want to build an electronic dog whistle

[ceteris]

want to make a thing that will let me create a tone from 20 to 50k

sort of an electronic dog whistle

dont know if any speaker exists that would go up that high

or what hardware can generate the signal

or what amplifier would amplify the signal w/ out rolling it off

anyone have any thoughts?

thanks

 

[503Timber]

Interesting thought......how loud do you need it?

 

[Andrew Eckhardt]

If you just want a tone you'd rather have an oscillator than an amplifier. Piezo benders are routinely used in that frequency range.

 

[ceteris]

would want it to go "pretty loud"

 

[DigitalJunkie]

A friend and I build up a crude circuit like this. We used a 555 timer,with a pot to adjust the frequency range from roughly 15K-30K,then we fed that to a HOT from an old TV. We used one of the cheap rectangular Motorola piezo horns,and powered it all from a 9V battery.

Don't know about dogs,but it was enough to annoy his roommate.

 

[Andrew Eckhardt]

A horn with a 20kHz cutoff can be made pretty small.

Is the 20-50k range for experiment? I doubt any dogs can hear to 50k. Maybe a bat sized dog.

 

[ceteris]

hey everybody, thanks for your help

andrew:

yes, 50k is way high, just threw that out there, 40k would probably allow me to find the top end of the hearing range

however, quick check on the digikey website turned up only ones that go up to 12k - or did I misunderstand you?

 

[ceteris]

quick search on piezo tweeters turns up some that go to 30k

dont see anything out there that goes to 40k

 

[Andrew Eckhardt]

I was thinking you'd make your own driver/horn combo. Piezo discs are used in ultrasonic humidifiers and the drive frequency is in the MHz. I'd start with a small disc and high natural resonant frequency.

Most of the piezo tweeters you're going to find have a paper cone glued to the disc, which is why they crap out at a certain point. I think so long as you have the current available you can get the actual element in them to go much higher.

 

[k2panman]

If one wanted to annoy his neighbors dogs as much as the #*%%* little yipe yipes annoy me, I wonder what frequency would be best? I would think that you need a lot of power - a little homade speaker may not produce enough amplitude to chase them back into their house.

 

[sofaspud]

I've seen this requested more than once... but am not aware of any successful application.
And unless you're gonna go stand by the dog, you'll need a lot of power.

 

[quadtech]

Try an ultrasound cleaner

http://www.diyaudio.com/forums/multi-way/96465-piezo-tweeter-dogs-6.html#post1202147

The rest of the "nice" doggie thread is here -

http://www.diyaudio.com/forums/multi-way/96465-piezo-tweeter-dogs.html

Oatley Electronics

 

[jorgealarcon]

An Experiment?

Is this for some sort of experiment project? Sounds like one.

 

[gmphadte]

I threw something once at him and again once more when he was barking. Some days now, barking has stopped.