home » Lighting » Do-it-yourself dog repeller - step-by-step instructions. Ultrasonic emitter Homemade dog repeller

Do-it-yourself dog repeller - step-by-step instructions. Ultrasonic emitter Homemade dog repeller

The ultrasonic model sends high-power ultrasound signals towards the dog. Ultrasound has a depressing effect on dogs, forcing them to turn around and even run away, while the device is completely safe for humans. As the dog approaches, the signal intensifies and the animal begins to feel discomfort. The device is compact and can be carried with you in a bag or pocket. As the animal approaches, it will react and the signal will increase. With a repeller, a whole pack of dogs is not scary, which is very convenient; you can do without blood and victims. There are a lot of electrical diagrams for this device on the Internet, so if necessary, you can assemble it yourself and buy the components at any radio store. The device is quite simple, and it will cost you much less.
An electric device or stun gun is no less popular. It’s also compact, and when you press the button it produces a characteristic crackling sound, which means that ozone is released, which is unpleasant to a dog’s sense of touch. The device is dangerous for an approaching dog; if the distance decreases, it can give an electric shock and temporarily paralyze. The device will also force the dog to open its jaws if the dog still grabs you.
Gas in the form of a gas canister with a chemical filler inside. When buying a spray can, pay attention to its technical characteristics, since not all products are effective; if a dog attacks, the product may simply fail. When sprayed, the dog should rush, run away and no longer show aggression. In principle, you can build a gas pistol yourself by filling the cartridges with red hot pepper. You can leave the device idle. Sound is effective against dogs; the device can also be made with a light signal reflector.
Repeller - smell. Everyone knows that dogs have an excellent sense of smell and they do not at all like, for example, the smell of medical or isopropylene alcohol. All you have to do is wet the tampon. But this method has a big disadvantage - the alcohol evaporates quickly, which means you need to carry it with you at all times when going outside. Hot capsicums are irritating to the dog's nose, skin, and eyes, as is the smell of lemon, orange, and vinegar.

Principle of operation

Inside the body of the ultrasonic repeller there is a generator with an electrical circuit and high-frequency pulses, thanks to which the signal propagates. The device is equipped with a power source; simple models run on batteries.

Devices can be stationary or portable. In the first case, they are installed on the object and begin to operate when the dog approaches the object. In the second case, you can carry it with you to avoid encounters with aggressive animals.

Advantages and disadvantages

The undoubted advantage of all repellent devices is their safety for humans, as well as:

Instant exposure of an animal to an ultrasonic or electronic device.
Convenient to use, just remove the pocket from the case, or press the button found on all modern devices.
High efficiency of devices.
The efficiency of the devices regardless of the time of day and weather conditions.
Compact dimensions of protective devices.
No skill required to use.
They begin to act at a distance of 25-30 meters.

How to make your own ultrasonic

To assemble an ultrasonic model, you need to select a microcircuit and 5 transistors.

1. Description of the circuit

This foreign scheme consists of:

Standard timer 555, frequency 40 kHz.
Amplifier based on transistors TP1.
Timer 555 IC2, generating an antiphase signal.
Ultrasonic transducer.
Power switch in the form of a button.
Lead-acid battery when using the device in stationary mode.

Required materials and tools:

You will need a piezo emitter for assembly; you can borrow them from the dynamics of old speakers, a music box, or a calculator.
The case can be taken from a radio that has failed Chinese equipment.
9V batteries
Transistors type KTV816
Diode printed circuit board
Piezosiren, suitable for a car
Oscilloscope
Indicator, LEDs
Resistor, suitable from an old TV.

Step by step guide:

Assemble the generator.
Adjust the frequency using resistor R3; the output of the circuit should produce 2 antiphase signals, frequency 25 kHz3.
Connect the emitter to the choke.
Connect a voltage of 5.6 V through a zener diode, LED D2.
Connect an indicator for low battery, and LED D3 to turn on the device.
Set the frequency to 25 kHz with resistor P35.
Check the operation of the pulses on the emitter using an oscilloscope.
If the assembly option is stationary, use more emitters in the device, up to 10 pcs.
Install powerful IRF640 transistors along the way.

How to make an electronic repeller

With the slightest knowledge of electronics, assembling the device is not at all difficult. Large financial costs will not be required either. You need to purchase a microcircuit and transistors. To regulate the frequency of sound, it will be necessary to create an additional unit consisting of resistors, transistors and diodes designed for protection in case of polarity reversal.
After assembling the device, you need to check the resistance of the resistors so that the load is applied to them evenly; additional installation of a piezoceramic emitter will be required.
Power supply for the repeller is a standard crown, voltage -9 V.
The LED flashlight is built into the front of the housing.
To increase the power, it is advisable to install 8 batteries (AAA standard), capacity 300 mAh, under the crown.
The essence of the electronic device is the activation of a high-frequency pulse generator when a dog approaches. The frequency is not perceptible to humans, but animals hear the noise of the generator very well.

Do not experiment with the device on your pets; if you point the repeller at them, you may be left without their trust in the future.
Set the frequency recommended by the manufacturer; if it is exceeded, the device will quickly fail.
Typically the device is designed for a range of 30 meters, which will prevent the animal from invading your territory.
When choosing a finished device, pay attention to the cost, ease of design, quality of all components, manufacturer’s brand, and production technology.
Please note that cheap devices may be ineffective, unreliable, and may not meet the parameters specified in the documentation.
Choose an acceptable type of device in advance; if you carry it in your pocket, it is better to buy a portable model. If you need to install it on a tree or wall, choose a stationary device.
Cobra is considered a new and high-quality model with 4 operating modes; it can be used as a security system. A small pocket device - Osa, costs only 1200-1500 rubles, is effective and convenient to carry in your pocket.
The ultrasonic device with a power of 130 dB is distinguished by high volume. At a distance of 1 meter for a dog, this is the noise of a jet plane, the effect on the animal is simply deafening, thereby you can put it in an aggressive state, you will only make things worse for yourself in particular.
Do not rush to use the device if the dog is calm and does not at all seek to harm you.
A distance of 4-15 meters is considered large for the repeller to work effectively; it may simply not have an effect on the animal and lose its power at a distance. Consider the range of the device when purchasing or designing a model yourself.
Do not panic when an animal approaches, do not make sudden movements. Keep your finger on the button; when attacking, it is better to let the predator get closer, the noise will be deafening, and the shorter the distance, the more effective the device will be.
Do not play with the repeller, do not turn it on unnecessarily, for example, pointing it at a quiet, innocent dog.
13.Do not let children play with the device; it is better to teach them how to handle it correctly.
Don’t be a provocateur by turning your pet against you; with the device turned on, you can provoke aggression, but why would you want to do that?

(ultrasonic repeller) produces a sound signal that does not harm dogs, but causes them discomfort. A person does not hear this signal, because its frequency is above the threshold of audibility for a person. The device produces sound at a level of 100 dB at a distance of 1 m.

The circuit uses a standard 555 timer, on the basis of which an oscillator is assembled, tuned to a frequency of 25 kHz. With resistor R3, the generator is tuned to the resonant frequency of the piezo emitter you are using.

Rice. 1 Ultrasonic dog repeller, scheme

About the autotransformer.

To obtain maximum output from the piezo emitter (B1), an increased alternating voltage must be supplied to it. This is achieved by connecting B1 through autotransformer T1.
An autotransformer can be made independently using iron from an output or matching transformer used in small-sized radio receivers.

For piezo emitter type 250ST180 (voltage with amplitude of at least 25 V). We remove the windings present in the transformer, and in their place we wind 100+800 turns with PEV wire with a diameter of 0.1 mm.
It is also convenient to use a transformer from old telephone models as T1. You only need to remove the top winding and instead wind 100... 150 turns with the same wire. The number of turns in the winding (2-3) depends on the supply voltage of the circuit and is taken to be maximum at Upit = 9...12 V.

The problem of stray dogs is very acute in almost all cities of Russia; they are especially dangerous for cyclists, not only because they can bite, but because when they suddenly jump out of the bushes, you can lose control of the road. Dog chasers can help here; their operating principle is based on the emission of ultrasonic waves, inaudible to humans, but perfectly perceived by the dog.

The scheme has a range of about 13 meters and causes severe panic in wild dogs, keep in mind that this does not frighten fighting breeds, but can only make them angry. This design has been repeatedly applied and tested on ordinary stray dogs.

The master oscillator is made on a domestic digital microcircuit and five transistors (VT1-VT5), the generated rectangular pulses with a frequency of 1.5 Hz are supplied to a transistor stage, which amplifies them. The amplifier's emitter load is the BF1 piezoceramic head. The power circuit of the microassembly is well protected from accidental reversal of the polarity of a Krona battery by a VD3 diode, and filter capacitances C4 and C7 ensure the transmission of high-frequency and low-frequency oscillations, respectively.

The ultrasonic rectangular oscillations generated at pins 10 and 11 of the DD1 microcircuit have a low output power. Therefore, they need to be strengthened, for which we use a push-pull bridge amplifier on VT2-VT5. The emitter load of the amplifier is the BF1 piezoceramic head.

The power supply circuit of the microcircuit is protected from accidental polarity changes by the GB1 battery by the VD3 diode, and filter capacitances C4 and C7 ensure the passage of high- and low-frequency oscillations. The K561LA7 logical microcircuit can be replaced with a K176LA7, K1561LA7 or 564LA7.

If instead of the SP-1 piezo element you use the ACT-10 car piezo siren, the range of the dog repeller will increase significantly.

A piezo emitter can also be found in cheap speakers or from a music box, etc. When you press the SB1 button, the device turns on the power. You can see the drawing of the printed circuit board below, but taking into account the prostate, it can also be mounted using wall-mounted installation.

Let's consider another simple circuit of an ultrasonic generator from dogs that can keep an animal at a distance, shown in the figure below. The circuit is built on two square-wave generators on DD1, an amplifier and an emitter.

Dazer - ultrasonic dog scarer, 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, mainly 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 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. According to the circuit, it is better to use Schottky diodes; all polar capacitors must be supplied with a voltage of 15 volts. This ultrasonic repeller has been used on dogs several times and each time it performed 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 increases 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!

Stray dogs can cause a lot of trouble: seriously frighten a child, bite a passerby and tear his clothes, cause severe injuries if the pack is large and aggressive. Dogs especially do not like cyclists, barking with hatred at people riding this type of transport. Sometimes it’s not easy for both postmen and ordinary passers-by walking through a wasteland favored by animals.

Therefore, it’s a good idea to have protection with you that can scare away four-legged aggressors. By the way, you can build this protection with your own hands. Read on to learn how you can make a chemical or electronic dog repeller with your own hands, look at the diagrams, and create masterpieces!

What you will need

For chemical repeller:

vinegar;
ground black pepper.

The second option for a chemical repeller:

ground black pepper;
shag;
mustard powder.

This video will show you how to make a low-power dog repeller with your own hands:

Manufacturing technologies

The easiest way to make an imitation is to take a plastic bottle with a capacity of up to 0.5 liters, fill it with vinegar and add a teaspoon of pepper. Then shake and put on the spray bottle. However, it is not very convenient to carry this with you.
In another option, they buy the most “vigorous” cheap shag, finely grind it together with black pepper in a coffee grinder and get a very pungent cayenne mixture. To enhance the effect, add mustard powder. Place everything in a small plastic container that is easy to open. in case of threat, apply to the dog (nose, eyes, mouth). You can also stuff a firecracker with this and shoot from afar.

Below we will tell you how to make, although not the most powerful, homemade ultrasonic dog repeller with your own hands, with a useful diagram.

How to make an ultrasonic DIY dog repeller

Such devices are also called dogchasers - taken from the English language. The operation of the device is based on ultrasonic radiation, which people do not feel, but dogs react to it by backing away and running away.

What you will need

Option 1

Ultrasonic device diagram one:

piezo emitter (can be pulled out of a speaker, speaker, music box, calculator);
battery type “Krona” with a voltage of 9 volts or type “L1028” with 12 volts, you can take two batteries from a mobile phone (lithium-ion);
microcircuit K5 61LA7 or K176LA7, K1561LA7, 564LA7;
three silicon small-sized diodes;
five capacitors;
five resistors per 100 kilo-ohms;
33 kilo-ohm resistor;
2 kilo-ohm resistor;
four transistors from the KT3102 or KT3107 series;
one silicon transistor with a base current gain of at least 30;
switch;
textolite;
solder and soldering iron.

A good device for scaring dogs can be made using this video:

Option 2

Ultrasonic device diagram two:

constant resistors with a power of 0.25 W - five pieces;
variable resistor;
piezo emitter (for example, ZP-1, ZP-18, ZP-25);
two transistors (type KT361B or 2T3307A, 2T3307V, KT3107);
two ordinary ceramic capacitors;
diode KD503A (protective);
toggle switch;
textolite;
solder and soldering iron;
a 9-volt Krona battery, a battery or a power supply with a voltage of 1.5 to 15 volts.

Another version of a homemade dog repeller is discussed in this video:

Manufacturing technologies

Option 1

Here we need only one microcircuit and five transistors. Two resistors, together with logic elements and capacitors, make up a rectangular pulse multivibrator with a frequency of one and a half hertz. And the second multivibrator, which includes two other resistors and a capacitor, as well as the logic elements of the microcircuit, produces rectangular pulses of 20 kilohertz.

The output pulses are amplified by a transistor bridge that has a piezo emitter as a load. It can be replaced with a car piezo siren to increase the range.

As a housing, you can take the housing from an old VHF radio station.

Scheme for making a dog repeller

Option 2

Simpler, contains only thirteen elements. Five terminal resistors serve to reduce voltage and limit current. They also set the operating points for the two transistors that form the frequency circuit together with the capacitors.

A variable resistor regulates the ultrasonic frequency. We select it by power. The protective diode serves one purpose: it saves the device if the poles of the power source are accidentally reversed. Its voltage can be from 1.5 to 12 volts. The higher it is, the more powerful the emitted vibrations.