Basic Electrical Theory

Co-founder Bryan Orr teaches a class on basic electrical theory. If you’re a fan of ours, be sure to share this video to show your friends and family how they too can experience “Simply Great Service!

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Links and Items Mentioned In This Video
  • Atomic theory
  • Potential difference
  • Lenz’s law
  • Electromagnetic theory
Transcript

So, today’s class is going to be on basic electrical theory. Even before applicable theory, I want to go through a little bit of atomic theory, going over what electrons are, protons, and those types of things. So, let’s go ahead and do that.

[Video Playing 1]

Narrator: Back to the small, where we begin our climb up the ladder of structure. This is how we represent an electron visually. The particle itself is a fundamental particle, and it’s too small to be seen by any imaginable instrument of observation. So, we instead represent the properties that allow the electron to interact. The central small dot represents the weak charge of the electron. This charge, entirely separate from electric charge, gives rise to the weak nuclear force. This force causes radioactive decay.

[Video 1 Paused]

This guy uses a lot of really fancy words, but don’t focus on the really fancy words. Focus on a lot of the visuals that he gives. The visuals are really good. He’s kind of impressed by some of the fancy words that he says and works on.

[Video 1 Playing]

Narrator: And its typical range is much smaller than the diameter of a proton. The larger volume of shifting purple is meant to represent the electric charge of the electron. This charge is the generator of the electromagnetic force, which has infinite range, although the drop-off of strength is pretty dramatic as we move away from the electron. The electromagnetic force is how electrons interact with other electrically charged particles and with magnetic fields. These interactions make the structure of atoms and molecules possible. This gives rise to almost all of the complexity that we see around us.

This is our depiction of a proton. It is composed of two up quarks and one down quark, as you can see from the tiny rings of color near the center of the quark. The overall charge of a proton is positive, and so we have given it a gold shell. Note that we can simply add the charges of the individual quarks to get the charge of a proton. Oh, protons taste sour, like vinegar and lemonade.

This is our depiction of a neutron. It is composed of two down quarks and one up quark, as you can see from the tiny rings of color near the center of the quark. The overall charge of a neutron is neutral, so we have given it a silver shell. Note that we can simply add the charges of the individual quarks to give the charge of the neutron.

The red, green, and blue colors of the quarks represent the color charge, which generates the strong nuclear force that holds them together. It comes in three different charges, represented here by three colors, and for different colors the force is attractive.

The mediator of the strong force, the particle that is exchanged in an interaction, is the gluon. We represent gluon exchange as the occasional wispy strain between the quarks. As you can see, gluons have color themselves, and each gluon exchange causes the quark involved to swap color. Although we show quark motion inside of the neutron as leisurely, they’re actually traveling close to the speed of light.

There are two kinds of quarks that are found in normal matter. Physicists call them “flavors” of quarks. These quarks are the up quark and the down quark. A proton is formed from two up quarks and one down quark, while its slightly heavier cousin, the neutron, is formed from two down quarks and one up quark. The red, green, and blue colors of the quarks represent a property that attracts them to one another. It is this color charge property of the quarks that hold them together in a proton or a neutron.

These protons and neutrons can then combine to form the nucleus of each element from the periodic table. One proton in the nucleus makes hydrogen; two form helium; six, carbon; eight, oxygen; 79 is gold; and 92, uranium.

Neutrons help hold the protons together. Because of their electric charge, protons would repel each other more strongly if neutrons were not present, and the heavier elements would come apart. There are approximately as many neutrons in each element as there are protons.

Atoms are formed when the positively charged proton and nucleus capture the negative electrons. Neutral atoms capture one negative electron for each positive proton in the nucleus. So, hydrogen has one electron to go with its one proton; helium, two electrons; carbon has six; oxygen, eight; gold has 79; and uranium, 92. They are nearly 90 stable elements. The largest of them contains close to 800 fundamental particles joined in a complex but stable structure.

But electrons cannot just gather around in a crowd. Once again, the strange wonderful world of the tiny has its idiosyncrasies. Electrons arrange themselves in shelves inside an atom like the layers of an onion, and only two electrons can fit per layer, so the more electrons an atom has, the further away from the nucleus the outer shells must be, and that means these electrons are more loosely held.

[Video 1 paused]

I want to say real quick about that, that scientists always try to explain things like that. Like for example, he said, “Only two electrons can be held in each one of these rings.” He doesn’t really know why. He’s just saying that that sort of been observed, but even then, you can’t see an electron, so they really don’t know what they’re talking about. What they’re trying to do is they’re making laws and principles in order to explain why what they observe actually occurs. So, they say things like it’s absolute when really, it’s just kind of what they come to based on theory.

[Video 1 playing]

Narrator: It is this difference in how title electrons are held in each different kind of atom that determines the chemical properties of the element. This accounts for the ability of metals to conduct electricity, the aloofness of noble gases, and the formation of molecules. It turns out that protons and two or more different nuclei can sometimes capture and fight over the same electron, and when that happens, atoms of different elements are joined together to form molecules. This oxygen molecule is sharing two of its electrons with two hydrogen atoms. This is how a water molecule is formed.

[Video 1 stopped]

The reason why I showed you a highly scientific view of what electrons are and what atoms are is to make it clear that it’s really not simple, and that’s important because the way that I explain it is simple or is simplistic in thinking. He starts by talking about quarks and how protons and neutrons are made up of different types of quarks and things. Well, if no one has ever seen an electron, they’ve certainly never seen a quark. It’s essentially a theory that they’ve developed that works, and they can apply it into science, but even when you break it down to that level, which is still a very simple level compared to quantum theory, it’s still very complex, and it has nothing to do with what we interact with on a day-to-day basis.

Basically, what I want you to understand when I say “an electron,” you’d know that an electron’s true nature is not really known. You don’t really know that much about an electron. So, I give examples of how we see them work in day-to-day life. All that he was talking about there is this idea of building opposing forces onto each other and the attraction and repelling nature of opposing forces. This is the very core thing that I always come back to when you’re thinking about basic electrical theory. Really, we can call it a negative force, we can call it a positive force, we can call it whatever, but it doesn’t matter what you call it. The concept is that this wants to go there, these two want to go towards each other, or these two want to go away from each other.

A good way of thinking about forces in a simplistic way that we all observe is you take a stone, you drop it, and it falls. One way of saying that is, “Well obviously, gravity means that what goes up must come down.” That’s a simplistic way of saying it, but really, energy tends towards equilibrium is another way. It’s the way I like to say it. So, for example, if you have a big container of water, a big jug of water here, and you poked a hole in it, that water is going to travel out because gravitational force and atmospheric pressure are forcing it out of the container. But what’s really happening is that it’s tending to a state of greater force to lesser force. Because of all the forces involved, it’s wanting to go to a state of equilibrium. Because you can think of it this way, let’s say that instead of it going on the ground, there’s a tank here full of water, and then there was another tank down here, and they both had water in them, but I put a hose from one to the other.  Well, it would fill up this tank until the two levels or these two tanks if they’re all set at the same level, and it would stop. The reason is that you have this natural equilibrium that occurs.

Another example of equilibrium and energy would be if I took an ice cube and I set it on this table, and this room is 75 degrees. What would happen to that ice cube? It would melt, and then once it melted, it would be what on the table?

Audience: Water.

It would be water, and then it would continue to warm up until it came to what temperature?

Audience: 212.

75 degrees.

Audience: Actually 74.

Well, I guess 70, but it will achieve an equilibrium with the thermal energy around it. So, it gets to that point the minute it doesn’t keep getting warmer. It just maintains its equilibrium. And so with atomic theory, we’re really always talking about the same thing. We’re talking about things wanting to attract each other and things wanting to repel each other. There are these forces at work, and like forces tend to want to repel each other, and opposite forces tend to want to attract to each other. There’s a song that talks about that. I’m sure Nathan knows it.

Audience: Yes.

Would you care to sing it for us?

Audience 1: He probably could.

Audience 2: Oh just a little.

Audience 3: Come on.

Nice, Paula Abdul. I wasn’t sure who it was. Thank you for enlightening me.

Audience 1: I wouldn’t mention that.

Audience 2: Who’s that?

The other force, electrodes. There’s a typo. Anyway, so, they tend towards equilibrium. That’s the important concept to understand.

[Video 2 Playing]

“The Flow of Electric Charge”

Here. There. Everywhere.

Narrator:  Imagine you are shuffling on a carpet and reached out to touch the doorknob, and zap! You get a mild shock. What’s happened is the friction between your feet and the carpet has produced a large buildup of negative electric charge on your finger. This creates what is known as electric potential difference or voltage between your finger and the doorknob.

V = VB – VA

electric                        electric potential                   electric potential

potential         =          at location B               –                       at location A

difference                       (finger)                                  (doorknob)

(voltage)

Narrator:  If the electric potential difference is large enough, a sudden flow of current, called an electric discharge, will occur.

[Video 2 paused]

Notice how they said negative electrical charge. So, you build up a negative electrical charge, and then when you touch the doorknob, it zaps you.

Audience:  [Unintelligible] is angry. Is that why it’s negative?

Well, that’s an interesting thing because, in science, electrons are given a negative charge. But what they are talking about in many cases is an actual loss of charge, and so from a differential standpoint, you actually have fewer electrons, and there’s a greater number of electrons, and then it zaps you. The electricity goes this way. Well, actually, it would be the opposite. So basically, it could mean either, and it really doesn’t matter. What they’re really saying, and I always like to point this out because they say you have a negative electrical charge, is that it wouldn’t matter. Either way, as long as you have a differential electrical charge from that of a doorknob, there’s going to be a shock when you touch the doorknob because it doesn’t matter if the electricity is traveling from your finger to the doorknob or from your doorknob to the finger. It doesn’t matter. From that standpoint of how much it’s going to shock you or the amount of arc. I always just find that kind of humorous how they always like to attribute what type of charge it is, when really, what you’re talking about more accurately is which direction the energy is flowing. Is it flowing from-to or to-from? And this makes it all the more confusing by the fact that in science, an electron is given a negative charge when you can think of an electron as being the positive charge.

[Video 2 playing]

Narrator: While this can be in the form of a zap to your finger, it also happens on much larger scales in many different places. In fact, violent electric discharges are responsible for some of the most spectacular displays of sudden energy releases on earth and in space. Let’s look at one other example that you might have come across in, say, an auto body shop or at a construction site. Between the welder’s tool and metal, there is a large electric voltage. This causes sparks to fly and ultimately for a strong electric current to flow. In turn, this generates a brilliant light display and enough heat to melt the metal and allow it to bond to another metallic surface.

What about electric discharge on even a larger scale? One form of electric discharge that many of us have witnessed takes place during a violent storm in the form of lightning. In massive storm clouds, the friction between large particles composed of many atoms builds up a large separation of electric charge and creates voltages approaching 100 million volts. With such a big voltage, things can get explosive, and the energy is released as a lightning bolt.

[Video 2 paused]

The reason why I like this one is for the reason that it talks about the concept of potential difference, and it explains some of the common places that we see it. The term “potential difference” is a term that is used to explain voltage, or when people talk about voltage differentials, sometimes, they’ll call it potential difference. It’s a really good word to know in order to have a good grasp of basic electrical theory. You can say the word “voltage.” Sometimes, that comes to mean electricity itself to us. Like, we’ll say, “There’s a lot of voltage to it,” but really, we don’t know what we’re saying. Whereas potential difference is a word that actually explains itself. And so, it’s the same way of saying, “Okay, the difference between this counter and an ice cube is not as great as the difference between an ice cube and molten metal bar. There’s a greater thermal difference between a molten metal bar and an ice cube than there is this desk and an ice cube.” We understand that difference right because we measure that in degrees. Well, when it comes to electrical potential, what we’re really talking about is the difference in electron charges between two objects, and it doesn’t matter what they are. It can be the earth and the cloud. It can be, in the case here, between this arc welder and the base metal being welded. There’s a great differential in the charges between these two, and that’s all due to electrons. But the differential in number in one of the electrons and being outside of all these atoms at the very core level. It’s just important to understand that the reason why this arc is jumping from the welder to the metal is because of that differential. In the same way, the heat energy is transferred between the ice cube in this room and the ice cube and the metal bar or the two vessels of water that had a difference in height. We understand it better in other contexts sometimes.

Getting right into the specific understanding of how we get that to occur or why that occurs in the first place because, in the case of an electric charge with static electricity, we understand that you grab a ball and your hair or whatever, you jump in the trampoline and for whatever reason, you developed an electrical charge and then you get shocked. Well, we don’t really understand why that happens when we’re thinking about it, but it’s important to recognize that we’re always interacting with different chemicals. We’re always interacting with the different surfaces that have different charges. And practically, the two ways that we see energy generated is through either magnetism or a chemical reaction, which is an electric battery, that sort of thing.

So, before I move on here, I would like to ask this question. This is my favorite example. So, how do you think a nuclear power plant creates energy?

Audience: When particles are fused, they release energy.

Correct. That is true. It’s actually fission. We would like fusion in our plants, but we’re actually splitting the nucleus of atoms through firing neutrons at them essentially and creating this chain reaction that we can control. But what does that actually do? How do we get from that explosive heat-creating reaction to actually being able to pull a switch in your house and actually see lights come on?

Audience: Heats water, creates steam.

Heats water, creates steam. That’s an interesting thing because you think all this super scientific nuclear power plant has to have some super scientific way that it actually creates the power–no. In fact, almost all power generation in the United States is actually coming from steam or some form of a driving turbine. Actually, heating something and then running a turbine and then turning the turbine, and then the turbine does what? The turbine turns big magnets and the magnets induce the magnetic flux into runs of wire. So, the next video gives a pretty good example of how that works.

[Video 3 playing]

Narrator: Electromagnetic Induction.

Can a magnet produce electricity? Let’s explore this. Michael Faraday, the English scientist, was the first person to prove that a magnet can create a current. To test this, he moved the magnet towards and away from the coil of wire connected to a galvanometer. He observed that there was a deflection in the galvanometer, indicating that a current is induced in it.

The current obtained due to the relative motion between the coil and the magnet is called induced current. The phenomenon by which an EMF or current is induced in a conductor due to a change in the magnetic field near the conductor is known as electromagnetic induction.

[Video 3 stopped]

So, that’s all we’re going to watch in that video. This magnet isn’t touching this wire at all. All he’s doing is taking the magnet and just running it up and down, up and down, up and down, and it’s actually creating a potential difference between these two poles. So, on one end, this guy has a galvanometer here. One end connects to one end of the top of the wire, and the other end connects to the other and spools around, and then it runs the magnet up and down through it, and it’s creating a potential difference. He’s calling it EMF. The EMF just means electromotive force. Electromotive force is exactly the same concept, same with potential difference. It’s just a different way of explaining what it’s doing–the force of moving electrons, electromotive force.

But there’s a differential being created between these two by doing that. So, one end to another, there’s flow of electrons from one end to the other.

I like this guy.

[Video 4 playing]

Male Speaker: Let’s talk about where your electricity comes from, how it is generated. And we need to start with Lenz’s Law. First, I have here a rare-earth magnet, a coil of wire, and then a galvanometer. So, this is a measure of how much electricity is produced.  Basically, Lenz’s law is like an old man. He’s trying to fight the change so, if I have a magnetic field that’s increasing, increasing, increasing, currents cannot flow in the loop to fight that change.

[Video 4 paused]

What’s interesting is the way that he talks about fighting the change. It’s kind of the same way of saying seeking equilibrium. It’s an opposite way of saying it, but he is really saying the same thing. What he’s saying is that it doesn’t want there to be this difference. There’s a difference created. There’s something that’s not a state of normalcy, and it’s trying to get back to that state of normalcy.

[Video 4 playing]

Male Speaker: And watch what happens as I bring the magnetic field closer. Notice that electricity is produced. As I bring it away, electricity is produced but in the opposite direction. That’s because as I bring it closer, the magnetic field is increasing, increasing, increasing. Electricity is being generated in this direction to create an opposing magnetic field to fight that change. Now, as I bring it away, now this magnetic field is getting smaller, smaller, smaller, so the electricity flows in the other direction like this to keep it strong, to keep it where it was, to fight that change.

So, let’s take a look a little closer. Now, if I move the magnetic field slowly, not much electricity is being produced, but when I move it quickly, you see a whole bunch of electricity is produced. So, time is a factor, and that has to do with the rate of change or the flux–flux being the magnetic field through this area–how quickly the flux changes. Well, that’s proportional to how much voltage is created, and if you look at the dial closely, I’ll do a quick jerk with the magnetic field, and you see a whole bunch of electricity is created.

Let’s stop for a second and talk about how your everyday use of electricity is created as I spin this magnet in the coil and you see the electricity being generated. Well, take a windmill. A windmill is just something that spins, right? The air spins it, and when it spins, it’s spinning the magnet, which is attached to it, and there’s a coil of wire around it–boom! Electricity is generated. For a coal-fired plant or a natural gas plant, well, you burn it, it creates heat, that steam comes up the smokestack, that steam turns the windmill-type thing, a turbine, if you like, and that has a magnet attached, so the magnet starts spinning in a coil of wire, and look at what happens–electricity is being created.

Nuclear power plant, same thing. The nuclear decays heat up the water, creates steam, turns a windmill, creates electricity. Hydro, the water turns a paddle well attached to a magnet. The magnet spins in a coil of water, electricity is created. This is called the generator, and now we know where your electricity comes from.

Cool, now we know where your electricity comes from or more specifically, how your electricity is created. And we also learned about Lenz’s law–as the magnetic field is increasing and increasing in this coil, well, electricity will flow in this direction, so it generates a magnetic field that opposes that change. Basically, it tries to keep it the same. Now, as I back the magnet out, then this magnetic field is getting smaller, smaller. Electricity is generated in this direction, which creates a magnetic field like this to try to keep it strong in that direction.

[Video 5 stopped]

So, what he is doing there is he is very simplistically trying to explain what’s known in magnetism and motor theory as the right-hand rule, and that’s why he keeps doing this and this because what he’s talking about is when you move in one direction, then the electrons flow in this direction, you can see your fingers like this. And when you move in the other direction, then they flow in this direction, and that’s what he’s kind of trying to show.

Now applicably, why does that matter to us? It’s very useful because there are all sorts of different applications. A couple of really common applications for us in the A/C field would be an A/C contactor. You apply power, potential difference, across the coil. It creates an electromagnetic force and pulls in a switch. So in that case, what you’re doing is you’re using electromagnetic force to create linear motion and pull the switch in, or in the case of a motor, you’re actually running electricity through a coil of wire that’s the exact opposite of this power generation where you’re running electricity through coils of wire and that alternating positive-negative, positive-negative, is causing a rotor to turn inside of a motor.

So, just like in this generator where he’s talking about spinning a magnet inside of a coil, it’s creating a voltage, and you saw when he was doing that, you see how the needle kept going like this and this, back and forth. It’s going from one state of positive charge to this state of negative charge. And again, it doesn’t matter because of the differential from the center point, you see the that needle always ended up in the center. Either way, there’s a flow of electrons, and we always think in terms of there being positive flows, negative, or whatever. But it really doesn’t matter that there’s a differential because you could say, for example, “All right. Well, I was talking about the ice, well, this ice here is going to transfer its heat into the room in order to establish equilibrium.”

Well, what happens if I took that ice and put it in this zero-degree freezer? Well, now the ice is going to transfer heat out of itself into the freezer. It’s the opposite effect of what would happen in this room, and the same is true, and so the same amount of energy may be transferred from what we would think of as being a cold object into a freezer as it would be from in this room to the room itself or from the room to the ice. The same theory or the same principle is true when it comes to electricity; it doesn’t matter which direction it’s flowing as long as it is flowing. And so when we see an alternating current, what we’re seeing is, as that magnet turns, the electricity is flowing one direction and other direction, one direction, and the other direction, and that’s what we see and what we mean when we talk about alternating current.

The principle here is that magnetism creates electron flow and that we see it all the time and in the other direction, electron flow can create magnetism.

[Video 6 playing]

Narrator:  An induction motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in house fans, blowers, and many domestic and industrial appliances. They are robust, cheap, and have no brushes. An AC induction motor has two basic electrical parts; a rotor and a stator. The stator is the stationary electrical component.  It is built by putting together iron layers, forming a group of individual electromagnets arranged in such a way that they form a hollow cylinder with one pole of each magnet facing toward the center of the group. Magnetic poles are built by winding clockwise and anticlockwise insulated copper wire. The coils are wound in such a way that when current flows in them, one coil is a north pole, and its pair is a south pole.

[Video 6 paused]

What he’s trying to explain here is that each pair has its own opposite. He’s not trying to say that the entire thing is north and south. What he’s saying is that when this is south, this is north, and vice versa, and so the way that I explain it is, think of a pinwheel. If you have a pinwheel and you want to spin this pinwheel. Well, if you take it and I go around slapping it like this, is that gonna spin the pinwheel?  Now, if I had a bunch of people who are all slapping in time around the pinwheel, and they were just dududududu like this, and then hitting it all in time in order to make it go a certain direction, then that would keep the pinwheel spinning. Well, that’s what this is doing is it’s hitting it with magnetic forces that are opposing each other in order to spin this motor and keep it going. And so essentially, when they show the rotor in there, that rotor isn’t touching the stator at all. The stator is just creating all these different electromagnets around it, and when the electricity flows around it, it’s changing those from negative to positive all the time, causing that rotor inside to continue turning. Does that kind of make sense?

So, we always tend to think in terms of things affecting each other by physical connection. We tend to think that the motor is running because something is driving that motor, but really, that part of that motor that’s turning isn’t actually touching anything. I mean it’s not touching the thing that’s actually causing it to spin. What’s causing it to spin are these electromagnets.

[Video 6 playing]

Narrator: When AC power is connected to the coils, directional flux is created depending on current’s direction and winding direction of each coil. See in this animation how the magnet’s polarity changes every half cycle of the AC power supply, creating an alternate magnetic field.

The rotor is the rotating electrical component. It also consists of a group of electromagnets arranged around a cylinder with the poles facing toward the stator poles. The rotor obviously is located inside the stator. As the magnetic field of the stator alternates due to the effect of the AC power supply, the induced magnetic field of the rotor will be attracted and will follow the rotation. It is a natural phenomenon that occurs when a conductor, aluminum bars, in the case of a rotor, is moved through an existing magnetic field or when a magnetic field is moved past the conductor. In either case, the relative motion of the two causes an electric current to flow in the conductor. This is referred to as induced current flow.

[Video 6 stopped]

He actually got pretty in-depth there about what actually goes on the rotor to actually cause it to be opposite of the forces. But you saw on the rotor, the part where it actually spins, how to release, kind of diagonal, slant magnets in there, and so even the way that the magnets are oriented to each other causes the motor to run in a certain direction, and the spin continues later in the same direction once it gets started in that direction. So, it’s a little bit more complex than simply explaining this rotating magnet or rotating iron cores through the magnetic field. I mean, there’s a little more to it than that, which there always is, like how we started with a super complex atomic theory. Understand that if we were to actually take the motors you see apart, you would find things in there and say, “What is this?” This is in addition to things like what we do with our capacitors and understanding capacitors and induced electromotive force and all those types of things into the rotor play.

So, boiling down to this principle, what we’re doing is we’re running electricity through wires, and that electricity running through wires is causing magnetism, which is then causing this thing to spin. If you make it much more complex than that in the way that you think about it, then it becomes, “Well, I don’t really understand electricity.” But if you take these basic building blocks and then build on it in order to understand the further connection, that’s when we get somewhere.

[Transformers and electricity] is something that I really like to talk about because I find it very interesting. I actually didn’t really fully understand this until very recently. If you’ve ever looked outside of your house, up on if you have a power pole, which I do, of course. So, you have this power pole. Up on this power pole, there is a transformer, and so you see these wires coming in, and coming out of that transformer, there are two wires but really one main wire maybe goes in, and then it goes into your meter box. And then there is a neutral wire down at the bottom, but it’s not as high. You know, it’s not the one that you need to be worried about, but you have two coming out and then a neutral going in. But generally speaking, the one going into your transformer, which is what I was trying to say, is just one main wire, and then a ground. Well, they take that one wire, and then they have two wires going out of that transformer. And when you’re looking at different appliances in your house, you’ll have some appliances that are 120V, and you’ll have some appliances that are 240V. For example, your air conditioner is 240V generally, your plugs in your house are gonna be 120V, your dryer is gonna be 240V, your oven is gonna be 240V.

So, how do you produce this 240V when coming into the transformer before it goes into your house?  You only have one wire. Well, first of all, understand that transformer is an interesting device in that there is no connection between primary and secondary transmission.  So you have this high-voltage power coming into the transformer, and then, you have coming out at your house, a usable voltage 120 and 240V. So, how does it go from being this high voltage to a lower voltage before it enters your house? Well, what it actually does is it uses magnetism. So, you have these wraps of wire on one side, you have a greater number of wraps on the higher voltage side, and then a lesser number of wraps on the lower voltage side that goes to your house. And the magnetism that’s created, there’s a magnetic field that’s created that induces the voltage it creates because magnetism causes there to be voltage flow or electron flow, electromotive force, potential difference, whatever you want to call it. Because you have fewer wraps of wire over here, you have a lower voltage, but again, it’s really that simple. So, for example, if I had 120V coming out, and I have 1200V going in, well, that is a 10:1 ratio. So, that means that there are ten times as many wraps on this side of the wire as there are on that side. You’d think it would have to be more complex than that, but it’s not. It’s just that ten times less wraps of wire, so you get the ten times reduction in the voltage output.

So there’s that side of it, but then how do you get two different wires? How do you bring one wire in and you get two different 240V wires? How do you get two different 120V wires, and how do you get 240V out of that? When it comes to understanding that whole thing about potential difference, this makes 120V and 240V make a whole lot more sense since you have the center line, which represents a state of normalcy.

This is what a 120V sinewave looks like. Really, this representation is exactly what’s created by that big magnet that’s turning over at the power plant. Because over at the power plant, you have this big turning magnet that’s then inducing this voltage into this wire and is creating this sinewave. So, the sinewave that’s being seen at your output is a direct connection to what’s occurring at the power plant, which I always think is interesting. So, you have this that’s occurring at 60 cycles per second. So, from here to here, you have 60 of this per second, which is where we get the term 60 Hertz (Hz). I’m sure you probably heard that before, 60 Hz. Essentially, the power is going on and off 60 times per second, making one full cycle 60 times per second. So, this is 120V, so it goes to peak power and then down to peak power because this is just the most peak power. This is peak power. It’s a difference from here to here. Again, it doesn’t matter which way.

But then at 240V circuit, it’s exactly the opposite. You have an exactly opposite 120V, exactly opposing 120V circuit. So, when you measure from here to here, it’s 120V. From here to here, it’s 120V. But from here to here, it’s 240V because they’re peaking and valleying at exactly opposite mounts.  Now, how does that happen because it starts with one wire going into your transformer? Here’s how it happens, which I think is fascinating: they take the two wires that are going into your house, and they wrap them in opposite directions around the cord. So, you have one going this way, wrapping around, and then you have another one wrapping around the opposite direction. So, as the magnetism is being induced into these wraps of wire going into your house, it’s creating one set of electrons flowing in one direction, you have one set that is going in the exact opposite direction within the same transformer. And so, then it outputs two separate 120V circuits to your house, which is very interesting, and the reason why they do it is for that reason that you can have more safe electricity to use, sort of general daily use in your computer or whatever, and then you have a higher voltage.

Audience: But both of the wires coming out of the transformer are 120 and independent? And then it gets combined in your house on the right grid?

I like to always use water whenever I can and I like to think of electronic flow like water. When I think of electrical potential, for example, I think of your outlet as being little spigots with high pressure, and then you can turn them on, and by turning them on, you allow the electrons to flow. Well, how do we turn them on is by plugging them in, and now you create a path for it to flow.

Because, unlike water, electricity wants to flow from one stage to another through a conductor, not just in the open air the way water can. I can switch it to water here, but in the electron world, this air between us is a great barrier. It’s the opposite. In the electron world, it would be happy to flow through a sheet of metal, a sheet of copper, or something because that would be the equivalent of air to it. But because of that, we don’t have a path. So, creating a path around the circuit is the same. I’m making a gateway by plugging in my plug to that outlet.  So, I’m creating a path or circuit for those electrons to essentially run, and it’s a really simplistic way of looking at it. So, when I create a circuit for them to run from here to here, that’s a 120V circuit. When I’m creating a circuit for them to run from here to here, now I’m creating a 240V circuit.

Audience: Did you explain that the metal section is neutral?

We’ll call it neutral, but really it’s a state of equilibrium because it can be ground too. The reason why they use the word neutral is that it’s neutral. It represents equilibrium. It represents the same way that air represents equilibrium for the ice or the hot metal bar. They work until they give up heat or absorb heat until they reach that state of equilibrium. So, this represents a state of equilibrium, but when you connect a path from here, instead of connecting a path from here to here, you’re connecting it from here to here; now you’re creating a greater differential.

So, how that looks practically is what Jason is saying that when we’re plugging into a plug in your wall, there’s one hot, which is 120V, and then one neutral. When it goes to neutral, that essentially is ground. It’s just an equilibrium state. When you go to a 240V circuit, you have the two opposing leads that are connecting to each other, so they’re hot, but they’re hot oppositely, which is why if you were to go up to a 240V circuit, stick your finger on one of them, I don’t advise that you do this, but stick your finger on one side, and then you grab something metal, it’s going to shock you exactly the same as it would if you stuck it in a 120V outlet in your house. Now, if you took both your fingers and you stuck in both of those sides of the 240 V circuit, now you’re gonna get the full 240 V. Does that make sense?

So, when we talk about potential difference, again, that’s why they use that term. There is potential difference creating flow. So, there’s a greater potential difference between here and here than there is from here to here.

I want to try to define some basic electrical theory terms that you’ll hear a lot, but I’ll do it in a very simplistic way. You’ll hear the terms amp, volt, ohm, and watt. It’s important to understand the difference. If you’re not going to understand anything else, it’s important to recognize that, in most cases where people are talking about electricity, they almost use amp, volt, and watt interchangeably. They’re just saying thatit is electricity, but really, they’re representing completely different concepts–completely different explanations of what’s happening with electricity or electron flow.

So first, I like to talk about these in terms of a highway. Think of a wire conductor as a highway. If I were to stand on a side of a highway that’s in rush hour traffic, and I were to take a picture, and it was just a still shot, and I saw all these cars lined up, and I share it with someone, I would say, “Look at that. That’s a busy road.”  There are a lot of cars on that road.

They’ll say, “Wow. There are a lot of cars on that road.” But these cars may not be moving at all, maybe just been sitting there. They may sit there for hours. I say “Look at all these cars.” Think of the cars on the road like amperage. We’re saying this is how many cars there are at this moment, snapshot, boom, cars. It has nothing to do with how fast they’re going.

In the same way, I could talk about voltage and I could say, I could go there at 2 in the morning and see a guy in a Kawasaki Ninja going 300 miles an hour over the night and it probably can’t go that fast. He’s going really fast. And I could say, “Wow! This road is busy because there’s a really fast guy on this road.” Well, it may not be busy. It’s just may be little one guy in this Kawasaki Ninja going awesomely fast, 300 miles an hour. Remember that.

So, neither really gives you the whole picture. One is telling us how fast the car is going. The other is asking how many cars are there at a given moment–how many cars are there, how many cars are there? So, how many cars are there? How fast are they going? It’s a really unscientific explanation, but it works as a way to kind of help us think about what we’re talking about when we say voltage. So, when we say voltage and amperage, what we’re really saying is velocity, force, that’s voltage. Quantity of electrons, that’s amperage. Wattage is combining the two. How many cars? How fast are they going? So, you could say something like wattage should be like, how many cars are passing at this point per minute. That would be a way of explaining kind of what wattage is.  It’s that overall picture of how many electrons are being moved over a period of time.

Does that make sense? Do you follow me there?

All right, now ohms. What are ohms?  Well, an ohm is the resistance to the flow. So, think of the road, and think of a bottleneck. So you’d say, all right, well, you got the capacity on this road that goes so fast, but then you reach this point and the road get started to get real small so the cars had to go one by one. Ohm represents resistance. So it’s saying how much resistance to the flow of cars is there on this road. And we could of think in terms of an ohm but really, when you’re talking about any type of conductor, any type of circuit, really all that matters is the total resistance of that circuit.

At A/C school, I had my instructor asked us in class. He said, okay, you have extension cords, one is a really big fat one, and one is a little skinny one and you got to run a really big saw at the end of this extension cord. How are you going to hook up the extension cord to get the most of what you got?  You got the big fat one, you got a little skinny one.  Are you gonna put the big fat one plug into the wall and then take the little skinny one, or are you going to put the little skinny one first and then hook up the big fat one? Which one are you gonna do? Any impressions?

Audience:  Fat one first.

Fat one first because that’s what everyone always does, fat one first. Right, and we hook up the fat one first and then the skinny one. Well, the truth is that it makes no difference because that electricity has to flow through that entire path, and so it doesn’t make any difference which you’re going to put first. It matters what the resistance of that entire circuit is. Does that make sense?

And so when we’re talking about Ohm’s law, “I,” this is kind of a funny thing, but “I” is amperage, “V” is voltage, “R” is resistance. So, amperage equals voltage divided by resistance. So, they have a correlating effect to each other so you can work that algebraically, and you can solve for any one of those if you have any other two. But in principle without going into the math of it, because the real world doesn’t apply to the math of Ohm’s law very much, the thing to understand is that the greater the resistance that you have, the less amperage you have. So, in a light bulb, in any circuit, if you apply more resistance to the circuit, you’re going to have less draw on the circuit. You’re going to have fewer electrons moving through the circuit. It becomes strange because I remember when I was working on a heat strip kit, and I had a heat strip kit, and it was drawing a little bit too high of amperage. Soh I said to myself, how am I going to reduce because all a heat strip is just a wrap of fire. It’s just, you know, another electron flow through it and it gets hot and air flows over and it heats air right?  So I thought to myself, I need to reduce the amperage of this circuit. What I am going to do? Well, of course, what am I going to do? I cut some off. Well, cutting some half actually increased the amperage because I reduced the resistance. Now, what’s interesting is that people will often think in terms of greater resistance equals more heat, and so heat–no. That’s all messed-up thinking.

Less resistance equals more amperage. More can flow through with less resistance, and then the voltage is essentially the rate or velocity of the force behind the electrons that causes them to flow through. So, if you have a voltage that’s a million volts, well, then you’re going to get more amperage at the same resistance because the resistance is usually static. Resistance stays the same. The light bulb, you measure it. It has so much resistance, and it doesn’t change. So, fluctuating the voltage will then change the amperage, but if you can fluctuate the resistance, that will also change the amperage. The amperage is kind of more the result of that equation. Well, when you throw in the time quotient, then you start to get the wattage and of the overall picture of how much current is made.

How does this all apply? What does it mean? It is pretty simple, but I could probably give about a 5-hour class on just basic electricity. Applied electricity is about generating electricity, creating paths, and controlling those paths. I like to talk about power generation because understanding power generation, how it’s created in the first place, and understanding magnetism opens up a lot of doors in your mind about why things work the way that they do. But understanding that really what we’re all talking about here with electricity is we’re talking about creating an energy differential and then creating a path for the electrons to get from here to here, and while they get from here to here, then they get their work, whatever it is that they want them to do–whether we want them to generate heat through an electrical coil, whether we want them to emit sound, whether or not we want them to create magnetism and drive a motor or go on a certain way with a magnet with the magnet or whatever. That’s really what we’re saying all along: how do we control the circuit? We can turn it on and off with a switch, opening and closing it or whatever, but we’re controlling this path.

Magnetism has a huge role in electrical generation. Practically speaking, we really only see two different uses of electricity in our day-to-day lives. We see in it resisted flow, which are things like heaters, and we see in magnetic flow. That’s pretty much what we’re doing, and really, what we’re doing usually with magnetism is we’re taking electricity, we’re turning it to kinetic energy, we’re turning it into something that moves something while using magnetism, or we’re turning it into light, which is really heat, honesty. I mean, they’re directly related to each other, which is, generally speaking, a resistive flow. We’re just running electricity through, which is creating heat, creating light byproduct.

But I think you should know, electricity seeks equilibrium normalcy by using the available paths is a useful way to think about how it looks. So, just like what I was saying about water, as pipes are to water, think of wires to electricity. So, when you’re thinking about a pipe, you’re not going to say, “Well, okay, I opened up the pipe, and the water didn’t flow.” Well, what’s the pipe hooked to? Why wouldn’t the water flow? These are kind of questions you would ask. And you opened up a faucet, no water comes out, you say, “What happened to the pump?” It’s the same with electricity. There are electrons all around us, and they’re not flowing in a very radical way, meaning that I can touch this desk. I’m full of electrons, the desk is full of electrons, and there is no transfer because we’re at equilibrium with each other.  Now, if I create a differential by dancing around on this rug in my socks and up and then I touch it, then maybe I’ll get shocked, or if I touch that chair. Anytime that you see something that’s occurring, especially if you’re technical or you want to know more about it, any time that you see something that’s occurring, just look up how that works, and you’ll find out that it always comes back, generally speaking, to the idea that a lot of magnetism and a lot of resistive flows are causing heat and light.

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