This Invention Got Nikola Tesla Inducted Into the Hall of Fame! : Jeremy Fielding #096

if you took a tour of the average modern home you would find one of these in nearly every single room in fact i think it could be argued that the electric motor is the most widely used device in the world starting in the bathroom we would find the exhaust vent in the ceiling walk into any bedroom and you're going to find a ceiling fan or possibly box fans in the window or on the floor if you have a washer and dryer that's two more right there but in the kitchen is where you're gonna find a motherlode we're talking about garbage disposal dishwasher your microwave has two of them your refrigerator has one these are all motors that we found before we even leave our homes but the induction motor in particular which is what this guy comes from is the one that i find most intriguing this guy right here is what converts the electricity from your wall into mechanical motion for example spinning your clothes or spinning your ceiling fan and it does so with no wires touching it it's really quite fascinating it was invented by nikola tesla probably the most prolific inventor of all time but it was the induction motor this guy that got him inducted into the national inventors hall of fame today we're going to build ourselves a simple model to explain how this guy works because it's really quite fascinating and we'll also talk about why this is considered to be one of the top 10 inventions of all time let's get started [Music] the topic for today's video was actually inspired by a new series coming out on the history channel but i'll tell you a little bit more about that later in the video before we can talk about what makes tesla's invention so incredible we should first talk about how we're going to take electricity and turn it into mechanical motion when you run electricity through a wire there's a magnetic field produced around the wire in fact that magnetic field has a north and a south pole to demonstrate this i'm going to use this compass that i have laying on my workbench here north is directly behind me and this wire currently is connected to a circuit that is off if i turn the power on and apply some voltage you'll see that the compass needle is starting to turn to align itself with the magnetic field of the wire that's because that magnet is a whole lot closer than the earth's magnetic field when i turn the power off it goes back to the earth's magnetic field it gets even better though if you take the wire and coil it up all in the same direction the strength of the magnetic field increases and if you take a piece of iron and shove it in the middle that also increases the magnetic field to illustrate how this works i've taken this transformer out of a microwave literally just a few minutes ago what's important to us is that it's a piece of iron with two coils of wire inside of it the one on this side is wrapped way more than this side so we're going to use this one and if we put electricity through it we ought to be able to turn this thing into a magnet so right now it's not magnetic right but we put power on it uh hmm it helps to plug it in one second it's on and now let's start to run some current through it okay that's definitely pulling on it now and let's put a little more yeah okay we have an electromagnet turn it off and uh as you can see it's not magnetic anymore turn it back on power off no magnetic field so now we ought to be pretty comfortable with the idea that if we run electricity through a wire we're going to get a magnetic field around the wire and that magnetic field gets stronger if you call the wire up this also works in reverse if we move a magnet over a wire we get electricity let me show you this is just a stack of ceramic magnets and as you can see as i move it closer to the coil i'm starting to read a voltage on my multimeter and that's because electricity is actually starting to flow through this top coil here if i move it a little faster and a little closer i actually get higher voltages meaning that more electricity is flowing but there's one more thing you want to know before we move away from this is if the magnet is still there's no voltage there has to be relative motion between the magnet and the coil of wire as long as i'm inputting some motion i'm going to get a voltage there all right we've gone one step further electricity can produce a magnetic field a magnetic field can produce electricity as long as there's relative motion between the two here's where things get interesting every kid who's ever played with a magnet knows that they can push on each other without touching each other right that magnetic field is almost like a force field around a magnet and if we can use one magnet to push on another magnet then we might be able to create some motion so if we want to make something spin with magnets we could take a permanent magnet and mount it to something that can pivot and then move a magnet around it so this is already starting to look like a motor right okay so this is a good start but the problem is we have to move the magnet on the outside which is pretty wasteful right that'd be a terrible motor what if this magnet could stay still and we could just change the pole we could also make the magnet on the inside move tesla wanted to design a motor using purely electromagnets and the magnet on the inside he wanted to electrify wirelessly and that's the part that gets really impressive let me show you how he did that both copper and aluminum are extremely good conductors of electricity but neither one of them is magnetic in fact i've got a magnet right here and you can see while it's attracted to my table it's not showing any attraction at all to the copper or the aluminum but it was well known in tesla's day that if a magnetic field was moving past the conductor like copper or aluminum it would tend to drag the copper or aluminum with it one of my favorite examples of this is just using a copper pipe and a small magnet i'm going to use my phone to give you another perspective here and possibly sacrifice my camera for science all right here we go dropping the magnet inside the copper and as you can see the magnet falls significantly slower than you would expect if you drop it the same distance in free space it's pretty much instant right well what's happening is pretty fascinating as the magnet falls down the copper tube electricity is starting to flow in the copper because of the moving of the magnetic field now that is electricity flowing in the copper tube the copper tube becomes an electromagnet and it starts pushing back against the magnet that's falling inside of it it's really quite amazing you might even think of it as the copper tube literally pulling up on the magnet as gravity was pulling down causing that nice slow descent tesla took that linear movement and turned it into a rotary movement let me show you so here we have one more demo and this should seal the deal for you right now my heart rate is actually picking up because this is truly truly exciting to me even though i understand how it works i'm still fascinated by it okay so here's what we're building this is an aluminum disc hot glued to a bearing so nothing special here we have some magnets north pole south pole north pole south pole also hot glued to a piece of acrylic hot glue to a bearing just so that they're free to spin there's a nut keeping these guys from touching and then i just made some plastic spacers to make sure that they're not rubbing directly on the net ready for this all right i'm going to spin the magnetic field and it's dragging the aluminum disc with it look they're not touching isn't that awesome i could do this all day now we're using permanent magnets here but electromagnets are completely scalable so the bigger we make the stator on the outside of the motor the stronger and more powerful the motor can be from little tiny motors like what i showed you earlier all the way up to the biggest industrial machinery that you can imagine can be run with induction motors really really quite amazing what tesla did but it gets even better because you don't have to connect wires to the spinning part of the motor you don't have a stationary object constantly rubbing against a moving object so there's much much less friction induction motors can run for decades without giving you a problem this is why induction motors are used in so many applications especially applications where the thing has to run for many years without any maintenance like the air conditioning unit in your house and finally we can look at a modern day induction motor this design hasn't changed very much since the 1880s when tesla originally designed this guy now no doubt there's been some changes for example tesla's design was a two-phase motor instead of three and there's a whole bunch of other nerdy details that i'm leaving out but essentially this is the same principle and the same type of functionality and that to me is pretty cool so if you look at this little bitty one that i'm showing you you'll see that there's a whole bunch of coils of wire going all the way around and when you scale this up is exactly the same each of these coils is like an individual magnet and if you remember what i said before if you flip the pole over you can actually push the magnet on the inside in our case because it's an electromagnet we can switch the direction that the electricity is flowing through the wire and that flips the poles of the magnet the north pole becomes south pole again amazing if you flip the pole of each of these magnets one after the other you get a rotating magnetic field which will drag the rotor with it giving you rotational power phenomenal engineering i want to make sure you understand how much this invention infects your daily life nearly everything that's hardwired in your house and moves is run by an induction motor your air conditioning unit is and many of the things that i mentioned earlier in this video like ceiling fans are all induction motors i just did a quick walk around of my shop and pretty much every power tool has an induction motor on it in fact i want to challenge you to take a tour of your house and count how many electric motors you interact with on a daily basis i think you're going to be astonished and i'd love to see some of those numbers in the comments section bonus points if you can distinguish whether it's an induction motor or another type the history channel is about to release a limited series called engineering that built the world and they reached out to me and asked me if i'd like to make a video about transformative engineering so i was like hmm do i want to make a video about engineering after giving a blood oath i was allowed to watch an early draft of the show and let me tell you it's pretty awesome as soon as i saw the topics of the episodes i knew i wanted to talk about tesla and the induction motor they made me swear not to give away any spoilers and i'mma keep my promise but let me tell you the showdown at the end of the railroad episode is worth seeing if you love engineering as much as i do i think you're really going to enjoy the entire series i appreciated how they showed the engineering problem but also presented the human side of it which is pretty much impossible to avoid when designing things at this scale the first episode premieres sunday october the 10th and i can promise you one thing i'll be sitting on my couch enjoying it with you now we're just scratching the surface on how induction motors work and we haven't talked about any of the other motor types but fortunately i've made a whole series of videos a beginner series where i talk about the different motor types how they work and i go through each element step by step i think you'll really enjoy that series if you want to go deeper i'm really excited about this video thank you to the history channel for collaborating with me on this and i'll see you in the next video thanks for watching you

Channel: Jeremy Fielding

Views: 12,623

Rating: 4.9749718 out of 5

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Id: hZxD1hwntqY

Length: 12min 19sec (739 seconds)

Published: Fri Oct 08 2021