Summer will soon come and there will be a lot of mosquitoes, mosquitoes and other annoying midges. Therefore, I propose to assemble a diagram of a simple but very necessary device - an ultrasonic repeller. The proposed device will protect you both during work and during rest from mosquitoes and even from annoying barking dogs if you increase the frequency of the generator to ultrasound.

The diagram of the ultrasonic repeller is shown below:

The sound-reproducing element of the device is a piezo emitter (ZP-1, ZP-3, ZP25... in general, any). With a slight modernization of the device, you can increase its power by adding a simple ULF and using a high-frequency speaker.

Operation of an ultrasonic repellent device. Diode VD1 is needed to protect against incorrect power connection. - battery or accumulator with voltage from 1.5V to 9V. But it is better to give the maximum voltage, since with increasing voltage the radiation power of the device increases and, accordingly, the efficiency. The frequency of the generator depends on the capacitance C1 and C2, and the resistance R1. Several more piezo emitters can be connected to the contacts of the ZP-shki. It is advisable to choose models that are more powerful.

About the details for the ultrasonic repeller circuit. Instead of the KT361 transistor, you can install any other pnp transistor with similar parameters (for example, a733, kt3107).

The ultrasonic repeller requires almost no adjustment, you just need to adjust the frequency of the generator using resistor R6 (you can use a frequency meter, to do this, connect the frequency meter in parallel with resistor R1).

The current consumption of the device is about 1.5 mA. The printed circuit board for the ultrasonic mosquito repeller is shown in the figure below:

The archive with the printed circuit board and circuit diagram in Lay format is on the forum. I wish you a great summer vacation, because now mosquitoes will fly around you for a kilometer! Material sent by R. Rybalko

Discuss the article DIAGRAM OF ULTRASONIC REPELLER

People who have been bitten by angry dogs suffer from obsessive phobia throughout their lives. The fear of homeless animals not only prevents you from moving around the city calmly, but also makes you worry about the safety of your own children. Sometimes getting to school or shopping requires scaring off a pack of stray dogs. A stick or stone against a whole pack is a disastrous idea, especially if a child has to defend himself.

How to scare dogs away

Using special dog repellers (daisers) is a real chance to protect yourself and your loved ones. These devices easily fit into a jacket pocket, backpack or handbag, and are just as quickly removed from there if necessary. It is important to understand the operating principles of different diffusers in order to choose the most powerful one. Among those currently on sale, the ultrasonic repeller is considered the most effective. . Its action is enough for 13 m, which means that the dogs will not have time to get close.

The cost of factory-made diffusers is quite high, so people often use homemade devices. Real craftsmen will be able to make any repeller with their own hands: chemical, ultrasonic or electric. Why buy an expensive device if the one you make yourself is no less effective?

Dog Repeller

Do-it-yourself chemical dog repeller: what and how to make it from

Chemical dispensers are devices filled with a composition that is toxic to animals and humans. The principle of operation of the repeller is to spray a caustic liquid onto the mucous membranes of the dog’s eyes, nose, and mouth. It is difficult to assess the effectiveness of such a diffuser. Firstly, its use involves close contact with angry animals, which in itself is very dangerous. Secondly, if a large number of dogs attack, there is simply not enough time to spray a can of “chemicals” on everyone.

For your information! Making a chemical repeller is easy. The work will require ingredients that can be found in any kitchen: ground black pepper, vinegar, mustard powder. Some people use shag instead of vinegar when making such a diffuser. The result is cans with different compositions.

How to make a chemical disperser at home?

Option #1:

1. Preparing the container for the chemical composition. As a rule, this is a 0.5 liter plastic bottle without a cap onto which a sprayer is placed.
2. Mixing the composition: add pepper to the vinegar, shake everything together.
3. The liquid is poured into the bottle and closed tightly. Not very convenient, but you need to carry it with you.

Option #2:

1. Preparing a container for a chemical mixture. It is convenient if it is a 0.25 liter jar with a tightly screwed lid.
2. Preparation of the caustic mixture: finely chop the shag, add pepper and mustard powder. Mix.
3. Transfer everything into a jar and close the lid. Carry with you, when an aggressive dog attacks, pour the contents onto the animal.

Do-it-yourself ultrasonic dog repeller: diagram, powerful diffuser

The ultrasonic dissipator, which produces a sound that is unpleasant to the dog's ear, is highly effective. The advantages of this device are that it is absolutely harmless to people and works even over long distances. Stray dogs immediately pay attention to the ultrasound signal, quickly leaving the meeting place with a person. By using the device in a critical situation, you will be able to immediately disperse the entire pack, rather than fighting off each dog separately.

Dog repeller circuit

You can make an ultrasonic dog repeller with your own hands using various designs of powerful detectors taken from the Internet. They can be remade if technical skills allow, or used in finished form. The universal circuit of an ultrasonic dog repeller requires the presence of a microcircuit, transistors, resistors, and diodes. At the stage of assembling the ultrasonic repellent device, it is important to follow the recommendations of specialists:

• use a piezoceramic emitter during the manufacture of the diffuser, which will evenly distribute the load;
• To turn on the light, select LEDs D3. Their installation is carried out in the farthest part of the device;
• In order for the repeller to work at a frequency of 25 kHz, you need to take a resistor P35, but you should not experiment with frequency parameters. In this regard, it is better to stick to the settings of factory models;
• The power of the ultrasonic diffuser should not exceed 130 dB. Otherwise, the device will not only scare away the animal, but will also cause significant harm to it;
• for long-term operation of the ultrasonic device, it should be equipped with slots for 8 9V batteries;
• checking ultrasound pulses is the final touch in the work. This can be done using an oscilloscope or a sound card compatible with a computer;
• if the device was prepared for stationary use (for example, for a summer residence), then it must be enclosed in a moisture-resistant case and equipped with clamps.

Electric dog repeller: components and assembly rules

An example of a homemade dog repeller

Due to ignorance of the principles of operation of an electric disperser, it is often confused with a conventional stun gun. Many people immediately refuse to purchase such a repeller, since it contradicts their ideas about humane treatment of animals.

Important! The electrodisser is not intended for close contact with the dog's body. The device only creates a loud intermittent noise effect that scares away aggressive animals.

To make an electric dog repeller at home, you will need the following elements: a plastic bottle, a high-voltage module, a micro button and a AA battery. The technology for creating a homemade device is simple:

1. Secure the AA battery and module using electrical tape.
2. Solder the button and wires to the surface of the battery.
3. After making the base for the repeller, you should cut the electrical wires.
4. Cut off the neck of a plastic bottle to create a diffuser to enhance the sound signal and protect against voltage.
5. Place the diffuser on the electrical module, making small cuts on the neck.
6. It is good to glue the junction of the neck and the module.

Visual information about making an electric dog repeller can be obtained from YouTube videos made by people with special technical skills. There, the electrodisser is shown in action: the sudden crackle of electrical discharges has a depressing effect on dogs, and they hide. No matter how many stray animals you encounter, the loud blasts of an electric repeller will send everyone running.

Note! Despite the tolerant attitude of most people towards homeless animals, it is unacceptable to be careless about one’s own safety. A dog is truly a man's friend, but only if it is cared for from puppyhood and kept in decent conditions.

Stray dogs live by different laws, and it is difficult to predict their behavior in a given situation. Due to the trials that street animals have to endure every day, they become embittered and increasingly attack passers-by.

A homemade dog repeller will always protect a person, the main thing is to keep the device with you. No one knows where a dangerous clash with a pack will happen: during an evening walk, in an unfamiliar area, on the way to the house. Stray dogs may share prey, territory, or chase a bitch; you should not deliberately attract attention to yourself and try to calm the animals down. Task No. 1 in this situation is to leave the dangerous territory as soon as possible, but if that doesn’t work, use a repeller.

Reading time: : 4 minutes

Stray dogs can cause a lot of harm to both adults and children. They can greatly frighten, bite and injure a person. Dogs have a negative attitude towards people who ride bicycles and motorcycles. In such cases, many people are looking for ways that could save them from. Some people carry gas cans with them, while others carry special ones. We’ll look at how to make a dog repeller with your own hands in detail in this article.

Can be made in several versions. Any repeller is also called a Dazer. It can be either a chemical device or an electronic one. Their power depends on the type of device. The most powerful ones work at a distance of approximately 13 meters. This result will be obtained if you apply . This is the best option; you won’t be afraid to walk the streets with it in the evenings.

The cost of devices that scare animals is not cheap, so many people invent a homemade electric or chemical repeller. Making the device yourself will be much more profitable than buying it. But to start doing something simple, you need to be patient and, of course, have special knowledge. If a person does not understand how to make it, then it is better to purchase a ready-made one and not waste your time.

For dogs, made by yourself, the most powerful and safest. A person will be able to protect himself and at the same time not get injured. The device simply gives a signal that only animals can hear. Dogs respond quite sharply to high-power ultrasound. They immediately turn away from the person and run away. The important thing is that the device scares not only one dog, but also an entire flock. The number of pets has no effect on the device's ability.

The device operates even at a fairly long distance. And the closer the animals stand, the stronger the sound will be.

How to make a chemical apparatus with your own hands?

To start making a simple chemical apparatus, you need to prepare the necessary ingredients. We need to take:

• vinegar;
• ground pepper.

Or you can use the second method:

• black pepper;
• shag;
• mustard powder.

Production technology

The easiest option without electricity is a parody of pepper spray. To do this, you need to take a 0.5 liter plastic container and fill it completely with vinegar. Next, add 1 tablespoon of pepper. Then we chop and put on the sprayer. But not everyone will be comfortable carrying a bottle with them.

For the second option, buy good shag, chop it finely and mix it with pepper. To enhance the effect, add more mustard. All products are poured into a bottle that is easy and quick to open. If the dog begins to pester, the entire mixture is thrown into its eyes, nose and mouth.

Do-it-yourself ultrasound machine

The device operates from a sound that only dogs can hear; this sound is absolutely safe for humans.

First option

The circuit looks like a powerful one, it consists of the following parts:

1. The speaker from which the sound will come. You can take it from a calculator, column or box.
2. Krona battery, which should have 9 volts or 12 volts. Regular phone batteries work just fine.
3. Scheme K5 61LA7 or K176LA7.
4. Three silicon small diodes.
5. Five pieces of capacitors.
6. Five resistors of 100 kilo-ohms.
7. One resistor is 33 kilo ohms, and another is 2.
8. Four pieces of KT3102 transistors.
9. Silicon transistor, which has a current of at least 30, one piece.
10. Switch.
11. Textolite.
12. Solder and soldering iron.

Second scheme

For the second electrical circuit you will need:

1. There are five resistors with a power of 0.25 W.
2. Variable resistor.
3. Speaker – ZP-1, ZP-18, ZP-25.
4. Two transistors, such types as KT361B or 2T3307A, 2T3307V.
5. Two simple ceramic capacitors.
6. One protective diode KD503A.
7. Tumblr.
8. Textolite.
9. Solder with a soldering iron.
10. 9 volt battery, accumulator or power source with an intensity of 1.5 to 15 volts.

Production technology of the first version

For such a device you will only need one electrical circuit and 5 transistors. For the resistor and at the same time for the capacitors, a multivibrator is made from orthogonal pulses that have a frequency of 1.5 hertz. The second multivibrator, which includes two more resistors and one capacitor, as well as the remaining logical parts, will have pulses of 20 kilohertz. The output sound is greatly increased due to the transistor bridge, which loads the device in the form of speakers. They can also be replaced with machine speakers to increase the operating range of the device.

Production technology of the second method

The second fundamental option is simpler, it includes only thirty elements. Five output resistors are needed in order to reduce the intensity and to limit the possibility of current. They also give a start to the operating points, namely two transistors. They do frequency control at the same time as capacitors.

Resistors control the frequency of sound, so they are selected according to power. A protective diode is needed to save the device in cases where the voltage poles are accidentally confused. Its power is allowed 1.5-12 volts. The higher the voltage, the stronger the vibrations emitted will be. a good invention, and most importantly a simple one.

What are dog repellers used for?

Stationary is used to scare dogs if they want to attack a person. They are also convenient to use for those who live in a private home. If suddenly the owner sees a stray pet in his yard or garden, then through the device the dog will be able to hear an unpleasant sound and quickly run away.

In addition, such a device can be used on a dog, but do not use very powerful devices. The dog will grow up obedient and will do everything. You should not forget about the rules for using the device. The battery needs to be charged every day. The device is aimed at the angry animal with a deviation of no more than 5 degrees. If for some reason the sound does not start working, then you need to turn on the flashlight.

At the moment of a collision, a person will have a few seconds to take out the repeller and use it, so it is advisable to carry it right in your pocket. The device works well through clothing, you just need to press a button and that’s it. Do not escalate the situation and provoke an angry pet. It is better not to touch the dog and come very close to him.

Summarize

Whether to use a protective agent or not is up to each person to decide for himself. It is important to protect children from evil animals. If a person is afraid of dogs, then it is better to do it yourself or purchase a ready-made device. If it is always in your pocket, a person will behave calmly and not be afraid to walk the streets.

Thus, if a person is confident in his defense, he will be in a good psychological state. Therefore, it doesn’t matter what kind it will be, homemade or purchased, the main thing is to follow the rules of use so as not to injure yourself.

When 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 consult a doctor in time. It is for these cases that smart human brains came up with an ultrasonic repeller.

Industrial repellers have a rather complex design and are made with rather scarce components.

In this article we will look at a version of such a repeller using the famous 555 series timer. The timer, as you know, can work as a square pulse generator; this is exactly the connection 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 tuning regulator, the generator can be adjusted to a frequency of 17-27 kHz.

The circuit itself contains only 6 components and will not cause any difficulties. It is advisable to use a multi-turn regulator for more precise tuning to the desired frequency.
The 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 in doing more.

The device operates effectively 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 the crown, or any other source with a voltage of 6 to 12 volts.

List of radioelements

Designation	Type	Denomination	Quantity	Note	Shop	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 µF	1			To notepad
C2	Capacitor	10 nF	1			To notepad
	Piezo emitter		1

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:

1. The first carrier frequency generating circuit is a symmetrical multivibrator assembled on two of the four logical 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. 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.
4. 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:

1. output power is regulated only by the voltage supplied from the battery;
2. The limiter is a protective diode. It can be replaced with an analogue, with an operating voltage from 5 to 12 V;
3. 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.