Nikola Tesla's Mysterious Electricity Generator | The Complete Physics

nikola tesla's mysterious invention the earthquake machine was actually designed to be an alternating current generator this intriguing oscillating generator was driven with a brilliantly designed piston cylinder and an air spring mechanism tesla's hope with this arrangement was to get constant frequency current output however this device did more than expected tesla claimed the vibrations this oscillator produced caused an earthquake in new york city let's explore whether the device really shook new york come along in the late 1880s alternating current generator development was on the forefront of innovation nikola tesla invented the rotary generator first and the reciprocating generator later the purpose behind the reciprocating design was to achieve constant frequency current output even if the steam pressure and electrical load varied which is a crucial characteristic in power generation application the rotary generators were inefficient to satisfy this requirement at that time the foundational principle of electricity generation was put forth by the genius mind of michael faraday who discovered that when you move a copper coil back and forth inside a magnetic field an electromotive force develops across the conductor as the circuit closes the current starts to flow into the coil nikola tesla replaced the permanent magnets with an electromagnet which is how he designed his electrical generator now we need a mechanism to generate the reciprocating motion for inducing coils what's better than a reciprocating steam engine just wind the copper coils to the end of the piston rod and voila let's understand how a steam engine works a boiler supplies the high temperature and pressure steam the sliding valve ensures that sometimes the high pressure steam exerts force on the top of the piston and at other times it acts from the bottom this variation will ensure that the piston has an oscillating motion and the flywheel makes the power output of the engine uniform nikola tesla was not happy with this complex steam engine mechanism so he came up with a simpler mechanism first he replaced the sliding valve by modifying the piston to act as a valve the piston has two l-shaped hollow channels that communicate with the cylinder on either side in this position only the cylinder's left-sided steam inlet engages with the piston's left channel so the high pressure steam enters the top volume of the cylinder forcing the piston downward once the piston reaches the bottom dead end the exact opposite happens to exhaust the steam of the previous stroke tesla added two pipes on either side what a brilliant and simple mechanism to produce reciprocating motion from high pressure steam here obviously the more steam pressure the greater the engine speed tesla wanted his device to produce a constant rpm output motion irrespective of the input steam pressure tesla claimed that he achieved it by simply attaching an air spring system consisting of a plunger enclosed in an airtight cylinder directly to the engine let's explore the working of this air spring to verify his claim if you displace the plunger the air on one side will compress like a spring and resist the plunger motion this arrangement is similar to a spring mass arrangement here is a small conceptual tip irrespective of the initial displacement you give the spring mass system always oscillates at a constant frequency known as the natural frequency when we connect the spring mass system to a motor it will oscillate at the motor's frequency this state is known as forced vibration nikola tesla claimed that when he connected his oscillating engine to the air spring the device operated at the air spring system's natural frequency his claim seems strange this is exactly opposite to the common physics however if you understand the nature of force acting on the piston you'll be convinced the force is not continuous it's intermittent as shown in this engine the high pressure steam gets disconnected after a small time duration this means a sudden force applies at the beginning of a stroke and again in the opposite direction at the end of the stroke in forced vibration cases such as the electric motor spring system the force acting on the spring is continuous in short tesla's oscillator air spring arrangement is not strictly a forced vibration case the best analogy to further understand nikola tesla's machine is a simple pendulum for an ideal case with no friction the pendulum when disturbed will oscillate forever at its natural frequency now suppose you increase the angle of initial displacement the pendulum velocity and amplitude will increase keeping the period constant now assume tesla is giving the ball a small push every time the ball reaches the extreme end what will happen will the time period remain the same when tesla adds an extra push at the end he is giving an initial velocity to the ball which is equivalent to dropping the ball from a higher angle we already know releasing the pendulum at a higher angle will not change the time period so in the case of the small push at the extreme end also the time period will remain the same but the amplitude of the oscillation keeps on increasing exactly the same kind of forces act on the tesla's oscillator also small duration forces at the extreme ends this means even if you increase the steam pressure of the tesla's oscillator the amplitude will increase but the period or frequency of the oscillation remain constant tesla observed that this effect held true for a wide range of steam pressure hooray nikola tesla has developed an engine that will run at a constant frequency irrespective of the incoming steam pressure in short he achieved his first goal interestingly the air spring system also acts as a flywheel that stores and releases the energy in the form of heat as per the requirement you can see before passing the input steam to the engine tesla passed it around the heated air spring cylinder to absorb heat from it the story isn't over yet now nikola tesla's second goal he wanted a constant frequency output from this machine even when he connected a generator and electrical load to it when the generator output circuit is open no current will flow through the output coils and the oscillating part of the generator won't have any electromagnetic resistance however when the circuit is closed the flowing current will magnetically oppose the oscillating motion and the machine's frequency will drop suddenly this opposing force is known as armature reaction you can see that the output emf and current are not in the same phase the greater the angle between these two quantities the greater the reactive force will be here the induced current lags behind the emf because of the inductance property of the inductor so to achieve his second goal he introduced variable capacitors in the circuit by adjusting the capacitor in the circuit tesla set the phase difference angle to zero for this condition the armature reaction force value will be minimal and the impact on the device's frequency will also be minimal in his patent tesla claimed that this method made the electrical system's effect on the mechanical side zero however it's impossible to make it zero he simply made it minimal sadly tesla couldn't achieve his second goal now back to the main topic tesla claimed that his device caused his seven-story building to shake like it would in an earthquake well can a steam power operated device cause huge buildings to shake to analyze nikola tesla's claims we need to know the concept of resonance and how sound waves travel sound waves are pressure variations which travel like this assume a glass window is near the sound source when the first sound wave hits the glass will undergo a vibration with natural frequency what if the second sound wave hits the glass exactly when it's back to the initial position the glass oscillation amplitude will keep increasing right here the frequency of the sound matches with the natural frequency of the glass a condition known as resonance eventually the glass will break due to the high amplitude this is the magic of resonance so if tesla's oscillator's oscillation frequency matched the seven story lab building's natural vibration frequency an earthquake could occur we did some surveys to find the natural vibration frequency of some buildings including tesla's building whose rough estimate is 1.42 hertz interestingly tesla initially designed the oscillator for 60 hertz frequency power production later he made the device tunable if tesla had achieved a frequency of 1.42 hertz for his device this would obviously lead to resonance and eventually an earthquake tesla's oscillator is obsolete as an electric generator instead it is used in telegeodynamics however beautiful this machine is alternators the rotary electric generators invented by tesla himself are less complex and more reliable only nikola tesla could compete with himself we thank the nikola tesla research and development center for their technical support of this video to learn more about nikola tesla's invention please check out their channel also support them on patreon thank you

Channel: Lesics

Views: 2,320,563

Keywords: Tesla oscillator, free vibration, forced vibration, resonance

Id: 0W-EUVhqv98

Length: 10min 35sec (635 seconds)

Published: Tue Aug 31 2021