Dog repeller: principle of operation of ultrasound, application of the device. Ultrasonic dog repeller How to make an ultrasonic dog repeller
The problem of stray or aggressive dogs walking without a muzzle is always acute in small towns or certain areas of metropolitan areas. A meeting with such an opponent can end very badly for a person. In addition to the necessary surgical intervention, a course of vaccination against rabies will probably be required.
A homemade ultrasonic dog repeller is an excellent alternative to a purchased device. Such a product can be finely tuned, manufactured in a convenient package, and obtain improved performance and reliability for less money.
The mechanics of operation of a do-it-yourself dog repeller are no different from commercially produced devices.
With the exception of the main parameter - it is more powerful and operates over a larger frequency band.
Using:
- Do-it-yourself ultrasonic dog repeller produces high-frequency sound;
- vibrations inaudible to humans affect the dog’s hearing organs, causing pain and disorientation;
- Unlike serial ones, if you make a dog repeller yourself, the device will change the radiation frequency within a wide range, further increasing the impact on the dog.
Homemade devices use fairly, so to speak, large-scale approaches to the formation of a strong sound wave. In serial products, piezoceramic emitters and speakers with a large diaphragm are rarely found, which the ultrasonic dog repeller circuit can boast of.
Therefore, a correctly configured and carefully assembled device works effectively, with an almost complete guarantee of a positive result.
A homemade dog repeller is a fairly simple device. If we look at proven and workable circuits, it is easy to see that they are built on simple principles and understandable mechanics of interaction between the main hardware parts.
To make a dog repeller yourself, you don’t need to order or look for rare, expensive elements. Most solutions are built on microcircuits and transistors, which can be easily purchased at any electronics store.
The basic principle on which the DIY dog repeller circuit is built is the interaction of two oscillatory circuits.
In this case it is observed:
- clarity of the base carrier frequency formation;
- high output power of the final stage;
- varying the frequency of sound over a very wide range.
Even a person with basic skills in working with a soldering iron and making printed circuit boards can understand how to make a dog repeller.
The microcircuits, transistors and diodes used do not belong to the micro-sized class. Therefore, it is easy to make a powerful dog repeller with your own hands without the use of a microscope, specialized solder, or a soldering station.
Ultrasonic repeller
If we turn to the experience of radio amateurs who have studied many circuits of serial devices in order to improve the device, it is easy to find two technical solutions on specialized forums.
Both feature high power output, use inexpensive, common parts, and are easy to set up.
One of the options for making a dog repeller yourself is to use a solution built using a K561LA7 digital elementary logic chip.
To assemble it you will need:
- digital element with 4 logical blocks K561LA7;
- transistors types KT3102 (3107)
- piezo emitter, class BF1 SQ-340L; instead, to increase the sound pressure, it is allowed to install a specialized ultrasonic emitter MFC-200.
The operating principle of the device assembled in this diagram is as follows:
- The first carrier frequency generating circuit is a symmetrical multivibrator assembled on two of the four logical elements of the microcircuit.
- The output of the primary generator is a rectangular signal with a frequency of about 1.5 Hz.
- The task of the secondary circuit is to generate an ultrasonic signal from the base frequency signal. A multivibrator, built on the two remaining logical elements of the microcircuit, creates a rectangular signal with a frequency of about 20,000 Hz, which quadruples every 0.66 s.
- A push-pull transistor amplifier is used to drive a speaker or piezoelectric element. Its emitter load is the sound-emitting element.
The circuit provides protection measures against power reversal, overvoltage, and also a frequency filtering system. This DIY electric dog repeller circuit requires some practical operating skills, as well as fine tuning. But the finished device is very effective, it starts with one button.
For those who are unfamiliar with the intricacies of soldering microcircuits, a simple circuit is intended for a do-it-yourself dog repeller. It contains only 13 elements, the key of which is the KD503A diode, which is simultaneously responsible for the maximum output power and protects the device from power reversal and other emergency modes.
For assembly you will need:
- resistors: 5 constant and one trimmer;
- piezoelectric sound emitter, class ZP-1, ZP-25;
- a pair of common transistors KT361B (3107);
- ceramic capacitors;
- protection diode KD503A;
switch, button - to supply power.
After manufacturing the printed circuit board, all that remains is to carefully install and solder the elements. You will get the most powerful ultrasonic dog repeller with your own hands, the entire setup of which comes down to adjustment with a resistor to form the optimal frequency.
Wherein:
- output power is regulated only by the voltage supplied from the battery;
- The limiter is a protective diode. It can be replaced with an analogue, with an operating voltage from 5 to 12 V;
- the variable resistor is responsible for selecting the frequency.
The installed battery is selected in accordance with the protective diode used. For KD503A - Krona 9V is suitable.
How to use a dog repeller correctly
When attacking an aggressive dog, it is important that the action of the device is unexpected and as sharp as possible. Therefore, there is no need to panic ahead of time.
- remove the device from your pocket or bag;
- bring the dog at a distance of at least a meter;
- point the repeller's sound emitter at the animal;
- press the start button.
In a moment of shock and short-term retreat, it is worth continuing to point the repeller’s sound emitter at the dog. However, if the animal moves a distance of a meter or more, the device should be turned off. It is worth understanding that sound pressure begins to drop sharply as the distance increases. Therefore, the effect of turning on the repeller a second time will be much stronger if the dog gets a little used to retreating without the influence of a weak ultrasonic signal.
It is not necessary to aim the line of sound emissions directly at the animal’s ear. The vibrations are well propagated by the bones of the skull, so it is enough to aim the repeller at the animal’s head. There is no need to waste time choosing some optimal direction.
Conclusion
Understanding how to make a dog repeller with your own hands and having some skills in working with a soldering iron, it is not difficult to create a device that will be much more powerful and efficient than commercially available models.
It is worth noting one feature of homemade products, which can serve as excellent advertising. Dog repeller circuit - involves the use of powerful, simple, inexpensive and common components.
The fault tolerance and reliability of a self-assembled device depends only on the accuracy of the radio amateur. At the same time, the efficiency of the device is higher, and the price is incomparably lower than that of the offered serial models of similar output power.
ULTRASONIC DOG REPELLER
Dazer - ultrasonic dog repeller, diagram and description of the device. Hello visitors to our site. Sometimes wandering through the dark alleys of the city at night is very dangerous, because besides you, an angry stray dog (sometimes very hungry) can go for a walk along the street and at any moment from a dark corner it can pounce on you and bite you terribly. Of course, you can rush into battle with her, but you can hardly get out of the battle without damage and injury, so there is a better option - a Dazer or an ultrasonic dog repeller. The following reasons prompted me to start making this device: firstly, I often came across advertisements on the Internet for industrial Dogcheisers, mostly made in China, and secondly, many sites published homemade “horror stories” for dogs, assembled according to various schemes, one of which most attracted my attention.
The device, as is already clear, is designed for repelling using ultrasound. The described device has a range of up to 13 meters and a qualitative effect on dogs that are about to bite you. As already mentioned, of the many schemes for ultrasonic dog repellers published on the Internet, the most common was the following.
On top of the board is the SQ-340L piezo emitter. We can recommend using the ultrasonic sounder MFC-200 instead, which has a high acoustic pressure of up to 85 dB, which means a longer range.
The piezo emitter can be obtained from speakers, also from speakers that people call pancakes, from a music box, from calculators, and so on. The box for assembling the ultrasonic repeller was the housing from a failed VHF radio station made in China; you can use any other housing that you have at hand, a walkie-talkie, etc., the dimensions of which were used to guide the development, manufacture and assembly of the device. On the right is the SB1 button, when pressed the power is turned on. The battery is of the Krona or Corundum type, the main thing is to have an operating voltage of 9 volts.
For convenience, you can use two lithium-ion batteries from a mobile phone. The appearance of the assembled board from the parts side is shown in the photograph.
The master oscillator is assembled on a domestic microcircuit; it sets the frequency we need, and the transistor stage amplifies it. Transistors VT3, VT5 - It is advisable to use high-frequency ones; the device works great if you use transistors like KT816. VT2 and VT4 - type KT315, KT368 or imported analogues like S9018, S9014. According to the circuit, it is better to use Schottky diodes; all polar capacitors must be supplied with a voltage of 15 volts. The printed circuit board of the device is also attached to the article. This ultrasonic repeller has been used on dogs several times and each time it performed even better than expected.
The dogs ran away and looking at the dog, you can see that the repeller makes a very unpleasant sound for them. Attention! You should not turn the device on people at close range (close to the ears and eyes), our ears catch ultrasonic waves, but the brain is not able to decipher them and for this reason we do not hear the world where communication is at an ultrasonic frequency. When the power is reduced to 3 volts, a quiet whistle is possible, which can be heard, and at 9 volts the frequency increases and we stop hearing the whistle, since the piezo emitter begins to emit ultrasound. In general, this device is an active weapon of self-defense against dogs and more!
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Among the many charger circuits for car batteries published on the Internet, automatic chargers deserve special attention. Such devices create a number of conveniences when servicing batteries. Among the publications devoted to automatic chargers, the following works should be noted. These devices not only charge batteries, but also train and restore them.A dog repeller is a useful device in the everyday life of a modern person. What is it for?
The problem of people living close to wild animals in cities is becoming increasingly urgent. Due to the abundance of food, dogs actively reproduce, gather in packs and begin to defend their habitat, demonstrating their direct aggression to passers-by. First of all, children who, due to their short stature, are not considered by predators as serious competitors are at risk. Having survived a wild animal attack once, a child receives psychological trauma for the rest of his life. Even adults experience painful treatment after bites. To combat the danger of attack, scientists have developed a dog repellent device that has proven itself in a variety of situations.
A dog repeller is a useful device in the everyday life of a modern person.
Operating principle
An ultrasonic device emits a directed sound signal towards the animal. To prevent a person from feeling discomfort, the frequency of the signal is higher than the human ear can hear. The dog hears a sharp sound, which intensifies as it approaches. As a result, the dog begins to panic from fright and runs away. The range of the device is 15-20 m. The most powerful models have an effect at 30 m.
Since an ultrasonic dog repeller uses sound, the device will not always work, particularly if the animal is deaf, has rabies, or has drooping ears. In addition, it may not work on trained dogs either.
You should also not use the device on calm animals, as this may anger them.
For additional protection, a special device is installed on the ultrasonic dog repeller - a powerful LED flashlight. It will blind the dog and help drive it away if the scaring sound does not work.
The problem of people living close to wild animals in cities is becoming increasingly urgent
The electronic dog repeller is powered by batteries. They need to be changed without waiting for discharge, as this affects the power.
Comparison of dog repellers (video)
Methods of protection
To scare away wild and feral animals, various means are used. For example, a stationary ultrasonic dog repeller is used to protect houses and areas. The device allows you to leave your cottage or garden plot unattended while the owners are away. The operation scheme is similar to a portable device. Power is supplied from the network, and it starts working when the motion sensor is triggered. In addition to dogs, the device works as a repeller for cats, foxes, and rodents. The frequency of the sound changes so that the animals do not get used to it and continue to be afraid to enter the territory.
Most devices do not have a noticeable effect on humans. The most powerful models can cause headaches and ringing in the ears.
Electric shock is effectively used as a repeller. The sharp sound of the discharge and flash with the release of a large amount of ozone scare animals already at a distance of 10-20 m. It is often installed on a bicycle so as not to reach it while moving.
Batteries power the electronic dog repeller
In addition to electronic ones, more traditional means of repelling dogs are also used, in particular, repellents and mixtures. The way they work is simple - they emit an unpleasant odor. After treating the area around the perimeter, animals will stop entering it. There is also a dog and cat version.
For tourists and athletes, it may be important to make a homemade dog repeller. It is an analogue of a gas cylinder. Consists of a container into which a mixture of vinegar and pepper is placed. This option is inhumane, but very effective. Other mixtures are also used, in particular, based on shag.
You can make a homemade ultrasonic repeller if you don’t trust the effectiveness of the devices being sold. This will require some knowledge of electrical engineering.
Sometimes the best defense is an attack. If you don’t have the device at hand, and you are surrounded by an angry flock, you can simply bend down to the ground and pretend that you are picking up and throwing a stone. This technique will scare away the dogs. Dogs are animals, they are devoid of reason, and instinct makes them afraid of such gestures.
Application area
You can use ultrasound to scare dogs away in different ways: to protect yourself, your family, your home or your garden. When walking with your dog, you can protect it from attack. In addition, the device allows you to train the animal, making it obedient.
You need to remember the rules for working with the device. The battery must always be charged. The device should be aimed at an aggressive animal with a deviation of no more than 5°. If the sound does not work, do not forget to turn on the flashlight.
From the moment of collision, you have literally a few seconds to use your repeller. Therefore, you need to carry it in your pocket. You can use the device without taking it out of your clothes; you just need to press the button.
Do not provoke the animal's aggression. The best way to avoid an attack is to stay away from the source of danger.
How to make a dog repeller (video)
Conclusion
Whether to use personal protective equipment is up to everyone to decide for themselves. Children, athletes, tourists are the main victims of attacks. If you are afraid, then you should buy such a device. The presence of a repeller does not mean that it will certainly be used; it may not be useful to you at all. However, the device gives a feeling of confidence and security, and therefore psychological comfort. And it’s not so important whether it’s a dog repeller, made with your own hands or bought in a store. The main thing is that the device makes it possible to avoid injuries and unpleasant consequences from a bite.
Attention, TODAY only!
This story began with the fact that my wife is very afraid of dogs. And I bought an ultrasonic repeller for her on Ali a long time ago. It has already been used with great success many times. It really works. And it was especially indispensable at the beginning of spring, when in our city dogs gathered in packs and behaved extremely aggressively. There were a lot of people bitten. I thought about purchasing a second repeller as a reserve, in case the first one breaks down, and it would be useful for me, I repeatedly took the repeller from my wife for a walk with my dog, and it always came to the rescue when a rabid flock was rushing toward us. No sooner said than done.
The order was sent to me on April 17, 2014, and on May 12 I received a standard yellow package in the mail:
What is a dog repeller?
This is an ultrasonic emitter with a frequency of 18,000 to 25,000 Hz, which causes significant discomfort to the animal. And if you combine the infliction of this discomfort with the execution of given commands, or vice versa, failure to perform given actions, then the dog will reflexively do what you are striving for.
And here I will make a small digression and write an important warning about using an ultrasonic repeller.
ATTENTION! IMPORTANT WARNINGS!
1. The repeller only works on dogs that are angry and in an aggressive (excited) state! The device may be ineffective against sick, deaf or heavily trained dogs.
2. Do not point the device at close range when the device is turned on. In such a situation, an ultrasonic repeller affects the hearing organs, the consequences of which can be “ringing” in the ears, headaches, etc. Do not point the flashlight in the direction of a person's eyes, especially in the dark.
3. Do not test the device on your pets - this will cause a negative attitude towards you as the owner.
4. Do not modify the design of the device! Do not cover the ultrasonic emitter with your hand or clothing.
5. Do not drop the device or allow moisture to enter the device.
6. Do not use the device against an indifferently wandering or peacefully lying dog - you may cause an ambiguous reaction from it;
7. Do not use the device against a dog in rooms with limited volume (elevator cabins, storage rooms, etc.) - you may cause an ambiguous reaction from it.
The repeller was packed in a cardboard box. By the way, the name of the company is different than on Ali.
Inside is, in fact, the repeller itself:
And the instructions are in Chinese and English.
Let's take a closer look at the ultrasonic repeller.
Specifications from the store page:
Specifications
Functions Dog training, Dog repelling, LED light
Dimension 130 x 40 x 22 mm/ 5.12 x 1.57 x 0.87" (L x W x H)
Weight 98g
Frequency 25 KHz
Max current 130 mA
Power 9V battery
Package Includes
1 x Ultrasonic dog trainer repeller
1 x User manual
1 x 9V battery
On the bottom of the case there is a slide switch for operating modes. Mode 1 – flashlight only, mode 2 – training, mode 3 – scaring. All this is illustrated near the switch.
The reverse side of the repeller. The battery compartment and a hologram that acts as a seal on the screw. There was no hologram on the repeller with Ali.
Name:
Front view, in the form of a dog's muzzle. Ultrasonic emitter and 2 LEDs. They shine quite brightly. In flashlight mode - constantly while the button is pressed. In scare mode they operate in strobe mode. The strobe is quite effective against dogs at night. (I have repeatedly used my flashlights, of which I have a few))) for these purposes.)
The light is white. On the repeller with Ali - with a very noticeable blue tint and duller.
Dimensions:
Let's compare 2 repellers. They are slightly different in color. In addition, the old one with Ali is already noticeably worn. In this case, the repeller from Ali is on the left, the new repeller from Tmart is on the right:
New below:
The body of the new repeller is made of much better quality. One example is the power button.
The battery included with Tmart is:
I didn’t want to disassemble the repeller with Ali, but then I decided that the truth was more valuable. And it was interesting to compare myself.
So, let’s look at the ultrasonic repeller with Ali:
The installation was done rather sloppily:
Now let's look at the ultrasonic repeller from Tmart:
To be honest, at first I was even taken aback when I saw a very small set of parts, which made me wonder how it actually works:
But as it turned out, the mounting on the board is double-sided (!) and made very carefully using SMD components, unlike the repeller from Ali:
The power of the new repeller is higher. Under equal conditions, and new batteries, the range is longer. If you nevertheless point the switched-on repeller at yourself, unpleasant sensations arise. My head is aching, my ears are squeaking. The effect is more pronounced when using a repeller with Tmart.
Various organizations also use similar repellers. For example, our staff who work with clients in rural areas are given EcoSniper repellers. The same China, only with a Russian name. It is considered effective, was selected by trial and those who use it are very satisfied. Let's take a look at it:
Doesn't remind you of anything?
I was not allowed to take it apart. Very fragile plastic on the case.
Instructions in Russian:
In terms of impact, it is approximately the same as the repeller from Ali and does not reach the level of the repeller from Tmart.
The body is made of thin plastic. Also has 3 functions. But it does not have a slide switch. The modes are activated by pressing inconvenient ones, which are also not labeled on the body. three buttons. Accidental clicks are possible. This product costs 1000 rubles.
Therefore, based on effectiveness, repellers can be arranged in the following order:
1 place. Repeller from Tmart.
2nd place. Repeller from Ali.
3rd place. Repeller EcoSniper. Of course, in terms of effectiveness, he could compete with Ali’s repeller and share 2nd place with him. But could not. It was pushed into last place by its inconvenient body in the hand and extremely inconvenient controls.
*A video of the process was intended here. But... I don't have a camera ready. And dogs tend to appear suddenly. I just don't have time to take it off. Besides, they mostly rush at me when I’m walking the dog. And there are simply no free hands. In one there is a leash, in the other there is a repeller. And the pack of dogs running around the neighborhood has become wiser. A few uses of the repeller were enough, now they are avoiding me and my dog.)))
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The product was provided for review by Tmart, for which we are very grateful.
This concludes the review. Let only kind dogs come across your path, for example, like this one.
The ultrasonic dog repeller was made relatively recently, and was included in the list of necessary weapons for self-defense. Indeed, using this device, you can scare the majority of dogs and even cats. But, often, the majority purchases such a device without delving into the technical capabilities, and this can lead to undesirable consequences at the right time, when the device becomes necessary.
What is ultrasound?
Human hearing abilities are limited by frequencies 16-18 thousand hertz, it happens very rarely when human ears can hear sounds at frequencies of 20 thousand hertz - that’s 20,000 vibrations every second. Of course, sound power has no limits and reaches megahertz. With such a sound spectrum, no destruction occurs, but vibration of the physical body begins. At enormous frequencies, electrons can oscillate and nothing more.
In the frequency range of 20-1000 kilohertz, the human ear is not able to hear, but, nevertheless, sound exists - this is called “ultra” sound or simply supersonic. Such a force, of course, cannot be heard, but this does not mean that nothing happens during the sound wave. Ultrasound properties:
- crushing and destruction;
- the ability to penetrate the material from the inside;
- with low attenuation it can be reflected from various obstacles.
Natural sounds, for example: the murmur of water, the sound of wind - high frequencies may be absent or have very weak strength. Ultrasound is created for a reason - it is the essence of many creatures. If we take bats as an example, they always use ultrasonic abilities, navigate in space through echolocation, and also hunt prey by sending waves that reflect back the found object.
Can a dog hear ultrasound?
Dogs and other small warm-blooded animals can hear ultrasound. This occurs due to the fact that, given their small size, communication occurs between them. only at high frequency. On the edge of a dog or cat's ear there is a special pocket that is necessary to capture these sensitive waves, a kind of antenna.
This is the basis for the entire working principle of dog repellers, based on ultrasonic frequencies. But the device should not only provide audibility to the animals, but also have an intolerance effect, as mentioned above - have a destructive and crushing effect. In this case, the device operates not only from power, but also from frequency radiation; if it is stronger, then the effect also becomes more effective. The dog experiences acute physical pain when the repeller is turned on.
Pain threshold
It has long been proven that a person cannot survive without injury if a very strong sound is applied to him. . Physiological intolerance ranges at 130 dB. This can be experienced when a person is 100 cm from a turbo plane that begins to take off.
To achieve a successful result, it is enough to use a repeller of 100 dB. This is comparable to the sound of a traumatic weapon, but using this pistol can lead to problems with law enforcement agencies. And an ultrasonic repeller will do the same job, only silently, therefore, no questions will arise from others.
Decibel value
Sound force refers to the energy that passes through an area in large quantities per unit time. The measurement takes place in watts. It turns out this way - the sound force ratio is directed towards an object whose hearing limit is significantly lower. This phenomenon is assigned a measurement - decibels.
Interesting fact! Sound power at 100 dB exceeds the limit of audibility by about 1010 times, so according to experts, if the level is below this number, then the effectiveness of ultrasonic weapons will be low, or even completely useless. You should not purchase ultrasonic dog repellers with a strength of 80-90 dB - this will not give any positive result.
Choosing the best dog repellers
Provided on the market wide selection of ultrasonic dog repellers, and new models almost always appear. Below will be provided devices that have been tested many times in practice and have shown effectiveness at the highest level:
- AD-100 device. Refers to budget options. The performance characteristics are significantly less, but, nevertheless, it is quite effective. The device has 3 special LED flashlights built into it. The working range is 1.5-6 m. This device can not only prevent attacks from aggressors, but can also be used in training your beloved pet. Average price 1000 rub.
- Dazer-2 device. Made in the USA and is a highly effective ultrasonic dog repeller. There are a small number of dissatisfied reviews, but this is due to the fact that buyers often purchase fakes or operate the device ineptly. The device has been repeatedly tested by experts and has proven that it can reliably perform its tasks. The range of influence is 15 m. The device can pacify not only the aggressive ardor of a dog, but also scare away other wild predators. On average it costs 4000 rubles.
- Domestic device “Dogs.net”. It occupies the highest position in the market of all existing devices. A huge number of positive reviews. There are standard models, as well as those equipped with modifications, one of which is a lot of chaotic bright light flashes to intimidate animals. The price ranges from 2500-4000.
Criteria for choosing a dog repellent device
You can make a bold conclusion! The best dog repeller is considered to be a device that has a power of at least 110 decibels, and a frequency of at least 24 kHz - the purchase of this device will be justified. Also, You should pay attention to the following characteristics:
- effective distance for using the repeller;
- device power;
- emitted frequency;
- form of radiation.
Self-defense experts say that in order to scare an attacking aggressive dog, you need to be at least 20 meters away from it. If we compare the models, the Dazer II (116.7 decibels) and the Osa (99.1 decibels) will be virtually the same in terms of engagement distance. But the repeller Grom-125, unlike Grom-250, is capable of operating effectively at a distance of 35 m, the second option has a range of 20 m. What is the shape of the emitter? – This, by the way, is an important criterion when buying a repeller. It is necessary when focusing the emitted beam; the energy must be directed and concentrated on the object.
Components, price and other little things
Homemade electronic dog repeller
A dog chaser is great for scaring– This electronic dog repeller is not difficult to make with your own hands. Dogchaser is a dog chaser, it is assembled with the following materials:
DIY ultrasonic dog repeller done according to this principle. Ultrasonic temporary removal occurs on resistors R3-R5, as well as capacitor C3 and transistor VT1 with diodes VD1 and VD2. The microcircuit does not have much power, therefore, it is necessary to provide additional amplification using push-pull bridges; transistors VT2-VT5 are used. The device starts working after pressing the SB1 button.
Passing low-frequency vibrations will be provided by capacitors C4 and C7. You can use a piezo siren from an AST-10 car and significantly increase the range. Microcircuits 564LA7, K176LA7, K1561LA7 are suitable. Any silicon diodes VD1-VD3. Any low power transistor with a coefficient of at least 30 is VT1. The remaining transistors can be replaced with the KT3102 series.
Advantages and disadvantages
The demand for ultrasonic repellers is constantly growing due to their positive aspects. Positive sides:
- No bodily harm.
- The device does not cause harm to humans.
- Ease of use. The device is very easy to use; even children can handle it without harming themselves.
- Defeat at a distance allows you to stop the aggressor dog on the way.
- The device is small and convenient to carry with you, even in your pocket.
Negative sides:
- The device is not always capable of forcing a specially trained dog or a predator that is purposefully attacking on the orders of the owner to retreat.
- The device has virtually no effect on dogs with deafness or rabies.
Final decision
To choose the best ultrasonic dog repeller, it is recommended to follow some important rules that will truly protect you from dog attacks. . Recommendations for purchasing:
When encountering aggressive stray dogs, you should exercise the utmost care and prudence, because a dog repeller cannot give a 100% guarantee.
