Thank u guys for the informations and guides, actually I had also gone through those article saying that this product doesn't works, unfortunately I had chosen this project as my final year project, so is there any suggestion so that I can make a little bit effort to improve this project, btw, I am currently using this circuit(as attached) which i found on google, now I am trying to calibrate 10 different frequencies on the CD 4017 IC (as what deepak george did), hopefully some of the frequency really works to repel any pest or rodent....

 

The CA3130 opamp in that very old circuit is not made anymore.

Are you allowed to simply copy the circuit designed by somebody else for your final year project? Aren't you supposed to design your own project?

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Uncle $crooge

 

I was able to here the flyback in the units many years ago. 12-15K range probably, I would guess. But as a kid, I could here it.

Sure I will not here it from the 60" HDTV now.

 

People who are deaf and old people cannot hear frequencies above 8kHz.
A hearing test does not measure above only 8kHz.

Old picture tube TVs used a high power high voltage horizontal frequency of 15,750Hz but new TVs are different.

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Uncle $crooge

 

Of course I am not going to copy the whole thing, just a reference for me in the project, so any other op-amp like UA741 will do for the op-amp replacement right? Is there any other implementation or features I can add in for the project? Thank You in advance

 

A 741 opamp is 42 years old. It was designed to amplify DC and low frequencies. Its output cannot have a full swing above only 9kHz.
At 30kHz its output has a max swing of only 8V p-p. At 30kHz its max voltage gain is only 15.

Use an audio opamp like a TL071 that has full output to 100kHz and at 30kHz has a max voltage gain of 100.

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Uncle $crooge

 

The op amp in this project is being used as an oscillator at 2 Hz. A 741, as ugly as it is, should work just fine.

The new squeaky clean TL071 suffers from phase inversion if you exceed its common mode range. This defect rears its ugly head in circuits like this.

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de KI6RWX

 

Yes of course.
The opamp oscillator slowly steps the frequencies of the 555 high frequency oscillator.

I wonder if you set the frequencies to play "Mary had a little lamb" over and over and over and over and over and over and ... them maybe it will drive away a pest.
Or maybe if you made it loud enough.

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Uncle $crooge