Maybe rats and mice don't like the smell of jet exhaust. The roar noise is probably louder that the high pitched whine noise.

EDIT: 40,000 RPM makes a frequency of only 667Hz doesn't it? Times the number of blades in the turbine?

Can you buy a high power ultrasonic piezo transducer in The Philippines?

__________________
Uncle $crooge

 

Only ceramic transducers are available.

I am thinking of building a power saver circuit. Do you think it's feasible to construct in 3weeks?

Or, do you have any useful project to that you could recommend? Any project that you think is feasible. I have checked the project forum but I didn't find any. Please do help me on this guru. Thanks again.

__________________
-zeit-

 

3 weeks you better start soon. How does it save power?

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

results in exactly 16,008Hz + harmonics + the engines didn't roar, just were audible with a high pitch sound.

__________________
Proper Planning Prevents Piss Poor Performance

 

Hmm.. Guys, please advise me on this.

Should I continue this project?

Or, should I try to pursue power saving circuit?

Or, do you have any project to recommend?

^^

__________________
-zeit-

 

Post the power saving circuit.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

@audioguru, Boncuk

I have an adaptor that converts 220V to 12V. The gadget tells that its output is 12V, 500mA. What does that mean? 500mA output to components? Or maximum of 500mA current that can be supplied? Thanks!

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-zeit-

 

500mA means it can supply a maximum of up to 0.5A (half an Amp), don't worry as long as your circuit uses less than the current rating, it'll be all right - components only use as much current as they need.

__________________

I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

May I know whether this project is really works or not? Since I am currently doing this project too, is there any tweeter or transducer that can play an ultrasonic sound?

 

Many articles in Google say an ultrasonic pest repellent does not work.
It might scare away some cats.

The old piezo tweeter used on guitar speakers has an erratic frequency response that drops above 18kHz but still has some output at its rated 27kHz.

Attached Thumbnails

 

__________________
Uncle $crooge

 

Old post,

I bought one years ago. Do not recall if it was 14KHz or 40KHz. The documentation said it made the sound of a dragon fly wings and whould keep mosquitos away. Bought it back when I used to fresh water fish. I agree with Google. They do "not" work, or I just had brave bug where I went. Original listerine does not work either if you read that on the net.

 

14khz is very audible and annoying if you are not deaf. Nobody can hear 40kHz.

__________________
Uncle $crooge

 

hey i suggest you drop this project...ultrasonic bug repellers have been around for a long time n only a few of them actually work....iv tried a variety of circuits..even calibrated the freqs exactly. and used high freq piezo transducers. All of them are of little or no use at all in driving the pests away...

cheers

 

Well, I recall as a young tech, I could hear like a 15KHz in the TVs. So it must have been 40KHz on that one I had.

No matter. It does not work.

 

TVs are not supposed to emit 15kHz. Some parts that are loose do.
A pest repeller is supposed to emit as loud a high frequency as is possible.
A huge difference.

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Uncle $crooge