Thread: Dog repeller schematics needed (and more...)

Hi all,

I'm looking for the schematics of a dog repeller circuit. You know, that little thing that you carry with you in your pocket and when a crazy dog approaches you just push a button and it emits an ultrasound wave that really pisses off the dog and makes him go away. If you don't have a schematic please let me know what's the frequency it works with (the frequency that disturbs the dogs). In fact I would prefer to know the frequency instead of a schematic ... I'm trying to build a similar device, but more powerful and with multiple speakers to install it on a motorcycle. Is this totally crazy? :) Do you think it will work? Do you think that I need some bigger-than-usual ultrasound speakers? If so, do you know where I could find some medium-sized ultrasound speakers? Thank you!

The frequency should be somewhere in the range between 20 and 40 kHz, this way humans can't hear it, but dogs can hear sounds up to 40 kHz.

You can use a piezo buzzer instead of a tweeter, for the ultrasound.

A simple search with google and you will find info about the hearing range of dogs and humans.

Here's a couple of links:
http://www.lsu.edu/deafness/HearingRange.html
http://www.madsci.org/posts/archives...8088.Gb.r.html
http://hypertextbook.com/facts/2003/TimCondon.shtml
http://www.pointingdogs.com/Pursuit/...th/hearing.htm

I used a sine wave generator driving a 12W Mylar (waterproof) cone speaker to annoy a neighbour once who was revving his outboard engine at the bottom of his garden for four days on the trot.

The frequency was set to produce an irritating, just perceivable high-pitched tone that left ringing in your ears when you walked away from it after a while and its direction couldn't be perceived easily either. Perhaps this might work with dogs at 18kHz upwards but bear in mind the frequency response is limited when using a speaker.

If you make it variable then you can experiment with it (at your own risk of course), plus driving a speaker shouldn't be a problem if you're power it from a bike battery.

Please take note of laws for not disturbing bats.


JJ

Originally Posted by junglejenny

Please take note of laws for not disturbing bats.


JJ

Which countries has such laws ? in USA? Quite interesting!

they run just higher than 20kHz, so they might annoy some people if very intense. try 25-30 khz, or better yet tune for the animal you'd like to repel. sounds like a great idea for motorcylists - hitting a deer at 100km/h would be really bad for both parties.

piezo transducers can be run at really really high wattage for their size. want to check it out? tune your circuit at 10kHz and see how painfully loud 1W will be. use two or three pointed in various forward directions (they're very directional at hi frequency) and it should work pretty good.

my only question is: any animal that would not be repelled by the noise of the bike itself may be pretty bold. if you market this, plz don't gurantee anything - you don't need a lawsuit for trying to help people! ;)

These laws are mainly in countries where bats live in the roof overhang of people's houses. I wonder if there are laws prohibiting the bats from doing harm to the humans.

http://www.mitedu.freeserve.co.uk/Ci...sc/whistle.htm

Here is a whistle schematic

with one of these

http://www.mitedu.freeserve.co.uk/Ci.../5_30timer.htm
for a dog that barks and barks
just time a same time frame as it barks
so the noise replys
in lenghts

http://www.mitedu.freeserve.co.uk/Ci...ng/soundsw.htm
deter a barking dog


http://www.mitedu.freeserve.co.uk/Ci...dio/2wamp.html

use this to give adjustments and as a driver
if you need a realy powerfull one

then you can try one of the design on elektroda for amplifiers
although chips have a certain responce this circuit is good to 1mhz
so will be fine for lf

as outputs what to do is use transducers you can get 2 or 5 watt versions that cover 1-100khz so this is fine

then if you need a directional amp
you can use some pipe {copper } ask robin hood for a device for listening {its on the board somewhere ago} and use the same technique in reverse

a resonator you can add fins to it to increase the overtones
makign a stack of pipes like a dog deterant organ

even play them barry manilo remodulated with a self adjusting linear bandblock up converter chip
you can buy these turns a deep voice into a very high pitch one
can go well above 20khz


and tune with a file all very interesting

a similar device is used to control snow faling and how it groups in airports


funny:

as a funny story:

it is a fact that the law can sometimes be in your favour
in the usa {as usual}

the court can order a noisey dog owner to have his dog de-barked
and you can also get a dog "de-clawed" or "de-fanged" quite crusum to do this to a defenceless animal and definalty one way to give it no defence so next time you get mugged it looks pretty stupid
only americans can do this .....


so after reading a few things as notes

1} Many commercial pest repellers based on this principle are available, most of them operating in the range of 30 to 50 kHz

2} you need simply to use a eor gate X2 as a doubler


This circuit is used to double the frequency of digital clocks. The circuit works by causing a delay, by using gate "a". This delayed clock is the XOR'ed with the original clock and this gives a short pulse at the beginning of the original clock "high" and a second pulse at the start of the original clock "low". The width of these logic high pulses is the number of nanoseconds of the gate delay. More delays may be inserted between gates "a" and "b" for different pulse widths. For CMOS applications, IC1 should be a 4070. For TTL any form of a 74386 ( 74LS386, 74AS386, etc.) should be used. For the 74AS386 the maximum clock-in is about 166 kHz. For a 74LS386 the maximum frequency is about 28 kHz. For a 74386 it is about 25 kHz.

Your responses are very helpful. I don't intend to make this a commercial product (well, not yet at least); I'm gonna get a bike soon and I have too many friends who had a lot of problems with dogs while riding their bikes. I know it's hard to believe, but there are some dogs (a lot in fact) that seem to be so deranged by the fact that the wheels of the bike are acutally moving that they ignore the sound of the motor and come near you, trying to bite. If you know how expensive a motorcycle suit is you'll know why this is so very undesirable :) Fortunately we don't have problems with bats at my location. I'll let you know how the project works ... so far I'm still searching for that dream bike :)

You guys are *** sent to me. I have been thinking of shooting my neighbor and blaming his dog for it.
Thanks for the info.

tdub

haha after his dog acts crazy for a week, maybe he will shoot it instead..


no just kidding guys - intentionally being an asshole to a neighbour or other guy is never a good thing. try to keep it on the level

Can anyone point me in the right direction to purchase these high frequency dog repellent gadgets on-line in the United Kingdom?

I know if this thread was very old one, but in case somebody that have a knowledge how to built dog repeller please be kind to share the working schematics.

Thanks before.

Hi NoRG,
Set up a 555 to oscillate at 30kHz and feed the output from pin3 to an NPN transistor driving a piezo buzzer.
Hope this helps.
Tahmid.