cat repellent

whats the best way to generate about 5-10W of 23Khz frequency ?
I am trying to build a cat repellent , if someone has ever tried it please advise me.

thanks

I know a Lady who swallowed a Dog ...........
............. to catch the Cat ................

Ramesh

Here's a proven way. It's been around before, but may give you some ideas: https://hackaday.com/2011/05/25/automated-hose-keeps-cats-from-watering-you/

John

5-10W of 23Khz frequency

Click to expand...

I think 1W would work. (for dogs)
When I was younger I could hear 23khz.
When I enter a store I can find the ultra sonic motion censers. Hear might not be the right word but I can find the motion detectors.

thats like my mum! i have a hearing defect like dads, apparently i can only hear certain words and phrases according to mum

Little Ghostman said:

thats like my mum! i have a hearing defect like dads, apparently i can only hear certain words and phrases according to mum

Click to expand...

I can not hear a sentence with the words "dirty dishes" in it.
'go shopping', 'weeds', 'laundry', 'my Mother needs...'

interesting replies
I can not find a piezo buzzer for this frequency range and power rating around 1-5 watt . can some one recommend?

aliyesami said:

interesting replies
I can not find a piezo buzzer for this frequency range and power rating around 1-5 watt . can some one recommend?

Click to expand...

Did you look here: **broken link removed**

23KHz is easily attained by many tweeter speakers. You can always use less power than the max rating.

John

hi John !
yes I can find many tweeters around 23Khz but their power requirements are high, I have a 10w amplifier , will that drive these 75W tweeters ?

ronsimpson said:

I think 1W would work. (for dogs)
When I was younger I could hear 23khz.
When I enter a store I can find the ultra sonic motion censers. Hear might not be the right word but I can find the motion detectors.

Click to expand...

Exactly like me. The frequency was so high that it wasn't a tone, it was something like a pressure in my ears.

Less than 1 minute ago I replied to this same thread on another website forum.

Some piezo tweeters produce a few peaks that sound awful but they do not produce ultrasonic frequencies.

Sweep the drive - eh, beers in the fridge - yeah ok.

Motorola do or did some cheap piezo tweeters, fairly naff for audio but probably god for this, a 555 can easily make your waveform.

aliyesami said:

hi John !
yes I can find many tweeters around 23Khz but their power requirements are high, I have a 10w amplifier , will that drive these 75W tweeters ?

Click to expand...

Yes your 10W amp can drive the 75W tweeters just fine. That's about all the power I would put into those tweeters. Probably 75w pk or p-p with a low duty cycle. Most speakers can not handle a continuous 75 watts.

audioguru said:

Exactly like me. The frequency was so high that it wasn't a tone, it was something like a pressure in my ears.

Less than 1 minute ago I replied to this same thread on another website forum.

Some piezo tweeters produce a few peaks that sound awful but they do not produce ultrasonic frequencies.

Click to expand...

hi audioguru !
the piezo tweeter rated at 23Khz wont produce ultrasonic freq ? I am not sure iam understanding .
how can I produce ultrasonic freq , using which device?
what do the existing dog /cat repellent use ? I thought they were using piezo tweeters

regards

A 23 khz sound wave will have a wavelength of about 0.6", if your tweeter dome is larger than this it'll have a job reproducing this freq, if its a soft dome then it has a chance of reproducing it as the cone will 'break up' into its resonance modes where only part of the dome (or whatever projects the sound wave) produces the sound wave, however at a reduced level and the device will be more directional (which might benefit you).
I reffered to cheap motorola tweeters further up (motorola ksn1005, affectionately known as 'lemon juicers' from their appearance and sound quality), I suggest you at least look into these, they have a response well into the ultrasonic range, and because they are horn loaded you'll probably get better dispersion, and being piezo are generally high impedance which means they are easier to drive and I've found them to be quite hardy, looking at pics of 'cat scarers', they look like a similar horn.

The copy of the old Motorola piezo tweeter is rated at 75 Watts PEAK or 75 Watts MAXIMUM. What is that? I think it is WHATS! Real power is RMS.

Here is the frequency response curve. It varies up and down in level a lot at different frequencies. It is loud at 5kHz then not loud at 9kHz. It is loud at about 14kHz and 18kHz but is not loud at 16kHz and 20kHz. We do not know its output level at 23kHz. It is probably VERY directional.