DIY electronic mosquito repellent. Outdoors without mosquitoes: ultrasonic repellers, traps and other means to combat blood-sucking insects outdoors. DIY ultrasonic mosquito repeller

Are mosquitoes afraid of ultrasound? There is a lot of controversy about this, but according to reader reviews this scheme ultrasonic repeller really works.

The schematic diagram of an ultrasonic “tweeter” capable of operating in a wide range of frequencies is shown in the figure below. Here BA1 is a powerful high-frequency dynamic head, for example, 6GDV-4, and is a source of acoustic vibrations. Although according to the passport the highest frequency of high-frequency radiation dynamic heads can only be classified as “near” ultrasound, experience shows that they are quite effective emitters of frequencies up to 40...50 kHz and higher.

The master oscillator of the device is assembled on inverters DD1.1 and DD1.2. The remaining elements of this microcircuit form the base currents in transistors VT1...VT4, alternately, with a frequency F=1/2(R2+R3)C1, connecting the emitter BA1 to the power source. In one half-cycle - through open transistors VT1 and VT4, in the other - through VT2 and VT3.

The generator transistors operate in switching mode and do not particularly need heat sinks. Although in difficult temperature conditions they may be required. Diode VD1 - any germanium.

The required radiation frequency (which one remains to be determined in a “live” experiment) is set with resistor R3. It can be equipped with a scale calibrated in advance using an oscilloscope. With the indicated ratings R2, R3 and C1, the generator covers the range of 16...60 kHz.

The power source of the ultrasonic generator must be capable of delivering current Ipot=(Upit-2)/Rн (Ipott - in amperes, Upit - supply voltage of the “tweeter” - in volts, Rn - in ohms).

Of course, for the creatures different types intolerant or frightening frequencies can and will most likely be different. But creating a multi-frequency “scarecrow” with “floating” or “jumping” frequencies, with one or another modulation or manipulation of them, is not a problem. The main thing is to establish in a direct experiment those ultrasound parameters at which a significant effect is achieved.

In this regard, we note that the ultrasonic “scarecrows” that have appeared on our markets almost always use a piezo emitter - an element with pronounced resonant properties. So a foreign device that frightens (if you believe the advertising) at its frequency some species of, say, a Taiwanese mosquito, may not make any impression on “ours.” And it doesn't seem to produce...

In the summer, you can afford to go on vacation to the country, to the forest, to the river or to another place closer to nature. Little annoying mosquitoes can ruin pleasant moments of relaxation and positive energy. Today we will tell you how to choose a mosquito repeller for the street, as well as how to make it yourself to protect against mosquitoes on outdoors became effective.

When going on vacation out of town, do not forget to take the ones you purchased in advance. effective means from mosquitoes. After all, regardless of whether you go to the country or on a hike, annoying insects can be a nuisance everywhere. The methods that are suitable for an open area are different from those that you use to protect your home. And if, for example, for a tent, room, gazebo you can use mosquito net, then this method is not suitable in open areas. Today, manufacturers are concerned that among the variety of devices - ultrasonic repellers, models of fumigators and liquids, repellents and traps - the consumer can choose exactly the product that will best protect him from mosquito bites.

Video “Ultrasonic repeller”

From the video you will learn how to use this tool.

Ultrasound against mosquitoes

Protection against mosquitoes outdoors can be done by using ultrasonic repellers. There are even compact devices that repel pests with a sound that is not perceptible to the human ear. Some models can be worn by one person. They can be placed in a clothing pocket or on a belt. They exert their effect within a radius of about 2 meters. Other units are designed to protect an entire room. The most expensive repeller options are great for evening relaxation in open areas and can cover an area of ​​up to 50 meters during operation.
The operating principle of the device is that during operation it emits signals that imitate the wings of a male. As a result, the female mosquitoes and midges fly away. Because under natural conditions, females diligently avoid males. Ultrasound is safe for humans. The device operates silently. Next, we will look at some models of repellers that are suitable for repelling mosquitoes outside the home.

For example, the “Light” keychain is capable of operating in an area of ​​no more than 10 square meters. Its emission frequency is 5.5 kHz; it requires an A-type battery to operate. The repeller works effectively on it for up to 27 days. It is made in China and weighs only 75 grams. Attached to the belt.

The “ML-338R” device is also battery-powered, manufactured in China, weighs about 100 grams, operates on an area of ​​1.5 square meters, provides sound pressure in the range of 80 dB, the frequency of its influence is 4 – 12 kHz. Takes up little space and can be placed in a pocket or bag. Visually it looks like a keychain with a flashlight. The device is equipped with a signal frequency regulator.

The EcoSniper AR112 repeller is a universal device. It can really be used as a mosquito repellent on the street, a siren or a flashlight. Operates at a frequency range of 13 – 20 kHz, produces sound pressure within 90 dB. It has an impact on an area of ​​no more than 10 square meters. Runs on AAA batteries. The manufacturer recommends wearing the device in your pocket or around your neck.

"Freetim" has pulse generator signal, the frequency of which changes sequentially, 4 operating modes with different powers. At maximum radiation, it can perform its functions perfectly for up to 500 hours. Outdoor protection is possible over an area of ​​about 1.5 meters. Powered by lithium battery, weighs only 10 grams, auto-off mode is activated after 8 hours. Such a device can be worn on the hand, on a belt or in a pocket, even for children. The start of its operation is signaled by LED lighting.

Fumigators and liquids

Being in nature, as in the house, it can be used to combat annoying insects. electric fumigators and cigarette lighters with liquid. They are very effective and have no unpleasant odor. Sometimes people simply set fire to the plate intended for the fumigator and fumigate the space with smoke. Fumigators can act due to active components such as insecticides, pyrethrins and pyrethroids. The first are harmless to people and animals, the second are extracts of their tansy, chamomile and other plants, and the third are artificially created substances. Models designed for both liquid and plates are available for sale. For example, the “Deta” home and garden kit.
It includes a bottle for liquid, a fumigator with a rotating fork with a power indicator. There are both electric and pyrotechnic types of fumigators. In them a heating element begins to work, after which the evaporation of the main substance begins. Electrical devices They operate from a power outlet and heat up quickly. Pyrotechnics have a spiral shape. It needs to be set on fire and extinguished. It smolders, spreading toxic substances around itself. Fumigators that use liquid last much longer.

Among the popular models of fumigators is the “Raid”. It requires liquid to work. One device lasts about a month – if you use it no more than 8 hours a day. Designed for a plot of up to 50 square meters.

The key component in it is pyrethrin. Exudes a pleasant eucalyptus scent. Almost all devices from this company have a function for regulating elements emitted into the air and a timer.

"Moskitol" is presented by the manufacturer in models for adults and children - with a less concentrated substance. A large bottle of liquid lasts about 1.5 months. It is not recommended to use the device for more than 8 hours. The manufacturer stated the time to get rid of insects is 1.5 hours. The children's version of the device contains chamomile extract, so it also acts as a flavoring agent.

"Fumitox" is also made on the basis of chamomile extract. It also contains antioxidants and organic solvent. It is odorless and works from a bottle for up to 30 days. There is an adult and children's version, the latter is considered less effective. A special feature of the fumigator is the ability to change the location of the fork.

Repellents

Repellents whose name comes from Latin word and translated as “repel” or “drive away”, are by individual means protection. They are most often produced in the form of sprays and aerosols that are applied to clothing or skin. There are also creams and lotions, spray lotions. Repellents contain components of natural and chemical origin - alcohols, essential oils with pungent odors, pyrethroids, diethyl phthalate. They drown out the pheromones of the human body, and an odor unpleasant to mosquitoes begins to emanate from it. Repellents based on pyrethroids belong to a new generation and are safer. But there are not many of them on the market yet, which is why the price for such protection is quite high. There are repellents with mixed effects. For example, against mosquitoes and ticks. Most often they are made on the basis of alphacypermethrin, that is, a poison with a nerve-paralytic effect.

The first category in terms of duration of work includes drugs that contain 30–40% of the active component. They last up to 5 hours and are not recommended for use by pregnant women, children, or people with allergies. The second category includes those whose validity period is up to 3 hours. Quantity active substance in them does not exceed 20 - 25%. Most short term work with drugs containing a toxic substance in a volume of 5 - 10% - up to 2 hours. These are approved for use even by pregnant women and children.

The disadvantage of repellents is that they are very toxic even to healthy person. Such drugs should be used carefully so as not to cause problems with respiratory tract and severe allergic reactions.

Popular sprays include Moskitol, Gardex, Stop Mosquito, and Deta-prof. Aerosols should not be sprayed onto wounds; they must be reapplied after swimming. Do not spray near fire. Reapply after 2 - 3 hours. Avoid getting the product in your eyes and be sure to wash the product off your skin after a walk. It is best to purchase repellents at a pharmacy.

Traps

To get rid of mosquitoes on the street, you can use trap lamps and cunning traps that attract rather than repel insects.

The principle of operation of the lamp is its ultraviolet radiation, which should attract insects. But since mosquitoes are not butterflies or midges, whether they will want to fly to such a device is a moot point. Flying up to the lamp, the mosquito will be destroyed by a current discharge, since metal grill is under electrical voltage.

Powered either from a 6V power supply or from lead battery 6.3V - then the device can be used on a picnic in the forest.

The circuit diagram of the RCD is shown in the figure below:

Myself ultrasonic generator assembled on logical inverters as part of a 561LN2 digital microcircuit. For transistors in the device, it is necessary to use radiators, since they get quite hot during operation.

It is best to use a speaker or pair of speakers for the device with a total resistance of 10-15 ohms. The diode must be germanium. A variable resistor can be used with a higher resistance than shown in the diagram - this will expand the boundaries of ultrasonic frequency adjustment. Ultrasonic repeller mosquitoes operate at approximately a frequency of 10 to 40 kHz. Operating frequency depends on the ratings of R2, R3 and C1.

The circuit was first tested on a breadboard, and later transferred to a printed circuit board, which can be downloaded in the archive along with the Lay format circuit -

The power supply should be from 4 to 6V with a current of about 250mA, I used a cell phone unit. Draw your own conclusion about the quality of the device, but this “squeaker” works great for me and really repels harmful insects.

Creams or special devices. It is quite possible to make an ultrasonic mosquito repeller with your own hands. This special device has many advantages and can be various shapes, type, design.

Advantages of repellers

A homemade repeller is easiest to assemble for radio amateurs or people who have an understanding of modern radio components. Although the simplicity of the design makes it accessible even to an inexperienced user.

Advantages of the device:

1. Duration of use. It can be used repeatedly without loss of quality.
2. Cheapness. The cost of such a device is not much different from a store-bought cream, but much cheaper than buying a ready-made one.
3. Efficiency.
4. Numerous positive reviews users who have personally tested repellers say that the device really works.
5. Mobility. When creating a device, you can immediately set its dimensions. As a result, it is possible to obtain a repeller of various sizes for mobile use.

It’s not difficult to make such a device; the most important thing is to choose the right circuit.

Possible applications

A device for repelling mosquitoes works on the principle of how insects perceive various sounds. When assembling ultrasonic models, special frequency microcircuits are used. It is inaudible to humans, but extremely unpleasant for mosquitoes.

Will only be used for assembly simple elements, which can always be purchased in specialized stores at an affordable price. The design is based on electronic circuits. They are the heart of the device. You can use one of the most common K555la3 microcircuits or buy another board and make it yourself by etching the tracks on a special canvas.

Manufacturing process printed circuit board includes the following steps:

1. Print the drawing with the tracks.
2. Etch the workpiece on the microcircuit in a ferric chloride solution.
3. Clear.
4. Cover with flux-gel.
5. Tin.

After this, you can begin soldering the mosquito repeller according to the chosen scheme.

The ultrasonic invention drawing also includes the following elements:

1. Power supply. It can be a regular battery.
2. Sound source.
3. Bipolar transistors.
4. Capacitors.
5. Variable transistor.
6. Toggle switch for putting the device into operation.

The figure shows a primitive diagram of an ultrasonic mosquito repeller.

1. VT1 - MP36 - MP38
2. VT2-MP40-MP42
3. R1-SPZ-b, SPO 100 kOhm
4. R-100kOhm
5. R -10 kOhm
6. C1. — 3300 uF
7. IN 1. -telephone capsule.

The range of action of a repeller made using the specified scheme, is about 1 meter.

Every year we buy many products that can protect us from mosquitoes. These are all kinds of creams, ointments, sprays, sockets, spirals, etc. However, all this costs a lot of money. To save a little money, we suggest you make your own mosquito repeller using available materials. Without spending a lot of time.

For the first version of the repeller we will need:
- matches;
- metal plate;
- mosquito repellent;
- round flat candle;
- pliers.

The first option works well at home or outdoors in the complete absence of wind.

We take a metal plate and use pliers to bend it on both sides at an angle of 90°. So that we get some semblance street bench without backrest.

Then on one side we fold one edge again. We will get an inclined plane.

After this, we place our curved metal plate on metal case lighted candle and place a mosquito repellent plate on top.

For the second version of the repeller we will need:
- a box with a metal lid;
- metal plate;
- ferrite ring:
- mosquito repellent;
- round flat candle;
- pliers;
- matches;
- glue gun:
- bolt and nut.

The second method can be used outdoors even in windy conditions.

We take a metal plate and make a small hole at one end. Then use pliers to bend it. After this, we make another bend on the same side so that our mosquito repellent plate fits on the remaining part of the plate. Once again we bend the ends of the plate so that it fixes it.

IN metal lid We cut out a round hole in the middle, as well as another small one at the edge.

Now we need to glue the ferrite ring onto the lid, aligning it with the large hole. You can use a narrow piece of any plastic pipe as such a ring.

We glue the metal candle stand inside the body of the box exactly in the middle. We insert the candle, close the lid and check how accurately the candle wick fits into the center of the hole. While the glue is not completely dry, center the candle body.

Then we take our metal plate, insert a bolt into the hole and secure it to the lid with a nut.

After this, light the candle and close the lid. If the candle goes out, make several holes in the lid.