Wireless transmission of electricity. Operating principle. New wireless power technology works like Wi-Fi

For many years, scientists have been struggling with the issue of minimizing electrical costs. There are different methods and proposals, but the most famous theory is the wireless transmission of electricity. We propose to consider how it is carried out, who is its inventor and why it has not yet been implemented.

Theory

Wireless electricity is literally the transfer of electrical energy without wires. People often compare the wireless transmission of electrical energy with the transmission of information, such as radios, cell phones, or Wi-Fi access to the Internet. The main difference is that radio or microwave transmission is a technology aimed at restoring and transporting information, and not the energy that was originally expended on transmission.

Wireless electricity is relatively new area technology, but quite dynamically developing. Methods are now being developed to efficiently and safely transmit energy over a distance without interruption.

How does wireless electricity work?

The main work is based specifically on magnetism and electromagnetism, as is the case with radio broadcasting. Wireless charging, also known as inductive charging, is based on several simple principles work, in particular the technology requires two coils. A transmitter and receiver, which together generate an alternating magnetic field of non-direct current. In turn, this field causes a voltage in the receiver coil; this can be used to power a mobile device or charge a battery.

If you send electric current through a wire, a circular magnetic field is created around the cable. Despite the fact that the magnetic field affects both the loop and the coil, it is most pronounced on the cable. When we take a second coil of wire that is not receiving any electric current passing through it, and a place where we place a coil in the magnetic field of the first coil, the electric current from the first coil will be transmitted through the magnetic field and through the second coil, creating an inductive coupling.

Let's take an electric toothbrush as an example. In it, the charger is connected to an outlet, which sends an electric current to a twisted wire inside the charger, which creates a magnetic field. There is a second coil inside the toothbrush, when current begins to flow and, thanks to the formed MF, the brush begins to charge without being directly connected to a 220 V power supply.

Story

Wireless power transmission, as an alternative to the transmission and distribution of electrical lines, was first proposed and demonstrated by Nikola Tesla. In 1899, Tesla presented the wireless transmission of power to a field of fluorescent lamps located twenty-five miles from the power source without the use of wires. But at the time, it was cheaper to wire 25 miles of copper wire rather than build the special power generators that Tesla's expertise required. He was never given a patent, and the invention remained in the recesses of science.

While Tesla was the first person to demonstrate practical possibilities wireless communications back in 1899, today there are very few devices on sale, these are wireless brushes, headphones, phone chargers, etc.

Wireless technology

Wireless energy transfer involves the transfer of electrical energy or power over a distance without wires. Thus, the core technology lies on the concepts of electricity, magnetism and electromagnetism.

Magnetism

It is a fundamental force of nature that causes certain types of material to attract or repel each other. The only permanent magnets are the Earth's poles. The flow current in the circuit generates magnetic fields that differ from oscillating magnetic fields in the speed and time required to generate AC(AC). The forces that appear in this case are depicted in the diagram below.

Electromagnetism is the interdependence of alternating electric and magnetic fields.

Magnetic induction

If the conductive loop is connected to an AC power source, it will generate an oscillating magnetic field in and around the loop. If the second conductive circuit is close enough, it will capture part of this oscillating magnetic field, which in turn generates or induces an electric current in the second coil.

Video: how wireless electricity transfer occurs

Thus, there is an electrical transfer of power from one cycle or coil to another, which is known as magnetic induction. Examples of this phenomenon are used in electrical transformers and generators. This concept is based on Faraday's laws of electromagnetic induction. There, he states that when there is a change in the magnetic flux connecting to a coil, the emf induced in the coil, then the magnitude is equal to the product of the number of turns of the coil and the rate of change of flux.

Power coupling

This part is necessary when one device cannot transmit energy to another device.

Magnetic coupling is generated when an object's magnetic field is capable of inducing an electrical current with other devices within its range.

Two devices are said to be mutually inductively coupled or magnetically coupled when they are arranged so that a change in current as one wire induces a voltage at the ends of the other wire by means of electromagnetic induction. This is due to mutual inductance

Technology

Two devices, mutually inductively coupled or magnetically coupled, are designed so that the change in current when one wire induces a voltage at the ends of the other wire is produced by electromagnetic induction. This is due to mutual inductance.
Inductive coupling is preferred due to its ability to operate wirelessly as well as its resistance to shock.

Resonant inductive coupling is a combination of inductive coupling and resonance. Using the concept of resonance, you can make two objects work depending on each other's signals.

As can be seen from the diagram above, resonance is provided by the inductance of the coil. The capacitor is connected in parallel to the winding. Energy will move back and forth between the magnetic field surrounding the coil and electric field around the capacitor. Here, radiation losses will be minimal.

There is also the concept of wireless ionized communication.

It can also be implemented, but it requires a little more effort. This technique already exists in nature, but it is hardly feasible to implement it, since it requires a high magnetic field, from 2.11 M/m. It was developed by the brilliant scientist Richard Walras, the developer of a vortex generator that sends and transmits heat energy over vast distances, in particular with the help of special collectors. The simplest example of such a connection is lightning.

Pros and cons

Of course, this invention has its advantages and disadvantages over wired methods. We invite you to consider them.

The advantages include:

1. Complete absence of wires;
2. No power supplies needed;
3. The need for a battery is eliminated;
4. Energy is transferred more efficiently;
5. Significantly less maintenance required.

The disadvantages include the following:

• Distance is limited;
• magnetic fields are not so safe for humans;
• wireless transmission of electricity using microwaves or other theories is practically impossible at home and with your own hands;
• high installation cost.

If history is to be believed, the revolutionary technological project was frozen due to Tesla’s lack of adequate financial resources (this problem haunted the scientist almost all the time he worked in America). Generally speaking, the main pressure on him came from another inventor, Thomas Edison and his companies, who were promoting direct current technology while Tesla was working on alternating current (the so-called “War of the Currents”). History has put everything in its place: now alternating current is used in city power grids almost everywhere, although echoes of the past continue to this day (for example, one of the stated reasons for breakdowns of the notorious Hyundai trains is the use of direct current power lines in some sections of the Ukrainian railway).

Wardenclyffe Tower, where Nikola Tesla conducted his experiments with electricity (photo from 1094)

As for Wardenclyffe Tower, according to legend, Tesla demonstrated to one of the main investors J.P. Morgan, a shareholder of the world's first Niagara hydroelectric power station and copper plants (copper, as you know, is used in wires), a working installation for wireless current transmission, the cost of which for consumers would be (if such installations were built on an industrial scale) an order of magnitude cheaper for consumers, after why he stopped financing the project. Be that as it may, they started talking seriously about wireless power transmission only 90 years later, in 2007. And while it's still a long way off before power lines completely disappear from the urban landscape, nice little things like wireless charging for your mobile device are available now.

Progress has crept up unnoticed

If we look through the archives of IT news from at least two years ago, then in such collections we will find only rare reports that certain companies are developing wireless chargers, and not a word about finished products and solutions (except basic principles and general schemes). Today, wireless charging is no longer something super-original or conceptual. Such devices are being sold with all their might (for example, LG demonstrated its chargers at MWC 2013), are being tested for electric vehicles (Qualcomm is doing this) and are even used in public places (for example, at some European railway stations). Moreover, several standards for such power transmission already exist and several alliances promote and develop them.

For wireless charging mobile devices respond to similar coils, one of which is located in the phone, and the other in the charger itself

The most famous such standard is the Qi standard, developed by the Wireless Power Consortium, which includes such well-known companies as HTC, Huawei, LG Electronics, Motorola Mobility, Nokia, Samsung, Sony and about a hundred other organizations. This consortium was organized in 2008 with the goal of creating a universal charger for devices from various manufacturers and brands. In its work, the standard uses the principle of magnetic induction, when the base station consists of an induction coil that creates an electromagnetic field when alternating current is supplied from the network. The device being charged contains a similar coil that reacts to this field and is able to convert the energy received through it into D.C., which is used to charge the battery (you can learn more about the principle of operation on the consortium website http://www.wirelesspowerconsortium.com/what-we-do/how-it-works/). In addition, Qi supports a data transfer protocol between chargers and charging devices at a speed of 2 kbps, which is used to transmit data about the required charging amount and the required operation.

Today, many smartphones support wireless charging using the Qi standard, and chargers are universal for all devices that support this standard.

Qi also has a serious competitor - the Power Matters Alliance, which includes AT&T, Duracell, Starbucks, PowerKiss and Powermat Technologies. These names are far from being at the forefront in the world of information technology (especially the Starbucks coffee chain, which is in an alliance because it is going to introduce this technology), - they specialize specifically in energy issues. This alliance was formed not so long ago, in March 2012, as part of one of the IEEE (Institute of Electrical and Electronics Engineers) programs. The PMA standard they promote works on the principle of mutual induction - a particular example of electromagnetic induction (which should not be confused with the magnetic induction used by Qi), when when the current in one of the conductors changes or when the relative position of the conductors changes, the magnetic flux through the circuit of the second one changes. magnetic field generated by the current in the first conductor, which causes the occurrence electromotive force in the second conductor and (if the second conductor is closed) the induced current. Just as in the case of Qi, this current is then converted to direct current and supplied to the battery.

Well, don’t forget about the Alliance for Wireless Power, which includes Samsung, Qualcomm, Ever Win Industries, Gill Industries, Peiker Acustic, SK Telecom, SanDisk, etc. This organization has not yet presented ready-made solutions, but among its goals , including the development of charges that would work through non-metallic surfaces and that would not use coils.

One of the goals of the Alliance for Wireless Power is the ability to charge without being tied to a specific location or type of surface.

From all of the above, we can draw a simple conclusion: after a year or two, the majority modern devices will be able to recharge without using traditional chargers. For now, the wireless charging power is sufficient mainly for smartphones, but such devices will also appear soon for tablets and laptops (Apple recently patented wireless charging for the iPad). This means that the problem of discharging devices will be solved almost completely - put or place the device in a certain place, and even during operation it charges (or, depending on the power, discharges much more slowly). Over time, there is no doubt that their range of action will expand (now it is necessary to use a special mat or stand on which the device rests, or it must be very close), and they will be universally installed in cars, trains and even, possibly, airplanes.

Well, one more conclusion - most likely, it will not be possible to avoid another format war between different standards and the alliances that promote them.

Will we get rid of wires?

Wireless charging of devices is, of course, a good thing. But the powers that arise with it are sufficient only for the stated purposes. With the help of these technologies it is still impossible to even illuminate a house, let alone operate a large household appliances. Nevertheless, experiments on high-power wireless transmission of electricity are underway and they are based, among other things, on Tesla’s materials. The scientist himself proposed installing around the world (here, most likely, developed countries at that time were meant, of which there were much fewer than now) more than 30 receiving and transmitting stations that would combine energy transmission with radio broadcasting and directional wireless communications, which would allow get rid of numerous high voltage lines transmission and contributed to the consolidation of electric generating companies on a global scale.

Today there are several methods for solving the problem wireless transmission energy, however, all of them so far allow us to achieve results that are insignificant in global terms; We're not even talking about kilometers. Methods such as ultrasonic, laser and electromagnetic transmission have significant limitations (short distances, the need for direct visibility of transmitting devices, their size, and in the case of electromagnetic waves, very low efficiency and harm to health from a powerful field). Therefore, the most promising developments involve the use of a magnetic field, or more precisely, a resonant field. magnetic interaction. One of them is WiTricity, developed by the WiTricity corporation, founded by MIT professor Marin Soljacic and a number of his colleagues.

So, in 2007, they managed to transmit a current of 60 W over a distance of 2 m. It was enough to light a light bulb, and the efficiency was 40%. But the undeniable advantage of the technology used was that it practically does not interact with living beings (the field strength, according to the authors, is 10 thousand times weaker than what reigns in the core of a magnetic resonance imaging scanner) or with medical equipment ( pacemakers, etc.), nor with other radiation, which means it will not interfere, for example, with the operation of the same Wi-Fi.

What’s most interesting is that the efficiency of the WiTricity system is affected not only by the size, geometry and configuration of the coils, as well as the distance between them, but also by the number of consumers, and in a positive way. Two receiving devices placed at a distance of 1.6 to 2.7 m on either side of the transmitting “antenna” showed 10% better efficiency than individually - this solves the problem of connecting many devices to one power source.

When it first appeared, alternating electric current seemed like a fantasy. Its inventor, the brilliant physicist Nikola Tesla, explored the problem of wireless transmission of electricity over long distances at the turn of the 19th and 20th centuries. So far, this problem has not been fully resolved, but the results obtained are encouraging.

Ultrasound for Energy Transfer

Any wave carries energy, including high-frequency sound waves. There are three approaches to wireless transmission of electricity:

• transfer of electrical energy through conversion to another type of energy at the source and reverse conversion to electricity at the receiving device;
• creation and use of alternative conductors of electricity (plasma channels, columns of ionized air, etc.);
• use of the conductive properties of the Earth's lithosphere.

The method of using ultrasound belongs to the first approach. In a special type of ultrasound source, when power is applied, a directed beam appears sound waves high frequency. When they hit the receiver, the energy of the sound waves is converted into electric current.

The maximum distance for transmitting electricity wirelessly is 10 meters. The result was obtained in 2011 by representatives of the University of Pennsylvania during a presentation at the exhibition “The All Things Digital”. This method is not considered promising due to several of its disadvantages: low efficiency, low voltage received, and restrictions on the strength of ultrasound radiation by sanitary standards.

Application of electromagnetic induction

Although most people don't even realize it, this method has been used for a very long time, almost since the beginning of alternating current. The most common AC transformer is the simplest device for wireless transmission of electricity, but the transmission distance is very short.

The primary and secondary windings of the transformer are not connected into one circuit, and when alternating current flows in the primary winding, an electric current appears in the secondary. Energy transfer occurs through an electromagnetic field. Therefore, this method of wireless power transmission uses the conversion of energy from one type to another.

A number of devices whose operation is based on this method have already been developed and are successfully used in everyday life. These include wireless chargers for mobile phones and other gadgets, and household electrical appliances with low power consumption during operation ( compact cameras video surveillance, all kinds of sensors and even LCD TVs).

Many experts argue that electric vehicles of the future will use wireless technologies to charge batteries or generate electricity for movement. Induction coils (analogues of the primary winding of a transformer) will be installed in the roads. They will create an alternating electromagnetic field, which, when a vehicle passes over it, will cause an electric current to flow in the built-in receiving coil. The first experiments have already been carried out and the results obtained give rise to cautious optimism.

The advantages of this method include:

• high efficiency for short distances (on the order of several meters);
• simplicity of design and mastered application technology;
• relative safety for human health.

The disadvantage of the method - the short distance over which energy transfer is effective - significantly reduces the scope of application of wireless electricity based on electromagnetic induction.

Using different microwaves

This method is also based on the conversion of different types of energy. Electromagnetic waves of ultra-high frequency serve as energy carriers. This method was first described and practically implemented in his installation by the Japanese physicist and radio engineer Hidetsugu Yagi in the twenties of the last century. The frequency of radio waves for wireless transmission of electricity is in the range from 2.4 to 5.8 GHz. An experimental installation has already been tested and received positive feedback, which simultaneously distributes Wi-Fi and powers low-power household electrical appliances.

A laser beam is also electromagnetic radiation, but with special property- coherence. It reduces energy losses during transmission and thereby increases efficiency. The advantages include the following:

• possibility of transmission over long distances (tens of kilometers in the Earth’s atmosphere);
• convenience and ease of installation for low-power devices;
• availability of visual control of the transmission process - the laser beam is visible to the naked eye.

The laser method also has disadvantages, namely: relatively low efficiency (45−50%), energy losses due to atmospheric phenomena (rain, fog, dust clouds) and the need to locate the transmitter and receiver in the field of view.

The intensity of sunlight outside the Earth's atmosphere is several tens of times higher than on the Earth's surface. Therefore, in the future, according to futurologists, solar power plants will be located in low-Earth orbit. And the transfer of accumulated electricity, in their opinion, will be carried out without live wires. A transmission method that copies lightning discharges will be developed and applied; it is planned to ionize the air in one way or another. And the first experiments in this direction have already been carried out. This method is based on the creation of alternative wireless conductors of electric current.

Obtained in this way from Earth orbit wireless electricity is impulsive. Therefore for him practical application powerful and inexpensive capacitors will be needed, and a method of gradually discharging them will need to be developed.

Most effective method

Planet Earth is a huge capacitor. The lithosphere mainly conducts electricity, with the exception of small areas. There is a theory that wireless energy transfer can occur through the earth's crust. The gist is this: the current source is in reliable contact with the surface of the earth, alternating current of a certain frequency flows from the source to the crust and spreads in all directions, and at certain intervals in the ground, electric current receivers are placed, from which it is transmitted to consumers.

The essence of the theory is to accept and use current of only one given frequency. Just as in a radio receiver the frequency of receiving radio waves is adjusted, so in such electrical receivers the frequency of the received current will be adjusted. Theoretically, this method will be able to transmit electricity over very long distances if the frequency of the alternating current is low, on the order of several Hz.

Prospects for wireless transmission of electricity

IN near future the massive introduction into everyday life of a PoWiFi system is expected, consisting of routers with the function of transmitting electricity over several tens of meters, and household appliances, which are powered by receiving electricity from radio waves. Such a system in at the moment is being actively tested and is being prepared for widespread use. Details have not been disclosed, but according to available information, the “zest” is that synchronization of the electromagnetic fields of the source and receiver of wireless electricity is used.

In the very long term, the option of abandoning the use of traditional power plants on a global scale is being considered - solar stations will be used in low-Earth orbit, converting the energy of sunlight into electrical energy. Electricity will presumably be transmitted to the surface of the planet through ionized air or plasma channels. And on the earth’s surface itself, conventional power lines will disappear, their place will be taken by more compact and efficient systems for transmitting electricity through the lithosphere.

Wireless transmission for the delivery of electricity has the ability to deliver major advances in industries and applications that rely on the physical contact of the connector. This, in turn, can be unreliable and lead to failure. Wireless power transmission was first demonstrated by Nikola Tesla in the 1890s. However, it is only in the last decade that the technology has been leveraged to the point where it offers real, tangible benefits for real-world applications. In particular, the development of a resonant wireless power system for the market consumer electronics showed that inductive charging brings new levels of convenience to millions of everyday devices.

The power in question is widely known by many terms. Including inductive transmission, coupling, resonant wireless network and the same voltage return. Each of these conditions essentially describes the same fundamental process. Wireless transmission of electricity or power from the power source to the load voltage without connectors through an air gap. The basis is two coils - a transmitter and a receiver. The first is excited by an alternating current to generate a magnetic field, which in turn induces a voltage in the second.

How the system in question works

The basics of wireless power involve distributing energy from a transmitter to a receiver through an oscillating magnetic field. To achieve this, the direct current supplied by the power supply is converted into high-frequency alternating current. Using specially designed electronics built into the transmitter. The alternating current activates a coil of copper wire in the dispenser, which generates a magnetic field. When the second (receiving) winding is placed in close proximity. The magnetic field can induce an alternating current in the receiving coil. The electronics in the first device then convert the AC back to DC, which becomes the power input.

Wireless power transmission circuit

The "mains" voltage is converted into an AC signal, which is then sent to the transmitter coil through an electronic circuit. Flowing through the distributor winding induces a magnetic field. This, in turn, can spread to the receiver coil, which is in relative proximity. The magnetic field then generates a current that flows through the receiver winding. The process by which energy is propagated between the transmitting and receiving coils is also referred to as magnetic or resonant coupling. And this is achieved using both windings operating at the same frequency. The current flowing in the receiver coil is converted into DC current by the receiver circuit. It can then be used to power the device.

What does resonance mean?

The distance over which energy (or power) can be transmitted increases if the transmitter and receiver coils resonate at the same frequency. Just like a tuning fork oscillates at a certain height and can reach a maximum amplitude. This refers to the frequency at which an object naturally vibrates.

Advantages of wireless transmission

What are the benefits? Pros:

• Reduces costs associated with maintaining straight connectors (such as in a traditional industrial slip ring);
• greater convenience for charging common electronic devices;
• secure transfer to applications that must remain hermetically sealed;
• electronics can be completely hidden, reducing the risk of corrosion from elements such as oxygen and water;
• Reliable and consistent power delivery to rotating, highly mobile industrial equipment;
• Provides reliable power transfer to critical systems in wet, dirty and moving environments.

Regardless of application, liquidation physical connection provides a number of advantages over traditional cable power connectors.

Efficiency of the energy transfer in question

The overall efficiency of a wireless power system is the most important factor in determining its performance. System efficiency measures the amount of power transferred between the power source (i.e., wall outlet) and the receiving device. This, in turn, determines aspects such as charging speed and propagation range.

Wireless communication systems vary depending on their level of efficiency based on factors such as coil configuration and design, transmission distance. A less efficient device will generate more emissions and result in less power passing through receiver. Typically, wireless power transmission technologies for devices such as smartphones can achieve 70% performance.

How is efficiency measured?

In the sense, as the amount of power (in percentage) that is transferred from the power source to the receiving device. That is, wireless power transmission for a smartphone with an efficiency of 80% means that 20% of the input power is lost between the wall outlet and the battery for the gadget being charged. The formula for measuring operating efficiency is: productivity = direct current outgoing, divided by incoming, the result obtained multiplied by 100%.

Wireless methods of transmitting electricity

Power can propagate through the network in question across almost all non-metallic materials, including but not limited to. These include solids such as wood, plastic, textiles, glass and brick, as well as gases and liquids. When a metallic or electrically conductive material (that is, is placed in close proximity to an electromagnetic field, the object absorbs power from it and heats up as a result. This in turn affects the efficiency of the system. This is how induction cooking works, for example, inefficient power transfer from the hob creates heat for cooking.

To create a wireless power transmission system, it is necessary to return to the origins of the topic at hand. Or, more precisely, to the successful scientist and inventor Nikola Tesla, who created and patented a generator capable of taking power without various materialistic conductors. So, to implement a wireless system, you need to collect everything important elements and parts, the result will be a small This is a device that creates a high voltage electric field in the air around it. At the same time, there is a small input power, it provides wireless energy transfer over a distance.

One of the most important ways energy transfer is inductive coupling. It is mainly used for near field. It is characterized by the fact that when current passes through one wire, a voltage is induced at the ends of the other. Power transfer occurs through reciprocity between the two materials. General example- this is a transformer. Microwave energy transmission as an idea was developed by William Brown. The whole concept involves converting AC power to RF power and transmitting it in space and re-transmitting it to AC power at the receiver. In this system, voltage is generated using microwave energy sources. Such as the klystron. And this power is transmitted through a waveguide, which protects against reflected power. And also a tuner that matches the impedance of the microwave source with other elements. The receiving section consists of an antenna. It accepts microwave power and an impedance and filter matching circuit. This receiving antenna, together with the rectifying device, can be a dipole. Corresponds to an output signal with similar sound notification rectifier block. The receiver block also consists of a similar section consisting of diodes, which are used to convert the signal into a DC alarm. This transmission system uses frequencies in the range of 2 GHz to 6 GHz.

Wireless transmission of electricity using a generator using similar magnetic oscillations. The bottom line is that this device worked thanks to three transistors.

Using a laser beam to transmit power in the form of light energy, which is converted into electrical energy at the receiving end. The material itself receives power using sources such as the Sun or any electricity generator. And, accordingly, it realizes focused light of high intensity. The size and shape of the beam are determined by the set of optics. And this transmitted laser light is received by photovoltaic cells, which convert it into electrical signals. It usually uses fiber optic cables for transmission. As in a basic solar power system, the receiver used in laser-based propagation is an array of photovoltaic cells or a solar panel. These, in turn, can convert rambling into electricity.

Essential features of the device

The power of a Tesla coil comes from a process called electromagnetic induction. That is, a changing field creates potential. It causes current to flow. When electricity flows through a coil of wire, it generates a magnetic field that fills the area around the coil in a certain way. Unlike some other experiments with high voltage, the Tesla coil has withstood many tests and tests. The process was quite labor-intensive and time-consuming, but the result was successful, and therefore was successfully patented by the scientist. You can create such a coil if you have certain components. For implementation you will need the following materials:

1. length 30 cm PVC (the longer the better);
2. enameled copper wire (secondary wire);
3. birch board for the base;
4. 2222A transistor;
5. connection (primary) wire;
6. resistor 22 kOhm;
7. switches and connecting wires;
8. battery 9 volt.

Stages of implementation of the Tesla device

First you need to place a small slot in top part tube to wrap one end of the wire around. Wind the coil slowly and carefully, being careful not to overlap the wires or create gaps. This step is the most difficult and tedious part, but the time spent will produce a very high quality and good reel. Every 20 or so turns, rings of masking tape are placed around the winding. They act as a barrier. In case the coil starts to unravel. Once finished, wrap some heavy tape around the top and bottom of the wrap and spray it with 2 or 3 coats of enamel.

Then you need to connect the primary and secondary battery to the battery. After that, turn on the transistor and resistor. The smaller winding is the primary winding and the longer winding is the secondary winding. You can additionally install an aluminum sphere on top of the pipe. Also, connect the open end of the secondary to the added one, which will act as an antenna. Everything must be built with great care to avoid touching the secondary device when powering up.

If used independently, there is a risk of fire. You need to flip the switch, install an incandescent lamp next to the wireless power transmission device and enjoy the light show.

Wireless transmission via solar energy system

Traditional wired energy implementation configurations typically require wires between distributed devices and consumer units. This creates many restrictions such as the cost of system cable costs. Losses incurred in transmission. And also waste in distribution. Transmission line resistance alone results in a loss of about 20-30% of the generated energy.

One of the most modern wireless energy transmission systems is based on the transmission of solar energy using microwave oven or laser beam. The satellite is located on geostationary orbit and consists of photovoltaic cells. They transform sunlight into an electric current that is used to power a microwave generator. And, accordingly, it realizes the power of microwaves. This voltage is transmitted using radio communication and received at the base station. It is a combination of an antenna and a rectifier. And is converted back into electricity. Requires AC or DC power. The satellite can transmit up to 10 MW of radio frequency power.

If we talk about a DC distribution system, then even this is impossible. Because this requires a connector between the power supply and the device. There is a picture: a system completely devoid of wires, where you can get AC power into homes without any additional devices. Where it is possible to charge your mobile phone without having to physically connect to a socket. Of course, such a system is possible. And many modern researchers are trying to create something modernized, while studying the role of developing new methods of wirelessly transmitting electricity over a distance. Although, from the point of view of the economic component, it will not be entirely profitable for states if such devices are introduced everywhere and standard electricity is replaced with natural electricity.

Origins and examples of wireless systems

This concept is actually not new. This whole idea was developed by Nicholas Tesla in 1893. When he developed a system of illuminating vacuum tubes using wireless transmission techniques. It is impossible to imagine that the world would exist without various sources of charging, which are expressed in material form. To make it possible for mobile phones, home robots, MP3 players, computers, laptops and other transportable gadgets to charge independently, without any additional connections, freeing users from constant wires. Some of these devices may not even require large quantity elements. The history of wireless energy transfer is quite rich, mainly thanks to the developments of Tesla, Volta and others. But today this remains only data in physical science.

The basic principle is to convert AC power into constant voltage using rectifiers and filters. And then - to return to the original value by high frequency using inverters. This low-voltage, high-fluctuating AC power then transfers from the primary transformer to the secondary. Converts to DC voltage using a rectifier, filter and regulator. The AC signal becomes direct due to the sound of the current. And also the use of the bridge rectifier section. The resulting DC signal passes through the winding feedback, which acts as an oscillator circuit. At the same time, it forces the transistor to conduct it into the primary converter in the direction from left to right. When current passes through the feedback winding, a corresponding current flows to the primary of the transformer in the direction from right to left.

This is how the ultrasonic method of energy transfer works. The signal is generated through the primary converter for both half-cycles of the AC alarm. The frequency of sound depends on the quantitative indicators of the oscillations of the generator circuits. This AC signal appears on the secondary winding of the transformer. And when it is connected to the primary converter of another object, the AC voltage is 25 kHz. A reading appears through it in the step-down transformer.

This AC voltage is equalized using a bridge rectifier. And then filtered and regulated to produce a 5V output to drive the LED. The 12V output voltage from the capacitor is used to power the DC fan motor to operate it. So, from the point of view of physics, electricity transmission is a fairly developed area. However, as practice shows, wireless systems are not fully developed and improved.

Everyone knows that Nikola Tesla is the inventor of such ubiquitous things as alternating current and the transformer. But not all scientists are familiar with Tesla’s other inventions.

We use alternating current. We use transformers. In any apartment. It is difficult to imagine how one can do without these inventions. But HOW do we use them? Tesla used these things known to us (as it seems to us) in a completely different way. How do we connect any electrical appliance to the network? With a fork - i.e. two conductors. If we connect only one conductor, there will be no current - the circuit is not closed.

Tesla demonstrated the effect of transmitting power through a single conductor. Moreover, in other experiments it transmitted power without wires at all. At the end of the 19th century, the great inventor was able to transmit electrical energy wirelessly over a distance of over 40 kilometers. Since this well-known Tesla experiment has not yet been repeated, our readers will certainly be interested in the details of this story, as well as current state problems of transmitting electrical energy without wires.

The biography of the American inventor, Serbian by birth, Nikola Tesla is quite well known, and we will not dwell on it. But let’s immediately clarify: before demonstrating his unique experiment, Tesla, first in 1892 in London, and a year later in Philadelphia, in the presence of specialists, demonstrated the possibility of transmitting electrical energy through one wire, without using grounding of the second pole of the energy source.

And then he had the idea to use the Earth as this single wire! And in the same year at the association congress electric lighting in St. Lewis he demonstrated electric lamps, burning without lead wires, and working without connection to electrical network electric motor He commented on this unusual exhibition as follows: “A few words about an idea that constantly occupies my thoughts and concerns us all. I mean transmitting signals, as well as energy, over any distance without wires. We already know that electrical vibrations can be transmitted through a single conductor. Why not use the Earth for this purpose? If we can establish the period of oscillation of the electric charge of the Earth when it is disturbed by the action of an oppositely charged circuit, this will be a fact of extreme importance, which will serve the benefit of all mankind.”

Seeing such a spectacular demonstration, such famous oligarchs as J. Westinghouse and J. P. Morgan invested over a million dollars in this promising business, buying his patents from Tesla (huge money, by the way, at that time!). With these funds, in the late 90s of the 19th century, Tesla built his unique laboratory in Colorado Springs. Detailed information about the experiments in Tesla’s laboratory is presented in the book of his biographer John O’Neill, “Electric Prometheus” (in our country, its translation was published in the magazine “Inventor and Innovator” No. 4-11 for 1979). We will give here only a brief excerpt from it, so as not to refer to later reprints: “In Colorado Springs, Tesla conducted the first tests of wireless transmission of electricity. He was able to power 200 incandescent light bulbs located 42 kilometers from his laboratory with the current drawn from the Earth during the operation of a giant vibrator. Each power was 50 watts, so the total energy consumption was 10 kW, or 13 hp. Tesla was convinced that with the help of a more powerful vibrator he could light a dozen electric garlands of 200 light bulbs each, scattered around the globe."

Tesla himself was so inspired by the success of these experiments that he announced in the general press that he intended to illuminate the World Industrial Exhibition in Paris, which was supposed to be held in 1903, with energy from a power plant located at Niagara Falls and transmitted to Paris wirelessly. It is known from numerous photographs and descriptions of eyewitnesses and assistants of the inventor that it was a generator of energy transmitted over 42 kilometers without wires (however, this is a purely journalistic term: one wire, which was the Earth, is present in this circuit, and this is directly stated both Tesla himself and his biographer).

What Tesla called a vibrator was a giant transformer of his system, which had a primary winding of several turns of thick wire wound on a fence with a diameter of 25 meters, and a multi-turn single-layer secondary winding placed inside it on a cylinder of dielectric. The primary winding, together with a capacitor, an induction coil and a spark gap, formed an oscillatory circuit-frequency converter. Above the transformer, located in the center of the laboratory, rose a wooden tower 60 meters high, topped with a large copper ball. One end of the secondary winding of the transformer was connected to this ball, the other was grounded. The entire device was powered by a separate 300 hp dynamo. Electromagnetic oscillations with a frequency of 150 kilohertz (wavelength 2000 meters) were excited in it. The operating voltage in the high-voltage circuit was 30,000 V, and the resonating potential of the ball reached 100,000,000 V, generating artificial lightning tens of meters long! This is how his biographer explains the work of Tesla’s vibrator: “In essence, Tesla “pumped” a stream of electrons into the Earth and extracted from there. The pumping frequency was 150 kHz. Spreading in concentric circles further and further from Colorado Springs, the electric waves then converged at a diametrically opposite point on the Earth. Large amplitude waves rose and fell there in unison with those raised in Colorado. When such a wave fell, it sent an electric echo back to Colorado, where an electric vibrator amplified the wave, and it rushed back.

If we bring the entire Earth into a state of electrical vibration, then at every point on its surface we will be provided with energy. It will be possible to capture it from the waves rushing between the electric poles simple devices like oscillatory circuits in radios, only grounded and equipped with small antennas the height of a rural cottage. This energy will heat and light homes using Tesla's tubular lamps, which require no wires. AC motors would only require frequency converters.”

Information about Tesla's experiments on transmitting electricity without wires inspired other researchers to work in this area. Reports of similar experiments often appeared in the press at the beginning of the last century. In this regard, it is worth citing an excerpt from an article by A.M. Gorky’s “Conversations on Craft,” published in 1930: “This year, Marconi transmitted electric current by air from Genoa to Australia and lit electric lamps there at an exhibition in Sydney. The same thing was done 27 years ago here, in Russia, by the writer and scientist M.M. Filippov, who worked for several years on transmitting electric current through the air and eventually lit a chandelier from St. Petersburg in Tsarskoe Selo ( that is, at a distance of 27 kilometers. -V.P.). At that time, no due attention was paid to this fact, but Filippov was found dead in his apartment a few days later, and his devices and papers were confiscated by the police.”

Tesla's experiments also made a great impression on another writer, Alexei Tolstoy, who was an engineer by training. And when Tesla, and then Marconi, reported in print that their devices were receiving strange signals of extraterrestrial, apparently Martian origin, this inspired the writer to write the science fiction novel “Aelita.” In the novel, the Martians use Tesla's invention and wirelessly transmit energy from power plants located at the poles of Mars to anywhere on the planet. This energy powers the engines of flying ships and other mechanisms. However, to build your own world system» to provide electricity to the population globe Tesla failed without the use of wires.

As soon as in 1900 he began to build a research laboratory town for 2000 employees and a huge metal tower with a giant copper plate on top on the island of Long Island near New York, the “wired” electrical oligarchs realized it: after all, the widespread introduction of Tesla’s system threatened them with ruin.

Wardenclyffe Tower (1902)

On billionaire J.P. Morgan, who financed the construction, was subject to severe pressure, including from government officials bribed by competitors.(or it was the other way around) There were interruptions in the supply of equipment, construction stalled, and when Morgan, under this pressure, stopped funding, it stopped altogether. At the beginning of the First World War, at the instigation of the same competitors, the US government ordered the explosion of a ready-made tower under the far-fetched pretext that it could be used for espionage purposes.

Well, then electrical engineering went the usual way.

For a long time no one could repeat Tesla’s experiments, if only because it would have been necessary to create an installation similar in size and power. But no one doubted that Tesla managed to find a way to transmit electrical energy over a distance without wires more than a hundred years ago. The authority of Tesla, who was rated as the second inventor after Edison, was quite high throughout the world, and his contribution to the development of alternating current electrical engineering (in defiance of Edison, who advocated direct current) is undoubted. During his experiments, many specialists were present, not counting the press, and no one ever tried to convict him of any tricks or manipulation of facts. The high authority of Tesla is evidenced by the name of the unit of magnetic field intensity after him. But Tesla’s conclusion that during the experiment in Colorado Springs energy was transmitted over a distance of 42 kilometers with an efficiency of about 90% is too optimistic. Let us recall that the total power of the lamps lit at a distance was 10 kW, or 13 hp, while the power of the dynamo that powered the vibrator reached 300 hp. That is, we can talk about efficiency. only about 4-5%, although this figure is amazing. The physical justification of Tesla's experiments on wireless transmission of electricity still worries many specialists.
www.elec.ru/news/2003/03/14/1047627665.h tml

Specialists from the Massachusetts Institute of Technology managed to make an incandescent lamp burn, located at a distance of 2 meters from the energy source. rus.newsru.ua/world/08jun2007/tesla.html

Wireless chargers from Intel odessabuy.com/news/item-402.html

"Arguments and Facts" No. 52, 2008 (December 24-30):
SCIENCE - Electricity without wires. They say that American scientists were able to transmit electricity with a power of 800 W without wires.