unit of your own would be a set of speakers that can put out tones in the 20,000 to 25,000 hertz range (most people can’t hear over 20,000hz), a power source for those speakers, and a tone generator.
Back in my youth I made a lot of circuits for one reason or another, and the most common time-base chip was the ubiquitous 555 Timer IC, a little 8 pin chip that would create very stable oscillations based on some resistors and capacitors you added to the circuit. I found this circuit online:
But with it you’re not really sure what you have until you hook the thing up to a schematic, or you have a dog handy to check the thing out with. And since I have some high range hearing loss, I could never be sure the neighbors weren’t hearing the noise, especially if kids or teenagers were around, because apparently they hear higher frequencies than adults. So I’m poking around on Amazon looking for other stuff and I run across THESE little beauties:
Programmable, stable, barely any soldering required, signal generators. So all I need is to punch up 23Khz, and drive a pair of speakers. But what speakers? And with what? Amazon again! I need speakers that can handle frequencies above the range of human hearing… and these fit the bill. They also handle up to 400 WATTS! Factory stereos don’t go that high. 100 Watts is a LOT of audio power. I had to look it up because I don’t know a lot about speakers but driven to their full rated power of 400 watts, at one meter from the source these things would be as loud as a chainsaw, but in the ultrasonic range. That’s loud. Much louder than a birdhouse running a 9 volt battery. And that’s EACH. So 2 chainsaws running side by side.
So what do you drive it with? Amazon, of course! To drive a speaker, you need an amplifier, and thankfully the car people can oblige:
According to the manufacturer, It could handle four of the little tweeters at reduced power if you wire two in series for the left channel and two for the right, if I’m reading it correct. I’ll have to do some more reading. But even at a reduced power, you’re still talking over 100 decibels, which is still the level of a garbage truck, farm tractor, or train. So yeah, I’m looking forward to that. Of course its all manually controlled so I would have to get up and turn the SOB on… but I don’t think it would take many times for the dogs to get the point that I really want them to shut the hell up. Just a few button presses when they are really annoying.
Of course, the best solution seems to be to put the tweeters inside pieces of PVC pipe, both to protect them from the weather and to make the sound more directional, and concentrate it in an area. I’ll get the tweeters and the signal generators in a few days and if I can make the speakers make noise, it may be time to start putting this thing together.