How Tesla met Landau, or Hyde on the construction of a high-energy room

In high school, we were told about electric current and magnets. It was said that a constant electric field generates a constant magnetic field, and an alternating electric field creates an alternating magnetic field. We nodded together, wrote it down in notebooks, and went home, forgetting the lesson topic in passing. We did not know what these fields look like, how electricity works, and where this knowledge can be applied in general.

If, then, there was a place where these principles are clearly demonstrated, perhaps some of us would remember what the teachers said and try themselves in science. Something like this, we reflected when we started building a high-energy room.
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Caution - a lot of interesting photos under the cut.

About Landau Center

The High Energy Room is an educational project for children. We launched it at the First Ukrainian University Center for Interactive Science, Landau Center, VN Karazin Kharkiv National University.

Landau Center is located in the northern building of KhNU, a pre-war building that previously housed the LA Govorov Military Engineering Radio-Technical Academy of Air Defense. In 2004, the Academy was reorganized and transferred to the building of Karazin University. In 2013, on the 1st floor of the right wing, several premises were provided for the Landau Center created by the university community. Later, after the successful start of work in 2014, the center received several classrooms on the 2nd floor and basements.

LandauCenter reminds many European science centers: Warsaw Copernicus, Gdańsk Experiment or Tartu AXHAA. These centers have common goals. One of them is teaching natural sciences in a playful way. For example, in the Landau Center, children try to lift a weight of 32 kilograms on the short and long arm of the lever and understand that if you make the shoulder long enough, you can develop any effort. The ancient Egyptians used the lever of Archimedes to move pieces of marble.

All exhibits are created by employees and students of the university with their own hands. So the main hall on the first floor was gradually filled, so for our project we chose one of the free rooms on the second.

About the team

Two architects, three builders, two consulting physicists, two electricians, one coordinator and many people who are not indifferent to science worked on the project.

The architects have made the project and the room renders. The builders brought the project to life in about six months. Physicists built the "Jacob's Ladder" and Tesla's largest coil in Ukraine. Electricians helped with the wiring and implementation of the launch system of these devices. The coordinator made the work go smoothly and without regular tricks of valerian.

Planning

We thought that it was possible to use one of the vacant premises of the center for an interesting project that would interest children in science and technology. But they did not know what exactly could be implemented. I wanted to do something useful, but at the same time spectacular, like the Ames room or the RGB room.

Scientists from the Landau Center have long dreamed of building a large Tesla coil. They told me that they had a mini-coil, and made a small demonstration. We really liked it and we decided to implement this idea.



At the beginning of 2016, we arrived at LandauCenter to inspect and measure the room once more.







For our project, the room was no good: the plastic suspended ceiling could easily catch fire, it was too light, the walls needed to be fixed in order to remove the facing layer and, possibly, to make a new one.







In order for visitors to be interested, they must be given the opportunity to launch appliances - but in such a way that there is no danger to their life and health. We consulted with architects and physicists and decided to divide the room into 2 zones: for visitors and for exhibits.

We decided that the visitors area would accommodate 25 people. For security, divide the zones with a Faraday cage. Arrange it so that it falls into the external electric field, which emit devices.

The Faraday cage works like this: free electrons move around it and concentrate in a certain way. Due to this, the opposite sides of the cell receive different charges, which create a new field directed opposite to the external one. As a result, charge compensation occurs, and it is absent inside the cell - that is, the cell completely absorbs electromagnetic waves from the coil.

In addition to the cell, we isolate the second zone from the visitors with glass, which will be described later. It will have a Tesla coil, Jacob's ladder, several fluorescent lamps and a large fan.

Now we had the blueprints, and we started the construction.



We decided to leave the parquet. They wanted the room to resemble a university audience, and deliver the project on time. They removed the top layer of wood together with the old varnish and covered it with a new one.



Electrical discharges are best seen in the dark. We decided to repel the plaster to the brick, and then paint the walls and ceiling black.

Here is how it looked on the renderers:





Fortunately, the walls were in good condition.



We are testing black paint. Looks good:



What happened in the end:

Job

While the builders dismantled the last putty, physicists from Landau Center collected the Tesla coil and Jacob’s Ladder.

Nikola Tesla patented the coil back in 1891. Since then, its design has not changed. You can build a simple version of the transformer for this video:


Physicists from Landau argue about the primary contour of the coil:



Now let's see how Tesla's transformer works:

There is a voltage source - 220 volts. Current is fed through a 200 watt incandescent bulb, which serves as a current-limiting resistor. If there were no light bulbs, turning on the Tesla coil would knock out the automatic switches.

The current goes to 4 transformers. They are in a plastic container and filled with synthetic engine oil. Oil - dielectric and protects against electrical breakdown, and also cools the transformers during operation.

At the output of the transformers, we get 8,400 volts. The current is closed through the air gap between the two contacts, which rotate on the motor.

When the engine is running, the contacts close and an oscillating circuit is formed. The primary winding has an inductance, and the capacitors in which energy accumulates are capacitance.

After that, a current with a frequency of more than 200 kilohertz begins to resonate in the primary circuit, and part of the energy is absorbed by the secondary winding.

As a result, we get the largest coil in Ukraine and almost half a million volts. For a coil height of 80 centimeters, the result is decent. But to cause any Tungus meteorite, this, of course, is not enough.

"Jacob's Ladder" is 2 copper electrodes, the length of each is 2 meters. They also carry a high voltage current - about 18,000 volts. Between the electrodes there is a breakdown of air and an electric arc, which rises up.



An electric arc in the air turns into a plasma, the temperature of which is 5000 º. Warm air is lighter than cold air; therefore, due to convection, it rises upward, dragging an arc behind it. When the arc reaches the widest gap between the electrodes, it breaks off. At the same time, a new arc discharge is ignited at the bottom of the electrodes, and the process repeats.

On the photo "Jacob's Ladder" on the right:



It is called the "Jacob's Ladder" because of the discharges that resemble steps. This is a reference to the biblical story of the patriarch Jacob, who in a dream saw a staircase leading to heaven.



"Ladder" consists of:

1. The two arcs, which at the top are fixed on the Faraday cage through insulators.
2. Four neon transformers. They are not in the oil, as for the Tesla coil, but poured with solid epoxy still in the factory.
3. Control boards duration start.

Testing

LandauCentre specialists finished the devices 2 months before the opening. Future exhibits had to be carefully checked.

The current from the coil has a skin effect - electricity passes over the surface of the skin and does not harm the person. But still we decided to put in front of the Faraday cage also a glass protective screen. Excess level of protection does not hurt: when visitors to the room are children, it is better to be safe.

The builders finished the finish and installed the grid. We thought about the schedule of the exhibits. We stopped at the fact that the coil and the "Ladder" will work for about a minute, and then switch off for almost 5 minutes. This will help avoid wear on transformers and other components. And an employee of the center at this time will tell visitors about electricity - or rest.

The exhibits are activated with buttons that are located in the guards next to the Faraday cage. In one panel there is a button for the coil, in the other - for the “Ladder”. Children all the time strive to press the buttons while the center employee is not looking. But after the end of the exhibits' session, pressing the button will give nothing. When the device is ready to start again, the lights are lit above the shields. If they are green - you can again hold a show!

After working the coil in the room it is very easy to breathe, as if you were outside after a thunderstorm. This is due to the fact that after the discharge of lightning a lot of ozone is formed. In large quantities, ozone can cause headaches, so the hood is constantly working in the room.

We installed the Faraday cage and proceeded to the installation of a protective glass that will help fight the ozone surplus. In the photo it can be clearly seen.





Coil and ladder operation is absolutely safe. But there are exceptions: when the coil is working, people with pacemakers and hearing aids cannot be in the room. The magnetic field, which produces a coil, affects the operation of these devices - they can begin to fail.







Tesla coil discharger is very noisy. Center staff bought several dozen noise insulation headphones to make children feel comfortable.



The included Tesla coil has a strong electromagnetic field. The fluorescent lamp next to it will glow. We have fixed several such lamps on the Faraday cage.

Opening

The fifth of January, the room opened to all comers.













Now Landau Center employees conduct interactive lectures and vividly explain how electricity works. For example, they say why it is impossible to walk in a thunderstorm in an open area. A strong electromagnetic field arises at the surface of the earth. The intensity of this field is very high near sharp conductors: trees, TV towers, lightning rods, a lonely person in the steppe. Therefore, they can hit lightning.

To demonstrate this, we put a coat hanger in the Faraday cage, which takes on the charges of the coil.



Plarium is a technical company and we want to popularize technologies by any available means. Last year, we held a series of events for uDev developers, in this we opened a high-energy room together with Landau Center. We are convinced that people can be interested only through their own experience. That science and technology are moving humanity forward, even if it strongly resists and is still brewing tea with grandmother's boilers.

Experiment and learn new things. Tesla said: "The action of even the tiniest creature leads to changes in the whole universe."