How a Tesla Coil Works ⚡ How to Make a Tesla Coil ⚡ Nikola Tesla

nikola tesla is probably one of the most appreciated scientists in the field of electronics because of all the inventions and technological advances that we use to this day the two topics most influenced by him are the use of alternating current and wireless power transmission and it is precisely the latter of which i want to talk to you in this episode and specifically through one of his most recognized inventions in this episode we will see how a tesla coil works before talking about how and why a tesla coil is capable of generating those gigantic electric arcs we have to understand what nikola tesla's objective and logic was when developing this device in the previous episode we talked about how an inductor or coil works and i explained how an electric current flowing through a coil can generate a magnetic field and also how the variation of a magnetic field can induce a current in another coil understanding these two physical phenomena it is easy to assume that we could apply current to a coil to generate a magnetic field and in turn use this magnetic field to induce a current in a nearby coil with which we would be transmitting power wirelessly the problem with this idea is that magnetic fields lose their strength quickly as we move away from the source and therefore when separating the two coils the energy transmission becomes more and more inefficient now let's see how the tesla coil overcomes this limitation taking this concept to the extreme the logic is the same to make an alternating current go through a coil but with extremely high voltage and a specific frequency to be able to transmit energy over greater distances to achieve this goal there are mainly two concepts that we must understand the first is the voltage rise through a transformer which in simple terms is made up of two coils a primary winding which is connected to a current source and generates a magnetic flux and a secondary winding which converts again that magnetic flux in a current but the interesting thing is that if the number of turns on the secondary winding is greater than the number of turns in the primary winding an output voltage larger than the input is generated a simple way to visualize this behavior could be to imagine that we have a few batteries in series every time we add a new stack the voltage adds up now if we make an analogy with each turn of the secondary coil we will realize that each one of them acts as a voltage source just like batteries and therefore every time we add a new loop it will add that voltage to the total and although in the next video we will talk in more depth about how a transformer works i still haven't mentioned one of its characteristics which is extremely important to the operation of tesla coils magnetic coupling this characteristic refers to the efficiency with which the primary coil affects the secondary coil that is if an alternating current wave enters by the primary coil the wave that will come out of the secondary coil will have the same shape but with a different voltage in most cases the idea is that the coupling is as high as possible but not on tesla coils precisely because of the second concept that governs their behavior using a resonant circuit a resonant circuit is made up of an inductor and capacitor which as we have seen in previous episodes are components capable of storing energy although they do it in a different way the capacitor with an electric field and the inductor with a magnetic field the effect of connecting these two components in a closed circuit is that in theory we could keep an electric current flowing cyclically indefinitely let's suppose that initially the capacitor is charged being in a closed circuit it will start to discharge and by doing this a current will go through the inductor which will start to form a magnetic field but when all the charges of the capacitor have been used this magnetic field will begin to lose its strength inducing a current in the opposite direction and recharging the capacitor until the inductor loses all its magnetic field starting the cycle again clearly in the real world this is not going to happen indefinitely because the circuit itself has a resistance which will gradually slow down the electron movement but this does not mean that we cannot benefit from this behavior a resonant circuit has two great benefits the first one is that even when they can't hold energy indefinitely they can do it for a certain period of time although losing strength in each cycle something similar to what would happen in a pendulum which just by pushing it once is able to keep oscillating at a regular frequency and also like a pendulum if we push it periodically at the exact moment we can amplify the end result even though we are only applying the same amount of force that we had initially used the second benefit of resonant circuits is linked to the fact that they have their own frequency at which they oscillate which is defined only by characteristics of its components that is to say the inductance of the inductor and the capacitance of the capacitor taking this into account the inductor of the circuit will generate an electromagnetic field whose oscillation is going to be equal to said frequency which let's remember is constant and did you know that another object does something similar a tuning fork which when hit generates a specific frequency and i mention it because you surely have heard of the following experiment in which when putting two tuning forks with the same frequency of vibration and hitting just one of them eventually the second tuning fork will start to vibrate because the pressure changes traveling through the air from the first tuning fork will move the second one just at the exact moment so that their movement is amplified exactly as in the case of the pendulum so thanks to this behavior if we position two resonant circuits but only the first one is active eventually electromagnetic waves generated by its inductor will begin to induce and amplify a current in the inductor of the second resonant circuit enabling power transmission wirelessly over much greater distances having taken all of this out of the way now we are able to go back to our tesla coil to see how it works nowadays there are several ways to get the same or better results but we are going to focus on one of the original models because of their simplicity the first thing we will need is an alternating current source which will be connected to a common transformer that is to say with a high magnetic coupling between the two coils with this we will obtain an alternating current with higher voltage but whose frequency is equal to that of the initial source say 50 or 60 hertz this new alternating current is brought to a resonant circuit with its corresponding capacitor and inductor which is usually called the primary coil also including an extra component which serves as a switch which basically consists of two pieces of metal that are extremely close but not touching the function of this section of the tesla coil is that the primary coil emits an electromagnetic field with the frequency of the resonant circuit when the transformer induces a current charges begin to accumulate in the capacitor without having any other possible way but as the source voltage grows with each oscillation the electrons try to find another path and the second best option is where the metal pieces are jumping through them with a spark this way the spark will allow the passage of the charges that were accumulating in the capacitor quickly discharging it but as soon as they do the spark will also disappear because the capacitor will be again the best path for the current repeating the cycle again this time the cycle will not be at the same frequency that the initial transformer was giving us but rather the frequency at which sparks occur and the capacitor charge in discharge that is the intrinsic frequency of the resonant circuit but now let's forget about the capacitor and let's focus on the primary coil again it will be passing an extremely high voltage which will be oscillating at the frequency of the resonant circuit and therefore it will generate an electromagnetic field oscillating at this same frequency which we can take advantage of with the secondary coil again we will have two coils nearby and with a big difference between the number of turns of each which means that we will have a second transformer in our tesla coil this will increase the voltage in the secondary coil which by the way if we analyze independently is connected to ground and in its upper part it has a metallic piece of toroidal shape it has this shape mainly to be able to accumulate a greater charge and prevent it from ending up escaping into the environment by the corona effect and therefore also preventing the voltage of the assembly from increasing further if you remember the episode on spiders that fly using electricity i mentioned that the corona effect generally occurs when there is a large potential difference between an element and the environment around it which is accentuated in high and pointed places like the masts of a ship well the top of a tesla coil is just the opposite or at least attempts to be because by preventing charges from moving into the environment they begin to accumulate and finally there comes a point where again the potential difference will be enough to ionize the air around it but this time with much more energy because we had more accumulated charges and ready to jump generating the electric shocks everyone knows and loves from tesla coils but that's not all about how a tesla coil works do you remember the properties of resonant circuits that i mentioned at the beginning although it doesn't seem like it the section with the secondary coil and toroid form a new resonant circuit in which there is not a physical capacitor but a capacitance more specifically a parasitic capacitance a phenomenon that occurs whenever two conductors with different voltages are relatively close and i say relatively because when we are talking about voltages as high as a tesla coil which can reach several hundred or thousands of kilovolts this phenomenon may be noticeable among conductors who may be several centimeters away or even meters away now that we are clear the two resonant circuits exist in theory we could take advantage of its ability to transmit energy more efficiently but for this to happen both circuits must have the same resonant frequency and the resonant frequency of the section with the secondary coil cannot be precisely modified because there is no capacitor to which we can measure its capacitance for this reason some method is usually included to vary the capacitance of the first resonant circuit in such a way that both are the same frequency with all this we would only be missing one more feature to fully understand how it works did you think it was going to be something simpler me too but we are talking about an invention of nikola tesla no wonder it is often said that he was ahead of his time so breathe subscribe give oxygen to your brain and let's continue the last detail of the operation of a tesla coil is in the form of the primary coil which is designed with the aim of reducing the magnetic coupling between both coils in practical terms this means that when a voltage oscillation goes through the primary coil the secondary coil will generate a higher voltage for the difference in the number of laps between both coils but it will also continue to oscillate even if the primary coil stopped working do you remember the pendulum example it's exactly the same we could say that the secondary coil is the pendulum and the primary coil is the force that pushes at the exact moment in this way it is possible to generate a much higher voltage than the one that had been started and which is also oscillating at the resonant frequency now that we fully understand how a tesla coil works let's get back to its goal transmitting power wirelessly the electrical discharges in the air are striking but in reality do not fulfill any function we could even say that they are undesirable so we will keep our tesla coil at a lower voltage to avoid these losses and to only generate the electromagnetic field if we position a fluorescent lamp near the coil it will turn on because to the electromagnetic field we'll give it enough energy so that the gas inside start emitting ultraviolet light which is later transformed by a phosphor layer in visible light in a similar way to what we saw in the episode on how a lighting knitting diode works but this way we will not take advantage of the potential of the tesla coil at all since we are not using its resonant circuit quality in fact the distance at which the lamp will light is quite short the true way to use a tesla coil to transmit power wirelessly is using another resonant circuit with the same frequency in this way we can be much further and still generate an electric current as a result just like the tuning fork we mentioned at the beginning and now to close this video the million dollar question why don't we use this technology to have wireless power everywhere and the answer is that we do use it practically every day just think of a radio signal on the one hand we will have a giant antenna emitting electromagnetic frequencies and on the other hand the radio that in its interior has a resonant circuit that we can adjust to receive only the frequency that interests us now how to use those frequencies to transmit information is another story maybe for a next episode remember to subscribe share and support me in patreon if you think what i do is worth it see you in the next episode

Channel: VirtualBrain [ENG]

Views: 1,010,073

Keywords: virtualbrain eng, how tesla coil works, tesla coil, tesla coil how it works, what is a tesla coil, how to make a tesla coil, nikola tesla, how it works, VirtualBrain Eng, how a transformer works, what is a transformer, electricity, electronics, how to build a tesla coil, how a tesla coil works, making a tesla coil, how does a tesla coil work, tesla coil music, tesla, Free energy

Id: JI3VpKF8IF0

Length: 14min 34sec (874 seconds)

Published: Wed Sep 01 2021