Transmitting electricity over a distance without wires. Introduction to Wireless Electrical Power Transmission

The principle of operation itself is clearly shown in a simple crafts, in which the LED can light up wirelessly at a distance of 2 cm from the energy source. The circuit, which acts as a step-up voltage converter as well as a wireless transmitter and receiver of electrical power, can be improved and implemented in many brain projects.

Step 1: We will need

NPN transistor- I took 2N3904, but you can use any NPN transistor (337, BC547, etc.), PNP transistor will also work, just be sure to observe the polarity of the connections.
winding or insulated wire - about 3-4 meters (wires can be “obtained” from many devices, transformers, speakers, motors, relays, etc.)
1 kOhm resistor - will be used to protect the transistor from burning out in case of overload, you can also use resistors up to 5 kOhm, you can even do it without a resistor, but then the battery will discharge faster.
LED - any will do, the main thing is to follow the diagram.
1.5V battery - do not use batteries with a higher voltage so as not to damage the transistor.
scissors or knife.
soldering iron (optional).
lighter (optional) for removing insulation from wires.

Step 2: Watch the video of the process

Step 3: Summarizing the Video

So, on a cylindrical object we wind a coil of 30 turns, this will be coil A. Next we wind a second coil of the same diameter, but at the same time we first wind 15 turns and make a tap, and then another 15 turns, this is coil B. We secure the coils against unwinding with any in a suitable way, for example, we simply make nodes from the coil leads. Important point: for the correct functioning of this crafts The diameters of both coils and the number of turns must be the same.

We clean the leads of both coils and proceed to soldering the circuit. We decide on the emitter, base and collector of our transistor and solder a resistor to the base. We solder the other terminal of the resistor to the free terminal of coil B, not to the tap terminal. Solder the second free terminal of coil B, again not a tap, to the collector.

For convenience, you can solder a small piece of wire to the emitter, this will make it easier to connect the battery.

The receiver circuit is easy to assemble: solder an LED to the terminals of coil A. AND brain trick ready!

Step 4: Circuit Diagram

Step 5: Visual Drawing

Step 6: Testing

To bring homemade products In a working state, we connect the output of coil B to the “plus” of the battery, and the “minus” to the emitter of the transistor. Then we bring the coils parallel to each other and the diode lights up!

Step 7: Explanation

Let me explain a little how it all works.

The transmitter in our crafts This is the oscillator circuit. You may have heard of the “Joule Stealing Circuit,” which is strikingly similar to our transmitter circuit. In the “Joule Stealing Circuit,” the electricity from a 1.5V battery is converted into a higher voltage, but pulsed. The LED requires 3V, but thanks to the “Joule-stealing circuit” it glows beautifully from 1.5V.

The "Joule Stealing Circuit" is known as a converter and oscillator, the circuit we created is also a oscillator and converter. And energy is supplied to the LED through induction occurring in the coils, which can be explained in brain example a regular transformer.

Let's assume that the transformer has two identical coils. Then, as electricity passes through one coil, it becomes a magnet, the second coil enters the magnetic field of the first and, as a result, current also begins to flow through it. If the voltage in the first coil is alternating, therefore, it pulses loses its magnetic properties, which means that the second coil pulses into the magnetic field of the first, that is, an alternating voltage is formed in the second coil.

In our homemade The transmitter coil creates a magnetic field into which the receiver coil enters, connected to an LED, which converts the received energy into light!

Submitted brain trick converts the received energy into light, but it can be used in more diverse ways. You can also apply the principles of this homemade products for creating magic tricks, fun gifts or science projects. If you vary the diameters and number of turns on the coils, you can achieve maximum values, or you can change the shape of the coils, etc., the possibilities are unlimited!

Step 9: Troubleshooting

When creating this homemade products The following problems are possible:
The transistor is getting too hot - check the resistor value, it may need to be increased. I didn't use a resistor at first, and the transistor burned out. Or, as an option, use a radiator for the transistor, or maybe another transistor, with a higher gain value.
The LED does not light - there can be many reasons. Check the quality of the connection, whether the base and collector are soldered correctly, make sure that the coils are of equal diameter, whether short circuit in the chain.

Today's induction experiment is over, thank you for your attention and good luck in your creativity!

The law of interaction of electric currents discovered by André Marie Ampère in 1820 laid the foundation for the further development of the science of electricity and magnetism. 11 years later, Michael Faraday experimentally established that a changing magnetic field generated by an electric current can induce an electric current in another conductor. This is how it was created.

In 1864, James Clerk Maxwell finally systematized Faraday's experimental data, giving them the form of precise mathematical equations, thanks to which the basis of classical electrodynamics was created, because these equations described the connection of the electromagnetic field with electric currents and charges, and the consequence of this should have been the existence of electromagnetic waves.

In 1888, Heinrich Hertz experimentally confirmed the existence of electromagnetic waves predicted by Maxwell. His spark transmitter with a Ruhmkorff coil chopper could produce electromagnetic waves up to 0.5 gigahertz, which could be received by multiple receivers tuned in resonance with the transmitter.

Receivers could be located at a distance of up to 3 meters, and if a spark occurred in the transmitter, sparks occurred in the receivers. This is how they were carried out first experiments in wireless transmission of electrical energy using electromagnetic waves.

In 1891, while studying alternating currents of high voltage and high frequency, he came to the conclusion that it is extremely important for specific purposes to select both the wavelength and the operating voltage of the transmitter, and it is not at all necessary to make the frequency too high.

The scientist notes that the lower limit of frequencies and voltages at which he was able to achieve the best results at that time was from 15,000 to 20,000 vibrations per second with a potential of 20,000 volts. Tesla received a current of high frequency and high voltage using an oscillatory discharge of a capacitor (see -). He noted that this type of electrical transmitter is suitable both for producing light and for transmitting electricity to produce light.

In the period from 1891 to 1894, the scientist repeatedly demonstrates wireless transmission and the glow of vacuum tubes in a high-frequency electrostatic field, while noting that the energy of the electrostatic field is absorbed by the lamp, converted into light, and the energy of the electromagnetic field is used for electromagnetic induction in order to obtain a similar The result is mostly reflected, and only a small fraction is converted into light.

Even using resonance when transmitting using an electromagnetic wave, it will not be possible to transmit a significant amount of electrical energy, the scientist argued. His goal during this period of work was to transfer precisely large quantity electrical energy wirelessly.

Until 1897, in parallel with Tesla's work, research on electromagnetic waves was carried out by: Jagdish Bose in India, Alexander Popov in Russia, and Guglielmo Marconi in Italy.

Following Tesla's public lectures, Jagdish Bose gave a demonstration of wireless transmission of electricity in November 1894 in Calcutta, where he ignited gunpowder, transmitting electrical energy over a distance.

After Boche, namely on April 25, 1895, Alexander Popov, using Morse code, transmitted the first radio message, and this date (May 7, new style) is now celebrated annually in Russia as “Radio Day.”

In 1896, Marconi, having arrived in Great Britain, demonstrated his apparatus, using Morse code to transmit a signal over a distance of 1.5 kilometers from the roof of the Post Office building in London to another building. After that, he improved his invention and managed to transmit a signal across the Salisbury Plain over a distance of 3 kilometers.

Tesla in 1896 successfully transmits and receives signals at a distance between transmitter and receiver of approximately 48 kilometers. However, none of the researchers has yet succeeded in transmitting a significant amount of electrical energy over a long distance.

Experimenting in Colorado Springs, Tesla would write in 1899: “The failure of the induction method seems enormous compared with the method of exciting the charge of the earth and air.” This will be the beginning of the scientist’s research aimed at transmitting electricity over significant distances without the use of wires. In January 1900, Tesla wrote in his diary about the successful transfer of energy to a coil “extended far into the field” from which the lamp was powered.

And the scientist’s greatest success would be the launch of the Wardenclyffe Tower on Long Island on June 15, 1903, designed to transmit electrical energy over a considerable distance in large quantities without wires. The grounded secondary winding of the resonant transformer, topped with a copper spherical dome, was supposed to excite the earth charge and conductive layers of air to become an element of a large resonant circuit.

So the scientist managed to power 200 50-watt lamps at a distance of about 40 kilometers from the transmitter. However, based on economic feasibility, funding for the project was stopped by Morgan, who from the very beginning invested money in the project in order to obtain wireless communications, and the transfer of free energy on an industrial scale over a distance was categorically not suitable for him as a businessman. In 1917, the tower, designed for wireless transmission of electrical energy, was destroyed.

Much later, in the period from 1961 to 1964, an expert in the field of microwave electronics, William Brown, experimented in the USA with microwave beam energy transmission paths.

In 1964, he was the first to test a device (a helicopter model) capable of receiving and using microwave beam energy in the form DC, thanks to an antenna array consisting of half-wave dipoles, each of which is loaded with highly efficient Schottky diodes. Already by 1976, William Brown transmitted a microwave beam of 30 kW power over a distance of 1.6 km with an efficiency exceeding 80%.

In 2007, a research group at the Massachusetts Institute of Technology, led by Professor Marin Soljacic, was able to wirelessly transmit energy over a distance of 2 meters. The transmitted power was enough to power a 60-watt light bulb.

Their technology (called ) is based on the phenomenon of electromagnetic resonance. The transmitter and receiver are two copper coils, each 60 cm in diameter, resonating at the same frequency. The transmitter is connected to a power source, and the receiver is connected to an incandescent lamp. The circuits are tuned to 10 MHz. The receiver in this case receives only 40-45% of the transmitted electricity.

Around the same time, Intel demonstrated a similar technology for wireless power transmission.

In 2010, Haier Group, a Chinese manufacturer of home appliances, presented its unique product- completely wireless LCD TV based on this technology.

In fact, in the 1970s, he technically realized the dreams of NATO and the United States about constant air patrolling of Iraq (Libya, Syria, etc.) with drones with cameras, hunting (or recording) “terrorists” on-line 24 hours.

In 1968, American space scientist Peter E. Glaser proposed placing large solar panels on geostationary orbit, and the energy they generate (5-10 GW level) is transmitted to the surface of the Earth with a well-focused beam of microwave radiation, then converted into direct or alternating current energy of a technical frequency and distributed to consumers.

This scheme made it possible to use the intense flux of solar radiation existing in geostationary orbit (~ 1.4 kW/sq.m.) and transmit the resulting energy to the Earth's surface continuously, regardless of the time of day and weather conditions. Due to the natural inclination of the equatorial plane to the ecliptic plane with an angle of 23.5 degrees, a satellite located in a geostationary orbit is illuminated by the flow of solar radiation almost continuously, with the exception of short periods of time near the days of the spring and autumn equinoxes, when this satellite falls into the Earth's shadow. These periods of time can be accurately predicted, and in total they do not exceed 1% of the total length of the year.

Frequency electromagnetic vibrations The microwave beam must correspond to those ranges that are allocated for use in industry, scientific research and medicine. If this frequency is chosen to be 2.45 GHz, then meteorological conditions, including thick clouds and intense precipitation, have virtually no effect on the efficiency of power transmission. The 5.8 GHz band is attractive because it offers the opportunity to reduce the size of the transmit and receive antennas. However, the influence of meteorological conditions here requires additional study.

The current level of development of microwave electronics allows us to talk about quite high value The efficiency of transmitting energy by a microwave beam from geostationary orbit to the Earth's surface is about 70% ÷ 75%. In this case, the diameter of the transmitting antenna is usually chosen to be 1 km, and the ground rectenna has dimensions of 10 km x 13 km for a latitude of 35 degrees. A SCES with an output power level of 5 GW has a radiated power density at the center of the transmitting antenna of 23 kW/m², and at the center of the receiving antenna – 230 W/m².

Various types of solid-state and vacuum microwave generators for the SKES transmitting antenna were investigated. William Brown showed, in particular, that magnetrons, well developed by industry, intended for microwave ovens, can also be used in SKES transmitting antenna arrays, if each of them is equipped with its own negative circuit feedback in phase with respect to the external clock signal (the so-called Magnetron Directional Amplifier - MDA).

The most active and systematic research in the field of SCES was carried out by Japan. In 1981, under the leadership of Professors M. Nagatomo and S. Sasaki at the Space Research Institute of Japan, research began on the development of a prototype SCES with a power level of 10 MW, which could be created using existing launch vehicles. The creation of such a prototype allows one to accumulate technological experience and prepare the basis for the formation of commercial systems.

The project was named SKES2000 (SPS2000) and received recognition in many countries around the world.

In 2008, Marin Soljačić, assistant professor of physics at the Massachusetts Institute of Technology (MIT), was awakened from a sweet sleep by the persistent beeping of his cell phone. “The phone didn’t stop talking, demanding that I put it on charge,” Soljacic said. Tired and not about to get up, he began to dream that the phone, once at home, would start charging on its own.

In 2012-2015 Engineers at the University of Washington have developed technology that allows Wi-Fi to be used as an energy source to power portable devices and charge gadgets. The technology has already been recognized by Popular Science magazine as one of the best innovations of 2015. The ubiquity of wireless data transmission technology in itself has produced a real revolution. And now it’s the turn of wireless energy transmission through the air, which developers from the University of Washington called (from Power Over WiFi).

During the testing phase, the researchers were able to successfully charge small-capacity lithium-ion and nickel-metal hydride batteries. Using the Asus RT-AC68U router and several sensors located at a distance of 8.5 meters from it. These sensors convert the energy of the electromagnetic wave into direct current with a voltage of 1.8 to 2.4 volts, which is necessary to power microcontrollers and sensor systems. The peculiarity of the technology is that the quality of the working signal does not deteriorate. You just need to reflash the router, and you can use it as usual, plus supply power to low-power devices. In one demonstration, a small, low-resolution surveillance camera located more than 5 meters from the router was successfully powered. Then the Jawbone Up24 fitness tracker was charged to 41%, which took 2.5 hours.

To tricky questions about why these processes do not negatively affect the quality of the network communication channel, the developers answered that this becomes possible due to the fact that the re-flashed router, during its operation, sends energy packets through channels unoccupied by information transmission. They came to this decision when they discovered that during periods of silence, energy simply flows out of the system, but it can be used to power low-power devices.

During the research, the PoWiFi system was placed in six houses, and residents were asked to use the Internet as usual. Load web pages, watch streaming videos, and then tell us what's changed. As a result, it turned out that network performance did not change at all. That is, the Internet worked as usual, and the presence of the added option was not noticeable. And these were only the first tests, when a relatively small amount of energy was collected over Wi-Fi.

In the future, PoWiFi technology could well serve to power sensors built into household appliances and military equipment in order to control them wirelessly and carry out remote charging/recharging.

Energy transfer for UAVs is relevant (most likely, already using technology or from the carrier aircraft):

The idea looks quite tempting. Instead of today's 20-30 minutes of flight time:
→
→

→ Intel operated the drone show during Lady Gaga's Super Bowl halftime performance -
get 40-80 minutes by recharging drones via wireless technology.

Let me explain:
-exchange of drones is still necessary (swarm algorithm);
-exchange of drones and aircraft (uterus) is also necessary (control center, correction of military protection, retargeting, command to eliminate, preventing "friendly fire", transfer of intelligence information and commands for use).

Who's next in line?

Note: A typical WiMAX base station emits power at approximately +43 dBm (20 W), and the station mobile communications typically transmits at +23 dBm (200 mW).

The permissible levels of radiation from mobile communication base stations (900 and 1800 MHz, total level from all sources) in sanitary and residential areas in some countries differ markedly:
Ukraine: 2.5 µW/cm². (the strictest sanitary standard in Europe)
Russia, Hungary: 10 µW/cm².
Moscow: 2.0 µW/cm². (the norm existed until the end of 2009)
USA, Scandinavian countries: 100 µW/cm².

The temporary permissible level (TLA) from mobile radiotelephones (MRT) for radiotelephone users in the Russian Federation is determined to be 10 μW/cm² (Section IV - Hygienic requirements for mobile land radio communication stations SanPiN 2.1.8/2.2.4.1190-03).

In the USA, the Certificate is issued by the Federal Communications Commission (FCC) for cellular devices, maximum level SAR of which does not exceed 1.6 W/kg (and the absorbed radiation power is reduced to 1 gram of human organ tissue).

In Europe, according to the international directive of the Commission on Non-Ionizing Radiation Protection (ICNIRP), the value Mobile SAR telephone should not exceed 2 W/kg (in this case, the absorbed radiation power is reduced to 10 grams of human organ tissue).

More recently, it has become safe in the UK SAR level the level was considered equal to 10 W/kg. A similar picture was observed in other countries. The maximum SAR value adopted in the standard (1.6 W/kg) cannot even be confidently attributed to “hard” or “soft” standards. The standards adopted in both the USA and Europe for determining the value of SAR (all regulation of microwave radiation from cell phones in question is based only on the thermal effect, that is, associated with heating the tissues of human organs).

COMPLETE CHAOS.

Medicine has not yet given a clear answer to the question: is mobile/WiFi harmful and to what extent? What will happen to the wireless transmission of electricity using microwave technologies?

Here the power is not watts and miles of watts, but kW...

Links, documents used, photos and videos:
“(JOURNAL OF RADIO ELECTRONICS!” N 12, 2007 (ELECTRIC POWER FROM SPACE - SOLAR SPACE POWER PLANTS, V. A. Banke)
“Microwave electronics - prospects in space energy” V. Banke, Doctor of Physical and Mathematical Sciences.
www.nasa.gov
www. whdi.org
www.defense.gov
www.witricity.com
www.ru.pinterest.com
www. raytheon.com
www. ausairpower.net
www. wikipedia.org
www.slideshare.net
www.homes.cs.washington.edu
www.dailywireless.org
www.digimedia.ru
www. powercoup.by
www.researchgate.net
www. proelectro.info
www.youtube.com

Wireless transmission of electricity

Wireless transmission of electricity- a method of transmitting electrical energy without the use of conductive elements in an electrical circuit. By the year, there had been successful experiments with energy transmission with a power of the order of tens of kilowatts in the microwave range with an efficiency of about 40% - in 1975 in Goldstone, California and in 1997 in Grand Bassin on Reunion Island (range of about a kilometer, research in the field of power supply to a village without laying a cable electrical network). Technological principles of such transmission include induction (at short distances and relatively low powers), resonance (used in contactless smart cards and RFID chips) and directional electromagnetic for relatively long distances and powers (in the range from ultraviolet to microwaves).

History of wireless power transmission

1820 : André Marie Ampère discovered a law (after named after its discoverer, Ampère's law) showing that an electric current produces a magnetic field.
1831 : Michael Faraday discovered the law of induction, an important basic law of electromagnetism.
1862 : Carlo Matteuci first conducted experiments on the transmission and reception of electrical induction using flat spiral coils.
1864 : James Maxwell codified all previous observations, experiments, and equations in electricity, magnetism, and optics into a coherent theory and rigorous mathematical description of the behavior of the electromagnetic field.
1888 : Heinrich Hertz confirmed the existence of the electromagnetic field. " Apparatus for generating an electromagnetic field"Hertz" was a microwave or UHF spark transmitter of "radio waves".
1891 : Nikola Tesla improved the Hertzian wave transmitter for radio frequency power supply in his patent no. 454.622, Electric Lighting System.
1893 : Tesla demonstrates wireless fluorescent lighting in a project for the Columbia World's Fair in Chicago.
1894 : Tesla wirelessly lights an incandescent lamp in the Fifth Avenue Laboratory, and later in the Houston Street Laboratory in New York, using "electrodynamic induction", that is, through wireless resonant mutual induction.
1894 : Jagdish Chandra Bose remotely ignites gunpowder and strikes a bell using electromagnetic waves, showing that communication signals can be sent wirelessly.
1895 : A. S. Popov demonstrated the radio receiver he invented at a meeting of the physics department of the Russian Physical-Chemical Society on April 25 (May 7)
1895 : Bose transmits a signal over a distance of about one mile.
1896 : Guglielmo Marconi submits a claim for the invention of radio on June 2, 1896.
1896 : Tesla transmits a signal over a distance of about 48 kilometers.
1897 : Guglielmo Marconi reports text message in Morse code over a distance of about 6 km, using a radio transmitter.
1897 : Tesla files the first of its patents on the use of wireless transmission.
1899 : In Colorado Springs, Tesla writes: “The failure of the method of induction appears enormous in comparison with method of exciting the charge of earth and air».
1900 : Guglielmo Marconi was unable to obtain a patent for the invention of radio in the United States.
1901 : Marconi transmits a signal across the Atlantic Ocean using a Tesla apparatus.
1902 : Tesla vs. Reginald Fessenden: US Patent No. Conflict. 21.701 “Signal transmission system (wireless). Selective switching of incandescent lamps, electronic logic elements in general.”
1904 : A prize is offered at the St. Louis World's Fair for a successful attempt to control a 0.1 hp airship engine. (75 W) from energy transmitted remotely over a distance of less than 100 feet (30 m).
1917 : The Wardenclyffe Tower, built by Nikola Tesla to conduct experiments on the wireless transmission of high power, is destroyed.
1926 : Shintaro Uda and Hidetsugu Yagi publish the first article " about an adjustable directional high-gain communication channel”, well known as the “Yagi-Uda antenna” or “wave channel” antenna.
1961 : William Brown publishes an article exploring the possibility of transmitting energy through microwaves.
1964 : William Brown and Walter Kronikt show on the channel CBS News a model of a helicopter that receives all the energy it needs from a microwave beam.
1968 : Peter Glaser proposes wireless transmission of solar energy from space using Energy Beam technology. This is considered the first description of an orbital power system.
1973 : First in the world passive system RFID demonstrated at Los Alamos National Laboratory.
1975 : The Goldstone Deep Space Communications Complex is conducting experiments on power transmission of tens of kilowatts.
2007 : A research team led by Professor Marin Soljačić from the Massachusetts Institute of Technology wirelessly transmitted over a distance of 2 m the power sufficient to illuminate a 60 W light bulb with efficiency. 40%, using two coils with a diameter of 60 cm.
2008 : Bombardier offers new product for wireless transmission PRIMOVE, a powerful system for use in trams and light rail engines.
2008 : Intel is replicating Nikola Tesla's 1894 and John Brown's 1988 team's experiments in wirelessly transmitting energy to light efficient incandescent light bulbs. 75%.
2009 : A consortium of interested companies, called the Wireless Power Consortium, has announced the imminent completion of a new industry standard for low-power induction chargers.
2009 : An industrial flashlight is presented that can operate safely and be recharged in a non-contact manner in an atmosphere saturated with flammable gas. This product was developed by the Norwegian company Wireless Power & Communication.
2009 : Haier Group introduced the world's first fully wireless LCD TV based on Professor Marin Soljačić's research on wireless power transmission and Wireless Home Digital Interface (WHDI).

Technology (ultrasound method)

Invention by students at the University of Pennsylvania. The installation was first presented to the general public at The All Things Digital (D9) exhibition in 2011. As with other methods of wirelessly transmitting something, a receiver and a transmitter are used. The transmitter emits ultrasound, the receiver, in turn, converts what is heard into electricity. At the time of presentation, the transmission distance reaches 7-10 meters; direct visibility of the receiver and transmitter is required. Among the known characteristics, the transmitted voltage reaches 8 volts, but the received current strength is not reported. The ultrasonic frequencies used have no effect on humans. There is also no information about negative effects on animals.

Electromagnetic induction method

The electromagnetic induction wireless transmission technique uses a near-field electromagnetic field at distances of about one-sixth of a wavelength. Near-field energy itself is not radiative, but some radiative losses do occur. In addition, as a rule, resistive losses also occur. Thanks to electrodynamic induction, an alternating electric current flowing through the primary winding creates an alternating magnetic field, which acts on the secondary winding, inducing an electric current in it. To achieve high efficiency, the interaction must be quite close. As the secondary winding moves away from the primary, more and more of the magnetic field does not reach the secondary winding. Even over relatively short distances, inductive coupling becomes extremely inefficient, wasting most of the transmitted energy.

An electrical transformer is the simplest device for wireless energy transfer. The primary and secondary windings of the transformer are not directly connected. Energy transfer occurs through a process known as mutual induction. The main function of a transformer is to increase or decrease the primary voltage. Contactless chargers mobile phones and electric toothbrushes are examples of the use of the principle of electrodynamic induction. Induction cookers also use this method. The main disadvantage of the wireless transmission method is its extremely short range. The receiver must be in close proximity to the transmitter in order to communicate with it effectively.

The use of resonance slightly increases the transmission range. With resonant induction, the transmitter and receiver are tuned to the same frequency. Performance can be improved further by changing the control current waveform from sinusoidal to non-sinusoidal transient waveforms. Pulsed energy transfer occurs over several cycles. In this way, significant power can be transferred between two mutually tuned LC circuits with a relatively low coupling coefficient. The transmitting and receiving coils are usually single-layer solenoids or a flat spiral with a set of capacitors that allow the receiving element to be tuned to the frequency of the transmitter.

A common application of resonant electrodynamic induction is to charge the batteries of portable devices such as laptop computers and cell phones, medical implants, and electric vehicles. The localized charging technique uses the selection of an appropriate transfer coil in a multilayer winding array structure. Resonance is used in both the wireless charging panel (transmitting circuit) and the receiver module (built into the load) to ensure maximum power transfer efficiency. This transmission technique is suitable for universal wireless charging pads for recharging portable electronics, such as mobile phones. The technique has been adopted as part of the Qi wireless charging standard.

Resonant electrodynamic induction is also used to power devices that do not have batteries, such as RFID tags and contactless smart cards, as well as to transfer electrical energy from the primary inductor to the helical resonator of the Tesla transformer, which is also a wireless transmitter of electrical energy.

Electrostatic induction

Alternating current can be transmitted through layers of the atmosphere having an atmospheric pressure of less than 135 mmHg. Art. The current flows by electrostatic induction through the lower atmosphere approximately 2-3 miles above sea level and by ion flux, that is, electrical conduction, through the ionized region located above 5 km. Intense vertical beams of ultraviolet radiation can be used to ionize atmospheric gases directly above the two elevated terminals, resulting in the formation of plasma high voltage lines power transmission lines leading directly to the conductive layers of the atmosphere. As a result, a flow of electric current is formed between the two elevated terminals, passing up to the troposphere, through it and back to the other terminal. Electrical conductivity through the layers of the atmosphere is made possible by a capacitive plasma discharge in an ionized atmosphere.

Nikola Tesla discovered that electricity can be transmitted both through the earth and through the atmosphere. In the course of his research, he achieved the ignition of a lamp at moderate distances and recorded the transmission of electricity over long distances. The Wardenclyffe Tower was conceived as a commercial project for transatlantic wireless telephony and became a real demonstration of the possibility of wireless power transmission on a global scale. The installation was not completed due to insufficient funding.

The earth is a natural conductor and forms one conductive circuit. The return loop occurs through the upper troposphere and lower stratosphere at an altitude of about 4.5 miles (7.2 km).

A global system for transmitting electricity without wires, the so-called "Worldwide Wireless System", based on the high electrical conductivity of plasma and the high electrical conductivity of the earth, was proposed by Nikola Tesla in early 1904 and could well have been the cause of the Tunguska meteorite, which resulted from a "short circuit" between a charged atmosphere and earth.

Worldwide Wireless System

The early experiments of the famous Serbian inventor Nikola Tesla concerned the propagation of ordinary radio waves, that is, Hertz waves, electromagnetic waves propagating in space.

In 1919, Nikola Tesla wrote: “It is believed that I began work on wireless transmission in 1893, but in fact I had been conducting research and constructing equipment for the previous two years. It was clear to me from the very beginning that success could be achieved through a series of radical decisions. High frequency oscillators and electrical oscillators had to be created first. Their energy had to be converted into efficient transmitters and received at a distance by suitable receivers. Such a system would be effective if it excluded any outside interference and ensured its complete exclusivity. Over time, however, I realized that for devices of this kind to work effectively, they must be designed taking into account the physical properties of our planet."

One of the conditions for creating a worldwide wireless system is the construction of resonant receivers. The Tesla coil's grounded helical resonator and elevated terminal can be used as such. Tesla personally repeatedly demonstrated the wireless transmission of electrical energy from the transmitting to the receiving Tesla coil. This became part of his wireless transmission system (U.S. Patent No. 1119732, Apparatus for Transmitting Electrical Energy, January 18, 1902). Tesla proposed installing more than thirty transceiver stations around the world. In this system, the take-up coil acts as a step-down transformer with a high current output. The parameters of the transmitting coil are identical to the receiving coil.

The goal of Tesla's worldwide wireless system was to combine power transmission with radio broadcasting and directional wireless communications, which would eliminate the need for numerous high-voltage power lines and facilitate the interconnection of electrical generating facilities on a global scale.

Notes

"Electricity at the Columbian Exposition", by John Patrick Barrett. 1894, pp. 168-169 (English)
Experiments with Alternating Currents of Very High Frequency and Their Application to Methods of Artificial Illumination, AIEE, Columbia College, N.Y., May 20, 1891 (English)
Experiments with Alternate Currents of High Potential and High Frequency, IEE Address, London, February 1892
On Light and Other High Frequency Phenomena, Franklin Institute, Philadelphia, February 1893 and National Electric Light Association, St. Louis, March 1893 (English)
The Work of Jagdish Chandra Bose: 100 years of mm-wave research (English)
Jagadish Chandra Bose
Nikola Tesla On His Work With Alternating Currents and Their Application to Wireless Telegraphy, Telephony and Transmission of Power, pp. 26-29. (English)
June 5, 1899, Nikola Tesla Colorado Spring Notes 1899-1900, Nolit, 1978 (English)
Nikola Tesla: Guided Weapons & Computer Technology (English)
The Electrician(London), 1904 (English)
Scanning the Past: A History of Electrical Engineering from the Past, Hidetsugu Yagi
A survey of the elements of power Transmission by microwave beam, in 1961 IRE Int. Conf. Rec., vol.9, part 3, pp.93-105 (English)
IEEE Microwave Theory and Techniques, Bill Brown's Distinguished Career
Power from the Sun: Its Future, Science Vol. 162, pp. 957-961 (1968)
Solar Power Satellite patent
History of RFID
Space Solar Energy Initiative
Wireless Power Transmission for Solar Power Satellite (SPS) (Second Draft by N. Shinohara), Space Solar Power Workshop, Georgia Institute of Technology (English)
W. C. Brown: The History of Power Transmission by Radio Waves: Microwave Theory and Techniques, IEEE Transactions on September, 1984, v. 32 (9), pp. 1230-1242 (English)
Wireless Power Transfer via Strongly Coupled Magnetic Resonances. Science (7 June 2007). Archived,
A new method of wireless transmission of electricity has been launched (Russian). MEMBRANA.RU (June 8, 2007). Archived from the original on February 29, 2012. Retrieved September 6, 2010.
Bombardier PRIMOVE Technology
Intel imagines wireless power for your laptop
wireless electricity specification nearing completion
TX40 and CX40, Ex approved Torch and Charger (English)
Haier's wireless HDTV lacks wires, svelte profile (video) (English) ,
Wireless electricity amazed its creators (Russian). MEMBRANA.RU (February 16, 2010). Archived from the original on February 26, 2012. Retrieved September 6, 2010.
Eric Giler demos wireless electricity | Video on TED.com
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I have to say here that when I filed the applications of September 2, 1897, for the transmission of energy in which this method was disclosed, it was already clear to me that I did not need to have terminals at such high elevation, but I never have, above my signature, anything announced that I did not prove first. That is the reason why no statement of mine was ever contradicted, and I do not think it will be, because whenever I publish something I go through it first by experiment, then from experiment I calculate, and when I have the theory and practice meet I announce the results.

At that time I was absolutely sure that I could put up a commercial plant, if I could do nothing else but what I had done in my laboratory on Houston Street; but I had already calculated and found that I did not need great heights to apply this method. My patent says that I break down the atmosphere "at or near" the terminal. If my conducting atmosphere is 2 or 3 miles above the plant, I consider this very near the terminal as compared to the distance of my receiving terminal, which may be across the Pacific. That is simply an expression. . . .

Nikola Tesla On His Work With Alternating Currents and Their Application to Wireless Telegraphy, Telephony and Transmission of Power

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. Broadcast wireless electricity 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 resonant wireless power systems for the consumer electronics market has shown 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, communication, 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 does the system in question work?

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 transmission of electricity 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 methods of 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. A common example 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 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 high voltage experiments, the Tesla coil withstood many tests and trials. 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:

length 30 cm PVC (the longer the better);
enameled copper wire (secondary wire);
birch board for the base;
2222A transistor;
connection (primary) wire;
resistor 22 kOhm;
switches and connecting wires;
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 wireless device transfer energy 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. The 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 placed in 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 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 in 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 technology. 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 many 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 DC voltage using rectifiers and filters. And then - to return to the original value at 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 a feedback winding, 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.