Do-it-yourself animal repeller. ultrasonic emitter

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 is likely to be required.

A homemade ultrasonic dog repeller is a great alternative to a purchased device. Such a product can be finely tuned, made in a convenient package, get improved performance and reliability for less money.

Do-it-yourself dog repeller in terms of the mechanics of action is no different from mass-produced devices.
With the exception of the main parameter - it is more powerful and operates in a larger frequency band.

Using:

• do-it-yourself ultrasonic dog repeller reproduces high frequency sound;
• fluctuations inaudible to a person act on the dog's hearing organs, causing pain, disorientation;
• unlike serial ones, if you make the dog repeller yourself, the device will change the radiation frequency over a wide range, further increasing the impact on the dog.

In home-made devices, quite, so to speak, large-scale approaches to the formation of a strong sound wave are used. 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 properly configured and neatly assembled device works efficiently, with almost a 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, understandable mechanics of the interaction of the main hardware parts.

To make a dog repeller yourself - you do not need to order or look for rare, expensive items. Most of the solutions are based on microcircuits and transistors, which can be easily purchased at any electronics store.

The basic principle on which a do-it-yourself dog repeller is built is the interaction of two oscillatory circuits.

At the same time, it is observed:

• the clarity of the formation of the base carrier frequency;
• high output power of the final stage;
• variation in the frequency of sound over a very wide range.

Understanding how to make a dog repeller is accessible even to a person who has basic skills in working with a soldering iron and making printed circuit boards.

The microcircuits, transistors and diodes used do not belong to the micro-sized class. Therefore, a powerful do-it-yourself dog repeller is easy to make 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 on how to make 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 logic blocks K561LA7;
• transistors of types KT3102 (3107)
• piezo emitter, class BF1 SQ-340L, instead of it, to increase the sound pressure, it is allowed to install a specialized ultrasonic emitter MFC-200.

The principle of operation of the device assembled in this scheme is as follows:

1. The first circuit for forming the carrier frequency is a symmetrical multivibrator assembled on two of the four logic elements of the microcircuit.
2. The output of the primary generator is a rectangular signal with a frequency of about 1.5 Hz.
3. The task of the secondary circuit is to generate an ultrasonic signal from the base frequency signal. The multivibrator, built on the remaining two logic elements of the microcircuit, creates a rectangular signal with a frequency of about 20,000 Hz, which quadruples every 0.66 s.
4. To build up a speaker or a piezoelectric element, a push-pull transistor amplifier is designed. Its emitter load is the sound emitting element.

The circuit provides protection measures against power reversal, overvoltage, as well as a frequency filtering system. This do-it-yourself electric dog repeller circuit requires some practical work 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 do-it-yourself dog repeller is a simple circuit. There are only 13 elements in it, 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 - for power supply.

After manufacturing the printed circuit board, it remains to carefully install and solder the elements. You will get the most powerful do-it-yourself ultrasonic dog repeller, the entire setting of which comes down to adjusting the resistor to form the optimal frequency.

Wherein:

1. output power is regulated only by the voltage coming from the battery;
2. A protective diode acts as a limiter. It can be replaced by an analogue, with an operating voltage of 5 to 12 V;
3. 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 properly use a dog repeller

When attacking an aggressive dog, it is important that the action of the device be unexpected and as sharp as possible. Therefore, it is not worth panicking ahead of time.

• take the device out of your pocket or bag;
• let the dog to a distance of at least a meter;
• direct the sound emitter of the repeller at the animal;
• press the start button.

At the moment of stupefaction and a short retreat, it is worth continuing to direct 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 should be understood that sound pressure begins to drop sharply with increasing distance. Therefore, the effect of reactivating the repeller will be much stronger if the dog is a little weaned, retreating without exposure to a weak ultrasonic signal.

It is not necessary to aim the sound emission line directly at the animal's ear. Vibrations are perfectly distributed by the bones of the skull, so it is enough to aim the repeller at the head of the animal. It is not necessary 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 more efficient than commercially available models.

At the same time, it is worth noting one feature of homemade products, which can serve as an excellent advertisement. Dog repeller scheme - 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 proposed serial models of similar output power.

Returning from work at night or wandering through dark alleys, there is a danger of being attacked by stray dogs, whose bites are sometimes life-threatening if you do not turn to the doctors in time. It is for these cases that smart human brains came up with an ultrasonic repeller.

Industrial repellers have a rather complex scheme and are made on rather scarce components.

In this article, we will consider a variant of such a repeller using the famous 555 series timer. The timer, as you know, can work as a generator of rectangular pulses, it is this connection that is used in the circuit.

The generator operates at a frequency of 20-22 kHz, as many animals are known to "communicate" in the ultrasonic range. Experiments have shown that frequencies of 20-25 kHz cause artificial fear in dogs, thanks to the construction regulator, the generator can be tuned to a frequency of 17-27 kHz.

The circuit itself contains only 6 components and will not cause any difficulties. It is desirable to use a multi-turn regulator, for more precise tuning to the desired frequency.
A piezo emitter can be taken from a calculator or any other musical toys, you can also use any HF heads with a power of up to 5 watts, there is simply no point anymore.

The device effectively operates at a distance of 3-5 meters, since there is no additional power amplifier in the circuit.

As a power source, it is convenient to use a crown, or any other source with a voltage of 6 to 12 volts.

List of radio elements

Designation	Type of	Denomination	Quantity	Note	Score	My notepad
	Programmable timer and oscillator	NE555	1			To notepad
R1	Resistor	2.2 kOhm	1			To notepad
R2	Resistor	1 kOhm	1			To notepad
R3	Variable resistor	4.7 kOhm	1			To notepad
C1	electrolytic capacitor	10 uF	1			To notepad
C2	Capacitor	10 nF	1			To notepad
	Piezo buzzer		1

Dog Repeller Diagram

In summer time, or how often the question arises, how to deal with dogs that stomp while you are away, in your summer cottage.

Your attention is given the answer to the question scare away dogs with ultrasound

Dog Repeller Diagram easy to assemble, and also suitable for a beginner radio amateur

Device Diagram:

The device, as is already clear, is intended for scaring using ultrasound.

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 of ultrasonic dog scarers published on the Internet, the following scheme turned out to be the most common, which is higher.

Top of the board- piezo emitter SQ-340L. It can be recommended to use the MFC-200 ultrasonic annunciator instead, which has a high acoustic pressure of up to 85 dB, which means a longer range.

A piezo emitter can be obtained from speakers, also from speakers that people call pancakes, from a music box, from calculators, and so on.

assembly box The body of the ultrasonic repeller was made from a failed Chinese-made VHF radio station, you can use any other case that is at hand, a walkie-talkie, and so on, the dimensions of which were guided by the development, manufacture and assembly of the device.

Right - button SB1, when pressed, the power is turned on. Battery type "Krona", "Korund", the main thing is to have an operating voltage of 9 volts.

You can also use lithium-ion batteries to power the device. Plus, it will be great that the ability to charge.

Master oscillator 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 fine if you use transistors like KT816. VT2 and VT4 - type KT315, KT368 or imported analogues of type C9018, C9014. It is better to use Schottky diodes according to the scheme, 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 pesticide has been repeatedly used on dogs and each time proved to be even better than expected.

The dogs fled, looking at the dog, it is clear that the scarer makes a very unpleasant sound for them.

Attention! You should not turn on the device on people from a close distance (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 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 rises 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!

The ultrasonic dog repeller was made relatively recently, and entered the list of necessary weapons for self-defense. Indeed, using this device, you can scare the prevailing number of dogs and even cats. But, often, the majority acquires 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 - this is 20,000 oscillations every second. Of course, the sound power has no limits and goes up to megahertz. With such a sound spectrum, no destruction occurs, but the vibration of the physical body begins. At huge frequencies, oscillations of electrons can occur and no more.

In the frequency range of 20-1000 kilohertz, the human ear is not able to hear, but, nevertheless, sound exists - this is called the sound of "ultra" or simply - supersonic. Of course, such a force cannot be heard, but this does not mean that nothing happens during a sound wave. Properties of ultrasound:

• crushing and destruction;
• the ability to penetrate the material from the inside;
• at low attenuation, it can be reflected from various obstacles.

Natural natural sounds, for example: the murmur of water, the sound of the wind - high frequencies may be absent or have a very weak strength. Ultrasound was created for a reason - it is the essence of many creatures. If we take bats as an example, they always use ultrasonic abilities, orient themselves in space due to echolocation, and also hunt prey by sending out waves that reflect back the found object.

Can a dog hear ultrasound?

Dogs and other small warm-blooded animals can hear ultrasound. This is due to the fact that, with their small size, communication occurs with each other. only at high frequency. On the edge of a dog or cat ear there is a special pocket that is necessary to capture these sensitive waves, a kind of antenna.

The whole working principle of the dog repeller device, made on the basis of ultrasonic frequencies, is repelled from this. But the device should not only provide audibility to animals, but also have the effect of intolerance, as mentioned above - to have a destructive and crushing effect. In this case, the device works 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 do without injuries if a very strong sound is applied to him. . Physiological intolerance fluctuates at 130 dB. You can experience this when a person is 100 cm from a turbo plane that starts to take off.

To achieve a successful result, it is enough to apply a 100 dB repeller. This is comparable to the sound of a traumatic weapon, but using this gun, you can run into problems with law enforcement. And the 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 the area in a large amount per unit time. The measurement is in watts. It turns out like this - the sound ratio of the force is directed to the object, in which the limit of audibility is significantly lower. This phenomenon is assigned a measurement - decibels.

Interesting fact! A sound power of 100 dB breaks the line of hearing by about 1010 times, so according to experts, if the level is below this number, then the effectiveness of ultrasonic weapons will be low, if not completely useless. You should not buy ultrasonic dog repellers with a power of 80-90 dB - this will not give any positive result.

Choosing the Best Dog Repellers

Provided on the market a wide range of ultrasonic dog repellents, and almost always there are new models. Below will be provided devices that have been repeatedly tested in practice and have shown efficiency at the highest level:

1. AD-100 device. Refers to budget options. The performance is significantly less, but it is still quite efficient. 3 special LED flashlights are built into the device. The working range of the defeat is 1.5-6 m. This device can not only prevent the attacks of aggressors, but can also be used in training your favorite pet. The average price is 1000 rubles.
2. 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 often buyers purchase fakes or ineptly manage the device. The device has been repeatedly tested by specialists and proved that it can reliably perform its tasks. The range of influence is 15 m. The device can pacify not only the aggressive ardor of the dog, but also scare away other wild predators. On average, it costs 4000 rubles.
3. Domestic device "Dogs.net". It occupies the highest place 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 draw a bold conclusion! The best dog repeller is considered to be the 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 the use of the repeller;
• device power;
• radiated 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, then the Dazer II (116.7 decibels) and the Wasp (99.1 decibels) will be virtually the same in terms of the distance of destruction. But, the Thunder-125 repeller, unlike the Thunder-250, is able to operate 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.

Accessories, price and other little things

Homemade electronic dog repeller

Dogchaser is great for scaring away- this electronic dog repeller is not difficult to make with your own hands. Dogchaser is a dog chaser, it is assembled in the presence of such materials:

Do-it-yourself ultrasonic dog repeller done in this way. Ultrasonic temporary drift falls 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 give additional amplification using push-pull bridges, transistors VT2-VT5 are used. The device starts working after pressing the SB1 button.

Passing low-frequency oscillations will provide capacitors C4 and C7. You can use the piezo siren from the ACT-10 car and significantly increase the range. Chips 564LA7, K176LA7, K1561LA7 are suitable. Any silicon diodes VD1-VD3. Any low power transistor with a coefficient of at least 30 - VT1. The remaining transistors can be replaced with the KT3102 series.

Pros and cons

The demand for ultrasonic repellers is constantly growing due to their positive aspects. Positive sides:

1. No bodily injury.
2. For humans, the device does not harm.
3. Ease of use. The device is very easy to use, even children can handle it without harm to themselves.
4. Defeat at a distance allows you to stop the aggressor dog on the way.
5. The device is small and easy to carry even in your pocket.

Negative sides:

1. The device is not always capable of forcing a specially trained dog or a predator, which purposefully attacks on the owner's order, to retreat.
2. The device has practically 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 really save you from dog attacks. . Buying advice:

When meeting with aggressive stray dogs, you should exercise the highest care and prudence, because a dog repeller cannot give a 100% guarantee.

Dazer - ultrasonic dog scarer, diagram and description of the device. Hello visitors of 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 terribly. Of course, you can rush into battle with her, but you can hardly get out of the battle without damage and injuries, 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 of industrial Dogcheisers, mainly made in China, on the Internet, and secondly, many sites published home-made "horror stories" for dogs, collected according to various schemes, one of which caught my attention the most.

The 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 following turned out to be the most common.

On the top of the board is a piezo emitter SQ-340L. It can be recommended to use the MFC-200 ultrasonic annunciator instead, which has a high acoustic pressure of up to 85 dB, which means a longer range.

A 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 a case from a failed Chinese-made VHF radio station, you can use any other case that is at hand, a walkie-talkie, and so on, the dimensions of which were guided by the development, manufacture and assembly of the device. On the right is the SB1 button, when pressed, the power is turned on. Battery type "Krona", "Korund", the main thing is to have an operating voltage of 9 volts.

Two lithium-ion batteries from a mobile phone can be used for convenience. The appearance of the assembled board from the side of the parts is shown in the photo.

The master oscillator is assembled on a domestic microcircuit, it sets the frequency we need, and the transistor stage amplifies it. It is better to use Schottky diodes according to the scheme, all polar capacitors must be supplied with a voltage of 15 volts. This ultrasonic repeller has been repeatedly used on dogs and each time proved to be even better than expected.

When the power is reduced to 3 volts, a quiet whistle is possible, which can be heard, and at 9 volts the frequency rises and we stop hearing the whistle, since the piezo emitter begins to emit ultrasound. In general, this device is an active self-defense weapon against dogs and more!