animal repeller

[Atenuator]

I have a hand held dog repeller. Is it possible to amplify this signal? Can I say..., disconnect the piezo buzzer that produces the sound, and connect those wires into a small guitar amp and run that to some speakers?

Thanks for your help

 

[Raven Luni]

Hahaha - I had thought about making a pocket device like that to secretly spook peoples dogs for a laugh. I dont think speakers would handle those frequencies very well. Youd have to look around for something more specialised.

 

[donkey]

could you hook up multiple peizos and somehow amplify the signal over them all?

 

[KrisBlueNZ]

The repeller presumably uses an ultrasonic signal to repel dogs. Normal loudspeakers don't reproduce ultrasonic frequencies. Some tweeters have a bandwidth that extends into the ultrasonic range. If you want to make the signal louder, you obviously need a more powerful transducer, probably with a more powerful amplifier. First you need to find out the frequency range of the signal, then you need to find a suitable transducer (maybe a tweeter) whose bandwidth comfortably includes this frequency range, then you need to find a suitable amplifier. Find out the frequency range first, and if possible, capture a snapshot of the signal on an oscilloscope. It would be useful to know whether it's a sinewave or a squarewave (or something in between) because this affects the type of amplifier you need. If it's just a squarewave you can probably use an H-bridge driver, perhaps with some filtering to reduce the amount of harmonics that the tweeter won't reproduce.
Actually I remember giving the same advice in another thread.
Do a site search on "ultrasonic". You'll find lots of similar threads that may answer your questions.