222 - How do Electric Motors Work?

That's when I pitched you an idea when we were talking about stuff that we'd kind of been saving up that we wanted to talk about and I had a sciencey question for you. Yeah. And you didn't let me do it. What do you mean?

I was like, hey, will you teach me about the thing I'm going to say in a minute? And you were like, I will not. Yeah. That's right.

I remember this. Is that because we're in a fight emotionally? No, it's because I'm not the guy to teach it. Who is the guy to teach it?

Chair me building. Well, then we should have him teach it. That's good. Because he's sitting right there.

Here I am. Okay. This is what I'd like to know. And I don't know how this thing works.

This is not performative. I would like to come into this conversation, not knowing the essentials of how an electric motor works. I would like to come out of this conversation, having a functional lay person's level knowledge of how an electric motor works. Interesting.

Is that the kind of thing you do? Is that the service you offer at this point in your life? Usually in video, yes, where I have all kinds of props and interesting things I can show. So it'll be a little bit of a challenge trying to describe it verbally, but I think I can do it.

I'll make it even a bigger challenge than that with an aptitude. I'll have to do it simply be me and it will get harder. I've studied motors before. And I know there are different categories of motors.

And so I think what I would like out of this conversation, Jeremy, if you could do us the honor, is I would like to back it down to first principles. Okay. Like all the way down to like how I get something to move from here to here with an electromagnet. Absolutely.

And then how do we get that to go around an axle? And there's many different ways to do that, right? Yes, yes, there is. So does that make sense?

Matt? Yes. So let's start with this question. What is the definition of a motor?

Well, specifically speaking about electric motors, as opposed to engines using gasoline or something like that, would be a device that takes magnetism and turn that into a machine. Motion would be, in my opinion, a simplest way to describe it. And so a motor is an inherently electrical device? Yes.

When you use a term motor, you would specifically be talking about electrical devices. Yeah. Something that performs a similar function using combustion is an engine. Correct.

Okay. Cool. So you're learning things. That's great.

Yeah. Yeah. There are hydraulic motors and things like that. But what you're thinking about, like he wouldn't be thinking about a hydraulic motor.

He's thinking about an electric motor. Yeah. That's a fair thing. And the concept is kind of similar except, well, but yeah, you're using hydraulic power to spin it and let's not go there.

But all of a motor is to make a thing spin. You can have, yes. I mean, in turn, you can have motors that move things linearly. I would say that it's better to say that the whole idea of the motor is to use that magnetism to get some kind of motion.

Okay. Yeah. And so that's why we call it a motor because it linguistically derives from the same word as motion to animate something. I'm not sure.

I don't know. Why do we use a term like fine motor skills or things like that, right? It's all converting power to motion, right? Fair enough.

There may be a relationship there, but I couldn't confirm that. Okay. Fair enough. We want to take electromagnetism and move crap with it.

Yes. Okay. We're winning so far and where would a normal person who doesn't think about these things be most likely to encounter a motor in their home or in their daily life? What devices will be touched all the time?

Absolutely. Every room everywhere, there's going to be an electric motor. If you think about ceiling fans, any kind of exhaust vent, your air conditioning unit, your heater, your microwave, your dishwasher, your refrigerator, if it has any moving parts or it has a fan inside of it, it has a motor inside of it. It's a fan, the most common place where we would probably encounter a motor in a household.

Yeah. I would say the fan is probably the one you encounter the most. That's an accurate statement. Yeah.

An automated lock. That's a motor converting electromagnetism, electricity from the battery to a motor that slides that deadbolt in and out. Specifically, you would call that a solenoid instead of a motor. What's a solenoid?

A solenoid is very similar to a motor. In fact, it'd be kind of hard to draw a line between it too because solenoids are giving you a linear motion and the stroke is very short. And because of that, that class of, I don't think you can actually call it a motor, but that class of device that's also using a magnet to move something with the solenoid. That solenoid is probably a great place to start, wouldn't you think?

That's the most basic unit of motion with electromotive force, right? Absolutely. Well, I would actually start simpler than that and start with the idea of just an electromagnet. Okay.

Yeah. Okay. How's that different than a magnet? Wait, do you remember that SNL skit where they made one of the insane clown posse?

ICP made a song about like, the world is full of magical mysteries. Maybe that's actually the parody. And then SNL did a parody of it and they were like, the lyrics were like, blanket. How do they work?

And then they were like, are children smaller or just very far away? And there's like all of these kind of like drunk eye kind of questions. But I'm legitimately asking, what is the difference between a magnet magnet that I think is at the, yeah, it's the electron level, right? That's your charges.

I don't think it attracted repel. I don't. Is it electrons? I don't even know.

Yeah. Well, there's, I don't think I want to break it down in this particular area. Yeah, I would say that, I mean, because there are rare earth magnets that just naturally have magnetism and, but that's a topic that I don't feel trained enough on to try to give it like an elementary explanation. That's in how magnets work, you know?

Yeah. I mean, Jeremy's referencing these things called load stones. So if you go way back, some of the first usable magnets, as I understand it were compasses. Yeah.

Somebody figured out like, if I take a needle and I hit it really hard, like literally hit it with a hammer, somehow something happens and it becomes magnetized. And if I float it in a cork, like if I stick a needle into a, did I say magnet? I meant needle. If I take a needle.

You said needle. Okay. If I hit a needle really hard, it'll become magnetized. I stick it into a cork, stick that in water.

It'll align to the same place every time. And it aligns with the earth's magnetic field. Incredible. And so when they figured that out, that was a really big deal for navigation because you could find something that was pointing in one direction all the time.

They didn't quite understand about magnetic declination and how here in Alabama that compass needle points three degrees off from the North Pole. But if you go over to where you're from and the western United States it points a little further off. Were you unable to think of what state I live in? No.

It's a terrific idea. Yeah. So it's an interesting thing. Once they figured that out and then at some point in time, they're like, huh, who was it that figured out the electromagnetic?

I don't know who that was. Was it on our own? I'm going to know. Yeah.

I'm going with Dick electromagnet. I think that was the guy's name and they named it after him. That's my guess. We all have a guess in.

That's good. Fair enough. So I guess maybe we should pick it up with the electromagnet. We'll do that.

So magnets are a magical mystery that no one understands, including the insane clown posse. However, electromagnets do, how do they work? How are they different? Well, what's interesting about electromagnets is the fact that this is how we discovered that there is a relationship between electricity flowing through a wire and magnetism.

And that is when you run current through a wire, let's just say you connect a wire to a battery and then you put that on top of a compass. The compass needle will actually turn and align itself with a magnetic field being produced around the wire because there's a magnetic field built up around the wire itself. If you call the wire up, it actually gets stronger. If you turn electricity off, it just goes back to pointing towards the earth's magnetic field because the magnetic field actually collapses.

It's gone. So when there's electricity flowing, you have a magnet. When there's no electricity flowing, no magnet. Huh.

So that expression that I use far too much about it kind of made my compass spin is a reference to that discovery that magnetic disturbance around the compass will make its compass. It's not aligning to you called it magnetic north. The earth's magnetic field. It's responding to it's interacting with this artificial magnetic field that we created using a battery using electricity.

Yeah, I wouldn't call it artificial, but I would say a new closer magnetic field that you've produced is now right next to it and it's affected stronger. And so now it's oriented towards that magnetic field. So you said the tighter we coil the wire, assuming copper for the wire just it could be copper. It could be aluminum.

Both of them are very good conductors of electricity and would give you a magnetic well. Anything conducting electricity would give you a magnetic field. And I think it's the number of coils, isn't it? I was going to say it's the number of turns.

As you stack them on top of each other, the strength of the magnetic field builds up. If it was 10 loops with a 10 foot diameter in the middle of the circle formed by the loops, it would produce the same amount. If you put the same electricity through that or one that was only one inch in diameter with the same number of coils. So let's say two coils, 10 rounds each, one is huge, 10 feet across, one is only one inch across, but we're connecting them to the same battery.

They produce the same amount, the size of the coil doesn't matter. Sort of. When you have a bigger distance, you've spread out the same magnetic power. I'm abusing that word a lot.

It's not the right word. I'm trying to make sense to me. You've spread it out of a much larger area. What you really need is magnetic density.

That's again, probably the wrong word, but you need it to be closer together. If you, what we normally do when we build an electromagnet is we put a piece of iron in the middle and we call the wire really tight around the iron and that actually helps to concentrate all of the magnetic field into that one space. Can dux the magnetic field very well. And so you'd get a much stronger effect.

Can I give you permission to do something Jeremy? So I saw you, I'm on the other side of the room, I saw you explaining something to Matt and I saw your eyebrows. They were furled just a little bit. You were trying, you were reaching for words and you're like, well, I could say this word, but Matt doesn't know that word in that context.

And so like words like flux and all these different things, you were trying to figure out the word to say, but you knew that the communication wouldn't happen. But I think what we do here is you are given permission to use the wrong words. The goal here is communication, not engineering precision. Does that work?

Or you can use the big word and I'll ask you a question. Yeah. And he did it like three times in that lesson. I saw it too.

He was being very considerate of names like power. It's flux, but it's not. He was saying a lot of things. Hey, I'm hurting my friend right now.

Yeah, yeah. Okay. So we're given permission to mess up. So if you're listening to this from here forward, just understand we know that we're going to use the wrong terms at time to time.

Okay. Okay. Good. Thank you.

Can I ask you a question about the iron, the piece of iron in the middle of the coil? Yes. Is that to intensify the electromagnetic field to localize the electromagnetic field or to weaponize it to make it transferable? Yeah.

So localize it is a really good way to think about it. You have it all focused in this one area as opposed to having the magnetic field spread out a little more widely in the air around it. It's now focused in the iron because it wants to flow there. Okay.

Next question. How does that help anything? How does that create motion? How do you harness that?

How is this anything more than a parlor trick at this point? Okay. Great. So let's think about this.

When you take two refrigerator magnets, right? And almost every kid's played with magnets and pushed them together. And we know that if you take like feels, you know, south pole to south pole and we try to push them together, there's resistance. It acts like a spring.

If you compress that spring, you've added some energy now and when you let go of one of them, it'll shoot away. Well, that's basically what motors do. A basic DC motor has two permanent magnets on the outside, direct current, direct current. Yeah.

And then you have an electromagnet. When you run electricity through it, it becomes a magnet and it wants to align itself with the other magnets. If we time it just right, turning that magnetic field on and off, we can make them push and pull at the right time. And thus you get rotation in this case.

So if you wanted to move a magnet on a table, I could lay your wire next to it and nothing happens until I put power to it. So what's a magnet? It pushes the other magnet away and you've got motion. We take that and we convert that into rotary motion, which we can get more into in a little bit.

So an electromagnet, the idea is to weaponize magnetic repulsion. What do you call that they don't want to go together? The bounce of partiness. What is the term for that?

It's actually called the bounce of partiness. I really like that. I love the bounce of partiness. I'm going to use that in my next video.

Okay. So the goal is just to weaponize this natural feature of magnets that they don't want to be together if they're the same pole is pointing at the same pole. Exactly. And also the opposite.

We also weaponize the opposite where they're attracted when it's opposite poles. If you want to pull, you can set up the magnetic field in one direction. If you want to push, you put it the other way. This is the clever part about electromagnets.

Not only can you turn it on and off, you can also decide which side is North Pole and South Pole by flipping which direction electricity is flowing. When it's flowing in one direction, the North Pole is on one end. We'll just say the top end, the South Pole is on the bottom. But if I flip the current, it'll flip the magnetic field in the South Pole and I'll be at the top.

North Pole. Okay. So we really have four possible positions combined for these switches. We have push on, push off.

We have pull on, pull off. Absolutely. Huh. I love that description.

That's great. Okay. Okay. I mean, it's starting to come into focus.

I can't picture what it looks like. The coil visual made sense. The put some iron in the middle of the coil. I mean, I guess I can picture that.

That makes sense. Like where the magnets are and how they push against each other. Are there literal magnets like you have on the back of the letters on your refrigerator when you were a kid that are in the motor somehow? Like little rocks in there or is this all manufactured from, I mean, do you have to go mind magnets or something to do this?

It depends on what kind of motor it is. So there are actually quite a few different types. Some of them have two electromagnets. Some of them have permanent magnets like a magnet that was manufactured, the kind you will put on your refrigerator, but much larger.

Okay. And then you can even shape them and curve them so that they fit inside the curvature of the motor. It doesn't have to be a flat disc. It can be curved and they often are.

And then some of them have an electromagnet and just an aluminum disc on the inside. There's no electromagnet. We actually induce current in this thing that's not electrically connected to anything. It's called an induction motor.

And that one is really will be a really fun challenge to try to explain here. But I've made a, I've talked about it so much as one of my favorite topics. But all right. So this is where I just, I just came alive in the conversation because all this before I was sitting over here, I was like, Oh, yeah, Matt doesn't know this.

You're like that a lot. Yeah. And then, and then once Jeremy started explaining the different classes of motor, I thought to myself, like, like the forest is getting darker for me. I know some things DC AC, brushless, servo, stepper, these kinds of things.

I know these words. And I think I know how some of them work, but Jeremy is getting to the place where I'm getting excited. I'm getting very excited because you're going to learn things or because I'm going to learn things and you're excited for me to learn them because I'm going to learn things. Yeah.

It does add up mistakes. It does make it more fun. Yeah. So I just keep asking questions because I have one.

I don't want to get too far ahead. Yeah. Go ahead. Please do.

What are magnets? Is it magnetite or is it a type of rock? Is it an element? Is it a compound?

Can you take any different layer? Are there multiple types of metal? Can you liquify a bunch of ingredients in a lab and pour them and smelt them and make a magnet from scratch? Do we have enough magnets in the world?

Where do we go? What is it? I mean, the most that I could speak intelligently about is I know that we can take iron and other materials and we can magnetize it and turn it into a magnet and there are also devices that can de-magnetize this metal. But how exactly that works?

I'm not entirely sure. I'm aware of ceramic magnets. I'm aware of rare earth magnets that Jeremy was talking about. I'm aware of typical iron.

I mean, iron can just be magnetized if everything is aligned. In fact, on the moon, for example, some parts of the moon, they were able to figure out where some rocks were pointing on the moon before a meteor came in and hit it because of the magnetic orientation and some of the rocks. There's some really neat things about magnets, but you're asking a very difficult question. It is not a dumb question.

So, okay, so this is what I'm getting at. What I'm hearing from both of you is that the actual magnet, and again, I'm picturing like a little black rock that I saw in gift stores and on the back of things I would put on the fridge that we played with as kids. People got magnets from like their dads, like real good magnets. Some of them were black, kind of like a matte black look, no sheen to them.

Some people got fancy magnets that looked almost like a polished rock kind of silver looking thing. The black ones would be ceramic magnets. The really polished shiny ones would be neodymium magnets. Neodymium?

They're much more powerful for the same size. Oh, well, they were much more fun to play with when we were kids. You could take one and they'd be like 15 and they'd all snap together like a snake or something. It was really cool.

But let me ask it this way. Are magnets rare? Is the category that is like naturally occurring magnets? Is that a rare earth?

What do we call these? Where does it fit in the grand scheme of resources? I wouldn't describe it as rare because we can manufacture them. But beyond that, it's a pretty challenging question to answer.

But I would say in terms of scarcity, I would say no. We can take material and make it a magnet. And that's something that's mass produced on an enormous scale. Okay.

So there's no scarcity of magnets. No problem there. What I think I'm hearing then is that the effect, okay, magnets exist in nature, right? There can just be like a rock and for no reason other than it's just that way, it's magnetic.

A load stone. Yeah. So the rock that's got some combination of like iron and oxides. I don't know.

There's some chemical element involving iron and oxygen and it's just like naturally occurring and it's a magnet. And so is there just some secret code when you draw a diagram of an element? Like Effie. Say we have the diagram of that element up here.

What's the atomic number? I'm iron? I don't know, Matt. Whatever it is.

Yeah, I've not yet. Okay. So I assume though, I mean, there's got to be some kind of subatomic charge issue, right? That makes this happen.

Like the right combination of elements, the right combination of valence electrons it adds up to your green. You're asking us to agree in the Trinity. Okay. So you're asking us to explain the Trinity.

We are not experts on this area. Okay. So magnets just happen, but we can make them happen and it can be applied to several different elements, several different compounds. And there are various ways we can make it happen.

You can bang a piece of metal with a hammer and through sheer magic, it makes a magnet. You can do a ceramics, a chemical process, right? Like you bake something to make ceramic ceramic magnets? Yeah.

Possibly. I don't know. I don't know. Okay.

So we can make them through some sort of process in a lab. We can bang metal with a hammer and it happens in nature. So magnet isn't a rock. Magnet is a feature, a buff, a bonus that can be applied to many different types of metallic materials.

So let me, I've always thought about this too. I don't know the answer to your question. I understand that there's this thing called light. I don't know what light is particle wave.

We can talk about that, but I do know that there are photons. That's a particle. There's also no other waves, but there's something that's some energy there in light. Likewise electricity, I understand to be the flow of electrons current.

I understand that. I don't know what the flow of magnet is. I don't know. I do know what seems to happen is much like an electric current likes to go in a circuit.

It likes to start at one place and end at the other side. Okay. It goes from a plus to a minus. I know magnets like to do that as well.

So a magnet likes to go out one side of a rock and it'll like loop around in the air and it'll come back into the other side of the rock. So I'm going to draw something here. But we don't call that plus minus. We call that north south when it comes to magnets.

So I've seen drawings of Earth that kind of have like this sort of like art lines going around it. The magnetic field, the Earth's magnetic field. So the Earth is a great big giant rock. And when I see drawings of that magnetic field thing with all the lines coming out of it on those parabolas, that's what you're talking about.

I don't know the same thing happens on like a little the same thing happens on a rock. I can hold in my hand or the planet. Yeah, those arced lines are just representing where the magnetic field is flowing to visualize it. But obviously it's visually transparent.

You can't see it. And one of the ways that we can force it to flow in one place would be using something like iron instead of it flowing through the air. It wants to flow more naturally through iron. And that's why we like using iron with the electromagnets instead of through the air.

This helped what you both said. Yeah. And there's another thing that I think is really interesting. I did this video where this company called Poly Magnet, they could use a laser or something to like eat up a rock in a certain way and they could like shape the magnetic fields.

Wow. They're basically designing the magnetic field. And so you could make instead of having one big loopy doo come out one side of the rock and go into the other side of the rock, you could make a bunch of little loopy doos come out of the face and go right back into the face. And so what that did is that they could shape the magnetic field instead of making a big arc.

They could make a bunch of small ones and it would have different gripping powers at different standoff distances. Why? I don't know. Because it's rad.

Why would they do that? Yeah. Well, if you could shape a magnetic field like Jeremy is going to tell us a little bit, you want your magnet to be a certain size and have a certain shape. I'm going to call them loopy doos.

You want certain loopy do, a field of influence in that magnetic field. But like Jeremy was saying earlier, the distance between the magnets matters. And so if you have a very small grip, I'll call it with the loopy doos. Yeah.

I'm getting stupid now, but I love where you're going. Yeah. And so this is the longer grip with like one big loopy doo, a magnetic field line is what it's actually called. Okay.

And so all this ties into this really special area of physics called Maxwell's equations. And I've told you about all I know about Maxwell's equations by saying that they exist. I mean, I would love to me one of the most interesting things about specifically shaping the magnetic field is that you can control the way it interacts with other magnets, whether you if you want something to not be attracted until it's in exactly the right position, then that's the effect you could get. It doesn't pull it doesn't pull and when it's exactly the way you want it snaps into place, like that's perfect.

And there are all sorts of mechanical applications where that would be really good. You want it to be in a very specific spot like an iPhone charger? Yeah. Okay.

So you said you can't see a magnetic field. I feel like I remember an experiment from 10th grade science or something where maybe we had a little film phone camera film case, full of little iron shavings or something. Yeah. Spread them out on a table.

Maybe we just got them all out flat and then we took different magnets and put it in the middle and it kind of I seem to remember that we could see the magnetic loopy doos using some sort of indicator, in this case iron. Does that sound like science? Absolutely. I mean, essentially you're taking this these little iron shavings and sprinkling them into the magnetic field and they will naturally align with the magnetic field that's present.

And so that gives you a visual representation of where the field lines are. Is there some kind of like magnet goggles you can put on to just see it? Like if you're trying to build this stuff? That company I was telling you about called Poly Magnet, they had this special just what you're describing.

It's that magnet paper kind of stuff. So basically it's a film and the film has I'm showing you a picture of it now. It's a smarter every day episode 153. It's a film where you can actually see the magnetic fields if you put this film over a magnet.

And this particular thing I'm showing you, it's a magnet and it says smarter every day on the magnet itself. And that was something they did. They actually printed that magnetic field on there and they made very small loopy doos. So it just comes right out of the face and the magnet goes right back in.

But the film that they're using there, I think it's called Magnet Paper or something or magnet. I don't know what's called. You have any other name of it. But I've seen it many times.

I know exactly what you're talking about. Yes. You made that video very early in our friendship. You sent it to me before you published it.

And it was I was blown away. That video was so good that you just pulled back up. It's a neat thing. I don't remember why it's good.

I just remember thinking after I got done previewing that for you, this is one of the best pieces of educational internet I've ever seen. And I imagine I still feel that way today. But what's the name of the video? Mind-blowing magic magnets.

Smarter every day 153. I see what you did there with the alliteration. Yeah. That was a very, very good video.

Fantastic. I did not remember that you had- Can we talk about motors now? We aren't talking- we're talking about magnets. I really like- I want to get to the part that I'm learning from Jerry.

But you guys are ready for that. I'm not. I don't care about your translation. I don't understand the translation apart.

Okay. Well, I do care about it. I'm pre-requisite park and I thank you both for your patience with me. Okay.

We've got a few things now as we get toward a motor. We have an electrical source. We have a coil. A coil of wire.

Maybe it's aluminum. Maybe it's copper. Do we always have these iron in there to contain and localize the magnetic field? Ideally, yes.

Okay. So we have that. And we have one of many different types of magnets now that we've established that there's a lot of different ways to get there. What happens next?

Well, the DC motor is- Can we do solenoid? Can you tell them about just like clicking a thing into the coil? Okay. So you can tell them about the way you're going.

I think so. Is solenoid and solenoid different? A lot of people say in different ways. Yeah.

It's the same thing. They said both ways and I don't know which ones the right one. Okay. I just say solenoid.

I've always said solenoid because that's what my grandpa said when he explained it to me and I didn't listen. S-O-L-E-N-O-I-D. But a lot of people say it the way you just said it. I've always imagined that like cylinder, noid.

I've had that wrong my whole life. Now you know. Okay. What are the M's?

Okay. Essentially, it's what we described a few moments ago. We said if you push two magnets together and you hold them, they kind of act like a spring. There's some energy store there now when you let go of one.

It pushes away. If you take an electromagnet or a wire rather and you put it next to something that's magnetic, nothing happens until you run electricity through the wire. But when you do, it'll push it away. In this case, we've created a cylinder and inside of it, you've got a coil of wire connected to a battery and a switch.

Right? Just a little bit outside of that coil, you've got some type of material that will respond to a magnet. Okay. Okay.

So if you turn a power on, flip the switch and you've got, you've turned your magnet on rather, it will be that piece of metal will be drawn into the magnetic film and whatever is attached to that piece of metal will move. So if you want to push something or pull something, that's what a solenoid does. It's basically just, oh, look at that. Yeah.

Okay. Interesting. Okay. You think it's very interesting.

You think Wavy Hand could try, but I'm ashamed of you and you're embarrassing. You've drawn a picture. Yeah. And Jeremy is a friendlier guy than I am.

Yeah. Right. Jeremy's being more like, I know you want to know, like you want to know. I do want to know.

Jeremy's like, Pat, and you want to, like, you're good job trying. You're doing good. But you patting the head of all people is good luck. This is what I drew.

Yeah. Oh, well, what do you know? The guy who almost has his PhD finished in mechanical engineering drew a superior model of a super simple electromagnetic part than the guy who hasn't had a class in his whole life did. Great job.

Well, maybe next week it go box infants. No, I mean, I gave you a hand wave. I'm like, yeah, it was a good effort. So what's the, no, it's very close.

So you've got a coil. I have a coil in a cylinder. I put it inside a cylinder. Somehow you're putting a battery into it.

Like you're like, physically putting the battery into the cylinder. Well, what I imagined was that the end of the coil is coming out here and it's going down to the nine volt. Well, just put the battery off to the side. Just like a race that battery that you got going into the cylinder and kind of put it off to the side.

All right. Battery's gone. The battery at the bottom didn't bother me. By the way, I thought it was fine.

Like I figured you were getting the idea that there's a power source and it's connected to the coil. Okay. So the coil is the positive and negative coming out opposite ends of the coil then. Where are the other ends of the, oh, wait, ask her, say the question again.

Let me just make sure I understand. Okay. The positive and the negative to connect to the battery to complete the circuit. Yes.

So I assume that one end of this coil, let's call that a positive and this other end of this coil, let's call that the negative. Yes. Okay. So then these got to come back around here to my, to my battery, thusly like that.

Yes. There's a positive side. There's a negative side. Yes, sir.

Okay. And I could probably put a switch in line somewhere on that so that I can kill that circuit and thus the solenoid doesn't do things. Now we're, yes, absolutely. So when I turn on the blinker to my 1974 Mercury comet on which I was told by the mechanic that the solenoid was out, when I hit that switch, what's happening is some little imaginary in-line switch on this circuit goes to the on position.

And now this is activated and it's firing off and on repeatedly to make the blinker light up and turn off. That's such a good question. Yeah. Yeah.

Because he's missed certain words. So, so like you're right, but like you missed half the words, but you have the understanding. Well, what I was going to say is that's actually a different kind of solenoid. Dang it.

It's a relay. It's a relay. What a relay is a solenoid. Never thought about this.

It is. Yeah. It's a okay. I mean, a whole video about this because I really love this topic.

Okay. Blinkers? No, no, no. solenoids and relays.

Okay. Okay. But in short, a relay is a switch that controls other switches. Now you might be thinking, why would you make a switch to flip on and off other switches?

That's exactly what I think is the matter of that. Yes. There are all sorts of reasons you'd want to do that. For one, if you want to power say a really large motor, right, or a really large motor, let's just something with thousands of horsepower, right?

It's going to have really big cables. Now imagine a switch for a cable that's as big as your arm. It's going to be a big switch, right? Lots of voltage, lots of power.

You don't want a man to stand next to that and flip that on and off and be that close to that much power. Oh, right. Because you'll get vaporized if something goes wrong. Yeah.

But what if you could flip a little tiny switch that pushed a magnet that pushed the switch? That's what a relay is. I would want that. Yeah.

So you can switch to switch to switch to switch to switch to switch to switch to switch to switch to switch to switch to switch to switch the biggest switch? Or can you go, can you scale a little one to a huge one and you only ever need one relay? Generally, you can scale a really small one to switch really big switches. Like you can control thousands of watts of power with milliamps.

Yeah. Really small switch. Huh. It's fantastic.

Why is it going to be a relay then? Okay. You tell me how it gets better. Because you can not just flip one switch, but you can have intelligent circuits now where when one thing is on, something else flips off.

Let's just say, for example, every time I walk out of my shop, I want to not only turn the lights off. I also want my air compressor to go off. It doesn't turn on in the middle of the night. Just made that up off the top.

Okay. All right. So I can connect a relay on the light switch that not only flips off the lights, it also flips off the power to my air compressor. And now both of them are turned off with one switch.

And you can get even smarter and make it like a computer where there are multiple solenoids connected together. When you flip one on, three other ones turn on and the third one turns off and it can just, it's basically like a mechanical computer at that point with zeros and ones. You can make a really complicated series of things happen with just one switch flip. So then Alexa or Google Home is just a soft ware rising of what you're doing mechanically.

Absolutely. Yeah. Okay. How is a blinker than a relay and not a solenoid?

Well, if you are having an issue with, in that particular situation, you've just separated the power sources. You want to have a little tiny wire come all the way inside of the car, which you can flip. But the thing in under the hood can be connected directly to the battery and have bigger power cables. But the starter for your car needs a lot of power to crank up your engine.

So you wouldn't want to run those big cables all the way into the steering wheel and have someone try to connect those two wires in the steering wheel. Instead, you have two little tiny wires come in, you flip a relay basically when you turn your key and that's what activates your starter. So ignition is a relay? Yes.

Huh. So all. So any electrical thing that you control from your wheel or your dash is going to be a relay because of the constraints of what it would take to run that full load through your steering column and just clutter things up and be a mess. Yeah.

I mean, a lot of that's handled electrically now because of modern technology, we have computer circuits that can, so it's not. Not in the 1974 Mercury Comet. Well, yeah, I was going to say the Ode to your car is the more likely there's a mechanical solution there. Yeah.

Okay. Okay. I think I understand it. So what are the applications for solenoid that I would experience around my house?

Where do I have those? Usually we use solenoids when you have a really short motion because the stroke is very limited. You're not going to get it to move very far. So if we're talking about moving something a quarter inch or maybe up to two inches, you could find a solenoid for that.

But generally, if it's, if you need to move it further than that, you would need something else, like linear actuator or motor or something like that. Is the movement happening entirely? Is it contained within the little cylinder? Does it expose when it fires, when it's in the on position to some actuator move outside?

Well, if you think of, there's usually like a little pen, it's sort of shaped like a, well, a pen is your right word. Just think about a metal rod. Okay. When you have that metal rod hanging in a sitting just outside of the coil of wire, when you turn the coil on, it gets sucked in.

It's magnetized. Okay. Okay. You can attach anything you want to the other end of that metal rod.

So you can have a hook hanging out of it. You can have a big fist hanging out of it and you can give a one inch punch if you want, like whatever it is that you want to do. But only when you pull it, it's you're going to get that action and solenoids can be set up to push or pull so we can start inside the coil and push it out or we can start outside the coil and get pulled in. Okay.

So solenoid versus electromotor, firstly, it's a question of scale. The technology is very similar. The principles are very similar, but the biggest divider between the two is how far do you want something to move? How long is this stroke?

Well, I think the most important thing to think about is Jeremy has explained to solenoid is you have a coil and when you apply a voltage to that coil, you get this electromotive force that pulls the plunger into the solenoid. Right? So it's got that magnet there and you want to pull something into the magnet, for example, right? Okay.

So that principle itself, when I apply this direction of current to that coil, it's going to pull that thing just a little bit while you'll pull it an inch, right? That concept is important because where Jeremy is about to go, I think, correct me if I'm wrong, Jeremy, is we're going to do that, but then you want to keep doing it in different ways to go around and around and around. Yeah. Okay.

So can I just imagine pulling something, I make a circuit and I pull something one inch. Yes. Just think about, you got that, right? Can I reverse that so that the metal, so that the iron rod lives in the coil in its neutral position, but when I activate the current, it pushes out?

You are. You are learning, sir. Absolutely. Okay.

Yeah. I can see the wheels turning. That's exactly right. It can be set up to push or pull.

Okay. So now I have something I'm looking at it. I'm learning how to make things and I realize all I know how to use are solenoids and I have something that needs to happen over a 12 inch stroke instead of one inch. Now I have to learn what an electromotor is.

What is that? Well, I think we go linear motor next. Or what do you do, Jeremy? I mean, functionally they operate pretty much the same, linear or rotary.

So. I mean, the way he asked the question, he said a solenoid pull something one inch. How do I go further than that? I agree.

The next leap would be a linear motor. Absolutely. Okay. So let me reframe the question.

I've been having trouble with intruders. So I use my knowledge of a solenoid to set up a home alone style booby trap whereby if an intruder walks in, a giant red boxing mitt will fire one inch. And it just isn't knocking out the intruders. They continue to loot myself.

So I'm wanting to get that up to 12 inches, which I think is going to be the optimal stroke length for knocking out the kooky intruders in this home alone scenario. But I don't want to kill them. Okay. Would you recommend a linear motor?

Well, I'd recommend maybe a rocket, but we'll do that. No, it's not. That's a good question. I think.

Oh, gosh. Okay. So let's go back to that first concept that we described of you have a magnet sitting on a table on a wire next to it. And if we run electricity through that wire, we can push that magnet just a little bit.

Well, if we go one step further and add a second wire, that's just a little bit further away. And then as the magnet, if we time it right, we run electricity through the first one, the magnet star is moving the permanent magnet that's laying on the table, starts sliding. And then we immediately fire the next one shut off the first one. The next wire is now attracting the magnet and pulling it.