Each of us has repeatedly heard the expression "ultrasound" - in this article we will consider what it is, how it is created, and why it is needed.
The concept of "ultrasound"
Ultrasound is mechanical vibrations that are significantly higher than the frequency range that the human ear hears. The ultrasonic vibrations are somewhat reminiscent of a wave similar to a light wave. But, unlike light-type waves, which propagate only in a vacuum, ultrasound needs an elastic medium - a liquid, gas or any other solid body.
The main parameters of ultrasound
The main parameters of the ultrasonic wave are considered to be the wavelength and period. The time it takes for a complete cycle is usually called the period of the wave, it is measured in seconds.
The most powerful generator of ultrasonic waves is considered an ultrasonic emitter. A person cannot hear the ultrasonic frequency, but his body is able to feel it. In other words, the human ear perceives the ultrasonic frequency, but the part of the brain that is responsible for hearing is not able to decipher this sound wave. High frequency is unpleasant for human hearing, but if you raise the frequency by another range, the sound will completely disappear - despite the fact that it is in the ultrasound frequency. And the brain makes efforts to decode it unsuccessfully, because of this a person has a terrible headache, dizziness, nausea and other not very pleasant sensations.
Generators of ultrasonic vibrations are used in all areas of technology and science. For example, ultrasound can not only wash clothes, but also weld metal. In the modern world, ultrasound is actively used in agricultural technology to scare away rodents, since the body of most animals is adapted to communicate with their own kind at the ultrasonic frequency. It should also be said that the ultrasonic wave generator can repel insects as well - today many manufacturers produce this kind of electronic repellents.
Varieties of ultrasonic waves
Ultrasonic waves are not only transverse or longitudinal, but also surface and Lamb waves.
Transverse ultrasonic waves are waves that move perpendicular to the plane of the direction of velocities and displacements of the particles of the body.
Longitudinal ultrasonic waves are waves whose movement coincides with the direction of the velocities and displacements of the particles of the medium.
A Lamb wave is an elastic wave that propagates in a solid layer with free boundaries. It is in this wave that the vibrational displacement of particles occurs both perpendicular to the plane of the plate and in the direction of motion of the wave itself. It is the Lamb wave that is the normal wave in platinum with free boundaries.
Rayleigh (surface) ultrasonic waves are waves with elliptical motion of particles that propagate on the surface of a material. The speed of a surface wave is almost 90% of the speed of a transverse wave, and its penetration into the material is equal to the wavelength itself.
Use of ultrasound
As already mentioned above, the diverse use of ultrasound, in which its most diverse characteristics are used, can conditionally be divided into three areas:
- receiving the information;
- active effect on the substance;
- signal processing and transmission.
It should be borne in mind that for each specific application, it is necessary to choose ultrasound of a certain frequency range.
The effect of ultrasound on the substance
If a material or substance falls under the active influence of ultrasonic waves, then this leads to irreversible changes in it. This is due to nonlinear effects in the sound field. This type of material exposure is popular in industrial technology.
Obtaining information using ultrasound methods
Ultrasonic methods are now widely used in various kinds of scientific research for a thorough study of the structure and properties of substances, as well as for a complete understanding of the processes taking place in them at the micro and macro levels.
All these methods are mainly based on the dependence of the speed of propagation and attenuation of acoustic waves on the processes occurring in them and on the properties of substances.
Signal Processing and Transmission
Ultrasonic generators are used to convert and analogly process various kinds of electrical signals in all branches of radio electronics and to control light signals in optics and optoelectronics.
DIY ultrasonic transducer
In the modern world, an ultrasonic generator is used quite widely. For example, in industry, ultrasonic baths are used to quickly and efficiently clean something. It should be said that such a cleaning method has proven itself only on the best side. Today, an ultrasonic generator is gaining popularity in use for other purposes.
Assembly of the ultrasound scan for scaring dogs
Many residents of the country's megacities daily encounter a rather tangible problem of meeting a pack of stray dogs. It is impossible to predict the behavior of the pack in advance, so here the UZG will come to the rescue.
In this article, we will discuss how to make an ultrasonic generator with our own hands.
To create an UZG at home, you will need such details:
- printed circuit board;
- world map;
- radio engineering elements.
It is not difficult to assemble a circuit yourself. In order to be able to control the pulses, it is necessary to fix the radio parts to the specific legs of the microchip with a soldering iron.
We will analyze the design of a high-power ultrasonic frequency generator. As a generator of ultrasonic frequency, the D4049 microcircuit works, which has 6 logical interters.
A foreign microcircuit can be replaced with an analogue of domestic production K561LN2. To adjust the frequency, a 22k regulator is required, with the help of its ultrasound it can be reduced to an audible frequency. Thanks to the 4 bi-polar transistors with an average power, signals from the microcircuit arrive at the output stage. There is no special condition for choosing transistors, here the main thing is to choose complementary pairs as close as possible in parameters.
Almost any RF head that has a power of 5 watts or more can be used as a radiator. The ideal option would be domestic heads of the type 10GDV-6, 10GDV-4 or 5GDV-6, they can easily be found in all speaker systems manufactured in the USSR.
The do-it-yourself scheme of the ultrasonic generator can only be hidden in the case. A metal reflector will help control the power of the ultrasonic generator.
Ultrasound Generator Circuit
In the modern world, it is customary to use an ultrasonic generator to scare away dogs, insects, rodents, and also for high-quality washing. UZG is also used to significantly reduce time spent on washing and etching printed circuit boards. Chemical processes in a fluid are much faster due to cavitation.
The UZG circuit is based on two rectangular rectangular pulsed generators and a bridge-type power amplifier. On the logic elements of type DD1.3 and DD1.4, a tunable pulse generator of ultrasonic frequency of the meander shape is installed. It should be remembered that its operating frequency directly depends only on the total resistance of the resistors R4 and R6, as well as on the capacitance of the capacitor C3.
Remember the rule: the lower the frequency, the greater the resistance of these resistors.
On the elements DD1.1 and DD1.2 made low-frequency generator, which has an operating frequency of 1 Hz. The generators are interconnected using resistors R3 and R4. In order to achieve a smooth change in the frequency of the high-frequency generator, you need to use capacitor C2. One secret should also be remembered here: if the capacitor C2 is bridged with the switch SA1, the frequency of the high-frequency generator will become constant.
The use of ultrasound: a wide range of applications
As we all know, ultrasound in the modern world where only not used. Surely each of us has undergone an ultrasound (ultrasound) test at least once in a lifetime. It should be added that it is thanks to ultrasound that doctors can detect the occurrence of diseases of human organs.
Ultrasound is actively used in cosmetology to effectively cleanse the skin not only from dirt and fat, but also from the epithelium. For example, ultrasonic phonophoresis is successfully used in beauty salons both for nutrition and purification, and for moisturizing and rejuvenating the skin. The method of using ultrasound phonophoresis enhances the protective mechanisms of the skin due to the action of an ultrasonic wave. Cosmetic procedures using ultrasound are considered universal and are suitable for all skin types. Ultrasonic phonophoresis echoes miracles!
The ultrasonic steam generator is actively used not only in Turkish hammams, Finnish saunas, but also in our modern Russian baths. Thanks to steam, our body is effectively cleaned of invisible dirt, our body gets rid of toxins and toxins, heals skin and hair, steam positively affects the human respiratory system.
Artificial fog generators are actively used to increase indoor air humidity, which has a beneficial effect on the climate in the apartment. This becomes especially relevant in the cold season, when central heating dries the air. Artificial fog generators are used both in residential premises and in a terrarium or conservatory. Experts advise having an ultrasonic fog generator for people with respiratory diseases or prone to allergic diseases.
Conclusion
In home use, an ultrasonic steam or fog generator is a very useful device that not only creates comfort and coziness, but can also enrich the air with invisible vitamins, light negative air ions, which are so numerous on the seashore, in the mountains or in the forest and there are very few inside our apartments. And this, in turn, will help to increase the emotional state and improve health.