Fun Science: The Magic of Nikola Tesla's Greatest Invention, the Induction Motor

[Ace-Garageguy]

This guy is one of the best teachers of basic science I've ever seen.

 

 

Edited January 28, 2022 by Ace-Garageguy

[peteski]

Yes, that is a a good explanation of all the basic principals of electricity and magnetism.  That guy is a very good educator, especially using hands-on examples, rather than theory.

As he says, those AC induction motors are probably most widely used motors in the world.  Since they are brushless, they are very reliable and low-maintenance.  But they only work on AC current (which in our world is not really a hindrance).

I might as well mention that the same principles described in that video are also used in all the mechanical automotive speedometers (and probably in mechanical tachometers).  The rotating speedometer cable spins a magnet inside the speedometer, There is also an aluminum cup very close to the spinning magnet.  The shaft on which that disk rotates is connected to the speedometer's pointer. There is also a "clock type" spring attached to this shaft. As the magnet rotates, it induces current in the aluminum disk which in turn generates magnetic field which interacts with the rotating magnet.  Due to that interaction, the disk (and the pointer) is rotated  proportionally to the the rotational speed of the magnet.  We have a speedometer!

Edited January 28, 2022 by peteski

[Ace-Garageguy]

[Bugatti Fan]

Interesting post as I thought that Joseph Faraday did experiments and discovered the basic principles of the electric motor. Maybe I am confusing this with something else he may have invented.

Edited January 29, 2022 by Bugatti Fan

[Ace-Garageguy]

4 hours ago, Bugatti Fan said:

Interesting post as I thought that Joseph Faraday did experiments and discovered the basic principles of the electric motor. Maybe I am confusing this with something else he may have invented.

Faraday was definitely in at the beginning of electric motor concept development, but early motors relied on commutators and brushes to transmit current to the armature, to produce magnetic fields in it. Many motors are still made with brushes and commutators; the small DC units that power slot-cars and model trains are good examples.

Tesla's unique contribution was his realization that he could induce magnetic fields within the armature with no electrical connections to it...hence the name, "induction" motor.  

[blunc]

as a follow-up to Ace, motors which have commutators and brushes to create the magnetic fields that make the armature to spin, require maintenance because the brushes eventually wear down and have to be replaced.

[Matt Bacon]

... the cynic in me also reckons you're going to get a lot more views for a video with "Tesla" in the title than "Ferraris" even though the latter was a couple of years earlier to the concept, though Tesla "invented" it independently in that interesting late 19th-century window of 50 years or so when the concept and bureaucracy of patents was widespread, but international communication and global lookup was rather slower...

But Jeremy Fielding IS a brilliant science communicator, without doubt...

best,

M.

 

[peteski]

So you are saying that an inventor named "Ferraris" invented the AC induction motor?!  I have never heard of Ferraris before now.

I am also amused that both Tesla and Ferrari are also names of contemporary famous automobiles.

Edited January 29, 2022 by peteski

[Keavdog]

I wasn't aware of Ferraris either.  Kinda like Newton & Leibniz with calculus.

[Ace-Garageguy]

17 hours ago, Matt Bacon said:

... the cynic in me also reckons you're going to get a lot more views for a video with "Tesla" in the title than "Ferraris" even though the latter was a couple of years earlier to the concept, though Tesla "invented" it independently in that interesting late 19th-century window of 50 years or so when the concept and bureaucracy of patents was widespread, but international communication and global lookup was rather slower...

Well sir, without a very thorough reading and analysis of the primary-source published and dated work of both Tesla and Ferraris (as opposed to going by secondary sources), which nobody is going to pay me to do anytime soon...though I might very well do for my own amusement after I retire...I'll be content to accept that Tesla had at least some original thought regarding the phenomenon of an induced magnetic field being capable of causing mechanical motion.

I have found over the decades that secondary and "interpretive" sources very often misunderstand, misinterpret, misrepresent, or just get technical concepts completely wrong, and ever afterwards, misinformation gets rebleated as fact. In particular I'm generally suspicious of anything related as "fact" by Wikipee. Inaccuracies there...and outright lies...are legion, often due to blatantly obvious bias on the part of the author(s).

Researching the history of various other technologies, I have found, for an unrelated example, disagreements between primary sources from the late 1920s through about '31-'32 and published so-called "authoritative" information, much repeated, regarding various particulars of the Supermarine S6B.

Just sayin', as they say.   

EDIT: And, as I personally have had ideas in a relative "vacuum", not influenced in any way, shape, or form by my knowledge of prior or contemporary work, I've been on multiple occasions highly disappointed to find somebody beat me to the punch, from a patent standpoint. Back in the late 1880s, as you allude, information traveled much slower that it appears to today.

Edited January 30, 2022 by Ace-Garageguy

[peteski]

Sort of reminds me of the story that the first telephone was not invented by Bell, but by a Russian scientist.  As it has been said, at that time there was a lot of experimentation being done by many crazy scientists, and documentation and patents were scarce.  It is also not all that unreasonable that multiple inventors woudl have come up with similar ideas.  But often a single one got to be famous.

[Bugatti Fan]

Bill, thanks for the Faraday Tesla feed back.

Looks like this thread has taken on a life of its own since my last post and is interesting reading.

Nice to read a good healthy debate with everyone expressing their views in a civilised manner.