WEBVTT - The Basic Components of Electronics 0:00:04.200 --> 0:00:12.280 Get in touch with technology with text stuff from dot com. 0:00:12.360 --> 0:00:15.800 Hey there, and welcome to text stuff. I'm Jonathan Strickland, 0:00:16.239 --> 0:00:20.240 and today I wanted to address some listener mail and 0:00:20.239 --> 0:00:24.520 and do a full episode based upon a request. This 0:00:24.640 --> 0:00:28.760 comes from Chris via email Now. Chris wrote an incredible email, 0:00:28.920 --> 0:00:31.920 very long, lots of different stuff in it and lots 0:00:31.920 --> 0:00:35.440 of different suggestions, one of which was about the topic 0:00:35.440 --> 0:00:38.000 will be covering today. So here's that section of the email, 0:00:38.520 --> 0:00:42.600 so don't don't be alarmed. I'm going in medias race. 0:00:42.720 --> 0:00:45.120 This is the middle of the email here or really 0:00:45.159 --> 0:00:48.320 the end. Lastly, I was hoping in the future to 0:00:48.360 --> 0:00:52.839 see topics covered like how electronics work, transistors, capacitors, chips, etcetera. 0:00:53.040 --> 0:00:55.240 I worked at radio Shack for five years and got 0:00:55.280 --> 0:00:58.360 really interested in electronic components, but found them pretty confusing. 0:00:59.080 --> 0:01:03.560 That is perfectly understandable. I still have to look up 0:01:03.640 --> 0:01:07.679 the various components and remind myself what each one does 0:01:07.760 --> 0:01:11.480 because I don't tend to work with electronic circuits that frequently, 0:01:11.959 --> 0:01:15.240 and I know in general what needs to happen, but 0:01:15.360 --> 0:01:18.960 sometimes I forget the specifics because there's a lot of 0:01:18.959 --> 0:01:22.120 stuff there, and if you aren't familiar. If you're not 0:01:22.160 --> 0:01:25.360 always working in that world, it can very easily slip 0:01:25.400 --> 0:01:27.800 away from you. And we are talking about lots of 0:01:27.800 --> 0:01:32.080 different components that you measure using different units, And after 0:01:32.120 --> 0:01:34.399 a while you just start to you know, if you again, 0:01:34.440 --> 0:01:36.959 if you're not just naturally inclined to this kind of stuff, 0:01:36.959 --> 0:01:39.039 you start to pull your hair out. Except in my case, 0:01:39.480 --> 0:01:41.360 that's already been done for me, so I just kind 0:01:41.360 --> 0:01:44.360 of rubbed my head. So let's start with the basics. 0:01:45.080 --> 0:01:48.360 And I know this is going to sound incredibly basic, 0:01:48.520 --> 0:01:51.040 but we have to build a foundation before we can 0:01:51.040 --> 0:01:54.480 start talking about the components. So electronics are all about 0:01:54.560 --> 0:01:59.600 leveraging electricity. Not a big surprise, you're you're leveraging electricity 0:01:59.600 --> 0:02:03.280 in order to do something to accomplish something like a 0:02:03.440 --> 0:02:08.440 radio is meant to receive and amplify radio signals and 0:02:08.440 --> 0:02:10.880 and convert them into acoustic signal so that you can 0:02:10.880 --> 0:02:14.760 actually hear them. That that's a simple example. A flashlight 0:02:15.240 --> 0:02:20.480 is meant to channel electricity to end up powering a 0:02:20.600 --> 0:02:23.240 light bulb, which is essentially a resistor. We will talk 0:02:23.280 --> 0:02:27.519 about those that heats up. We're talking about a basic 0:02:27.560 --> 0:02:30.960 incandescent light bulb here, Um and gives off light as 0:02:30.960 --> 0:02:35.280 a result. That's your basic use of that kind of electronics. 0:02:35.639 --> 0:02:41.119 So we're gonna talk about how electronics control electricity. These 0:02:41.160 --> 0:02:44.799 basic components are all used to do that so that 0:02:44.840 --> 0:02:49.160 you can accomplish whatever the goal of your electronic device is. Now, 0:02:49.160 --> 0:02:52.760 most electronic devices have lots and lots of different components 0:02:52.760 --> 0:02:56.919 to them, sometimes worked in various configurations, whether they're in 0:02:57.040 --> 0:02:59.839 series or in parallel. I'm not going to get into 0:02:59.880 --> 0:03:02.880 all all of that because that's beyond what I really 0:03:02.919 --> 0:03:07.040 wanted to focus on in this episode. Instead, in this episode, 0:03:07.360 --> 0:03:11.200 I want to talk about the very basic components and 0:03:11.240 --> 0:03:14.519 what they are intended to do. These are the things 0:03:14.560 --> 0:03:17.360 that make up the circuits that you would see in 0:03:17.400 --> 0:03:20.360 physical circuitry. So if you ever have, uh, you know, 0:03:20.400 --> 0:03:23.480 an old electronic device and you were to take it 0:03:23.520 --> 0:03:26.600 apart and you saw all these little weird do dads 0:03:26.680 --> 0:03:29.200 on a circuit board, I'm gonna tell you what those 0:03:29.200 --> 0:03:35.520 do dads do. Dad. Alright, So first we describe an 0:03:35.560 --> 0:03:39.760 electronics materials is having electrons that fall into certain energy 0:03:39.800 --> 0:03:43.240 bands or electronic bands. Now, the two important ones that 0:03:43.320 --> 0:03:46.560 to talk about are the valence band and the conduction band. 0:03:47.200 --> 0:03:49.640 Electrons and the conduction band are able to move freely 0:03:49.680 --> 0:03:52.760 through the material in question, assuming the conduction band isn't 0:03:52.760 --> 0:03:54.880 totally full. You can think of it kind of like 0:03:54.960 --> 0:03:59.160 a think of it like a nightclub. It's a nightclub 0:03:59.200 --> 0:04:04.480 that's maybe you know, full, so you can still move 0:04:04.520 --> 0:04:08.240 through it freely. Now that nightclubs packed, you're not going anywhere, 0:04:08.280 --> 0:04:10.520 so there has to be you know, almost but not 0:04:10.600 --> 0:04:12.640 quite full for you to be able to move around. 0:04:13.160 --> 0:04:18.159 That's the conduction band. That's the basics of electrical conductivity. UH. 0:04:18.279 --> 0:04:21.279 Whereas the valance band is kind of this um this 0:04:21.279 --> 0:04:24.800 this basic energy level, and there is a gap between 0:04:24.800 --> 0:04:27.680 the valence band and the conduction band. UH. It is 0:04:27.720 --> 0:04:31.200 called the band gap. And depending upon the material, that 0:04:31.240 --> 0:04:33.680 band gap will be of a certain size, and in 0:04:33.720 --> 0:04:37.719 some cases the gap is insurmountable. You cannot get electrons 0:04:38.240 --> 0:04:41.840 from the valence band into the conductance band, and you 0:04:41.880 --> 0:04:45.240 cannot get them to flow, at least not under normal 0:04:45.279 --> 0:04:50.360 operating circumstances. So in that sense, think of you've got 0:04:50.360 --> 0:04:52.520 a like a holding room before you can get into 0:04:52.560 --> 0:04:58.240 the nightclub, and the the doorway going into the nightclub 0:04:58.279 --> 0:05:00.200 has got a big old bouncer and that a goal 0:05:00.200 --> 0:05:04.000 bouncers not letting anyone through. That's your band gap. You 0:05:04.160 --> 0:05:08.240 cannot there's no one even collectively all of you working together, 0:05:08.320 --> 0:05:11.359 you're not gonna be able to budge that bouncer. That 0:05:11.400 --> 0:05:14.200 would be as if you were in a non conducting 0:05:14.279 --> 0:05:16.839 material and I'll get into more of that later. Whereas 0:05:16.880 --> 0:05:20.239 if you're in a room where there's a wide open 0:05:20.320 --> 0:05:22.840 door and you're allowed to go through as long as 0:05:23.120 --> 0:05:26.279 someone else is coming in, that would mean that you 0:05:26.320 --> 0:05:30.080 could flow through properly. You've got you got electrical electrical 0:05:30.080 --> 0:05:33.040 conductivity going on there, and I'll talk more about that 0:05:33.080 --> 0:05:35.880 in a second. I realized this analogy isn't perfect, but 0:05:36.000 --> 0:05:39.279 I'm just trying to simplify things for those who haven't 0:05:39.279 --> 0:05:43.600 really taken this kind of class in physics. So a 0:05:43.720 --> 0:05:47.520 large gap would represent a great deal of energy needed 0:05:47.520 --> 0:05:51.520 to move electrons from the valence band to the conductance band, 0:05:52.480 --> 0:05:55.799 and sometimes that gap is so large as to be 0:05:56.240 --> 0:06:02.279 impossible to cross again under normal operating conditions. So let's 0:06:02.320 --> 0:06:08.920 look at the basic materials that we talk about in electronics, conductors, insulators, 0:06:08.960 --> 0:06:16.120 and semiconductors. Pretty simple to understand. Conductors have high electrical conductivity. 0:06:16.160 --> 0:06:19.479 That means they facilitate the flow of electrons. Uh. They 0:06:19.480 --> 0:06:22.680 have a nearly full but not completely full conduction band. 0:06:23.000 --> 0:06:26.880 Electrons can move freely through this material in response to 0:06:26.880 --> 0:06:29.960 an electric field applied to that material. So you apply 0:06:30.000 --> 0:06:33.080 an electrical field to this material, it will then allow 0:06:33.120 --> 0:06:37.040 electrons to flow through freely. This is the stuff that 0:06:37.080 --> 0:06:40.080 moves electrons from point A to point B. You apply 0:06:40.160 --> 0:06:43.080 a voltage across it, you get electrons to flow. That's current, 0:06:43.440 --> 0:06:47.720 Although technically current flows from positive to negative as opposed 0:06:47.720 --> 0:06:50.560 to the flow of electrons, which is from negative to positive. 0:06:51.200 --> 0:06:56.960 We can thank lots of early UH thinkers for that confusion. 0:06:57.520 --> 0:07:00.400 So current flow and electron flow are in opposite to actions. 0:07:00.400 --> 0:07:05.080 Thank you, Benjamin Franklin. Uh. Alright, So then you've got insulators. 0:07:05.560 --> 0:07:08.400 These do not have electrons within the conduction band or 0:07:08.480 --> 0:07:11.680 they have a full conduction band, so again no room 0:07:11.720 --> 0:07:15.000 for electrons to move around, so there are no free electrons. 0:07:15.400 --> 0:07:19.280 They impede the flow of electrons through that material, and 0:07:19.320 --> 0:07:23.560 most solids fall into this category. Metals are UH an exception, 0:07:23.680 --> 0:07:28.680 but most solids are insulators. So at normal operating parameters, 0:07:28.680 --> 0:07:31.080 you wouldn't be able to apply a strong enough electric 0:07:31.160 --> 0:07:35.239 field to make them conduct electricity. So you could apply 0:07:35.240 --> 0:07:38.920 an electric field to these things, but it wouldn't be 0:07:39.000 --> 0:07:42.480 able to jump that gap between the valence band and 0:07:42.520 --> 0:07:46.800 the conductance band, so it would just stop. You wouldn't 0:07:46.800 --> 0:07:49.320 have any electrical flow through that at all. So we 0:07:49.480 --> 0:07:52.960 use insulators for things like insulation on wires where we 0:07:53.160 --> 0:07:58.760 wrapped the wires in that to help prevent leakage or interference, because, 0:07:58.800 --> 0:08:02.160 as we've talked about many times on this show, the 0:08:02.160 --> 0:08:07.400 flow of electricity is also very closely related to magnetism 0:08:07.440 --> 0:08:10.080 and vice versa. So you have to be able to 0:08:10.200 --> 0:08:14.360 limit interference between different wires if you don't want there 0:08:14.400 --> 0:08:19.400 to be that interaction obviously, otherwise you can end up 0:08:19.600 --> 0:08:23.400 causing shorts, which is when you have an unintended connection 0:08:23.440 --> 0:08:26.360 between two different elements of a circuit and it allows 0:08:26.360 --> 0:08:29.440 electricity to pass from one to the other, almost like 0:08:29.480 --> 0:08:31.360 you think of it like a short cut, you know, 0:08:31.400 --> 0:08:34.400 when we say an electrical short and it means that 0:08:34.440 --> 0:08:37.880 the device itself will not work properly because the electricity 0:08:37.960 --> 0:08:40.840 is not flowing through the pathway you had intended it 0:08:40.920 --> 0:08:44.000 to go in. All right, then we've got semi conductors, 0:08:44.040 --> 0:08:45.960 and we'll talk more about them a little bit later, 0:08:46.800 --> 0:08:49.960 but in general, semi conductors have an almost empty conduction 0:08:50.080 --> 0:08:53.920 band and an almost full valence band, and the band 0:08:53.960 --> 0:08:58.200 gap is relatively narrow. So if you don't apply a 0:08:58.200 --> 0:09:01.800 strong enough electric field at as an insulator, but when 0:09:01.880 --> 0:09:04.920 you apply the right amount of energy and electric field, 0:09:04.920 --> 0:09:07.520 it will allow electrons jump from the valance band to 0:09:07.520 --> 0:09:10.520 the conductor band and move freely within the material. You 0:09:10.600 --> 0:09:14.000 do this by doping the material, which is when you 0:09:14.200 --> 0:09:20.160 insert impurities into the semiconductor on purpose. Doping a semiconductor, 0:09:20.240 --> 0:09:26.280 which is all about introducing impurities specifically at at predetermined levels, 0:09:26.960 --> 0:09:29.959 will determine the energy levels required to do this, and 0:09:30.000 --> 0:09:33.200 that's the basis for slid state electronics. We'll get into 0:09:33.240 --> 0:09:37.640 more about semiconductors towards the end of this. And we 0:09:37.679 --> 0:09:41.280 also have to remember voltage and current, something that I 0:09:41.400 --> 0:09:45.600 always have trouble remembering. So voltage is a lot like 0:09:45.679 --> 0:09:48.960 water pressure, all right. That's that's the the amount of 0:09:49.600 --> 0:09:54.320 electrical pressure being applied, and the higher the voltage, the 0:09:54.360 --> 0:09:59.160 more electrons want to move from the concentration of electrons 0:09:59.200 --> 0:10:03.480 to the or positive side. Now, the actual flow of 0:10:03.480 --> 0:10:07.959 electricity is the current, so they are related but not 0:10:08.000 --> 0:10:10.679 the same thing. So voltage and current, and then you 0:10:10.760 --> 0:10:13.280 multiply those two dependent together and you get the power. 0:10:13.679 --> 0:10:17.440 So voltage times current equals power. Alright, So those are 0:10:17.440 --> 0:10:20.520 your basics. Now we're gonna go through and talk about 0:10:20.640 --> 0:10:24.760 the very individual components and what they do. So first 0:10:24.800 --> 0:10:28.680 we have resistors. Resistor does pretty much what it sounds 0:10:28.720 --> 0:10:32.319 like it does. It resists but does not halt the 0:10:32.320 --> 0:10:36.800 flow of electricity. I'm gonna talk a lot about electricity 0:10:36.800 --> 0:10:39.880 in terms of water because it is a useful analogy, 0:10:39.960 --> 0:10:44.480 and it's also very common to talk about the similarities 0:10:44.520 --> 0:10:49.000 between electricity flowing and water flowing when you're discussing these components. 0:10:49.520 --> 0:10:52.319 So let's say that you have two different pipes. You've 0:10:52.320 --> 0:10:56.040 got a brand spanking new pipe. It's shiny and beautiful 0:10:56.120 --> 0:11:00.880 and free from any any irregularities, and it allows water 0:11:00.960 --> 0:11:04.080 to flow through with a minimum of resistance. That water 0:11:04.120 --> 0:11:07.360 is just flowing right through easily. You've got a second, old, 0:11:07.400 --> 0:11:11.440 gnarly pipe, and this one's got calcium build up in it. 0:11:11.559 --> 0:11:13.880 They're all these bumps and stuff on the inside. So 0:11:13.960 --> 0:11:18.600 water actually encounters resistance friction, if you will, as it's 0:11:18.600 --> 0:11:22.840 flowing through, and it does not flow through as easily. 0:11:23.440 --> 0:11:26.800 Resistors are like that old gnarly pipe, and they are 0:11:27.400 --> 0:11:32.280 invented on purpose for specific reasons. So why would you 0:11:32.320 --> 0:11:36.520 want to have an electronic component that actually slows down 0:11:36.600 --> 0:11:39.560 or impedes the flow of electricity for some reason. Well, 0:11:40.360 --> 0:11:42.640 sometimes you have to limit the amount of electricity that 0:11:42.640 --> 0:11:45.360 can flow through part of a circuit within a given 0:11:45.400 --> 0:11:49.360 amount of time, sort of like how a faucet going 0:11:49.400 --> 0:11:51.600 back to water, how fauce it can limit how much 0:11:51.600 --> 0:11:54.440 water can flow through your water pipes into your sink. 0:11:55.200 --> 0:11:58.160 So you wouldn't want just an on off switch for 0:11:58.240 --> 0:12:00.560 the water coming into your home. That water is at 0:12:00.559 --> 0:12:02.959 a much higher pressure, you know, it's it's a higher 0:12:02.960 --> 0:12:05.640 pressure to deliver the water to your house. And if 0:12:05.679 --> 0:12:08.040 all you had wasn't on off switch and you flipped it, 0:12:08.320 --> 0:12:12.760 you would have water blasting through the pipe according to 0:12:12.800 --> 0:12:14.760 the amount of pressure that was built up behind it. 0:12:15.280 --> 0:12:18.440 That'd be a little bit nerving, especially if you just 0:12:18.440 --> 0:12:21.080 wanted to have a nice frosty glass water. So you 0:12:21.120 --> 0:12:23.720 want to have some sort of limiter on that to 0:12:23.920 --> 0:12:26.719 control the amount of water that's or the pressure of 0:12:26.760 --> 0:12:29.880 the water that's coming in. So resistors reduced the amount 0:12:29.880 --> 0:12:34.040 of voltage placed on other electronic components within a circuit 0:12:34.440 --> 0:12:36.960 by restricting the amount of current that can flow through 0:12:37.000 --> 0:12:40.800 the resistor. The reason why this is important is that 0:12:41.360 --> 0:12:47.240 we cannot create a battery for every single type of 0:12:47.320 --> 0:12:51.520 electronic device that's out there. It's not practical. So batteries, 0:12:51.600 --> 0:12:56.839 different batteries, Different types of batteries have different voltages. So 0:12:57.400 --> 0:13:02.840 you could, in theory, develop a battery specifically for a 0:13:03.360 --> 0:13:07.320 particular type of electronic device that would not require resistors 0:13:07.400 --> 0:13:11.240 because the battery is providing exactly the voltage needed for 0:13:11.440 --> 0:13:15.840 whatever electronic components are in net. But it's not practical 0:13:15.880 --> 0:13:19.480 to do that for everything. We want standardized batteries, and 0:13:19.520 --> 0:13:22.599 then we use things like resistors to help control the 0:13:22.720 --> 0:13:26.280 voltage in those electronic components so that the right amount 0:13:26.320 --> 0:13:29.240 of voltage is applied to those specific parts of the 0:13:29.240 --> 0:13:34.120 electronic circuit, rather than having to have a billion different 0:13:34.120 --> 0:13:38.280 types of batteries. That would not be practical. So there 0:13:38.320 --> 0:13:41.280 are many different types of resistors designed to work on 0:13:41.360 --> 0:13:45.480 specific amounts of electrical power. Now, some have changeable resistor 0:13:45.640 --> 0:13:49.040 values dependent upon the amount of voltage placed across them. 0:13:49.120 --> 0:13:54.560 They're called nonlinear or voltage dependent resistors. Resistor values can 0:13:54.559 --> 0:13:58.440 also change when the temperature of the resistor changes UH. 0:13:58.640 --> 0:14:01.760 Different types of resistors do this. Some can also be 0:14:01.920 --> 0:14:06.360 mechanically adjusted. So it all depends upon what you need 0:14:06.400 --> 0:14:08.719 the resistor for and why what you needed to do. 0:14:08.880 --> 0:14:12.360 That's what would determine which type of resistor you would use. 0:14:13.000 --> 0:14:15.600 The unit of measurement for a resistor is the ohm 0:14:16.440 --> 0:14:20.440 oh h M. Resistor values are ten percent apart from 0:14:20.440 --> 0:14:24.080 each other, and resistors are color coded with bands of 0:14:24.120 --> 0:14:27.520 color or rings of color. So the first ring represents 0:14:27.560 --> 0:14:30.600 the first digit of the resistors value. So what you 0:14:30.600 --> 0:14:32.160 would do is you would look at the first ring, 0:14:32.280 --> 0:14:35.040 whatever color it was, you would cross reference that with 0:14:35.640 --> 0:14:39.880 the with a color UH index, and it would tell 0:14:39.880 --> 0:14:42.440 you what the value of the resistor is for the 0:14:42.480 --> 0:14:45.840 first digit. The second ring tells you the value of 0:14:45.840 --> 0:14:48.920 the second digit. So then you've got the two UH 0:14:49.120 --> 0:14:51.400 the two digits that are involved. The third tells you 0:14:51.440 --> 0:14:54.760 the power of ten to multiply by, so it might 0:14:54.880 --> 0:14:58.880 be ten thousand, and then you would multiply. Let's say 0:14:58.880 --> 0:15:01.920 that your first two digits are a twenty two and 0:15:01.960 --> 0:15:04.080 a seven, and you would multiply that by ten thousand. 0:15:04.120 --> 0:15:07.320 You have twenty seven thousand poems there, and the fourth 0:15:07.720 --> 0:15:10.000 ring would tell you the tolerance of the resistor plus 0:15:10.120 --> 0:15:14.480 or minus whatever percentage. Uh So, the physical size of 0:15:14.520 --> 0:15:16.600 the resistor and the amount of power it can handle 0:15:16.640 --> 0:15:18.960 tends to be proportional. So in other words, the larger 0:15:19.000 --> 0:15:23.120 the resistor, the more power it can handle. In general. 0:15:23.560 --> 0:15:27.640 So those are resistors covers that basic component. Now let's 0:15:27.640 --> 0:15:33.240 move on to capacitors. Alright. So capacitors are similar to 0:15:33.280 --> 0:15:37.120 batteries and that it's a means of storing electrical energy, 0:15:37.480 --> 0:15:43.000 but unlike batteries, instead of creating an a uh, electrical 0:15:43.040 --> 0:15:46.680 flow through a chemical reaction that is steady the entire 0:15:46.800 --> 0:15:51.440 time it is designed to release a it's it's entire 0:15:51.520 --> 0:15:57.880 stored electrical charge all at once. So let's say they've 0:15:57.880 --> 0:16:01.080 got two leads of a capacitor. You have a difference 0:16:01.120 --> 0:16:04.320 in voltage across these two leads. That's when a capacitor 0:16:04.440 --> 0:16:07.760 is charged. So one lead has a greater build up 0:16:07.760 --> 0:16:11.400 of electrons than the other lead does. Uh. Now, if 0:16:11.440 --> 0:16:14.640 you were to connect the leads together, you would short them. 0:16:15.080 --> 0:16:18.200 You would have a discharge of that capacitor and the 0:16:18.280 --> 0:16:21.480 voltage would equalize across the two, so you get a 0:16:21.520 --> 0:16:25.240 release of a quick burst of electricity. So capacitors can 0:16:25.280 --> 0:16:29.040 pass alternating current freely. A C current will just pass 0:16:29.080 --> 0:16:31.640 through a capacitor as if it were not really there. 0:16:32.320 --> 0:16:35.200 Direct current, however, will charge a capacitor. It will have 0:16:35.400 --> 0:16:39.480 that build up of electrons on one side, while the 0:16:39.520 --> 0:16:42.120 other side doesn't get that build up of electrons, and 0:16:42.160 --> 0:16:45.720 then you have that difference in voltage. Alternating current just 0:16:45.960 --> 0:16:50.640 will pass back and forth through it without any problems. 0:16:50.640 --> 0:16:54.400 So capacitors contain the same fundamental parts. You have at 0:16:54.480 --> 0:16:59.040 least two conductive plates separated by a non conductive material. 0:16:59.120 --> 0:17:02.680 That's the dilector. The amount of charge held by capacitor 0:17:02.760 --> 0:17:06.040 is measured in units called faret's. But a faret is 0:17:06.119 --> 0:17:10.520 a large amount of capacitance, so large that you don't 0:17:10.600 --> 0:17:13.760 really ever talk about a ferret. Instead we end up 0:17:13.800 --> 0:17:17.600 talking about micro farets, which are about a well, which 0:17:17.640 --> 0:17:22.439 are one million of a ferret, so much smaller. Faret, 0:17:22.520 --> 0:17:26.560 by the way, not ferret, two different things. Nice Mormot 0:17:26.880 --> 0:17:31.800 capacitance is dependent upon surface area, so it's directly proportional 0:17:31.840 --> 0:17:35.960 to the surface area of those leads. Those those capacity plates. Um. 0:17:36.000 --> 0:17:40.520 It is indirectly proportional to the distance between the plates. 0:17:40.600 --> 0:17:43.480 So the greater the distance between the plates, the lower 0:17:43.520 --> 0:17:49.520 the capacitance. Uh. It's also uh dependent upon the dielectric 0:17:49.600 --> 0:17:53.879 constant of the insulating material. And they are used for 0:17:53.960 --> 0:17:56.679 things that need a quick release of electricity rather than 0:17:56.720 --> 0:18:01.000 a steady flow. So, for example, a tradition all flash 0:18:01.119 --> 0:18:03.960 on a camera. So you've got an old camera and 0:18:04.000 --> 0:18:07.160 you've got the the the flash, Uh, you know it 0:18:07.200 --> 0:18:09.560 bursts in this quick burst of light. Well, it needs 0:18:09.640 --> 0:18:12.600 that quick It needs access to a quick burst of 0:18:12.720 --> 0:18:16.240 electricity in order to do that, and that's what capacitors 0:18:16.240 --> 0:18:18.440 are good for. And it takes some time for the 0:18:18.480 --> 0:18:20.719 capacitors to build up the charge again so it can 0:18:20.760 --> 0:18:23.080 do it another time. That's sort of you know, if 0:18:23.119 --> 0:18:27.000 you're using the old ones, you hear that noise. It's 0:18:27.040 --> 0:18:30.800 the the discharge and then charging of the capacitors that 0:18:31.000 --> 0:18:34.600 require you to take a moment between taking pictures with 0:18:34.680 --> 0:18:40.240 those old style camera flashes. Now obviously newer ones used 0:18:40.280 --> 0:18:43.760 different a different approach, but you often have capacitors that 0:18:43.840 --> 0:18:48.159 actually provide the electricity for those. Now, the voltage of 0:18:48.160 --> 0:18:53.400 a capacitor cannot change instantly, it's important to remember, and 0:18:53.560 --> 0:18:58.720 quick voltage changes in a capacitor produced large current changes. 0:18:59.080 --> 0:19:02.440 Capacitor store energy in an electric field. Now, the reason 0:19:02.520 --> 0:19:05.280 I mentioned all that is because we're now going to 0:19:05.320 --> 0:19:10.960 talk about inductors, and inductors are kind of, um the 0:19:11.040 --> 0:19:14.800 opposite of capacitors, or really maybe not even opposite is 0:19:14.840 --> 0:19:17.439 the right way of saying it. In many ways that 0:19:17.720 --> 0:19:20.800 they behave in opposite ways than capacitors do, but we'll 0:19:20.840 --> 0:19:31.639 get to that. So basically, an inductor at its most 0:19:31.760 --> 0:19:34.800 basic level is a coil of wires, so sometimes we 0:19:34.880 --> 0:19:39.640 just call them coils and not inductors. Uh. They deal 0:19:39.760 --> 0:19:44.479 with what is the electrical equivalent of momentum. So if 0:19:44.480 --> 0:19:48.320 you're familiar with momentum, essentially this is that idea that 0:19:48.359 --> 0:19:51.119 you get a you know, objects in motion tend to 0:19:51.119 --> 0:19:54.440 stay in motion. So let's say you've got a large 0:19:54.480 --> 0:19:58.200 mass moving at a particular velocity. It has a certain 0:19:58.240 --> 0:20:00.960 amount of momentum, and you have to overcome that momentum 0:20:01.000 --> 0:20:05.680 to slow down and stop that uh, that that mass. 0:20:05.720 --> 0:20:08.119 So it's the same type of thing with inductors, except 0:20:08.119 --> 0:20:11.240 we're talking about the electrical equivalent of momentum. We're talking 0:20:11.280 --> 0:20:15.320 about the flow of electricity. So again going back to 0:20:15.359 --> 0:20:19.119 the water analogy, Let's say that you've got a water hose, 0:20:19.359 --> 0:20:22.320 a really long one, several hundred feet long, and you've 0:20:22.320 --> 0:20:26.320 coiled it up so it's in a nice long coil 0:20:26.840 --> 0:20:30.040 and it's filled with water. There are gallons of water 0:20:30.240 --> 0:20:33.080 inside this hose, and the end of the hose is 0:20:33.119 --> 0:20:34.919 tilted at such an angle so the water is not 0:20:35.000 --> 0:20:37.840 just flowing right out. You put a plunger into the 0:20:37.920 --> 0:20:41.400 other end and you start to press on the plunger 0:20:41.520 --> 0:20:44.440 to push the water out. Now, all of that water 0:20:44.560 --> 0:20:47.920 is not just going to simultaneously start to move together. 0:20:48.040 --> 0:20:50.719 It actually is going to take some time for the 0:20:50.760 --> 0:20:54.600 pressure you are applying to exert enough force to push 0:20:54.640 --> 0:20:59.159 the water out to overcome the inertia within that coil 0:20:59.440 --> 0:21:02.760 of water hose. And once you get that water coming 0:21:02.800 --> 0:21:05.600 out at the speed at which it can come out 0:21:05.680 --> 0:21:07.359 and you let go of the plunger, the plunger is 0:21:07.359 --> 0:21:12.119 going to continue going down that tube because of inertia. 0:21:12.400 --> 0:21:14.800 That's the same sort of thing with inductors, except instead 0:21:14.840 --> 0:21:18.080 of water, we're talking about electricity. So coils of wire 0:21:18.119 --> 0:21:22.320 will pass d C current but will block a C current. 0:21:22.400 --> 0:21:25.920 So in other words, direct current can flow through an inductor, 0:21:26.640 --> 0:21:30.280 but alternating current would be blocked because it cannot flow 0:21:30.359 --> 0:21:33.760 the opposite way through the coil. So that makes it 0:21:34.359 --> 0:21:38.520 the opposite of capacitors. Remember, capacitors would pass alternating current 0:21:38.560 --> 0:21:41.679 that can flow straight through, but would block direct current. 0:21:41.760 --> 0:21:44.440 Direct current would charge a capacitor a capacitor, but could 0:21:44.440 --> 0:21:47.520 not just flow through the capacitor. In this case, direct 0:21:47.520 --> 0:21:51.360 current can flow through an inductor, but a c alternating 0:21:51.400 --> 0:21:55.359 current would be blocked. The standard unit of inductance is 0:21:55.680 --> 0:21:59.159 the henry. I wish I could tell you why, but 0:21:59.280 --> 0:22:02.159 I honestly don't know. I'm sure some of you out there, 0:22:02.200 --> 0:22:05.680 you electricians, are very familiar with the reason why and 0:22:05.760 --> 0:22:09.160 could tell me and feel free to I I honestly 0:22:09.240 --> 0:22:12.280 do not off hand. No, the inductance of a coil 0:22:12.400 --> 0:22:15.679 is indirectly proportional to the length of the coil, but 0:22:16.040 --> 0:22:20.679 directly proportional to the cross sectional area of the wire, So, 0:22:20.720 --> 0:22:23.880 in other words, the gauge of the wire is important here. 0:22:24.040 --> 0:22:26.600 It's also proportional to the square of the number of 0:22:26.720 --> 0:22:30.040 turns in the coil, and it's directly proportional to the 0:22:30.080 --> 0:22:33.840 permeability of the core material. Now the core is whatever 0:22:34.000 --> 0:22:36.160 this coil is wrapped around. Now it could be wrapped 0:22:36.200 --> 0:22:39.280 around air, or it could be wrapped around something like iron, 0:22:39.480 --> 0:22:43.240 which is incredibly effective. So those are that's what we're 0:22:43.240 --> 0:22:45.919 talking about with the cords, whatever the wire or is 0:22:46.000 --> 0:22:51.520 coiled around. So when current first starts flowing into the coil, 0:22:51.640 --> 0:22:55.280 the coil wants to build up a magnetic field. We've 0:22:55.280 --> 0:22:58.919 talked about this again and again that you start running 0:22:58.960 --> 0:23:04.560 electricity through a coil of wire that's coiled around like 0:23:04.600 --> 0:23:07.159 an iron core, like a nail, and you start to 0:23:07.240 --> 0:23:11.600 you create an electro magnet. Well, once that field is built. 0:23:11.960 --> 0:23:14.600 While while the magnetic field is building, the coil inhibits 0:23:14.640 --> 0:23:17.439 the flow of current through the wire. But once the 0:23:17.480 --> 0:23:20.960 field is built, current can flow normally through the wire. 0:23:21.760 --> 0:23:26.119 So if you were to have an inductor hooked up 0:23:26.160 --> 0:23:29.119 to a light bulb, let's say and you flip a 0:23:29.160 --> 0:23:32.360 switch so that you know, technically in an electronics would 0:23:32.359 --> 0:23:34.520 say that you close the switch, so you have created 0:23:34.560 --> 0:23:38.280 a closed path so electrons can flow through. The electrons 0:23:38.280 --> 0:23:40.520 would flow through the inductor, which would start to build 0:23:40.560 --> 0:23:43.520 up a magnetic field. So at first you would get 0:23:43.560 --> 0:23:46.000 the light bulb coming on, then it would start to 0:23:46.119 --> 0:23:48.920 dim a bit because as that magnetic field is getting 0:23:48.960 --> 0:23:52.719 built up the lightbulb, you know, the electricity would be 0:23:52.800 --> 0:23:55.320 limited to the light bulb. It would actually act as 0:23:55.320 --> 0:23:57.680 sort of resistor, and the light bulb would start to 0:23:57.680 --> 0:24:01.400 get dimmer. But then eventually then that magnetic field would 0:24:01.400 --> 0:24:03.720 get charged up as much as it can because it's 0:24:03.800 --> 0:24:07.480 direct current, not alternating current, and you would reach a 0:24:07.600 --> 0:24:11.880 level where it was stabilized. Current would flow fine. At 0:24:11.880 --> 0:24:17.280 that point, you can actually turn off the switch, you 0:24:17.320 --> 0:24:20.680 can open it. In other words, the magnetic field around 0:24:20.720 --> 0:24:23.719 the coil would keep current flowing through the coil until 0:24:23.840 --> 0:24:27.040 that magnetic field collapsed. So even though you turn the 0:24:27.040 --> 0:24:31.360 switch to off, because you have an inductor, that lightbulb 0:24:31.359 --> 0:24:35.520 would stay lit until the magnetic field and the inductor collapsed, 0:24:35.560 --> 0:24:38.520 in which case it would stop inducing current to flow 0:24:38.560 --> 0:24:42.760 through and the light bulb would go off. So the 0:24:42.840 --> 0:24:45.959