Tesla transformer (the principle of operation of the apparatus will be discussed later) was patented in 1896, September 22. The device was presented as a device that produces electric currents of high potential and frequency. The device was invented by Nikola Tesla and named after him. Let's consider this device in more detail.
Tesla transformer: working principle
The essence of the operation of the device can be explained by the example of the well-known swing. When they swing under conditions of forced oscillations, the amplitude, which will be maximum, will become proportional to the applied force. When swinging in free mode, the maximum amplitude will increase many times over with the same efforts. This is the essence of the Tesla transformer. An oscillatory secondary circuit is used as a swing in the apparatus. The generator plays the role of the applied effort. With their consistency (pushing at strictly necessary periods of time), a master oscillator or a primary circuit (in accordance with the device) is provided.
Description
A simple Tesla transformer includes two coils. One is primary, the other is secondary. Also, the Tesla resonant transformer consists of a toroid (not always used),capacitor, arrester. The last - the interrupter - is found in the English version of Spark Gap. The Tesla transformer also contains an "output" terminal.
Coils
Primary contains, as a rule, a large-diameter wire or a copper tube with several turns. The secondary coil has a smaller cable. Its turns are about 1000. The primary coil can have a flat (horizontal), conical or cylindrical (vertical) shape. Here, unlike a conventional transformer, there is no ferromagnetic core. Due to this, the mutual inductance between the coils is significantly reduced. Together with the capacitor, the primary element forms an oscillatory circuit. It includes a spark gap - a non-linear element.
The secondary coil also forms an oscillatory circuit. The toroidal and its own coil (interturn) capacitances act as a capacitor. The secondary winding is often covered with a layer of varnish or epoxy. This is done to avoid electrical breakdown.
Discharger
The Tesla transformer circuit includes two massive electrodes. These elements must be resistant to high currents flowing through an electric arc. Adjustable clearance and good cooling are a must.
Terminal
This element can be installed in a resonant Tesla transformer in different versions. The terminal may be a sphere, a sharpened pin, or a disc. It is designed to produce predictable spark discharges with a largelength. Thus, two connected oscillatory circuits form a Tesla transformer.
Energy from the ether is one of the purposes of the apparatus functioning. The inventor of the device sought to achieve a wave number Z of 377 ohms. He made coils of ever larger sizes. Normal (full) operation of the Tesla transformer is ensured when both circuits are tuned to the same frequency. As a rule, in the process of adjustment, the primary is adjusted to the secondary. This is achieved by changing the capacitance of the capacitor. The number of turns at the primary winding also changes until the maximum voltage appears at the output.
In the future, it is planned to create a simple Tesla transformer. The energy from the ether will work for humanity to the fullest.
Action
Tesla transformer operates in pulsed mode. The first phase is a capacitor charge up to the breakdown voltage of the discharge element. The second is the generation of high-frequency oscillations in the primary circuit. A spark gap connected in parallel closes the transformer (power source), excluding it from the circuit. Otherwise, he will make certain losses. This, in turn, will reduce the quality factor of the primary circuit. As practice shows, such an influence significantly reduces the length of the discharge. In this regard, in a well-built circuit, the arrester is always placed parallel to the source.
Charge
It is produced by an external high voltage source based on a low-frequency step-up transformer. The capacitor capacitance is chosen so that it forms a certain circuit together with the inductor. Its resonance frequency should be equal to the high voltage circuit.
In practice, everything is somewhat different. When the calculation of the Tesla transformer is carried out, the energy that will be used to pump the second circuit is not taken into account. The charge voltage is limited by the voltage at the breakdown of the arrester. It (if the element is air) can be adjusted. The breakdown voltage is corrected by changing the shape or distance between the electrodes. As a rule, the indicator is in the range of 2-20 kV. The sign of the voltage should not "short" the capacitor too much, which is constantly changing sign.
Generation
After the breakdown voltage between the electrodes is reached, an electrical avalanche-like gas breakdown is formed in the spark gap. The capacitor discharges onto the coil. After that, the breakdown voltage decreases sharply due to the remaining ions in the gas (charge carriers). As a result, the circuit of the oscillation circuit, consisting of a capacitor and a primary coil, remains closed through the spark gap. It generates high frequency vibrations. They gradually fade, mainly due to losses in the arrester, as well as the escape of electromagnetic energy to the secondary coil. Nevertheless, the oscillations continue until the current creates a sufficient number of charge carriers to maintain a significantly lower breakdown voltage in the spark gap than the amplitude of oscillations of the LC circuit. In the secondary circuitresonance appears. This results in high voltage at the terminal.
Modifications
Whatever type of Tesla transformer circuit, the secondary and primary circuits remain the same. However, one of the components of the main element may be of a different design. In particular, we are talking about a generator of high-frequency oscillations. For example, in the SGTC modification, this element is performed on the spark gap.
RSG
Tesla's high power transformer incorporates a more complex spark gap design. In particular, this applies to the RSG model. The abbreviation stands for Rotary Spark Gap. It can be translated as follows: rotating / rotary spark or static gap with arc extinguishing (additional) devices. In this case, the frequency of operation of the gap is selected synchronously with the frequency of capacitor charging. The design of the spark rotor gap includes a motor (usually it is electric), a disk (rotating) with electrodes. The latter either close or approach the mating components to close.
The choice of the arrangement of contacts and the speed of rotation of the shaft is based on the required frequency of the oscillatory packs. In accordance with the type of motor control, spark rotor gaps are distinguished as asynchronous and synchronous. Also, the use of a rotating spark gap significantly reduces the likelihood of a parasitic arc between the electrodes.
In some cases, a conventional spark gap is replacedmultistage. For cooling, this component is sometimes placed in gaseous or liquid dielectrics (in oil, for example). As a typical technique for extinguishing the arc of a statistical spark gap, purge of the electrodes using a powerful air jet is used. In some cases, the Tesla transformer of classical design is supplemented with a second arrester. The purpose of this element is to protect the low-voltage (feeding) zone from high-voltage surges.
Lamp Coil
The VTTC modification uses vacuum tubes. They play the role of an RF oscillation generator. As a rule, these are quite powerful lamps of the GU-81 type. But sometimes you can find low-power designs. One of the features in this case is the absence of the need to provide high voltage. To get relatively small discharges, you need about 300-600 V. In addition, VTTC makes almost no noise, which appears when the Tesla transformer operates on the spark gap. With the development of electronics, it became possible to significantly simplify and reduce the size of the device. Instead of a design on lamps, a Tesla transformer on transistors began to be used. Usually a bipolar element of appropriate power and current is used.
How to make a Tesla transformer?
As mentioned above, a bipolar element is used to simplify the design. Undoubtedly, it is much better to use a field effect transistor. But bipolar is easier to work with for those who are not experienced enough in assembling generators. Coil winding andthe collector is carried out with a wire of 0.5-0.8 millimeters. On a high-voltage part, the wire is taken 0.15-0.3 mm thick. Approximately 1000 turns are made. A spiral is placed at the "hot" end of the winding. Power can be taken from a transformer of 10 V, 1 A. When using power from 24 V or more, the length of the corona discharge increases significantly. For the generator, you can use the transistor KT805IM.
Using the instrument
At the output, you can get a voltage of several million volts. It is capable of creating impressive discharges in the air. The latter, in turn, can have a length of many meters. These phenomena are very attractive outwardly for many people. Tesla transformer lovers are used for decorative purposes.
The inventor himself used the device to propagate and generate oscillations, which are aimed at wireless control of devices at a distance (radio control), data and energy transmission. At the beginning of the twentieth century, the Tesla coil began to be used in medicine. Patients were treated with high-frequency weak currents. They, flowing through a thin surface layer of the skin, did not harm the internal organs. At the same time, the currents had a healing and tonic effect on the body. In addition, the transformer is used to ignite gas discharge lamps and to search for leaks in vacuum systems. However, in our time, the main application of the device should be considered cognitive and aesthetic.
Effects
They are associated with the formation of various kinds of gas discharges during the operation of the device. Many peoplecollect Tesla transformers to be able to watch the breathtaking effects. In total, the device produces discharges of four types. It is often possible to observe how the discharges not only depart from the coil, but are also directed from grounded objects in its direction. They can also have corona glows. It is noteworthy that some chemical compounds (ionic) when applied to the terminal may change the color of the discharge. For example, sodium ions make spark orange, while boron ions make spark green.
Streamers
These are dimly glowing branched thin channels. They contain ionized gas atoms and free electrons split off from them. These discharges flow from the terminal of the coil or from the sharpest parts directly into the air. At its core, the streamer can be considered visible air ionization (glow of ions), which is created by the BB field near the transformer.
Arc Discharge
It forms quite often. For example, if the transformer has sufficient power, an arc may be formed when a grounded object is brought to the terminal. In some cases, it is required to touch the object to the exit, and then retract to an increasing distance and stretch the arc. With insufficient reliability and coil power, such a discharge can damage components.
Spark
This spark charge is emitted from sharp parts or from the terminal directly to the ground (grounded object). Spark is presented in the form of rapidly changing or disappearing bright filiform stripes, strongly branched andoften. There is also a special type of spark discharge. It is called moving.
Corona discharge
This is the glow of ions contained in the air. It takes place in a high voltage electric field. The result is a bluish, pleasing to the eye glow near the BB components of the structure with a significant curvature of the surface.
Features
During the operation of the transformer, a characteristic electrical crackle can be heard. This phenomenon is due to the process during which streamers turn into spark channels. It is accompanied by a sharp increase in the amount of energy and current strength. There is a rapid expansion of each channel and an abrupt increase in pressure in them. As a result, shock waves are formed at the boundaries. Their combination from expanding channels forms a sound that is perceived as crackling.
Human impact
Like any other source of such high voltage, the Tesla coil can be deadly. But there is a different opinion regarding some types of apparatus. Since the high-frequency high voltage has a skin effect, and the current is significantly behind the voltage in phase, and the current strength is very small, despite the potential, the discharge into the human body cannot provoke cardiac arrest or other serious disorders in the body.
