Speaker 1: Welcome to tex Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host
Speaker 1: job and Strickland. I'mond executive producer with I Heart Radio
Speaker 1: and how the tech area. It is time for a
Speaker 1: classic episode of tech Stuff. This episode originally published on
Speaker 1: June two thousand fifteen. It is titled The Basic Components
Speaker 1: of Electronics. I bet you'll never guess what it's about.
Speaker 1: Don't be alarmed. I'm going in medias race. This is
Speaker 1: the middle of the email here or really the end. Lastly,
Speaker 1: I was hoping in the future to see topics covered
Speaker 1: like how electronics work, transistors, capascitors, chips, etcetera. I worked
Speaker 1: at Radio Shack for five years and got really interested
Speaker 1: in electronic components, but found them pretty confusing. That is
Speaker 1: perfectly understandable. I still have to look up the various
Speaker 1: components and remind myself what each one does, because I
Speaker 1: don't tend to work with electronic circuits that frequently, and
Speaker 1: I know in general what needs to happen, but sometimes
Speaker 1: I forget the specifics because there's a lot of stuff there,
Speaker 1: and if you aren't familiar, if you're not always working
Speaker 1: in that world, it can very easily slip away from you.
Speaker 1: And we are talking about lots of different components that
Speaker 1: you measure using different units, And after a while you
Speaker 1: just start to you know, if you again, if you're
Speaker 1: not just naturally inclined to this kind of stuff, you
Speaker 1: start to pull your hair out. Except in my case
Speaker 1: that's already been done for me, so I just kind
Speaker 1: of rubbed my head. So let's start with the basics.
Speaker 1: And I know this is going to sound incredibly basic,
Speaker 1: but we have to build a foundation before we can
Speaker 1: start talking about the components. So electronics are all about
Speaker 1: leveraging electricity. Not a big surprise, you're you're leveraging electricity
Speaker 1: in order to do something to accomplis something like a
Speaker 1: radio is meant to receive and amplify radio signals and
Speaker 1: and convert them into acoustic signals so that you can
Speaker 1: actually hear them. That that's a simple example. A flashlight
Speaker 1: is meant to channel electricity to end up powering a
Speaker 1: light bulb, which is essentially a resistor. We will talk
Speaker 1: about those that heats up. We're talking about a basic
Speaker 1: incandescent light bulb here um and gives off light as
Speaker 1: a result. That's your basic use of that kind of electronics.
Speaker 1: So we're gonna talk about how electronics control electricity. These
Speaker 1: basic components are all used to do that so that
Speaker 1: you can accomplish whatever the goal of your electronic device is. Now,
Speaker 1: most electronic devices have lots and lots of different components
Speaker 1: to them, sometimes worked in various configurations, whether they're in
Speaker 1: series or in parallel. I'm not going to get into
Speaker 1: all of that because that's be on what I really
Speaker 1: wanted to focus on in this episode. Instead, in this episode,
Speaker 1: I want to talk about the very basic components and
Speaker 1: what they are intended to do. These are the things
Speaker 1: that make up the circuits that you would see in
Speaker 1: physical circuitry. So if you ever have, uh, you know,
Speaker 1: an old electronic device and you were to take it
Speaker 1: apart and you saw all these little weird do dads
Speaker 1: on a circuit board, I'm gonna tell you what those
Speaker 1: do dads do. Dad. Alright, So first we describe an
Speaker 1: electronics materials is having electrons that fall into certain energy
Speaker 1: bands or electronic bands. Now, the two important ones that
Speaker 1: to talk about are the valence band and the conduction band.
Speaker 1: Electrons and the conduction band are able to move freely
Speaker 1: through the material in question. Assuming the conduction band isn't
Speaker 1: totally full, you can think of it kind of like
Speaker 1: a think of it like a nightclub. It's a nightclub
Speaker 1: that's maybe you know, full, so you can still move
Speaker 1: through it freely. Now that nightclubs packed, you're not going anywhere,
Speaker 1: so there has to be you know, almost but not
Speaker 1: quite full for you to be able to move around.
Speaker 1: That's the conduction band. That's the basics of electrical conductivity. UH.
Speaker 1: Whereas the valance band is kind of this um this
Speaker 1: this basic energy level, and there is a gap between
Speaker 1: the valence band and the conduction band. UH. It is
Speaker 1: called the band gap. And depending upon the material, that
Speaker 1: band gap will be of a certain size, and in
Speaker 1: some cases the gap is insurmountable. You cannot get electrons
Speaker 1: from the valence band into the conductance band, and you
Speaker 1: cannot get them to flow, at least not under normal
Speaker 1: operating circumstances. So in that sense, think of you've got
Speaker 1: a like a holding room before you can get into
Speaker 1: the nightclub, and the the doorway going into the nightclub
Speaker 1: has got a big old bouncer, and that big old
Speaker 1: bouncers not letting anyone through that's your band gap. You
Speaker 1: cannot there's no one even collectively, all of you working together,
Speaker 1: you're not gonna be able to budge that bouncer. That
Speaker 1: would be as if you were in a non conducting
Speaker 1: material and I'll get into more of that later. Whereas
Speaker 1: if you're in a room where there's a wide open
Speaker 1: door and you're allowed to go through as long as
Speaker 1: someone else is coming in, that would mean that you
Speaker 1: could flow through properly. You've got you got electrical electrical
Speaker 1: conductivity going on there, and I'll talk more about that
Speaker 1: in a second. I realized this analogy isn't perfect, but
Speaker 1: I'm just trying to simplify things for those who haven't
Speaker 1: really taken this kind of class in physics. So a
Speaker 1: large gap would represent a great deal of energy needed
Speaker 1: to move electrons from the valence band to the conductance band,
Speaker 1: and sometimes that gap is so large as to be
Speaker 1: impossible to cross again under normal operating conditions. So let's
Speaker 1: look at the basic materials that we talk about in electronics, conductors, insulators,
Speaker 1: and semiconductors. Pretty simple to understand. Conductors have high electrical conductivity.
Speaker 1: That means they facilitate the flow of electrons uh. They
Speaker 1: have a nearly full but not completely full conduction band.
Speaker 1: Electrons can move freely through this material in response to
Speaker 1: an electric field applied to that material. So you apply
Speaker 1: an electrical field to this material, it will then allow
Speaker 1: electrons to flow through freely. This is the stuff that
Speaker 1: moves electrons from point A to point B. You apply
Speaker 1: a voltage across it, you get electrons to flow. That's current,
Speaker 1: Although technically current flows from positive to negative as opposed
Speaker 1: to the flow of electrons, which is from negative to positive.
Speaker 1: We can thank lots of early thinkers for that confusion.
Speaker 1: So current flow and electron flow are in opposite directions,
Speaker 1: Thank you, Benjamin Franklin. Uh. Alright, So then you've got insulators.
Speaker 1: These do not have electrons within the conduction band, or
Speaker 1: they have a full conduction band, so again no room
Speaker 1: for electrons to move around, so there are no free electrons.
Speaker 1: They impede the flow of electrons through that material, and
Speaker 1: most solids fall into this category. Metals are uh an exception,
Speaker 1: but most solids are insulators. So at normal operating parameters,
Speaker 1: you wouldn't be able to apply a strong enough electric
Speaker 1: field to make them conduct electricity. So you could apply
Speaker 1: an electric field to these things, but it wouldn't be
Speaker 1: able to jump that gap between the valence band and
Speaker 1: the conductance band, so it would just stop. You wouldn't
Speaker 1: have any electrical flow through that at all. So we
Speaker 1: use insulators for things like insulation on wires where we
Speaker 1: wrapped the wires in that to help prevent leakage or interference, because,
Speaker 1: as we've talked about many times on this show, the
Speaker 1: flow of electricity is also very closely related to magnetism
Speaker 1: and vice versa. So you have to be able to
Speaker 1: limit interference between different wires if you don't want there
Speaker 1: to be that interaction obviously, otherwise you can end up
Speaker 1: causing shorts, which is when you have an unintended connection
Speaker 1: between two different elements of a circuit and it allows
Speaker 1: electricity to pass from one to the other, almost like
Speaker 1: you think of it like a short cut, you know,
Speaker 1: when we say an electrical short and it means that
Speaker 1: the device itself will not work properly because the electricity
Speaker 1: is not flowing through the pathway you had intended it
Speaker 1: to go in. All right, then we've got semiconductors, and
Speaker 1: we'll talk more about them a little bit later, but
Speaker 1: in general, semi conductors have an almost empty conduction band
Speaker 1: and an almost full valence band, and the band gap
Speaker 1: is relatively narrow, so if you don't apply a strong
Speaker 1: enough electric field, it acts as an insulator. But when
Speaker 1: you apply the right amount of energy and electric field,
Speaker 1: it will allow electrons jump from the valence band to
Speaker 1: the conductor band and move freely within the material. You
Speaker 1: do this by doping the material, which is when you
Speaker 1: insert impurities into the semiconductor on purpose. Doping a semiconductor,
Speaker 1: which is all about introducing impurities specifically at at predetermined levels,
Speaker 1: will determine the energy levels required to do this, and
Speaker 1: that's the basis for solid state electronics. We'll get into
Speaker 1: more about semiconductors towards the end of this. And we
Speaker 1: also have to remember voltage and current, something that I
Speaker 1: always have trouble remembering. So voltage is a lot like
Speaker 1: water pressure, all right. That's that's the the amount of
Speaker 1: electrical pressure being applied, and the higher the voltage, the
Speaker 1: more electrons want to move from the concentration of electrons
Speaker 1: to the more positive side. Now, the actual flow of
Speaker 1: electricity is the current, so they are related but not
Speaker 1: the same thing. So voltage and current, and then you
Speaker 1: multiply those two de patent together and you get the power.
Speaker 1: So voltage times current equals power. Alright, So those are
Speaker 1: your basics. Now we're gonna go through and talk about
Speaker 1: the very individual components and what they do. So first
Speaker 1: we have resistors. Resistor does pretty much what it sounds like.
Speaker 1: It does. It resists but does not halt the flow
Speaker 1: of electricity. I'm gonna talk a lot about electricity in
Speaker 1: terms of water because it is a useful analogy, and
Speaker 1: it's also very common to talk about the similarities between
Speaker 1: electricity flowing and water flowing when you're discussing these components.
Speaker 1: So let's say that you have two different pipes. You've
Speaker 1: got a brand spanking new pipe. It's shiny and beautiful
Speaker 1: and free from any any irregularities, and it allows water
Speaker 1: to flow through the minimum of resistance. That water is
Speaker 1: just flowing right through easily. You've got a second, old,
Speaker 1: gnarly pipe, and this one's got calcium build up in it.
Speaker 1: They're all these bumps and stuff on the inside. So
Speaker 1: water actually encounters resistance friction if you will, as it's
Speaker 1: flowing through, and it does not flow through as easily.
Speaker 1: Resistors are like that old gnarly pipe, and they are
Speaker 1: invented on purpose for specific reasons. So why would you
Speaker 1: want to have an electronic component that actually slows down
Speaker 1: or impedes the flow of electricity for some reason. Well,
Speaker 1: sometimes you have to limit the amount of electricity that
Speaker 1: can flow through part of a circuit within a given
Speaker 1: amount of time, sort of like how a faucet going
Speaker 1: back to water, how fauce it can limit how much
Speaker 1: water it can flow through your water pipes into your sink.
Speaker 1: So you wouldn't want just an on off switch for
Speaker 1: the water coming into your home. That water is at
Speaker 1: a much higher pressure, know it's it's a higher pressure
Speaker 1: to deliver the water to your house. And if all
Speaker 1: you had wasn't on off switch and you flipped it,
Speaker 1: you would have water blasting through the pipe according to
Speaker 1: the amount of pressure that was built up behind it.
Speaker 1: That'd be a little bit nerving, especially if you just
Speaker 1: wanted to have a nice, frusty glass water. So you
Speaker 1: want to have some sort of limiter on that to
Speaker 1: control the amount of water that's or the pressure of
Speaker 1: the water that's coming in. So resistors reduced the amount
Speaker 1: of voltage placed on other electronic components within a circuit
Speaker 1: by restricting the amount of current that can flow through
Speaker 1: the resistor. The reason why this is important is that
Speaker 1: we cannot create a battery for every single type of
Speaker 1: electronic device that's out there. It's not practical. So batteries
Speaker 1: different batteries. Different types of batteries have different voltages. So
Speaker 1: you could, in theory, develop a battery specifically for a
Speaker 1: particular type of electronic device that would not require resistors
Speaker 1: because the battery is providing exactly the voltage needed for
Speaker 1: whatever electronic components are in net. But it's not practical
Speaker 1: to do that for everything. We want standardized batteries, and
Speaker 1: then we use things like resistors to help control the
Speaker 1: voltage in those electronic components so that the right amount
Speaker 1: of voltage is applied to those specific parts of the
Speaker 1: electronic circuit, rather than having to have a billion different
Speaker 1: types of batteries. That would not be practical. So there
Speaker 1: are many different types of resistors designed to work on
Speaker 1: specific amounts of electrical power. Now, some have changeable resistor
Speaker 1: values dependent upon the amount of voltage placed across them.
Speaker 1: They're called nonlinear or voltage dependent resistors. Resistor values can
Speaker 1: also change when the temperature of the resistor changes UH.
Speaker 1: Different types of resistors do this. Some can also be
Speaker 1: mechanically adjusted. So it all depends upon what you need
Speaker 1: the resistor form. Why what you needed to do, that's
Speaker 1: what would determine which type of resistor you would use.
Speaker 1: The unit of measurement for a resistor is the ohm
Speaker 1: oh h M. Resistor values are ten percent apart from
Speaker 1: each other, and resistors are color coded with bands of
Speaker 1: color or or rings of color. So the first ring
Speaker 1: represents the first digit of the resistors value. So what
Speaker 1: you would do is you would look at the first ring,
Speaker 1: whatever color it was, you would cross reference that with
Speaker 1: the with a color UH index, and we'll tell you
Speaker 1: what the value of the resistor is for the first digit.
Speaker 1: The second ring tells you the value of the second digit.
Speaker 1: So then you've got the two the two digits that
Speaker 1: are involved. The third tells you the power of ten
Speaker 1: to multiply by, so it might be ten thousand, and
Speaker 1: then you would multiply. Let's say that your first two
Speaker 1: digits are a twenty two and seven, and you would
Speaker 1: multiply that by ten thousand. You have twenty seven thousand homes.
Speaker 1: There and the fourth ring would tell you the tolerance
Speaker 1: of the resistor plus or minus whatever percentage. Uh. So
Speaker 1: the physical size the resistor and the amount of power
Speaker 1: it can handle tends to be proportional. So in other words,
Speaker 1: the larger the resistor, the more power it can handle.
Speaker 1: In general, So those are resistors covers that basic component.
Speaker 1: Now let's move on to capacitors. Alright, So capacitors are
Speaker 1: similar to batteries and that it's a means of storing
Speaker 1: electrical energy, but unlike batteries, instead of creating an a uh,
Speaker 1: electrical flow through a chemical reaction that is steady the
Speaker 1: entire time, it is designed to release a it's it's
Speaker 1: entire stored electrical charge all at once. So let's say
Speaker 1: they've got two leads of a capacitor. You have a
Speaker 1: difference in voltage across us these two leads. That's when
Speaker 1: a capacitor is charged, So one lead has a greater
Speaker 1: build up of electrons than the other lead does. Uh. Now,
Speaker 1: if you were to connect the leads together, you would
Speaker 1: short them. You would have a discharge of that capacitor,
Speaker 1: and the voltage would equalize across the two, so you
Speaker 1: get a release of a quick burst of electricity, so
Speaker 1: capacitors can pass alternating current freely. A C current will
Speaker 1: just pass through a capacitor as if it were not
Speaker 1: really there. Direct current, however, will charge a capacitor. It
Speaker 1: will have that build up of electrons on one side
Speaker 1: while the other side doesn't get that build up of electrons,
Speaker 1: and then you have that difference in voltage. Alternating current
Speaker 1: just will pass back and forth through it without any problems.
Speaker 1: So capacitors contain the same fundamental parts. You have at
Speaker 1: least two conductive plates separated by a non conductive material
Speaker 1: that's the dielectric. The amount of charge held a capacitor
Speaker 1: is measured in units called faret's. But a faret is
Speaker 1: a large amount of capacitance, so large that you don't
Speaker 1: really talk about a ferret. Instead we end up talking
Speaker 1: about micro ferrets, which are about a well, which are
Speaker 1: one million of a ferret, so much smaller. Ferret, by
Speaker 1: the way, not ferret, two different things. Nice Marmot capacitance
Speaker 1: is dependent upon surface area, so it's directly proportional to
Speaker 1: the surface area of those leads, those those capacity plates.
Speaker 1: Um it is indirectly proportional to the distance between the
Speaker 1: plates so the greater the distance between the plates, the
Speaker 1: lower the capacitance. Uh. It's also uh dependent upon the
Speaker 1: dielectric constant of the insulating material. And they are used
Speaker 1: for things that need a quick release of electricity rather
Speaker 1: than a steady flow. So for example, a traditional flash
Speaker 1: on a camera. So you've got an old camera and
Speaker 1: you've got the the the flash, Uh, you know it
Speaker 1: bursts in this quick burst of light. Will It needs
Speaker 1: that quick It needs access to a quick burst of
Speaker 1: electricity in order to do that, and that's what capacitors
Speaker 1: are good for. And it takes some time for the
Speaker 1: capacitors to build up the charge again so it can
Speaker 1: do it another time. That's sort of you know, if
Speaker 1: you're using the old ones, you hear that noise. It's
Speaker 1: the the discharge and then charging of the capacitors that
Speaker 1: require you to take a moment between taking pictures with
Speaker 1: those old style camera flashes. Now, obviously newer ones use
Speaker 1: different a different approach, but you often have capacitors that
Speaker 1: actually provide the electricity for those Now, the voltage of
Speaker 1: a capacitor cannot change instantly, it's important to remember, and
Speaker 1: quick voltage changes in a capacitor produced large current changes.
Speaker 1: Capacitor store energy in an electric field. The reason I
Speaker 1: mentioned all that is because we're now going to talk
Speaker 1: about inductors, and inductors are kind of, um, the opposite
Speaker 1: of capacitors, or really maybe not even opposite is the
Speaker 1: right way of saying it. In many ways that they
Speaker 1: behave in opposite ways than capacitors do. But we'll get
Speaker 1: to that. We'll be back with more of this classic
Speaker 1: episode of tech stuff after this quick break. So basically,
Speaker 1: an inductor at its most basic level is a coil
Speaker 1: of wires, so sometimes we just call them coils and
Speaker 1: not inductors. Uh. They deal with what is the electrical
Speaker 1: equivalent of momentum. So if you're familiar with momentum, essentially,
Speaker 1: this is that idea that you get a you know,
Speaker 1: objects in motion tend to stay in motion. So let's
Speaker 1: say you've got a large mass moving at a particular velocity.
Speaker 1: It has a certain amount of momentum and you have
Speaker 1: to overcome that momentum to slow down and stop that uh,
Speaker 1: that that mass. So it's the same type of thing
Speaker 1: with inductors, except we're talking about the electrical equivalent of momentum.
Speaker 1: We're talking about the flow of electricity. So again going
Speaker 1: back to the water analogy, Let's say that you've got
Speaker 1: a water hose, a really long one, several hundred feet long,
Speaker 1: and you've coiled it up so it's in a nice
Speaker 1: long coil and it's filled with water. There are gallons
Speaker 1: of water inside this hose, and the end of the
Speaker 1: hose is tilted at such an angle so the water
Speaker 1: is not just flowing right out. You put a plunger
Speaker 1: into the other end and you start to press on
Speaker 1: the plunger to push the water out. Now, all of
Speaker 1: that water is not just going to simultaneously start to
Speaker 1: move together. It actually is going to take some time
Speaker 1: for the pressure you are applying to exert enough force
Speaker 1: to push the water out to overcome the inertia within
Speaker 1: that coil of water hose. And once you get that
Speaker 1: water coming out at the speed at which it can
Speaker 1: come out and you let go of the plunger, the
Speaker 1: plunger is going to continue going down that tube because
Speaker 1: of inertia. That's the same sort of thing with inductors,
Speaker 1: except instead of water, we're talking about electricity. So coils
Speaker 1: of wire will pass D C current but will block
Speaker 1: a C current. So in other words, direct current can
Speaker 1: flow through an inductor, but alternating current would be blocked
Speaker 1: because it cannot flow the opposite way through the coil.
Speaker 1: So that makes it the opposite of capacitors. Remember, capacitors
Speaker 1: would pass alternating current that can flow straight through, but
Speaker 1: would block direct current. Direct current would charge a capacitor
Speaker 1: a capacitor, but could not just flow through the capacitor.
Speaker 1: In this case, direct current can flow through an inductor,
Speaker 1: but a c altering current would be blocked. The standard
Speaker 1: unit of inductance is the henry. I wish I could
Speaker 1: tell you why, but I honestly don't know. I'm sure
Speaker 1: some of you out there, you electricians, are very familiar
Speaker 1: with the reason why and could tell me and feel
Speaker 1: free to I I honestly do not off hand. No,
Speaker 1: the inductance of a coil is indirectly proportional to the
Speaker 1: length of the coil, but directly proportional to the cross
Speaker 1: sectional area of the wire, So, in other words, the
Speaker 1: gauge of the wire is important here. It's also proportional
Speaker 1: to the square of the number of turns in the coil,
Speaker 1: and it's directly proportional to the permeability of the core material. Now,
Speaker 1: the core is whatever this coil is wrapped around. Now
Speaker 1: it could be wrapped around air, or it could be
Speaker 1: wrapped around something like iron, which is incredibly effective. So
Speaker 1: those are that's what we're talking about with the cords,
Speaker 1: whatever the wire or is coiled around. So when current
Speaker 1: first starts flowing into the coil, the coil wants to
Speaker 1: build up a magnetic field. We talked about this again
Speaker 1: and again that you start running electricity through a coil
Speaker 1: of wire that's coiled around like an iron core, like
Speaker 1: a nail, and you start to you create an electro magnet. Well,
Speaker 1: once that field is built. While while the magnetic field
Speaker 1: is building, the coil inhibits the flow of current through
Speaker 1: the wire, But once the field is built, current can
Speaker 1: flow normally through the wire. So if you were to
Speaker 1: have an inductor hooked up to a light bulb, let's
Speaker 1: say and you flip a switch so that you know,
Speaker 1: technically in an electronics we'd say that you close the switch,
Speaker 1: so you have created a closed path so electrons can
Speaker 1: flow through. The electrons would flow through the inductor, which
Speaker 1: would start to build up a magnetic field. So at
Speaker 1: first you would get the light bulb coming on. Then
Speaker 1: it would start to dim a bit because as that
Speaker 1: magnetic field is getting built up the lightbulb, you know,
Speaker 1: the electricity would be it did to the light bulb,
Speaker 1: it would actually act as sort of a resistor, and
Speaker 1: the light bul would start to get dimmer. But then
Speaker 1: eventually that that magnetic field would get charged up as
Speaker 1: much as it can because it's direct current, not alternating current,
Speaker 1: and you would reach a level where it was stabilized.
Speaker 1: Current would flow fine. At that point, you could actually
Speaker 1: turn off the switch, you can open it. In other words,
Speaker 1: the magnetic field around the coil would keep current flowing
Speaker 1: through the coil until that magnetic field collapsed. So even
Speaker 1: though you turn the switch to off, because you have
Speaker 1: an inductor, that light bulb would stay lit until the
Speaker 1: magnetic field and the inductor collapsed, in which case it
Speaker 1: would stop inducing current to flow through and the light
Speaker 1: bulb would go off. So the experience you would have
Speaker 1: is turn the switch on, light bulb comes on, light
Speaker 1: bulb starts to get dim, light bulb gets bright again,
Speaker 1: You turn the switch off, light bulb stays lit for
Speaker 1: a while, and then turns off. That's what it would
Speaker 1: look like to you, So pretty interesting to me now. So,
Speaker 1: an inductor stores energy in its magnetic field, and it
Speaker 1: tends to resist any change in the amount of current
Speaker 1: flowing through it, thus making it different from capacitors. Because
Speaker 1: capacitors store things an electric field, inductor store things energy,
Speaker 1: not just things. Capacitor store energy and electric fields, and
Speaker 1: inductor store energy and magnetic fields. And capacitors resist changes
Speaker 1: to voltage, whereas inductors resist changes to current. So really
Speaker 1: interesting about that. We've got more to say in this
Speaker 1: classic episode of tech stuff after these quick messages. So
Speaker 1: because of this relationship between inductors and capacitors, these two
Speaker 1: different components are sometimes referred together as duel components because
Speaker 1: they they are opposites that complement one another. The current
Speaker 1: in an inductor cannot change instantly the quick current changes
Speaker 1: produced the large voltage, and inductors store their energy in
Speaker 1: those magnetic fields. That's what sets them opposite of capacitors,
Speaker 1: because they are all the opposite of those things. And
Speaker 1: you might wonder, well, what are inductors used for. I mean,
Speaker 1: that light bulb example seems kind of crazy. Well, they're
Speaker 1: used for lots of stuff. For example, if you've ever
Speaker 1: gone to uh, like traffic lights, that are the respond
Speaker 1: to the presence of vehicles. Most of those are using inductors.
Speaker 1: So underneath the pavement where you're driving on top of
Speaker 1: you know, there are giant coils of wire, and when
Speaker 1: you stop your car at a stoplight that has one
Speaker 1: of these systems, your car starts to act as the
Speaker 1: core for that inductor loop. You've got this massive amount
Speaker 1: of steel that's right there that affects the inductance of
Speaker 1: the that cable. You of a meter attached to the
Speaker 1: cable that measures the inductance. So when it measures a
Speaker 1: change in inductance, that meter knows there's a vehicle at
Speaker 1: that location and sends that information to the control unit
Speaker 1: for the traffic system and thus changes the traffic cycle
Speaker 1: so that you get a green light faster. So if
Speaker 1: you're ever at one of those intersections where the the
Speaker 1: light cycles depend heavily upon whether or not their cars
Speaker 1: present at the intersection, that's generally speaking, what is happening.
Speaker 1: You've got these inductors. The inductance changes, sends the message
Speaker 1: to the meter, or rather the meter detects the inductor
Speaker 1: the change in inductance and then sends that onto the
Speaker 1: traffic control system. That will then, at least in theory,
Speaker 1: gets you on your way a little faster. So that's inductors.
Speaker 1: Now let's take a look at transformers, which are more
Speaker 1: than meets the eye. So I'm not talking about autobots
Speaker 1: in Decepticon, as much as I would love to do that,
Speaker 1: instead of talking about the basic electronic component. So let's
Speaker 1: say you've got a single core, like like that iron nail.
Speaker 1: Let's say and you put multiple coils of wire over
Speaker 1: this same iron core, and then you force a DC
Speaker 1: current through one of those coils of wire, not all
Speaker 1: of them, just one. Now, as that current charges, it
Speaker 1: will induce current to flow through the other coils wrapped
Speaker 1: around that same core, and constantly changing the voltage of
Speaker 1: that primary coil. The one that you've got attached to
Speaker 1: some sort of voltage generator, will cause currents that change
Speaker 1: in a similar fashion in the other coils. Now, if
Speaker 1: the other coils have more loops than the primary coil,
Speaker 1: the voltage will be greater, but the current will be lower.
Speaker 1: I'll explain that in a second. So let's say we've
Speaker 1: got we'll make it really simple. We'll just do two coils.
Speaker 1: Let say we've got an iron core and we've got
Speaker 1: a primary wire coiled a fund it ten times, and
Speaker 1: we have a second wire coiled in the same direction
Speaker 1: around that iron core, but it is coiled twenty times,
Speaker 1: and we apply a varying voltage across the primary wire.
Speaker 1: The voltage across the second wire will be twice as
Speaker 1: much because there are twice as many coils, but the
Speaker 1: current will be half as much as that in the
Speaker 1: primary coil. And that's because you have to conserve power.
Speaker 1: You cannot create or destroy power. You have to conserve it.
Speaker 1: And power, like I said earlier, is equal to voltage
Speaker 1: times current. So if we double the voltage, but ultimately
Speaker 1: the power in the secondary coil has to be the
Speaker 1: same as the primary coil, and the only way to
Speaker 1: address that is to have the current. So that's you know,
Speaker 1: that's what happens. So if the second coil is coiled
Speaker 1: in the same direction as the primary, like I was
Speaker 1: saying before, the voltage is in the same polarity as
Speaker 1: that of the generator the primary coil. If second coil
Speaker 1: is coiled in the opposite direction of the primary coil,
Speaker 1: then the voltage is in the opposite polarity from the
Speaker 1: primary coil. Polarity is really important, but also pretty complicated,
Speaker 1: So I'll probably spend another episode to explain that concept
Speaker 1: because it's really a bit much to go into right now.
Speaker 1: But anyway, this is the basics for power transmission using
Speaker 1: alternating current. It's the reason why we have alternating current
Speaker 1: distributing our power instead of direct current. So then that
Speaker 1: old Tesla versus Edison argument, really i should say Westinghouse
Speaker 1: versus Edison argument, where Edison was saying direct current was
Speaker 1: best and westing Us was saying no alternating current was best.
Speaker 1: The things that let alternating current win out over direct
Speaker 1: current where that using transformers you could boost the voltage
Speaker 1: to huge high voltage numbers, which were great for power transmission.
Speaker 1: You could transmit over vast distances using high voltage wires,
Speaker 1: and then you would use other transformers on the opposite
Speaker 1: end to step down the voltage until you reach the
Speaker 1: level that was safe for homes, which in the United
Speaker 1: States is two forty volts. Uh. Now, keep in mind
Speaker 1: that when you're talking about transmission voltages, it could be
Speaker 1: anywhere between a hundred fifty five thousand to seven d
Speaker 1: sixty thousand volts, So we're talking huge differences here, and
Speaker 1: it's all because you can use this basic element of
Speaker 1: electronics with these transformers to step up or step down
Speaker 1: the voltage simply by using different coils along a core.
Speaker 1: So that was incredibly useful. You could end up transmitting
Speaker 1: power over great distances. Direct current, however, is very different.
Speaker 1: It is most efficient if it is close to whatever
Speaker 1: the load is on the line. So the load is
Speaker 1: whatever the electricity is meant to power. So in the
Speaker 1: case of homes, you would want the power plant to
Speaker 1: be relatively close to the homes that are receiving electricity.
Speaker 1: If you were using direct current, um this is you know,
Speaker 1: it would be incredibly useful to have direct current powering
Speaker 1: our homes because most of the stuff we have relies
Speaker 1: on direct current. It actually has to convert the alternating
Speaker 1: current that comes to the house into direct current. You
Speaker 1: have these converters that are part of the electronics that
Speaker 1: allow it to do that. If you had direct current
Speaker 1: being uh supplied directly to your house, you wouldn't need
Speaker 1: the conversion part of those devices. However, you wouldn't be
Speaker 1: able to transmit it over great distances like you can
Speaker 1: with alternating current. So in case you're wondering about the
Speaker 1: power grids in the United States. We I mentioned that
Speaker 1: you have those those high voltage lines that are carrying
Speaker 1: between a d to center sixty volts. When you get
Speaker 1: to distribution levels, you step down that voltage to less
Speaker 1: than ten thousand volts typically, and then you get to
Speaker 1: distribution busses that have transformers that reduce it further to
Speaker 1: seven thousand, two hundred volts or less. And then you
Speaker 1: have the homes that are connected to a final transformer
Speaker 1: that step it down again to the voltage of volts
Speaker 1: or so. So incredibly useful and here at how stuff works. Recently,
Speaker 1: as of the recording of this podcast, we had a
Speaker 1: lovely transformer fire right next to the building we work in,
Speaker 1: which cut power to our part of the building for
Speaker 1: some time. So if you've ever been near a transformer
Speaker 1: when it's blown, it's a pretty spectacular thing. It's usually
Speaker 1: lots of sparks and a really loud bang and often
Speaker 1: requires the work of dedicated personnel to repair. And it
Speaker 1: does also typically mean that you have a loss of
Speaker 1: power for at least a localized area. Pretty impressive when
Speaker 1: it happens. Luckily, it doesn't happen all that frequently the
Speaker 1: electrical storms and areas of or times of great use
Speaker 1: can make the more vulnerable. Now let's move on to
Speaker 1: semiconductors and how they are used in electronics. So we've
Speaker 1: got lots of different uses for semiconductors. I'm going to
Speaker 1: talk about two specific ones. There are diodes. Diodes are
Speaker 1: really useful. They allow current to flow in only one direction,
Speaker 1: so it's like a one way channel or a valve.
Speaker 1: So electricity flowing one way is fine, but it cannot
Speaker 1: flow back the other way, and semiconductor doping allows for
Speaker 1: this to happen. Remember I mentioned earlier. Doping is when
Speaker 1: you have introduced impurities into the semiconductor material to give
Speaker 1: its specific UH features. So there are two different types
Speaker 1: that we're going to talk about. There's IN type layers
Speaker 1: of semiconductors, so you can think of that as an
Speaker 1: excess of electrons. It has lots of negative electrons that
Speaker 1: are just ready to flow out of there. And then
Speaker 1: you have of P type layers, and these have electron
Speaker 1: holes or at least you know, in other words, of
Speaker 1: the capacity to take on electrons. So if you pair
Speaker 1: this together, you get what's called a P N diode,
Speaker 1: which all only allows electricity to flow in one direction.
Speaker 1: It can the electrons can come through UH and flow
Speaker 1: to the holes, but they can't go the other way,
Speaker 1: so very useful and electronic components where you need to
Speaker 1: direct the flow of electricity along a particular path and
Speaker 1: prevent it from coming back through that pathway. Transistors are
Speaker 1: another type of semiconductor that use a small amount of
Speaker 1: current to control a large amount of current. So while
Speaker 1: a diode is p n, transistors are either P n
Speaker 1: P or N p n, and if you apply an
Speaker 1: electrical current to the center layer, which is also known
Speaker 1: as the base, electrons will move from the N type
Speaker 1: side to the P type side, and that initial small
Speaker 1: current allows for much larger current to flow through the
Speaker 1: material at that point. So transistors act as switches or amplifiers.
Speaker 1: Incredibly useful. So when we talk about transistors in solid
Speaker 1: state electronics, these are the things that allow us to
Speaker 1: build logic circuits. And it's because we can allow electrons
Speaker 1: to either flow or prevent them from flowing. It's also
Speaker 1: why things like electron tunneling can be such a problem.
Speaker 1: Electron tunneling is a quantum effect, so you can think
Speaker 1: of an electron as not really existing in a specific
Speaker 1: point in space at any given time, but rather having
Speaker 1: the potential to exist in an area of space at
Speaker 1: any point in time. So think of it like a
Speaker 1: cloud where an electron could be, and that cloud covers
Speaker 1: all the potential places the electron could be, and there's
Speaker 1: different probability for different parts of the cloud. If your
Speaker 1: transistor gates are so small, so narrow, so thin, I
Speaker 1: guess I should say not narrow, that the cloud of
Speaker 1: potential can overlap the transistor gate. That means there is
Speaker 1: the possibility that at some point the electron could exist
Speaker 1: on the other side of the transistor gate, even if
Speaker 1: the gate never opened. And if there's a possibility, that
Speaker 1: means sometimes it does appear on the other side of
Speaker 1: the gate. We call it electron tunneling. It's not really tunneling.
Speaker 1: It's just if there is the possibility they could be
Speaker 1: on the other side, sometimes it is on the other side,
Speaker 1: which means that you cannot actually control the flow of electrons.
Speaker 1: In that case, it would mean that your transistors would
Speaker 1: be ineffective in doing what they're supposed to do. They
Speaker 1: wouldn't really be able to act to switches reliably and
Speaker 1: you would get errors in your computations. I might work
Speaker 1: most of the time and then only some of the
Speaker 1: time not work, but even then that's problematic, which is
Speaker 1: one of the engineering challenges that transistor designers and multi
Speaker 1: around their microprocessor designers encounter all the time, you know.
Speaker 1: Finding new materials that are better at acting as transistors
Speaker 1: switches it's a big part of it. And coming up
Speaker 1: with different architectures to really take advantage of electron flow
Speaker 1: is another big part of it, all right. So those
Speaker 1: are the basics the basic electronic components that you can
Speaker 1: talk about with, you know, if you're looking at it
Speaker 1: from a very high level. Obviously there's tons of other
Speaker 1: stuff that I didn't get into, and some of it
Speaker 1: just requires you to pair up or otherwise put into
Speaker 1: series or parallels some of the components I've mentioned to
Speaker 1: to get whatever effects you want. I hope you enjoyed
Speaker 1: that classic episode of tech Stuff as we covered the
Speaker 1: basic components of electronics. It's probably something I'll end up
Speaker 1: covering again in various Tech Stuff tidbits episodes where I
Speaker 1: really focus on specific components and their place in electronics
Speaker 1: and their purpose. Because us you can always do a
Speaker 1: better job, right. I mean, I'm always proud of the
Speaker 1: work I do, but I also recognize when I could
Speaker 1: do it even better, and I think it's about time
Speaker 1: I try and do that. If you have suggestions for
Speaker 1: topics I should cover in future episodes of tech Stuff,
Speaker 1: reach out to me on Twitter to handle for the
Speaker 1: show is tech Stuff hs W, and I'll talk to
Speaker 1: you again really soon. Text Stuff is an I Heart
Speaker 1: Radio production. For more podcasts from I Heart Radio, visit
Speaker 1: the I Heart Radio app, Apple Podcasts, or wherever you
Speaker 1: listen to your favorite shows.