The Current Wars

this conversation. Yeah. Today we're going to talk about A C and d C electrical currents and what they mean, and why do we have them? And who are you? Oh now, the third one we're gonna skip now that

who are you? As a different band entirely h C SID so anyway, he C d C. So we're talking about direct current that would be d C and alternating current that's a C. That's the two main forms of electricity that we're familiar with, and they have a pretty long history that includes one of the most famous rivalries in technology. And we've talked about it before and we're gonna talk about it again. Yes, as uh as we speak, I currently have a picture of Nicola Tesla staring at

the side of my head. He's on the wall here. He wants to make sure you get this right. Yeah, we also have Edison somewhere in this room. Actually he's further back in the other part of the studio, but yes, Edison is also here. So Edison and Tesla are the two names of the the inventors who were kind of the the the face behind these two technologies. Edison, of course was a direct current guy, and Tesla was all about the alternating current. And they both are argued that

their approach was the best. And it kind of makes sense that Edison did it because there was a lot of money at stake. Well, and and to some degree both of them were right and both of them were wrong, and sort of depends on the application. All depends on the application and the and the source of power that you're using. So, uh, should we talk about the actual power? Well, before we do that, I just wanted to make one other,

one other mention. So those were the men, right, you had Edison and Tesla, those were the two men who were really at the forefront of this fight. Well there was one other, George Westinghouse. Yes, Well that's what I was going to say, is that behind these men were companies you had you had Westinghouse, who wasn't really a company, but you know west We now know of Westinghouse as a company. But we had Westinghouse on one side, in

General Electric on the other. Yeah, and Westinghouse was backing Tesla, and General Electric of course was Edison's Companies is backing Edison. Um, so should we should we start with the the actual current and what it does and stuff like that, and then we can talk about the people. Let's talk about the current first because that's the easiest. So we know, we've talked about circuits, and we talked about batteries. That's

an easy way to understand direct current. With direct current, you've got you have a negative poll and you have a positive poll on whatever or your power source is. So let's say it's a battery. You've got your your negative end and your positive end. The negative end that's where all the electrons are. Electrons have a negative charge, positive end. There is an absence of electrons. Now electrons, you know, like charges repel each other and opposite charges

attract each other. Yes, so those electrons really want to get to that positive end because they do not like being all crammed up together. So when you put a power source into a circuit, that circuit is really a pathway. It's a pathway from the negative end to the positive end. And the electrons say, yippie, we can go to the positive end. And they just run as fast as they can, except they don't really run because electrons don't have legs. But they go as fast as they can through the pathway.

And let's say that you decide, you know what, while these guys are running really fast, I'd like them to do a little work. I want them to light a light bulb. So I'm gonna put a light bulb right here in the middle of the pathway that they have to go through before they can get to the other side. The electrons say, don't care, just want to get to the positive end. We and they run through that pathway. They run through the lightbulb, they light up the light bulb,

but they keep on going till they hit the positive end. Right. That's direct current. It's all moving in one direction. You know. They play that little song too before they and then they have to pay royalties to that guy who's suing the bugle. Yeah, you haven't heard about that. That's a different discussion. We'll we'll leave it off for it for this but anyway, so yeah, that's excuse me, that's direct current.

It's it's a very simple way of delivering electricity. However, Uh, simple does not always mean good because simple also means that you are limited. And uh, and so now I guess we should talk about what alternating current is and then we can talk about why there was this rivalry between direct and alternating current. Yeah. Well, so Edison believed that direct current was the best application of electricity to bring power to people's homes, and so all his stuff

use this technology. But Tesla saw a different way to do this, and he decided that alternating current would work better. Now, alternating current it's sort of weird because, uh to think about because and when you learn about basic circuits um in for example, shop class or something like that, where you're creating a simple circuits that you've got your battery and your light bulb at a switch and you hook everything up and you flip the switch and like is on.

They unflipped the switch or flip it back the other way and the light goes off, Like okay, I got it. You know, exactly what Jonathan just said. It went from one end to the other. But alternating current goes change, it changes direction within the wires every every so often it goes let's just oversimplify, as we are apt or are prone to do on this show. Uh, left to right and then from right to left. So that's a little bit more difficult to explain. Yeah, it's using it's

essentially using magnets. Really, it's using magnets too. If you were to think of it in the sense of the battery, it'd be swapping the the battery ends really really rapidly. But it's what it's doing. This through magnets, not through batteries. And uh. And by moving this back and forth, you are changing the flow of electricity through those wires several times a second. Um, I believe. Let's see, in the United States, I believe that's sixty times a second, and

in Europe I think it's fifty. I believe that is correct, which is why why you have to have various adapters when you move between the United States and Europe. And you know sort of thing happens in other nations as well. Yes, I was correct, um, And we do have an article on the website about how electricity works that goes into alternating current and direct current. I do recommend you check that out because it'll have a lot some helpful information.

We also have information on other elements will be talking about shortly, like transformers, but we'll get into that in a second. So, yeah, and the alternating current, the current reverses sixty times per second in the US or fifty times in a second in Europe. And that's what you get out of the wall socket. And you might say, well, why would you want to to have the alternating current

moving back and forth like that? Well, on its on on the face of it, if you were just saying direct current versus alternating current, and you're just looking at the way that they are providing power to whatever load you've put on the pathway, like in my example it was that light bulb. If that's all you're looking at, there's no real huge advantage of direct current over alternating

current or vice versa. They both are providing power to the load you're talking about it It only comes when it only gets down to when you are talking about generating power and delivering that power to another location. That's when you start looking at uh the advantages of alternating current over direct current, and that's the the that was

the heart of the issue between Tesla and Edison. Edison had a lot of money invested in direct current, and he had a lot of patents uh that were directly involved with direct current, and he was drawing royalties from those patents. Because you had power stations that would be using direct current, they'd have to pay a fee to Edison. So it was within his financial interest to really promote

direct current. And Edison was a master promoter. That was one of the things he was amazing at along with you know, he was a brilliant inventor as well, but he was also a great marketer. Tesla not as much, but Tesla felt that he was in the right. We get that argument a lot through the whole Tesla story. Yeah, Tesla. Tesla though, like to do demonstrations with electricity that showed him basically holding onto a source of electricity and there were sparks and things, and it it freaked a lot

of people out. But Edison had had a particular demonstration. Well, we will have to talk about that really freaks people up to I'm hoping that we can keep that discussion to a minimum because that still turns my stomach. But anyway, so we should we should continue talking about the delivering power. So um yeah, the for edison to use the direct current doesn't doesn't really travel well, or didn't back in

the day. They have found ways to to provide to help it travel long distances better now, But at the time, you had to have local power stations, very local power stations, like within a mile or two of wherever it was you were delivering power, and you could you had to deliver the same amount of power that your load was going to require. Um. In other words, you can't change

the voltage easily on a direct current system. And the reason why that's important is let's say that you have a h you have you have a device, or you have you know, you have some sort of electronic load that's going to require oh um a certain number of volts will say a hundred volts, and that means that for a direct current uh generator, you would have to generate a hundred volts actually be around a hundred and

ten because you do lose some electricity. There's a leakage issue with direct current that that that gets worse over distance. So you would have to um, you would have to actually have a generator that created the same voltage as what you were going to consume. And if you had a lot of different demands on this electricity, like you had a lot of different things that use different voltage, then you would have to have a different generator for

each kind. And that's not very efficient either. And uh and because this these two problems, the fact that you could not send power over really long distances and you couldn't change the voltage easily, there were some disadvantages to this, and the biggest one is probably the distance thing, because it meant that you had to build generators all over the place if you wanted to distribute electricity over a region.

And this got problematic, particularly when you go out to rural areas, because are you going to build a generator for every couple of houses that are miles and miles and miles Apart that that's not very cost effective for the people who live there, why would they even adopt

electricity if that? If it meant essentially that they had to have their own generator right there, and and so alternating current got around this, and I guess I guess to really understand this you kind of have to talk about, uh, current versus voltage. So because voltage is is really and this is sort of weird to think about, it's a unit of electrical pressure rather than current, which is the

number of electrons. Really, so you you measure we talked about current in terms of amps, and amps really refers to the number of electrons that are moving through that that circuit. Voltage, like you said, is more like pressure. It's the amount of power you've put behind those electrons. So if you had high voltage low low amps, then you would have relatively few electrons moving with a lot

of power. If you had low voltage high amps, you have a lot of electrons moving at low power um And if high voltages travel further, it's because you know, you've put a huge amount of energy into this this current, and it's going to push the electrons further than it would with less leakage than it would if you had a low voltage. See now I'm thinking of a different

song by the same band you quoted initially. Voltage. So in other words, in other words, let's say that you've got imagine you have a pipe in front of you and it's a you've got a bowling ball that will fit inside this pipe. So that's a pretty big diameter, right, doesn't matter. It doesn't matter the reason why I'm saying. Let's say that let's say that you get a little kid to give that bowling ball a push. Well, that

bowling ball is only gonna go so far. And then let's say you get a guy in the World's Strongest Man competition to get come along and give it a push as hard as he can. That ball is gonna go much further. Well with direct current because the generator had to be the same voltage as whatever the this that the actual receiving um appliance or or load was going to be. You couldn't crease that voltage to make the current go further because if you did, then your

loads wouldn't work anymore. They be overloaded because you know, the voltage would be way too high. But alternating current, because those electrons change direction, they create something else that allows you to boost and then reduce the voltage along power lines. So the power that comes out of a power generator, uh, the electricity that comes out of a generator plant doesn't necessarily have to be the same voltage as what's actually traveling through the power lines on the

power grid. Now you need something to step up the voltage, which is the transformer. And they are indeed more than meets the eye, but they are not robots that change

into other forms. A transformer, UH is a way to change from one voltage to another, and it's actually at its heart, a transformer is incredibly simple and it all has to do with the relationship between electricity and magnetism, which we have talked about many, many times on this podcast, but in general, if you've forgotten, if you if you

have if you're just tuting it. Yeah, if you have current moving through a wire and you and that will generate a magnetic field, particularly if you're alternating that current, it creates a an alternating magnetic field. All right, So the currents reversing back and forth through this line that's creating this this uh magnetic field that itself is changing over and over again. So let's say you've got a coil of wire next to an alternating magnetic field, of

magnetic field that's influx, it's changing over and over again. Well, if the magnetic field is changing and the coil of wire is close enough, that's going to induce electrons to flow through the wire. All right, So using this we can make alternating current and create a and create a transformer. You have one coil of wire, that's your primary coil. You're running electricity through this coil and it's an alternating current, so it's going back and forth, reversing direction through through

this coil. You put a secondary coil near the primary coil. The magnetic field generated by the primary coil will induce electricity in the secondary coil. And here's the really cool thing. The number of coils in the primary coil versus the number of coils in the secondary coil will determine how the voltage changes. So it's very simple. Yeah, let's say that you have one coil in your primary coil, so you just do one turn and that's it, and you

have ten coils in your secondary coil. The amount of voltage in the secondary coil that's generated from that magnetic magnetic flux will be ten times as strong as the primary coil, so you have stepped up the voltage. So what you do is at your power generation plant, you have a primary coil that is a certain number of coils, and your secondary coil has way more coils, and the

ratio there will determine how much the voltage changes. You then transmit that electricity through wires to wherever, you know, through to a residential neighborhood, let's say, Well, as the the electricity travels there, once it hits the the the the power lines, the power poles that have the connection to your house, there's a transformer on those those uh, essentially their telephone poles. That's what we think of them as, right,

they have they have transformers too. Now in that case, they their primary coils have more coils than the secondary coils, so the voltage is stepped down. And that means that even though the voltage in the power line that's coming down the street is really really high, way higher than what you need in your house, in fact, so high that it's you know, incredibly deadly. Um, once it goes through that transformer and goes to your house, it's going

to be at the right voltage for your home. Yes, and we usually in the United States that would be a hundred and twenty volts. Because remember we talked about it reversing sixty times a second, Well, you have to add the two sixties, right, the sixty positives and the sixty negatives for lack of a better term, add those together and it's not like sixty plus negative sixty at

sixty plus sixty hundred twenty volts. And that solves the problem that you were talking about earlier with the need for the generating Russian to be to match exactly the the the load at the other end, right, And it it solves the problem of the distance issue too, because you've you have upped the voltage so high that it's going to transmit over a much greater distance than direct current will and so um, you've just solved that issue of how do you deliver electricity in an efficient way

so you don't have to build generators every couple of miles and uh, Tesla and Westinghouse I thought this was a brilliant idea. Edison of course, did not like it because it did not it was it was it was a competing standard to his own, and it was going to mean that he was going to be out some

serious dough. So there there became a kind of a series of one upmanship demonstrations across well mostly the northeast, but uh, it was an attempt to to make to to try and have one standard come out the supreme leader in electricity. Yeah. We uh, we've talked about these things,

not in then and then not terribly distant past. At this point when we're recording is um and I believe I revealed at one point that I had read the book Empires of Light by Jill Jonas Um and I'm probably still mispronouncing her last name, UM, which is about this about the current wars, and uh, it paints a really unflattering picture of Edison really when you learn a lot more about it. Um. Now, Tesla was sort of a eccentric. He was an eccentric. He also kind of

liked to live the high life. Uh. He liked expensive stuff and eccentric dandy who got progressively crazier as he got older. I wouldn't say crazy, No, I would still be alive in some capacity. Um. Now I'm a crazy one. So yes, my co host is joining Tesla. No there, it's it's fun to just, you know, make those jokes. Uh. No, he uh, he wasn't really in the business of He he liked to invent stuff and he actually at one point worked for Edison. Um. They didn't always see eye

to eye. Before all this happened. Um and uh, I think Tesla sort of felt like, based on what I've read, Tesla sort of felt like he was underappreciated and wanted to strike out on his own. And this was one of the things, one of the many, many things. Of course, we talked about radio and how he worked on that. He's um, he got involved with a lot of different

kinds of things. And I've also read that that in general, and this may be an over generalization, but in general that Edison took a very experimental approach to learning things, Like he he was all about doing something and if that worked, then that's great, solve that problem. Whereas Tesla was more about understanding and thinking things through and then designing stuff that builds on that knowledge. So you know,

it's two different approaches. And I've even seen it referred to as Essen's approach being more of a brute force approach, like you know, you try something and if it doesn't work, well, that's too bad. You go on and you do something else, and whereas Tesla was more of an architect, someone who would think things through before actually committing to action. Although one would argue based upon some of Tesla's later works

that that was not always true. So we're talking about the one upsmanship, the battles between these two well Edison Edison was really UM did a lot of his own promotion UM and Tesla UH did a lot of his own personal promotion. UM. So they were really kind of different people. I mean Thatison was really working on his company and building that up UM and Tesla licensed his

patents to UH George Westinghouses company. Westinghouse. He would also be sort of an interesting person to talk about with on his own show, if we ever get around to that. But he invented a railroad break that was very very popular. He made a lot of money doing this, and he saw a way too. He started getting into the electric game two. He saw himself as a somebody who could actually take on Edison and some of the others who

were involved in this. They weren't the only two um because this was you know, it's like a lot of stuff like UH computers and so many other things, the internet, uh phones. You know, at that point when when Edison and Tesla were really doing this, they were all there were many many inventors working on solutions to these problems. How were you going to wire up homes, building the infrastructure and that kind of stuff. So Westinghouse licensed Tesla's

patents and began building equipment. Um, and they've been They began competing for different projects, such as the Colombian Next Exhibition in Chicago, which was the World's Fair, and who was going to light the World's Fear because they really wanted to do this thing right. They wanted light bulbs everywhere because really, I mean there were very few people who had their homes wired for light. Um, this was gonna be really cool, and they were. When they succeeded

in doing so. Um, that was a huge, huge thing because people wanted to see it at night when everything was lit up with electric power. Yeah, that was in So while they are arguing over who gets to light up the World's Fair, Dr H. H. Holmes is creating his his Reign of Terror as America one of America's first serial killers. Yeah, just like i'd throw that out there. Stuff. You should know did a show about him? Really? Yeah.

There's actually a fantastic book called The Devil in the White City that is the story both about H. H. Holmes and his activities and the the preparation and execution of the World's Fair. And frankly, the World's Fair sections in that book were to me ten times more interesting than the story about the one of America's first serial killers.

And it's kind of but it was. It's because you have these incredible personalities that were all mixing to make the World's Fair, and Tesla and Edison were two of them, and ultimately Tesla one and that was a bitter fight. Yeah, and UH and Edison. You know, he was not above some pretty outrageous displays to try and win people over

to his side. One of his arguments was that because alternating current had these transformers, and because alternating current would UH would transform a low voltage into an incredibly high voltage flow of electricity, he argued that all turning current was was inherently dangerous and direct current was safe or

considerably safer. Exactly so he would demonstrate this, and this is absolutely horrifying to anyone who's an animal lover, by holding UH a public hearing and then using alternating current to electrocute as in, to kill animals with electricity. UH. The the probably the most famous example of which was an elephant named Topsy. Yeah, Harold Brown sort of a bit player in this whole drama. Um was a guy that from what I can tell, uh and Empires of Light sort of came out of nowhere. He wasn't really

an employee of of the Edison company, but um. He was also of the belief that alternating current was extremely dangerous. And Edison saw a way to promote the idea that a senating current was dangerous and direct current was safer, um by using Brown's experiments. And he you know, basically experimented on on animals and showing that, uh, the amount of current of alternating current would take to kill somebody was considerably less than the amount of direct current it

would take to kill somebody. Um. And they did experiments on animals both and and if I'm not mistaken, in private and in public the public demonstrations, you know, they they electrocuted dogs and other animals, including Topsy the elephant. And then they decided to uh promote a new way of uh dispensing justice. They built the electric chair. Look how dangerous alternating current is. They can use it to

put criminals to death. And they promoted this as a way to you know, for one thing, they were uh theoretically providing a public service, right, you know, it's a new way to to execute convicted criminals. But also it promoted their ends by saying, look, how dangerous alternating current is, so we should all invest in direct current. Ultimately, that argument did not win, and so alternating current because it just made more sense financially as far as a way

of distributing electricity across wide areas. Uh, that's what went out, I mean, and it makes sense in that use case. Right, It's not like direct current went away. It's not like we don't use direct current. And lots of different things right now. Yep. And in fact, um, depending on the device,

you may be using both. You know, they're um, some of the adapters that you plug in for portable electronics have a DC output even though they're taking their you know, yeah, exactly, you're you're taking alternating current from the wall and then the converter converts it from alternating current to direct current before it delivers the elector to whatever device you're using. Yes, yeah,

there there are plenty of examples of that. And of course if you have anything with a battery in it, well that's you know, a battery, Like we said, in the very first example, that's direct current unless you are having some weird way of swapping the batteries poles over and over again, which I can't imagine you're doing that. Um then quick, yeah, yeah, that's a direct current. So

so we still use both. And there are a lot of reasons why you would want to use direct current for especially for anything that's like, you know, not connected to a power source, or not a power source but a power plant. Um So there's we still use direct current and plenty of applications. But when it comes to delivering electricity across huge distances, alternating currents the way to go. It makes perfect sense. By the way, have you ever seen a transformer blow? No, but I've heard them. I've

seen it a few times. It is a pretty spectacular and incredibly startling thing to see. Yeah. Yeah, every once in a while you will hear one, uh you know, blowout in your neighborhood or actually there was one here in the Atlanta area just yesterday that started a brush fire when it when it exploded. Yeah, you usually see a lot of sparks, and there's normally a very loud bang. Actually, there's always gonna be off really loud bang and it's Um.

I remember the first time it happened. I thought someone fired a shotgun off next to the car I was in, because it was we were going down downtown Atlanta in a thunderstorm and a power surge caused the transformer to overlow and overload rather and it uh and it blew out the transformer. Uh. Yeah. And and transformers are a little more complicated than just two coils of wire. That's just the basic that's the that's the core of a transformer. Yeah,

we wanted you to understand the concept. You can. There's there's plenty of reading to be done, believe me, on on these things. Yeah. Check out our articles on electricity and transformers. Uh. They are They are very helpful. There are a lot of really cool illustrations, and I think you'll find it interesting. Um. It definitely helped me understand a little better about the subject before we came in

here today. Yeah. Yeah. And and although we were joking about the the toy slash movie transformers, we have articles about that too. So if you are highly entertaining, if you want to read her about optimist prime, we've got you covered. And real transformers or sort of actually, I think the one that's about the robots is called what are Real Transformers? Yeah? Exactly, Uh so, well, so yeah,

check them out. Check them out. It's good stuff. And uh, let's know, if you guys want us to talk about any particular subjects, We've been getting a lot of really good suggestions from Facebook, from Twitter, from email. Keep them coming because it makes our jobs much easier when we know what our listeners want to hear. And you know, we try not to concentrate on any one particular type of subject for too long other than technology. We seem to be stuck on that for some reason, So let

us know. You can let us know on Facebook or Twitter are hand Gold. There is text stuff h s W or you can send us an email on that addresses tech stuff at how stuff Works dot com and Chris and I will talk to you again really soon. Be sure to check out our new video podcast, Stuff from the Future. Join how Stuff Work staff as we explore the most promising and perplexing possibilities of tomorrow. The How Stuff Works iPhone app has arrived. Download it today

on iTunes. Brought to you by the reinvented two thousand twelve camera. It's ready, Are you