DIY flat tesla coil. Switching on, checking and adjusting

I already had this article once on a website dedicated to the brilliant Nikola Tesla. But the site no longer exists, I just didn’t have enough hands to do everything. However, there were interesting articles there, they have been preserved, and I will slowly publish them here.

The published article is intended FOR INFORMATION ONLY!

I’d like to straight away dot the i’s, this device works with high voltages, so compliance with basic safety rules is MANDATORY! Failure to follow the rules will result in serious injury, remember this!

I would also like to note that the main danger in this device is the ISKROVIK (discharge arrester), which during its operation is a source of wide-spectrum radiation, including X-rays, remember this!

I’ll tell you briefly about the design of “my” Tesla transformer, in common parlance “Tesla coil”. This device is made on a simple element base, accessible to everyone. The block diagram of the device is shown below.

In this article I will talk about the Tesla transformer device I assembled and the interesting effects that were observed in it during its operation.

As you can see, I did not reinvent the wheel and decided to stick to the classic Tesla transformer circuit, the only thing added to the classic circuit is an electronic voltage converter, the role of which is to increase the voltage from 12 Volts to 10 thousand volts!

In the high-voltage part of the circuit, the following elements are used: The VD diode is a high-voltage 5GE200AF diode - it has high resistance - this is very important! Capacitors C1 and C2 have a nominal value of 2200pF, each rated for a voltage of 5 kV. As a result, we get a total capacitance of 1100 pF and an accumulated voltage of 10 kV, which is very good for us!

I would like to note that the capacitance is selected experimentally; the pulse duration in the primary coil depends on it, and of course on the coil itself. The pulse time must be less than the lifetime of the electron pairs in the conductor of the primary coil of the Tesla transformer, otherwise we will have a low effect and the pulse energy will be spent on heating the coil, which we do not need! Shown below assembled structure devices.

The design of the spark gap deserves special attention; most modern Tesla transformer circuits have a special spark generator design driven by an electric motor, where the discharge frequency is regulated by the rotation speed, but I decided not to follow this trend, since there are many negative points. I went along classic scheme arrester. The technical drawing of the arrester is given below.

Cheap and practical option It doesn’t make noise or light up, I’ll explain why. This arrester is made of copper plates 2-3 mm thick with dimensions 30x30 mm (to act as a radiator, since the arc is a heat source) with threads for bolts in each plate. To prevent the bolt from unwinding during discharge and to ensure good contact, it is necessary to use a spring between the bolt and the plate.

To dampen the noise during a discharge, we will make a special chamber where the arc will burn, my chamber is made from a piece of polyethylene water pipe (which does not contain reinforcement), the piece of pipe is clamped tightly between two plates and it is advisable to use sealing, for example, I have a special double-sided tape for insulation . The gap is adjusted by screwing in and unscrewing the bolt; I’ll explain why later.

Primary coil of the device. The primary coil of the device is made of copper wire type PV 2.5mm.kv and here the question arises: “Why such a thick wire?” I'll explain. The Tesla transformer is a special device, one might say anomalous, which is not of the same type as ordinary transformers, where the laws are completely different.

For a conventional power transformer important its operation is self-induction (counter-EMF) which compensates for part of the current; when a conventional power transformer is loaded, the counter-EMF decreases and the current increases accordingly; if we remove the counter-EMF from conventional transformers, they will flare up like candles.

But in the Tesla transformer the opposite is true: self-induction is our enemy! Therefore, to combat this disease, we use a thick wire that has low inductance and, accordingly, low self-inductance. We need powerful electromagnetic pulse and we get it by using this type coils. The primary coil is made in the form of an Archimedes spiral in one plane in the amount of 6 turns, the maximum diameter of a large turn in my design is 60 mm.

The secondary coil of the device is a regular coil wound on a polymer water pipe(without reinforcement) with a diameter of 15 mm. The coil is wound with enamel wire 0.01mm.kv turn per turn, in my device the number of turns is 980 pcs. Winding the secondary coil requires patience and endurance, it took me about 4 hours.

So, the device is assembled! Now a little about adjusting the device, the device consists of two LC circuits - primary and secondary! For proper operation devices - it is necessary to introduce the system into resonance, namely into resonance of the LC circuits.

In fact, the system is brought into resonance automatically, due to the wide frequency spectrum electric arc, some of which coincide with the system impedance, so all we have to do is optimize the arc and equalize the frequencies according to the power in it.

This is done very simply - we adjust the gap of the arrester. The arrester must be adjusted until best results in the form of arc length. An image of the working device is located below.

So the device was assembled and launched - now it works for us! Now we can make our observations and study them. I want to immediately warn you: although high-frequency currents are harmless to the human body (in terms of the Tesla transformer), the light effects caused by them can affect the cornea of ​​the eye and you risk getting a corneal burn, since the spectrum of the emitted light is shifted towards ultraviolet radiation.

Another danger that lurks when using a Tesla transformer is an excess of ozone in the blood, which can lead to headaches, since large portions of this gas are produced during operation of the device, remember this!

Let's start observing a working Tesla coil. It is best to make observations in complete darkness, so you will most of all experience the beauty of all the effects that will simply amaze you with their unusualness and mystery. I made observations in complete darkness, at night and for hours I could admire the glow that the device produced, for which I paid the price the next morning: my eyes hurt like after a burn from electric welding, but these are trifles, as they say: “science requires sacrifices.”

As soon as I turned on the device for the first time, I noticed a beautiful phenomenon - this is a glowing purple ball that was in the middle of the coil, in the process of adjusting the spark gap, I noticed that the ball moves up or down depending on the length of the gap, the only thing on at the moment my explanation is the phenomenon of impedance in the secondary coil, which causes this effect.

The ball consisted of many purple micro arcs that exited one area of ​​the coil and entered another, forming a sphere. Since the secondary coil of the device is not grounded, an interesting effect was observed - purple glows at both ends of the coil.

I decided to check how the device behaves with the secondary coil closed and noticed another interesting thing: intensification of the glow and increase in the arc originating from the coil while touching it - the amplification effect is obvious.

A repetition of Tesla's experiment, in which gas-discharge lamps glow in the field of a transformer. When a conventional energy-saving gas-discharge lamp is inserted into the transformer field, it begins to glow, the brightness of the glow is approximately 45% of its full power, which is approximately 8 W, while the power consumption of the entire system is 6 W.

Just a note: a high-frequency electric field appears around the operating device, which has a potential of approximately 4 kV/cm2. An interesting effect is also observed: the so-called brush discharge, a luminous purple discharge in the form of a thick brush with frequent needles up to 20 mm in size, reminiscent of an animal’s fluffy tail.

This effect is caused by high-frequency vibrations of gas molecules in the field of a conductor; in the process of high-frequency vibrations, gas molecules are destroyed and ozone is formed, and the residual energy manifests itself in the form of a glow in the ultraviolet range.

The most striking manifestation of the brush effect occurs when using a flask with an inert gas, in my case I used a flask from a HPS gas discharge lamp, which contains Sodium (Na) in a gaseous state, and a bright brush effect occurs, which is similar to the burning of a wick only with very frequent formation of sparks, this effect is very beautiful.

Results of the work carried out: The operation of the device is accompanied by various interesting and beautiful effects, which in turn deserve more careful study, it is known that the device generates a high frequency electric field, which causes the formation of large amounts of ozone, as a byproduct of ultraviolet glow.

The special configuration of the device gives reason to think about the principles of its operation; there are only guesses and theories about how it works of this device, but no objective information was ever put forward, just as there was no thorough study of this device.

At the moment, the Tesla transformer is collected by enthusiasts and used only for entertainment for the most part, although the device in my opinion is the key to understanding fundamental basis the universe that Tesla knew and understood.

Using a Tesla transformer for fun is like hammering nails with a microscope... Super single effect of the device..? maybe... but I don't have it yet the necessary equipment to determine this fact.

Once again I warn you about the danger self-made device!

The article is not mine, here it is

In 1997, I became interested in the Tesla coil and decided to build my own. Unfortunately, I lost interest in it before I could launch it. A few years later I found my old spool, re-counted it a bit and continued building. And again I abandoned it. In 2007, a friend showed me his reel, reminding me of my unfinished projects. I found my old spool again, counted everything and this time completed the project.

Tesla Coil- This is a resonant transformer. These are basically LC circuits tuned to one resonant frequency.

A high voltage transformer is used to charge the capacitor.

As soon as the capacitor reaches a sufficient charge level, it is discharged into the spark gap and a spark occurs there. Happening short circuit primary winding of the transformer and oscillations begin in it.

Since the capacitance of the capacitor is fixed, the circuit is adjusted by changing the resistance of the primary winding, changing the point of connection to it. At correct setting, Very high voltage will be at the top of the secondary winding, resulting in impressive discharges in the air. Unlike traditional transformers, the turns ratio between the primary and secondary windings has little effect on the voltage.

Construction stages

Designing and building a Tesla coil is quite easy. For a beginner, this seems like a difficult task (I found it difficult too), but you can get a working coil by following the instructions in this article and doing small calculations. Of course, if you really want powerful coil, there is no way other than studying the theory and doing a lot of calculations.

Here are the basic steps to get started:

1. Selecting a power source. The transformers used in neon signs are probably best for beginners since they are relatively cheap. I recommend transformers with an output voltage of at least 4 kV.
2. Making a spark gap. It could be as simple as two screws a couple of millimeters apart, but I recommend using a little more force. The quality of the arrester greatly influences the performance of the coil.
3. Calculation of capacitor capacity. Using the formula below, calculate the resonant capacitance for the transformer. The capacitor value should be about 1.5 times this value. Probably the best and most effective solution There will be an assembly of capacitors. If you don't want to spend money, you can try making a capacitor yourself, but it may not work and its capacity is difficult to determine.
4. Manufacturing of the secondary winding. Use 900-1000 turns of enamel copper wire 0.3-0.6mm. The height of the coil is usually equal to 5 times its diameter. PVC drainpipe may not be the best, but available material for the reel. A hollow metal ball is attached to the top of the secondary winding, and its bottom part grounded. For this, it is advisable to use a separate grounding, because When using common house grounding, there is a chance of damaging other electrical appliances.
5. Manufacturing of the primary winding. The primary winding can be made of thick cable, or better yet, copper tubing. The thicker the tube, the less resistive losses. A 6mm tube is sufficient for most reels. Remember that thick pipes are much more difficult to bend and copper will crack if it is bent too many times. Depending on the size of the secondary winding, 5 to 15 turns at 3 to 5 mm pitches should be sufficient.
6. Connect all the components, set up the coil, and you're done!

Before you start making a Tesla coil, it is strongly recommended that you familiarize yourself with the safety rules and working with high voltages!

Also note that transformer protection circuits were not mentioned. They have not been used and there are no problems so far. The key word here is yet.

Details

The coil was made mainly from those parts that were available.
These were:
4kV 35mA transformer from neon sign.
0.3mm copper wire.
0.33μF 275V capacitors.
I had to buy a 75mm drain PVC pipe and 5 meters of 6mm copper tube.

Secondary winding

The secondary winding is covered with plastic insulation on top and bottom to prevent breakdown

The secondary winding was the first component manufactured. I wound about 900 turns of wire around drain pipe height about 37cm. The length of the wire used was approximately 209 meters.

Inductance and capacitance of the secondary winding and metal sphere(or toroid) can be calculated using formulas that can be found on other sites. Having these data, you can calculate the resonant frequency of the secondary winding:
L = [(2πf) 2 C] -1

When using a sphere with a diameter of 14 cm, the resonant frequency of the coil is approximately 452 kHz.

Metal sphere or toroid

The first attempt was to make a metal sphere by wrapping a plastic ball in foil. I couldn't smooth out the foil on the ball well enough, so I decided to make a toroid. I made a small toroid by wrapping aluminum tape around a corrugated pipe rolled into a circle. I couldn't get a very smooth toroid, but it works better than a sphere because of its shape and the larger size. To support the toroid, a plywood disk was placed under it.

Primary winding

The primary winding consists of copper tubes 6 mm in diameter, wound in a spiral around the secondary. The inner diameter of the winding is 17cm, the outer diameter is 29cm. The primary winding contains 6 turns with a distance of 3 mm between them. Due to the large distance between the primary and secondary windings, they may be loosely coupled.
The primary winding together with the capacitor is an LC oscillator. The required inductance can be calculated using the following formula:
L = [(2πf) 2 C] -1
C is the capacitance of the capacitors, F is the resonant frequency of the secondary winding.

But this formula and calculators based on it give only an approximate value. Correct size The coil must be selected experimentally, so it is better to make it too large than too small. My coil consists of 6 turns and is connected on the 4th turn.

Capacitors

Assembly of 24 capacitors with a 10 MΩ quenching resistor on each

Since I had large number small capacitors, I decided to collect them into one large one. The value of capacitors can be calculated using the following formula:
C = I ⁄ (2πfU)

The capacitor value for my transformer is 27.8 nF. The actual value should be slightly more or less than this, since rapid growth voltage due to resonance may damage the transformer and/or capacitors. Quenching resistors provide some protection against this.

My capacitor assembly consists of three assemblies with 24 capacitors each. The voltage in each assembly is 6600 V, the total capacity of all assemblies is 41.3 nF.

Each capacitor has its own 10 MΩ quenching resistor. This is important because individual capacitors can retain a charge for a very long time after the power has been turned off. As you can see from the figure below, the capacitor voltage rating is too low, even for a 4kV transformer. To work well and safely it must be at least 8 or 12 kV.

Arrester

My arrester is just two screws with a metal ball in the middle.
The distance is adjusted so that the arrester will only spark when it is the only one connected to the transformer. Increasing the distance between them can theoretically increase the spark length, but there is a risk of destroying the transformer. For larger coil it is necessary to build an air-cooled arrester.

The Tesla coil is probably familiar to many computer games or feature films. If anyone doesn’t know, let’s clarify this, this is a special device that creates high voltage, high frequency. To put it simply, thanks to a Tesla coil you can hold a spark in your hands, light a light bulb without wires, and so on.

Before you start making our reel, we suggest you watch the video

We will need:
- 200 m of copper wire with a diameter of 0.1 to 0.3 mm;
- wire with a diameter of 1 mm;
- 15-30 cm plastic sewer pipe diameter from 4 to 7 cm;
- 3-5 cm of sewer pipe with a diameter of 7 to 10 cm
- transistor D13007;
- radiator for the transistor;
- variable resistor 50 kOhm;
- constant resistor of 75 Ohm and 0.25 W;
- power supply 12-18 volts and current 0.5 per ampere;
- soldering iron, solder and rosin.

A long piece of pipe is needed for the secondary winding, and a short piece for the primary. If you cannot find a pipe of this diameter, you can replace it with ordinary tape, as the author does. Copper wire can be obtained from old transformers or simply purchased on the market.

Now that you've sorted out the materials, you can start assembling. According to the author of the video, it is better to start the assembly not from the primary, but from the secondary coil, that is, a long pipe. To do this, we take a pipe, which from now on will be the frame, and fasten the wire to it.

Now you need to wind about 1000 turns, making sure that there are no overlaps, long distances between turns. The author claims that this is not as difficult to do as it might seem at first glance, and if you wish, you can finish the job in an hour and a half.

When the winding of the secondary frame is finished, it is recommended to cover it with varnish or simply cover it with tape so that the structure does not deteriorate over time.

Now you can proceed to the primary winding. It is made with ordinary wire with a diameter of 1 mm. Absolutely any wire can be used. You need to wrap about 5-7 turns.

We attach the D13007 transistor to the radiator, then solder the wire going from the secondary winding to one contact of the transistor.

We solder a constant resistor to the same contact.

On the other end constant resistor solder a variable resistor.

Now let's take primary winding, put the secondary into it and solder two wires that go from it to a variable resistor and resistor D13007.

We connect the positive and negative wires to the same resistors and connect our tesla coil to the source. If the desired effect is not observed, then you just need to swap the wires coming from the primary winding.

Operation of CRT TVs, fluorescent and energy saving light bulbs, remote charging of batteries is provided by a special device - a Tesla transformer (coil). To create spectacular light charges purple, reminiscent of lightning, a Tesla coil is also used. The 220 V circuit allows you to understand the structure of this device and, if necessary, make it yourself.

Mechanism of operation

A Tesla coil is an electrical device capable of increasing voltage and current frequency several times. During its operation, a magnetic field is formed, which can affect electrical engineering and the human condition. Discharges released into the air contribute to the release of ozone. The transformer design consists of the following elements:

• Primary coil. It has an average of 5-7 turns of wire with a cross-sectional diameter of at least 6 mm².
• Secondary coil. Consists of 70−100 turns of dielectric with a diameter of no more than 0.3 mm.
• Capacitor.
• Discharger.
• Spark glow emitter.

The transformer, created and patented by Nikola Tesla in 1896, does not have ferroalloys, which are used for cores in other similar devices. The power of the coil is limited by the electrical strength of the air and does not depend on the power of the voltage source.

When voltage hits the primary circuit, high-frequency oscillations are generated on it. Thanks to them, resonant oscillations arise on the secondary coil, the result of which is electric current, characterized high voltage And high frequency. The passage of this current through the air leads to the appearance streamer- a purple discharge resembling lightning.

Circuit oscillations that occur during the operation of a Tesla coil can be generated in different ways. Most often this happens using a spark gap, lamp or transistor. The most powerful devices are those that use double resonance generators.

Source materials

For a person with basic knowledge of physics and electrical engineering, it will not be difficult to assemble a Tesla transformer with your own hands. You just need to prepare a set of basic parts:

A mandatory element of the primary coil is a cooling radiator, the size of which directly affects the cooling efficiency of the equipment. A copper tube or wire with a diameter of 5-10 mm can be used as a winding.

The secondary coil requires mandatory insulation in the form of treatment with paint, varnish or other dielectric. An additional part of this circuit is a series-connected terminal. Its use is advisable only for powerful discharges; for small streamers, it is enough to move the end of the winding upward by 0.5-5 cm.

Connection diagram

The Tesla transformer is assembled and connected in accordance with electrical diagram. Installation of a low-power device should be carried out in several stages:

The assembly of a more powerful transformer follows a similar scheme. To achieve high power, will be required:

The maximum power that a properly assembled Tesla transformer can achieve is up to 4.5 kW. This indicator can be achieved by equalizing the frequencies of both circuits.

A self-assembled Tesla coil must be checked. During test connection follows:

1. Set the variable resistor to the middle position.
2. Monitor the presence of a discharge. If it is missing, you need to bring it to the coil fluorescent lamp or an incandescent lamp. Its glow will indicate the presence of an electromagnetic field and the operability of the transformer. Also, the serviceability of the device can be determined by self-igniting radio lamps and flashes at the end of the emitter.

The first start-up of the device should be carried out while monitoring the temperature. When heating is strong, additional cooling must be connected.

Transformer Application

The coil can create different types charges. Most often, during its operation, a charge appears in the form of an arc.

Glow of air ions in electric field with increased voltage is called corona discharge. It is a bluish radiation formed around coil parts that have significant surface curvature.

A spark discharge or spark passes from the transformer terminal to the surface of the earth or to a grounded object in the form of a beam of rapidly changing shape and fading bright stripes.

The streamer looks like a thin, weakly glowing light channel, which has many branches and consists of free electrons and ionized gas particles that do not go into the ground, but flow through the air.

Creation various kinds electrical discharges using a Tesla coil occur with a large increase in current and energy, causing a crackling sound. The expansion of the channels of some discharges provokes an increase in pressure and the formation of a shock wave. The combination of shock waves sounds like the crackle of sparks when a flame burns.

Transformer effect this kind was previously used in medicine to treat diseases. High-frequency current flowing through human skin gave a healing and tonic effect. It turned out to be useful only under conditions of low power. When power increases to large values the opposite result was obtained, negatively affecting the body.

Using such an electrical device, gas-discharge lamps are ignited and leaks are detected in the vacuum space. It is also successfully used in the military sphere for the purpose of quickly destroying electrical equipment on ships, tanks or buildings. A powerful pulse generated by the coil in a very short period disables microcircuits, transistors and other devices located within a radius of tens of meters. The process of destroying equipment occurs silently.

The most spectacular area of ​​application is demonstrative light shows. All effects are created due to the formation of powerful air charges, the length of which is measured in several meters. This property allows the transformer to be widely used when filming films and creating computer games.

When developing this device, Nikola Tesla planned to use it to transmit energy on a global scale. The scientist’s idea was based on the use of two strong transformers, located at different ends of the Earth and operating with an equal resonant frequency.

In case successful use Such an energy transmission system would completely eliminate the need for power plants, copper cables, and electricity suppliers. Every inhabitant of the planet would be able to use electricity anywhere absolutely free of charge. However, due to economic unprofitability, the famous physicist’s plan has not yet been (and is unlikely to ever be) realized.

June 19, 2014 at 04:41

Tesla coil from a hardware store

• DIY or Do It Yourself

Having a pathological craving for plumbing fittings, I just can’t train myself to use them for their intended purpose. Ideas always pop into my head about what to make out of pipes, fittings and adapters so that I will never use them in plumbing again. This is what happened this time too. We make a high-voltage Tesla generator using plumbing fittings.

Why this choice? It's very simple. I'm a fan of elegant and repeatable technical solutions. A minimum of mechanics, finishing, finishing, finishing. Life should delight you with ease of decisions and grace of forms.

What will you need?

The store had everything in stock and the purchase took literally a few minutes.

Everything you need is in the picture. I bring original titles from store labels
1. Pipe 40x0.25m
2. Adapter ring to 40mm pipe
3. High-voltage varnish (was in the arsenal)
4. Adapter coupling to plain end cast iron pipe at 50mm
5. Rubber cuff 50mm
6. Copper wire 0.14mm PEV-2 (from old stocks)

The cost of all accessories is about 200 rubles. When purchasing, it is better to choose a larger store so as not to explain to security guards and managers why you are connecting unconnected elements with each other and how to help you find what you need. We will also need a few more inexpensive parts, which will be discussed a little later. But first, let's digress a little...

Tesla coils and all that

A lot of different things have been said about Tesla, but most people (including me) are unanimous in their opinion - Tesla did a lot for the development of science and technology for his time. Many of his patents have come to life, but some still remain beyond understanding. But Tesla's main achievements can be considered research into the nature of electricity. Especially high voltage. Tesla amazed his acquaintances and colleagues with amazing experiments in which he easily and safely controlled high-voltage generators that produced hundreds of thousands and sometimes millions of volts. In this article I describe the manufacture of a miniature Tesla generator, the theory of which has been studied quite well and in detail. Now let's get down to business!

What should we get?

In the end, we must assemble our device as shown in the photo:

Step 1. Winding the high voltage coil

We wind the main high-voltage coil onto the tube with a 0.1-0.15 mm wire. I had 0.14 mm wire in stock. This is perhaps the most boring activity. Winding must be done as carefully as possible, turn to turn. You can use a rig, but I wound the spools by hand. By the way, I always do something in at least two copies. Why? First of all, skill. The second product turns out to be just candy, and there will always be a person who will start begging for the device (give it as a gift, sell it, let it be used, etc.). I give away the first, the second remains in the collection, the eye is pleased, friendship grows stronger, harmony in the world increases.

Step 2: Insulate the High Voltage Coil

The next important step is to insulate the high voltage coil. I won’t say that the reel needs to be impregnated with wax 20 times, wrapped in varnished cloth, or boiled in oil. All these are Kolchak approaches. We are modern people, so we use high-voltage varnish (see the first photo. I don’t indicate the brand of varnish, you can Google it) and wide heat shrink. Apply varnish in two to three layers. Dry the layer for at least 20-30 minutes. The varnish applies perfectly. The result is great! The reel becomes simply eternal! The cost of varnish is not high. Three hundred rubles cylinder. I think there will be enough for a dozen similar devices. BUT!!!

The varnish turned out to be VERY TOXIC! Literally a minute later I had a headache and the cat started vomiting. The work had to be stopped. Urgently ventilate the room and stop applying varnish. I immediately had to run to the store. I should buy beer and milk for the cat to recover from poisoning:

By good application The varnish must be applied under a hood, but (after saving myself and the cat) I did it outside. Fortunately, the weather was favorable, there was no wind or dust, and it didn’t rain. Then you need to put on a wide heat shrink and shrink the coil with a hot air gun. This must be done carefully, from the middle to the edges. It should be tight and even.

Step 3. Making an inductor and assembling the entire structure

Perhaps the most critical part of the generator. I have analyzed many designs of similar devices and many authors make the same mistake. Firstly, it is used enough thin wire, secondly, there is no uniform and significant (at least 1 cm) gap with the high-voltage coil and many turns are used. This is completely unnecessary. 2..4 turns in the first third of the high-voltage coil are enough. For the inductor we use a hollow annealed copper tube with a diameter of 8 mm, which ensures minimal inductance and simply excellent characteristics of the generator during operation. We wind three turns on rubber cuff into the grooves. To prevent the tube from breaking, fill it tightly fine sand. Then carefully pour out the sand. After assembling the entire structure, everything should look like in the photo:

The copper tube is perhaps the most expensive item in this homemade product. As much as 150 rubles. Also purchased from a hardware store.

Some subtleties...

Subtleties are associated with the design of the inductor contacts. They are made of annealed copper strip and covered with heat shrink. This ensures minimal design inductance, which is very important. The contacts are hidden inside the coupling. All connections should be as short as possible and made with wide copper strips, which reduces various losses. We put an adapter-ring on the top of the device, which presses the copper round contact onto which the upper terminal of the high-voltage coil is soldered. The structure at the top is poured liquid rubber. There is a mini-jack in the center.

Step 4. Connect and test the generator

There are approximately 2 million ways to power such a device. Let's focus on the simplest - using the diagram shown in this figure:

You will need a couple of resistors, a capacitor, and don’t forget to place a transistor on the radiator. Denominations are indicated. I think the resource of the circuit is not large, but given the cheapness of transistors and the urgency of the desire to see the result, this no longer counts.

If everything is assembled correctly, the circuit will work immediately. If there is no generation, then switch the inductor contacts the other way around. It worked for me right away. Generation starts at 5-7 volts. Already at 6 volts the generation is stable, at 12 volts everything around is blazing. In the photo you can see that the entire structure is blown by a fan, since the transistor gets quite hot, even though it is placed on a radiator. Surprisingly, the circuit is very reliable. At 12 volts it works for hours and is very stable. When the lights are off and the light bulb is “dead,” it shines brightly. It is better to take a more powerful power source for the coil (with an output current of at least 2-3 amperes).

You can watch a video of the device working