i saw this pest repeller circuit, to be able to produce up to 80kHz.
but i do not know how the calculations is done. could any1 be kind to help me understand the flow & calculations on this circuit?
the circuit is as attached.

is there anway to increase the frequency from 80kHz to 1MHz?
if so, how can it be done?

 

Yes, and No. The electronics can do it, but that speaker will be doing good to produce 80Khz. I have seen 1Mhz ultrasonics, but it requires some very special transducers (speakers).

 

i saw this pest repeller circuit, to be able to produce up to 80kHz.
but i do not know how the calculations is done. could any1 be kind to help me understand the flow & calculations on this circuit?
the circuit is as attached.

is there anway to increase the frequency from 80kHz to 1MHz?
if so, how can it be done?

I agree with those who have stated that it is very unlikely that you will be able to modify this circuit to produce an output from the piezo-speaker that is much above the existing frequency of 30KHz to 40KHz.

hgmjr

 

Look up the 555 IC datsheet.
That is what is producing the frequency.
There is a note at the bottom of the print telling whick resistors change the frequency.

 

Hi Lostdort,

Hey I've got that diagram, so in the epe mag... & I tell you its a good circuit.. I dabbled in this a few years ago!! anyhow.. 1st what pests are you trying to repel? eg. Cats.. I think of the top of my memory, they get annoyed at around 60khz to around I spose to 80khz <wait though depends on the cat/dog age... so you could be directing your device at the pest and its stone deaf!!! thought of that Yes"Trial & error" here..

I have not buit that but other kit I bought which was audible, then goes up to the dog/cats hearing range... I read the write up on you diagram that device.. & it said if you change c3 to 100nf your hear the Tone yourself!! and apprently its Loud.. but dont forget.. change the o/p from the Transducer your using to a Piezo horn, there very good
I find the Ultrasonic 40khz if not done right are flipping hopeless!! thats my opinion..

Right the specs of the P/horn is
FReq range 4khz to 40khz
Power 150Wmax/ 75Wrms
impedence 250-50 ohms...
and all the diameters.. you can get recessed horn or protruding horn!!<< if I've got that right.. there made in cHina..
and like bill said very effecient...
I dont know about ultrasonic transducers they bore me... and quite hard to drive..
well I personally think so...
IF you want a really good repeller then email me.. its ready made.. 130db.. sound pressure..
!!!! juicy a?
But one thing I dont get you on is Why do you want to go as high as 1meghz?? the pests as I see it wont hear it but proberly feel it more.. ok
HTH.
regards
redlight.000
byeeeeeeeeeeee

 

Hi again, lostdort,

here's a few frequencies..
rigg up a 555 in Astable mode. ok R1 =4.7k
R2 = 10k
thats R1+R2 is the resisitor bit..
now for the C/value.. you can put in
eg example
10uf electrolitic cap =5.8hz
1uf electro = 58hz
100nf <nano farads normal cap =580hz
10nf ^^^^^^same = 5.8khz
1nf ^^^^ =58khz... so you have to work out the exact or around abouts the caps bit.. yes its maths.. thats taken me a while to do But I got there its 50/50 with this game..
anyhow so you got 58khz.. now go lower picofarads.. then your going up in Freq) got it.. Just dabble a freq counter is handy because you getting a proper reading near as damm it..
Ive got a basic freq/counter thats from 5hz to 10mhz...
that suits me.. all this may NOT apply to you but its the maths involved.. ie if you want to design a circuit of your own like Ive done.. & Yes its Not easy grrrrr..
hope this is of use... if not ..
leave it.
regards
redlight000

 

Look up the 555 IC datsheet.
That is what is producing the frequency.
There is a note at the bottom of the print telling whick resistors change the frequency.

Nonsense. The OP is asking to stretch it up to 1 MHz.

 

Look up the 555 IC datsheet.
That is what is producing the frequency.
There is a note at the bottom of the print telling whick resistors change the frequency.

That's wrong. The CA3130 and the R's and C around it determine the frequency.

 

Hi again, lostdort,

here's a few frequencies..
rigg up a 555 in Astable mode. ok R1 =4.7k
R2 = 10k
thats R1+R2 is the resisitor bit..
now for the C/value.. you can put in
eg example
10uf electrolitic cap =5.8hz
1uf electro = 58hz
100nf <nano farads normal cap =580hz
10nf ^^^^^^same = 5.8khz
1nf ^^^^ =58khz... so you have to work out the exact or around abouts the caps bit.. yes its maths.. thats taken me a while to do But I got there its 50/50 with this game..
anyhow so you got 58khz.. now go lower picofarads.. then your going up in Freq) got it.. Just dabble a freq counter is handy because you getting a proper reading near as damm it..
Ive got a basic freq/counter thats from 5hz to 10mhz...
that suits me.. all this may NOT apply to you but its the maths involved.. ie if you want to design a circuit of your own like Ive done.. & Yes its Not easy grrrrr..
hope this is of use... if not ..
leave it.
regards
redlight000

wat will the effect be? will the frequency be strong enough to actually move/blow the pest away?

 

will the frequency be strong enough to actually move/blow the pest away?

Why not just use a fan?