Ultrasonic speaker or ??

[MrDEB]

Spent the last 30 minutes trying to locate a Piezo element or ?? that will output a frequency of 30-60khz.
Going to or hope to connect to a PIC with an amp.
But locating a Piezo unit to produce sound.
I see resonant frequency but isn't that the element frequency output?
maybe I is stupid in this audio stuff?
I see lots of elements that have 3 wires and only requite one transistor to drive it.
Need some direction.

 

[Nigel Goodwin]

What EXACTLY are you trying to do?, piezo's generally are resonant at a specific, and fairly exact, frequency.

This isn't audio by the way, it's ultrasonics, and really quite different.

 

[magnatro]

ultrasonic transducers of 44 khz are readily available in market. you must go through it.. find it in your nearest electronics shop.
you are really speaking about the piezo element in the buzzers aint you?
the 3 elements are for producing the desired noise in AUDIO frequency..
by looking @ your post you really need an ultrasonic transducer..

 

[Hero999]

44kHz is easy to find, he wants 30kHz to 60kHz which is a wide bandwidth so a 44kHz transistor won't do.

 

[magnatro]

wide bandwidh huh? i think there is some attunation in his frquency range but 44khz will do nicely..? (sorry if iam wrong)

 

[Hero999]

A typical 44kHz transducer will only have a bandwidth of a couple of kHz, it will work from 43kHz to 45kHz but beyond that the output will fall.

I suggest you read a few datasheets for ultrasonic transducters and you'll see what I mean.

 

[MrDEB]

I must be lost or ??
I want to produce an ultrasonic sound to scare away critters.
A speaker or ?? that will produce the ultrasonic sound. All I find are transducers for cleaning etc. Nothing I assume that I can use.
Any suggestions as I am confused. Assume that this ultrasonic is audio ??

 

[Nigel Goodwin]

Use a piezo tweeter, intended for PA use - they are probably the easiest to obtain (and cheap) and will provide reasonable power levels beyond human hearing.

As to it keeping critters away, that's a different question.

 

[Hero999]

You don't need to go that high, a 20kHz to 30khz sweeping tone will do.

You can buy alarm sound generator ICs which can be configured to generate ultrasonic frequencies.

https://www.electro-tech-online.com/custompdfs/2010/04/1616.pdf
https://www.electro-tech-online.com/custompdfs/2010/04/1812.pdf
M3764 pdf, M3764 description, M3764 datasheets, M3764 view ::: ALLDATASHEET :::
UTC 1616

 

[MrDEB]

27,000 is about the highest I have found
**broken link removed**
Unless I am not looking for right part??

 

[MrDEB]

I am skeptical as this WAVE VARIANCE TUNING sounds like a snake oil carnie sales pitch
**broken link removed**
this Hornet device uses a 5khz square wave then a secondary frequency of 18-21khz and they call it wave variance tuning??

 

[MrDEB]

RESONANT FREQUENCY and FREQUENCY RANGE
???????????????????

 

[Hero999]

27,000 is about the highest I have found
**broken link removed**
Unless I am not looking for right part??

That should do for 20kHz to 30kHz, the slightly lower volume at 30kHz won't matter too much.

 

[Birdman Adam]

I bought one of those ultrasonic mouse-deterrent things. Never worked for me! Maybe I'll take it apart to see what they actually put in it...

 

[magnatro]

hey,
if you need a pest controller, then you need to search for the specific frequency that the critter hates the most and design a frquency switching circuit for the control of more than 1 pest.
you need a high powered tweeter for the speaker.

magnatro...

 

[MrDEB]

The circuit I have already uses a PIC that output a random frequency from 2khz to 6kh.
My new design idea is cycle from 2 khz to 8 khz and a second "sounder" that outputs from 15khz to 20khz.
I think a PIC can output a frequency that high.
THEN add an amp maybe?
ALL using a single PIC. We don't need no stinking badges oh i MEAN 555 ETC.
Reason for the lower frequencies is a study done at some University that showed that deer responded better at 2 - 8 khz than at ultrasonic frequencies.

 

[audioguru]

A piezo tweeter has many resonant peaks. Here is one with a 12dB peak at about 12kHz and another at about 18kHz. We don't know what is its output level above 20kHz but it probably drops off. It won't be loud enough to scare away an animal unless its power is 64W and the animal wears it.

 

[MrDEB]

The target species that I am wanting to scare off is a deer. Deer can hear up to a mile away and ability to determine direction.
Just what EXACTLY is FREQUENCY RESPONSE vers FREQUENCY RANGE?
That "speaker" you posted looks like a winner but driving it may be a whole other ball game.
Planning on MAYBE a small amp. Saw a schematic that uses 4 NPN transistor in a push pull type amp.
Was/am contemplating on even an LM386 but using a better amp may be a better decision.

 

[MrDEB]

here is link to an amp I am considering
Audio - Electronic circuits - Radioland
not sure how efficient or loud seeing how it will be powered on 12v

 

[MrDEB]

crazy idea or not??

Got to contemplating what would happen??
inputing two different signals into a push pull amp.
One input 5khz and second input 20khz.
Using LT SPICE with 1hz and 4hz inputs.
Would it even work??
not after High Fidelity, just want to scare the xrap outa some deer
Probally emits an ungodly sound that it would cause a stampead!!--LOL
now that would be a sight!!