Pragmatic 53: Overlapping Signals

16 January, 2015


There is a growing trend to eliminate the wires and go wireless for data and for power. Can it work? Is it practical? Dive in.

Transcript available
Welcome to Pragmatic Pragmatic is a weekly discussion show contemplating the practical application of technology. Exploring the real-world trade-offs, we look at how great ideas are transformed into products and services that can change our lives. Nothing is as simple as it seems. This episode of Pragmatic is sponsored by Igloo, an intranet you'll actually like. Built with easy to use apps like file sharing, blogs, calendars, task management and much more, visit to get started. It's free to use for up to 10 people. This episode is also sponsored by is the easy and affordable way to learn where you can instantly stream thousands of courses created by experts in their fields of business software, web development, graphic design and lots more. lots more. Kickstart your new year and challenge yourself to learn something new. Visit to get a free 10 day trial. There's something for everyone. So if you ever want to learn something new, what are you waiting for? We'll talk more about our sponsors during the show. I'm your host, John Chidjie, and I'm joined today, as always, by my co-host, Vic Hudson. How are you doing, Vic? I'm good, John. How are you? Very good. Thank you. Well, today I'd like to talk about the trend of going from wired to wireless. And when I say that, I mean, it's something I've been noticing, particularly Apple doing, but not just Apple, although a lot of their stuff is going this way where they're getting rid of wires and they're going to wireless. And what's prompted this is, and I don't do topic based episodes and besides, I certainly don't do rumors, but I still will take I if I see something that sparks off something that I think is worth discussing then, you know, fine. So what triggered this off is a gentleman by the name of Mark Gurman. Are you familiar with this gentleman? I think I might have heard some things he's written about. OK, so he revealed, quote unquote, revealed that the next MacBook Air would come in a 12 inch model with a single power and data port power slash data port based around USB type C connection and only a headphone jack would remain on the other side. Yeah. Now, of course, you realize they're going to change this now since he leaked it. Leaked what? A mock up? Bottom line is it's a digital mock up. Yeah, I'm not I'm not mocking the mock up. Actually, hang on. I am. But never mind that. The truth is that I'm not interested in whether or not that's actually true. But here's what is true reflect on the fact that in the last six or seven years Apple have released a wireless Bluetooth keyboard. Actually no, before the Aluminium Bluetooth keyboard there was the white plastic Bluetooth keyboard. I had one of those as well. And the Magic Mouse is also wireless and now the Magic Trackpad as well. So they're moving away from And there's no wired option. You can't get a wired Apple mouse anymore. You can't get a wired magic trackpad, for example. It's wireless or it's nothing. Yeah. So, it's pretty clear to me that Apple is going for the whole "here is a beautiful iMac on your desk", let's say. You want to have a keyboard, you want to have a mouse, you want to have a trackpad to interface with this thing, then there are going to be no wires between it and the computer. So, that's what they're pushing. They even brought out their own little battery charger with Eneloops, I believe they are, Rebadge, something like that. I don't know that. Anyway, point is that they are systematically eliminating wires. All in with the Bluetooth low energy. But see, it got me thinking with Wi-Fi, with Bluetooth, especially Bluetooth for low energy, there is undeniably a trend that wireless is the way to go. But problem I've got is that that simply is not true for a lot of things. So I thought it might be interesting to explore that and figure out why. What do you think? I think it sounds good. Cool. All right. Pure and simple, energy can be transported wirelessly. Essentially, you know, data is modulated power, essentially low power, but it's modulated energy. And of course, power is purely about moving a charge from one place to another. So, data and power need to be tackled separately. So, let's start with the simplest and easiest, which is wireless data. So, let's talk about optical. Wireless data in an optical sense, the very first kind of wireless data optically was infrared. It doesn't immediately come to mind for a lot of people because they think, you know, wireless data, well, yeah, we're talking about Wi-Fi, right? We're talking about Bluetooth, that's what we're talking about. But from an optical point of view, infrared came before that. - Yes. - Now, wavelengths aside, obviously, it's infrared, but think about a laser in a fiber optic cable. The laser is essentially bounces inside between the inner core and the outer sheath of the fiber optics. And I'm not going into a long protracted discussion about fiber optics, a whole other episode, but think of infrared like unbounded fiber optics. So you're transmitting an LED or a laser an infrared transmitter and it's essentially bouncing around the entire room. So it's wireless and it's broadcast unlike fibre optic, which is essentially transmitted down a single fibre and a single cable. See, infrared on the surface sounds like a great idea, but it's very prone to interference. So you're going to get a lot of reflections off the walls. you're going to get a very different bid error rate in a reliability essentially, based on whether the room is brightly lit or if it's daytime versus if it's dark in the room or if it's nighttime. So that's going to affect its performance. The data rates, therefore, have to be much lower. Otherwise, you're simply not going to get an accurate, you're not going to get a consistently accurate data transfer from one point to another. Yeah. Very lousy. - Yeah, it is exactly. So low data rates, therefore means low bandwidth, therefore means you can't transfer very much. So it's really great for basic messaging, like a remote control, but not for much else. Like turn this on, turn that off, select this button, this channel, up volume, up volume, down. Beyond that, there's not much else you can do. Now I've played with a few IR infrared blasters, IR blasters, and there's a way to Neelye. And infrared communications links, I've actually had a couple of those. I played around with one in the late nineties and again in about 2005. And I have not seen one since the mid noughts. And that was a professionally for an infrared link, data link. And that was around about the time that wifi was becoming more ubiquitous in an industrial environment. So, you know, it's pretty unusual to get an IR data link that is not a remote control. But the bottom line is that generating that infrared is in fact very low power. And that's the other main reason. It's also been around for a long time, it's low cost. So there's lots of good reasons to use infrared. There's also a lot of bad things about infrared. So infrared operates between a series of infrared wavelengths. problem with that is that it basically means that you don't have many options. Because if you change your wavelength too much, then it ceases to be, well, it ceases to be infrared. But, okay, why is that a problem? What it means is that because it's scattered, because it has, it's prone to a lot of interference, there's only a small subset of channel of wavelengths that they will use on, because they don't want to have invisible light. Otherwise, every time you push a button, you'd see the flashing and that's going to be distracting for a lot of people. Yeah. So it's got to be outside the visible spectrum and that's fine. But you just got a much narrower spectrum. And because it's anyone can do it. So if I have three remote controls in the room and I all push a different button at the same time, God only knows which one will get through to the infrared receiver. So it's a party line, just like any other radio communications channel. But because you're transmitting optically, you know, there is no you cannot do code division, multiple access photonically. For people that want to dive into the physics as to why it should be obvious as to why, but never mind that. OK. So basically, it limits the way you can manipulate the signal to embed data into it, right? Yeah, exactly. And the bottom line is that in a room, think of the analogy this way, I've got Wi-Fi in my room. Okay. And I've got multiple iPhones. Now, what if those iPhones were talking to a base station sitting in the corner, there has to be a visible link between the two. You have to be able one has to be able to see the other. And if they're all talking to it at once, it won't work. Yeah. That's the problem. So it's not a good multiple access protocol. It's extremely limited in range, it's prone to interference, it's low bandwidth. And in other words, it's just not a winner. Okay, so that's our first example of wireless data. So I've already mentioned the radio equivalents. So the radio equivalents of wireless are the predominant standards. And there are a lot of standards, but I'm just going to cover the two biggies, which are Bluetooth and Wi-Fi. And I'm really not going to talk too much about them because frankly, that's not what's interesting. I'm sorry, I don't think that that's as interesting as what I would rather talk about. So let's just say that Bluetooth low energy It still uses more energy than infrared, but it's a hell of a lot better than the earlier versions of Bluetooth. Wi-Fi is not energy efficient at all, which is why low energy devices will prefer Bluetooth. There's a bunch of reasons why, but that's another show all unto itself. But the Wi-Fi will give you the high bandwidth. But unfortunately, high bandwidth and high data rates means more power, and that makes it a bad choice for wireless devices typically. The only reason it can go on a smartphone is because you charge your smartphone every day. Can you imagine having a remote control that you had to charge every single day? I mean, and I know that the Harmony One remotes, you have like they're rechargeable batteries in them, I believe. Yes? I'm not sure I'm not familiar with them. I think they are. The point is that, you know, you don't have to charge them every single day. And I think that having a remote control that worked on Wi-Fi that you had to charge every single day, no. that be a bit of a downer? Yeah, it's the sort of technology that it's great for something that has a lot of data to transfer, but most things don't, unless it's a smartphone or a tablet. Most of the other devices around the house, they don't need that. So, you know, headphones, for example, light switches or television remotes, all that stuff. So, radio, there you go. And of course, the great thing about radio is it works between walls. You can digitally encode it so that you can have overlapping signals and using cross-correlation, you can actually extract overlapping signals from on top of each other on spread spectrum technology, which means you can have multiple access. You can have CDMA technologies. You can have MIMO, you can have all sorts of other different things I've talked about in different episodes of the show, not going to go there. However, cables. So we've talked about going wireless and wireless data and other different options there, but you know what, what about the cables? So just briefly, the most common cables you're going to use for data transfer are going to be made out of copper, single core, stranded, doesn't matter, twisted pair, copper is the most common, by far the most common. It's flexible, it's relatively cheap, although the price would keeps going up because people keep needing it. Or aluminum, which is cheaper again, but it's not as flexible. So, aluminum is, or aluminum if you prefer the North American brand name that everyone has come to associate with the metal itself, but the name of the metal is aluminium. So anyhow, although it'll be an aluminium alloy, sometimes steel is used as well, far less common because steel has not as good a resistance. It's got a higher resistance than both copper and aluminium. So, you know, that's how you will get the data around. However, I mentioned optical before, obviously you can trap it in fibre optics, single mode fibre, multi-mode fibre, PCF, which is plastic core fibre. You know, bottom line, fibre optics, the light bounces around inside the fibre optics, taking the light pulses from one end to the other. Hey, Presto, are you carrying data? That is a whole nother topic, how that works for another day, maybe. Bottom line, it can't carry any power. It's only carrying light and light does not have enough energy in it. So, it's only good for data. Whereas copper is capable in larger diameters of carrying energy for charging. And that is actually very, very useful. So as I was saying before, wireless methods are best thought of as one enormous cable, transmission line, whatever you want to call it. It's a large room and any device can talk at any time and there's no control. There's a limited amount of bandwidth in wireless. Once it's gone, it's gone. But if you encapsulate that in a cable, you can have... Technically, you'll have less bandwidth. It's not as a wide open ocean as the ether, right? That is true, you'll get less bandwidth, but you can have bandwidth stacked up against each other. in space, right? But I hate this expression, space division, multiple access. Seems like a cop out to me because everyone's like, oh yeah, you've got an SDMA system. I'm like, space division, yeah. Conjures up images of some kind of thing in outer space or something. But space division, multiple access, I mean, it's just an expression I've heard people use for I've been using lots of cables bundled together. But the cables, because they contain all of that information, all that energy inside them, you can then stack up a whole bunch of them next to each other. And in parallel, you can pass enormous amounts of information. When you lay a fiber optic cable, the fiber cores are tiny, really small micrometers, you know, in diameter, you can have 48 core cable is very common. Like a project worker on the moment, 48 core cable is the standard. Now, we're using something like a dozen of those cores, maybe two dozen, you know, and that's half utilised. Yeah. So, and that's an enormous amount of data and each of these fibre optics are single mode fibre, you can get gigabit data over 110 kilometres of range. That's huge, you know. And that technology is improving all the time, you put a bunch of those fibres in parallel and hey, Presto, you've got, you know, not just gigabit fibre, you've got terabit fibre. You know, and you will never get terabit wireless between those two points for anywhere near that amount of cost. You just won't. Yeah. So, wireless has issues with a lot of people talking at once. It's behind the amount of bandwidth you can do on a cable, but not because the bandwidth in and of itself, in and of itself, the bandwidth is actually better because you've got no impediments other than the radio transmitting and receiving. But the ether itself has less restrictions than a cable does. The capacitance of a cable increases, the fiber optics, the aberration, you reach a certain point where you can't put more data and they're making all sorts of strides with wavelength division, multiple access technologies, wavelength division multiplexing, I should say, on fiber optics that is improving, but there's still a limit where the different wavelengths are going to start interfering with each other. And there's only so far you can push it before the physics get in the way. So encapsulating it causes more problems in a lot of respects. But because you can stack it up next to each other, you get a higher net transfer rate because you're higher, your transferred, your data transfer density, think of it that way, maybe is better with cables. The other best part, there's no interference to or from other users in same physical proximity. And I mean for shielded stuff. So you know, decent, any fiber optic cable, the fibers are sending light, the lights contained within the fiber, there is no interference, and I can't be affected by interference. It's perfect. It's beautiful. And I love fiber. However, you know, as long as you've got shielding on like using a coaxial cable for your transmission line, or if you're using shielded cat5, cat6, cat6e, whatever the heck you're using, doesn't matter. Yeah, and it's well shielded, you can stack up as many as you want next to each other. And in fact, the twisted pairs that they use for the standard unshielded cat fives is usually good enough to avoid interference and cross talk. So, you know, generally speaking, your cables aren't going to interfere with each other. Whereas with wireless, no, wireless, you will get interference. Okay. So that's all well and good. And you might just say, "Rararar, hang on, I like cables. Well, hold on a second. Why do we want to get rid of cables in the first place? Well, freedom. It's freedom, baby. Yeah. Oh, that was such a bad Austin Powers quote. Anyhow, shoot me now. Cables can get damaged. Actually, is Austin Powers still cool? I mean, on a coolness scale, is it still cool or is it just over? I still enjoy watching them every now and then. I did hear a rumor a little while back about a possible fourth movie in the works. Oh, Spaceballs 2, the search for more money. It'd be interesting if that ever happens, but if it was anything like the fourth Indiana Jones, I'll gouge my eyeballs out when it's done. OK, and then and then reinsert them promptly so I can find my way to the exit of the theatre. Moving on. Cables can get damaged. I mean, you can always get a cricket bat and have a swipe at the air if you want, but you're not going to break it. Well, I mean, you know, you might break your back or your cricket bat, you know, careful, but you're not going to hurt the ether. Mind you, if you had like a quantum singularity or a black hole, that... I can't throw one of those, though. Connectors also have a finite number of connect-disconnect cycles before they are worn out. And we've talked about this previously on... I'll take the gold plated something or other. Extra oxygen cables, please. Yeah, that was one of the longest titles of an episode. I think it was 17. Anyway, there'll be a link in the show notes. But yeah, there's a limited number of connectors connect cycles for every connector. So obviously, connectors suck. But the biggest and simplest problem with cables is that you have to carry them. So imagine if your iPhone could only talk to the Internet if it was connected by a cable. I mean, that would suck, right? That device just lost a lot of appeal. Well, exactly. So you'd need to carry a cable around everywhere with you. You know, that's ridiculous, right? We think that's ridiculous. So, all right. Before I go any further, though, I'd like to talk about our first sponsor, and that is Igloo software. 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There's no credit card required, no obligation. Just sign up and have a play today. And I say play because honestly, it doesn't feel like you're doing work. So I'd like to thank Igloo once again for sponsoring Pragmatic. So let's just talk about mice and keyboards quickly, the whole USB and the wireless thing about that, I mentioned them earlier, but I thought it might be fun because regular listeners know I have a strange idea of what's fun, but this is fun. Let's figure this out. Power that enters the household off of the grid, let's assume you're going straight into the mouse, like it used to back in the good old days. So there's no batteries, there's no wireless and not anything. It's just as you need to use it, electrons are used, they are consumed. There is no loss. Well, there is loss, but there's not much loss. So consider that your baseline. Now, I'm going to charge a set of batteries through the proprietary charger, OK? The loss that we've talked about on previous episodes is between five to 10% when you charge a battery. So you have to put in 110% or thereabouts of the energy that you're going to try and extract that 100% of energy out. So you need to put in an extra five to 10, if you want to think of it that way. It depends on how you want to spin it. But the idea is that there's 5-10% worth of loss there, right? Yeah. Because once... Oh, yeah. And the other downside is, of course, that energy dissipates over time, even if the battery isn't in use, it'll naturally dissipate, which, you know, if you're drawing electricity from the outside world, that is not the case, right? Electricity is always there on the grid. You draw it down only when you need it. Now, you know, obviously that it's the law of large numbers, it's a grid, there's a whole lot of other inefficiencies and all sorts of little caveats to that, but essentially think of it that way. Think of it as an infinitely small impedance. You can simply draw whatever the heck you want, whenever you want with no significant loss. Whereas with the battery, you have to put that charge in. And once you take those batteries out, put into the device, the device is still going to consume exactly the same amount of energy. It's just it's going to draw it from the batteries. The batteries are dissipating energy. The batteries have already lost energy in their charging cycle. So you've already lost energy twice by going to a battery. OK, there is absolutely no doubt whatsoever that batteries will use more power than if you were to plug a wire into them directly into the wall that has an infinite supply of electricity. Okay, but having said that, there are certain applications where going wireless with a battery is the preferred method for usability reasons and that's fine. So I said before, how would you feel about walking around with your iPhone tethered to the wall. Well, first of all, that would suck bad. That would be extremely a high level of suckage. So when people say, you know, about the keyboard and mouse thing, let's get rid of the power cable because I want to clean up my desk. It irritates me. And I've even, I have even from time to time flirted with that expression, I'll put my hand up. So therefore, I must by extension have irritated myself. And I did. Anyhow, there's no real measurable functional benefit from having a wireless keyboard or a wireless mouse. And I say that and I mean that there is no measurable functional benefit. Now there is a visual benefit. I'm not looking at cables. But honestly, there's really no other advantage because it makes whatever device you're using heavier because it's got to carry the the batteries now. It essentially increases the complexity of the device. Well, generally speaking, yes, I think it does. And honestly, you have to go through the mechanism of removing the batteries, putting in freshly charged batteries, all that extra little thing you got to do. And maybe that's only once a month, maybe that's twice a month. You know what? If you plug your laptop mouse in and it's always plugged into a desktop, You never have to do that ever. You'll leave it plugged in. How many people plug and unplug their mouse from their iMac or their Mac Pro? All three people in the world that have a Mac Pro these days, you know, whatever you've got, Mac mini. If you've got a laptop that you're constantly disconnecting and reconnecting and taking taking to and from work like I do, that's different. But I don't unplug the mouse. You know, I don't unplug the keyboard more accurately. No, no, no. What do I do? I have a hub. I unplug the hub, you know. So I already have to do that. What's the point of having a wireless keyboard on top of that? There's no point because I've already got unplugged something. Yeah. You know, so when people sort of say, oh, yeah, but, you know, I can now type in my lap, it's far more convenient. Well, you know, you can type in your lap with a cable. Are you going to trip over the cable? Is that a functional benefit? Well, you know what, from an RSI point of view, that makes me cringe. typing with a keyboard sitting in your lap is generally not the best angle for the vast majority of people. So that's going to be bad for RSI anyway. And I refer to you to the episode I recently did with the guest host, John Siracusa, where we talked about RSI. You know, it's all about the angles. Yeah. And that's not a good angle. So you're far better to create more room on your desk using a monitor arm than you are by replacing wired devices with wireless devices, in my opinion, because you can always bundle the cables and keep them off to one side. And frankly, you want to reclaim desk space. If you got a monitor on a stand, well, that sucks. A monitor arm will give you a bunch of space underneath. That's what I've done. I've gone to a monitor arm on my desk now. I've got the the Onyx Blackjack. I've got speakers. I've got my keyboard can slide in underneath there to get it out of the way to give me more workspace because I can do that now. I've got that space underneath now. I can put whatever I want into there. and all of my cables were all bundled together. And essentially, I just have like the power and a couple of USB connections in and the external monitor. I mean, yes, I could put it all on Thunderbolt and one power connector if I wanted, but that's expensive. Yeah. So, you know what I'm saying? It's like, I do not see the benefit. I just don't. I just don't. So you're essentially accepting inefficiency for tidiness and additional expense because it's more expensive with having to maintain batteries and so on. So then I thought to myself, OK, let's think about the connector failure versus battery failure. So in other words, let's think about the reliability, the long-term reliability of this, because the problem I've got is that batteries fail. I mean, if you're using rechargeables, if you're using alkalines, then, oh, dear, you know, you're going to have to new one of those that's going to cost money. And then you've got a recycling problem and then you've got environmental questions. You know, there's no question that rechargeable batteries are better for the environment overall. No question. Plenty of studies. I haven't cited any, but I know that that is the case. Feel free to look that one up. But the bottom line is that that. those batteries are still going to fail. Now, how often do connectors fail versus how or connectors and cables file versus batteries failing? So if we're going to go all in with wireless on the basis that there are no connectors, and that's our advantage, that's one of the reasons that we're doing it. So I want to get away from connectors. Well, then we need to eliminate devices with changeable batteries, because every connection point for a battery is a point of failure. And people say, "Oh, but they don't fail. They're simple." No, they get gunked up all the time. They get corroded, things go wrong. Okay. How many times have you had a device where the spring that's keeping a AA battery in place just gets loose over time? Yeah. You know, it's happened to be lots and lots and lots, usually on cheaper gear. But you know what? It happens a lot to me. And it's not just it's like everything from radio control cars to you know, to my keyboards, to wireless mice that I've tried at different points in my life, you know, it just it happens. So a lot of people say, oh, it's great having changeable batteries. Well, yeah and no. Actually, I almost think that if you're trying to go with the argument of I'm going to get rid of all of my connectors, well, go to an integrated battery, you know. And they're like, oh, but you can't change the battery then. Well, if the rechargeable batteries last five years or 10 years. Aren't you just going to buy a new device? Yeah. How many people are still using the same keyboard they did 10 years ago? All of the listeners with a mechanical keyboard or an Apple Extended 2 keyboard, raise your hand now. Okay. Hello. You are the minority. The vast majority of people use the keyboard their computer came with. On a laptop, that's easy. But you know what I mean? They just, only the nutters will keep their keyboard. And I mean that in an affectionate way too, by the way, nutters. Oh, dear. OK, I've just offended the nutters. But you know what? It's fine. You want to have a keyboard you use for 10 years, but seriously, your 20 years, good on you. But that's just that's just not the majority of people. I'm sorry. Yeah. OK, so honestly, I think that the integrated battery makes more sense because you eliminate the connectors. Okay, so let's look at the connector failure on a USB keyboard. How often do you actually unplug a USB keyboard? And I sort of alluded to this before. It's not often, is it? It really isn't. So for batteries to really win in terms of overcoming connectors connect, they need to be integrated without connectors, when that means rechargeable. In some applications where the current drain is very, very low, you just don't change the battery ever. And I thought about this, How many devices out there like that have got a forever battery in them? An unchangeable lifetime battery, like a long life lithium. I thought of one, a new one. It's the Tile. Do you know what the Tile is? I do not. Okay, the Tile is a Kickstarter project. I'm pretty sure it's Kickstarter. And it's a very small and the dimensions escape me, but I think it's like half an inch square or about, you know, like 10 mil, 12 mil square. It's relatively thin. And these things are like they're white, they got a little small hole in the top left corner, I think it is. And what the tile is, it's a Bluetooth low energy device that you can connect to a set of keys so you can put that the the springy... Oh, God, I don't know the technical name of this. Someone can correct me, I'm sure, unless you know the answer, which is, you know, the round split ring thing that you put your keys on and a key kind of key ring. Yeah, that thing. So you can put one of those through the hole. You can have an adhesive and you can stick it to things. And what this thing does is it allows you to track things within a 30 meter range. Is it 30 meter or sorry, 30 foot, 10 meter range. So it's all well and good to say, find my iPhone. Okay. There's a problem. iPhone battery is dead. Stick one of these things to the back of it and it'll find it when you get physically close to the thing. So you can find its last known location was in the house. You just don't know where in the house where you can use the tile to find it. So you buy these in packs of, I don't know, you can buy them individually or buy them in packs of five, 10, whatever. And I'm not, I haven't tried them, but by all accounts, they're pretty cool. And the battery in them will last, I think it's about a year or so, maybe something like that. Because you never change the battery. That's the concept. It's disposable. They sell enough of these things, if they take off, they work well and they're popular. If, if, if, if, then I'll mass produce them on a bigger scale. Price will come down. Economies of scale. That's how Motorola made pages. So cheap, I say cheap, they weren't that cheap. But anyway But that's a very, very small subset, right? How many devices are there out there really that you can get away with doing that in? You need to have something rechargeable. And once you embrace that you embrace inefficiency and additional cost. So it has to be really worth it. The connectors argument, I think fails. You want to get rid of the connector issue from connectors gunking up or you want to waterproof something that's different. And we talked about this on the on the Watch This Time and Space, episode 38, and we talked about that. So again. OK, so. I think that's enough about connectors and batteries. Let's talk about the bulk of what I want to talk about on this is beaming power, because I heard a couple of theories about this one. And I find the idea to be fascinating. Yeah. Although also insane at the same time. Insanely fascinating. Okay. Beaming power. And I want to start by talking about Crystal Radios. Do you know what Crystal Radio is? I do not. All right. So, Crystal Radios, built one of these when I was a kid. Absolutely, totally spiffing, brill, you know, tops, mad. Trying to think of other slang expressions for an appropriate level of excitement was experienced. So before there was mains power, it was commonplace to have a crystal radio because crystal radios draw their energy from the radio waves themselves. They essentially oscillate, vibrate and data, data, good God, you know what I mean? Audio from the radio, from AM radio. It's directly converted from the radio energy into audible energy through small, low power earpieces. So you put the earpiece in, you can hear the crystal radio. So and the crystal part of the radio refers to the Galena crystal detector that was commonly used in the early days of crystal radios. That was before the mid 1920s happened. And in the mid-1920s, they had valve amplifiers and that changed the entire experience because you went away from having to have an earpiece to having a powered loud speaker that you could hear the radio on from anywhere across the room. So that sort of took over very quickly. Now, it sort of sounds ideal, the idea of a crystal radio, because you're essentially powering the radio, plus you're transmitting the data and you're doing it all wirelessly. That sounds perfect, right? It's like, yes, success. It does sound nice. However, it was cool at the time and you can still get away with it, but their effectiveness is diminished as the distance increases away from the radio transmitter. Because inverse square law, again, talked about this before, as your distance doubles, it's basically one over the square of the distance in terms of power because it's an expanding wave front, assuming an omnidirectional antenna and it's propagating as a perfect sphere and nothing's a perfect sphere. And there's no such thing as an isotropic radio because there's no such thing as a single point source of a radio signal, blah, blah, blah. Point on. Point is that moving on. Wow. I just said point is moving on. It's point on. OK. I've had too much coffee or not enough coffee. You're on a roll today. I'm really doing a bad job here. I'm sorry. OK, so eventually, though, people wanted to have a louder and more consistent audio from their radio. So the power transmitters that they came up with in the mid 1920s, they gave them that. So you could be 10 miles away, you could be 40 miles away and you would get the same sort of quality experience from the same radio. And that's what people wanted. The crystal radio simply did not gather enough power further or too far away from the radio transmitter. So eventually they became an oddity rather than the mainstream. From a portability point of view as well, things had to evolve quite a lot. So crystal radios actually persisted for quite a while because they were smaller, more portable, and of course, early days didn't need batteries. But as batteries improved and, you know, things like super heterodyne receivers improved and frequency stability improved and all that other good stuff, you know, crystal radios sort of went the way of the dodo. And we went to, we went to powered transistor radios and for portability reasons, And now we've just given up and we just do podcasts. Yeah. Yeah. Some of us, some of us do that. Anyway, OK. So the next thing to talk about is microwave energy. But before we do talk about microwaves, I'd like to talk about our second sponsor for this episode, and that is Now, is an easy and affordable way to learn. You can instantly stream thousands of courses created by experts in their fields of business, software, web development, graphic design, audio and lots and lots more. Too many to list here. 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OK, microwaves, just to be clear, is a range of the radio spectrum. So again, talked about this before, the exact frequency range doesn't matter. The point is that high frequency range. RFIDs are an example of microwave energy being used to transmit power. But as we talked about on episode, I think it was episode 47, which was the interrogation signal, we talked about this when we were talking about RFIDs there. It only has enough power to make the e-toll beeper go beep a few times before it goes flat. That's it. Yeah. So the thing with microwaves and their properties for heating, though, just as a little aside, since you mentioned heating things, is Percy Spencer in 1946 after the Second World War. The story, which may well be apocryphal, but here it is anyway, was said to have accidentally melted a chocolate bar in his pocket before he realised the microwave antenna that was in front of him was what was doing it. Many years later of refinement, and a bunch of companies sort of, you know, it ended up with the microwave oven. Okay. Honestly, the concept behind the microwave oven hasn't really changed a hell of a lot. It's more about like in the last 40 years, it's all changed, it's all become more about controlling the amount of energy going in there. But really, you pulse a bunch of energy in, let it bounce around, gets absorbed by the food, pulse some more in. That's basically it. And you just don't want to overcook things. So it's the control of how much energy goes in, the monitoring of how well cooked what is in the microwave is, that's where the technological advancement is. But the actual magnetron they use to generate the microwaves is pretty, it's a lot lighter than it was, made of lighter materials but generally speaking, there's really not a hell of a lot that's advanced in that. I've done a few microwave links on projects that I've worked on and they are a lot of fun to align your dishes. Anyway, and once upon a time, a long, long time ago when I was a young teenage boy and I was getting into amateur radio and CB radio, this is before I left, I was still in high school at this point, I would go on excursions, I guess you would call them, just with the amateur radio club because I was just that kind of kid, I guess. We went to a radio installation on top of a water tower in Rockhampton where I grew up and there was a particularly low-hanging microwave dish. I don't know whose it was, probably Telstra's, it doesn't really matter, but it was a microwave dish, doing a point to point link from the range across to Mount Archer. And I, being the young, you know, kid that I was, having climbed partway up this tower, not it wasn't very high off the ground. There was a very, very low hanging. So, you know, and even that, I would think now looking back, I didn't have any harness on, I didn't have any safety training, I didn't have any gear. I was just the youngest one and they're all older guys. So they're like, hey, John, can you go up there and adjust the antenna direction? Yeah, why not? Sure thing, man. I'm thinking there's not a happy ending to this story. It's actually not that bad, but it's illustrative of the problem. Okay. So, I got up this- It wasn't that high up there and I'm like, oh, microwave dish. So, I kind of put my hand up in front because I'm like, microwave. I wonder what that feels like. Wow. Shut up, you. I was young. How bad did it hurt? Actually, it didn't hurt, but I could feel my hand getting warm. After a little while. And- How long is a little while, John? I'm not going to tell you, but I'm just going to say sometimes we conduct experiments on our own body and this was one of them. Anyway, look, bottom line, I'm going to have to keep an eye on my left hand as I get older to see if there's any cancers that form. But I doubt it. I'm sure I'm fine. Look, OK, I'm really just kidding it. I'm digging myself in so deep here. Look, I felt what they referred to as the thermal effects, right? Because the way a microwave works is it causes the water molecules to vibrate at a molecular level. That generates molecular friction, that generates heat. And that's the heating that cooks the food. You put in something there that is completely dry and there is much less for the microwave energy to essentially agitate, then you don't have an issue. What's the problem with the human body? What percentage are we of water? Very high percentage of water. Therefore, you shove living tissue in front of a microwave or in a microwave, what's going to happen? It's going to get hot, right? You are cooking your own hand. Well, I was, stupid John, stupid teenage John. Anyway, bottom line, it's different from DNA damage, It's not the same thing. Damaging actual DNA strands requires a different level of power. It's a different kind of an effect. And near field effects seem to be, and this is the bit that's not conclusive, seem to be more of a problem. Now, we talked about SAR limits before, which is absorption limits for electromagnetic radiation. And we talked about that on the very first episode of Pragmatic, Faraday's Cage. So a quick refresher, the maximum absorption deemed to be safe is 1.6 watts per kilogram, and that's averaged in one gram of body tissue. That's the IEEE ANSI standard. So all devices are measured against this. As a maximum. Mobile phones generally nowhere near that anymore, used to be closer, but not anymore. Ever since we went to lower power stuff like GSM, CDMA, TDMA, a lot of it's dropped back. Again, talked about this before, not going over that again. So I thought to myself, what's a standard exposed microwave signal that the average person is exposed to every day? Well, that a person could potentially be exposed to every day. Because I'm going to assume the average person isn't a young, stupid teenage boy that shoves their hand in front of a microwave dish. So, let's assume that that is not the majority of people because more people have more common sense. Anyway, at least I hope they do. These things just happen. Don't try that at home. So, bottom line is I thought long and hard about this and I came up with one. The eToll transponder in your vehicle. Now, a lot of people are going to say, hey, I live in the sticks. I don't have a transponder because I don't have any free flow electronic tolling in my vehicle. And that's fine. Some people are going to say, I don't drive a car. Okay, that's fine, too. My point is, though, that's the only one I could come up with. Maybe there's more, but that's what I came up with. Yeah. So these particular ones, what they'll do is they will actually shoot microwave, focus, microwave energy at the roadway so that when a vehicle crosses the motorway, the actual transponder inside is an RFID. It's a passive RFID for most of them. So it will get charged from that microwave energy. It'll use that to return a signal. It'll transmit a response on a different frequency, much lower frequency, usually back to the receivers that are mounted right next to the transmitters up on the overhead or the... as long as they mount them on the sides of the roadway, either way. And that'll have information about the license plate, the identity of the vehicle, that stuff, right? Yeah. Those systems, because they're not 100% reliable, will also often take a number plate photo and they'll try and match the two up where they don't, where there's a discrepancy, they'll, you know, whatever. Bottom line, though, that is the one that you people are exposed to. But here's the thing, the maximum absorption is an average. So I thought to myself, okay, I wonder how long would you have to stand in front of an eTol transmitter before you accumulated the maximum absorption dose permitted by the SAR limits? I really wanted to calculate that. Did you try this too? Because I'm... Not yet, for reasons I'm about to explain. Okay, so it all sounds all well and good, but, you know, let's face the facts. If you got e-toll on a roadway, it's going to be well trafficked. You're not going to put all the money and expense into either free flow tolling on a road that gets no cars on it. That's just dumb. No one would do it economically, right? Because it's expensive. So you wouldn't do that. So that means it's going to be a lot of traffic there, which means you're not going to be able to stand in front of this thing anyway. So my whole hypothetical argument is flawed from the beginning because no one's going to do it. No one's going to stand in front of one of these things. And so I cross their arms and, you know, play crossy road while they're not crossy in the road. And that was not a preplanned joke, that was bad, that was impromptu bad humour. Anyway, so bottom line, bottom line is. I couldn't figure it out anyway, because there's too many variables. Realistically, if you're inside a vehicle, there's going to be a degree of shielding. So and that shielding is going to vary based on the kind of vehicle you're going to get different level of shielding from a minivan versus an SUV versus a compact car versus, you know, you just, you know, The ragtop convertible. Yeah. Oh, good example. Yes. Ragtop convertible. So you got canvas on top of you. That's great. That's going to really help you anyway. In an accident, it'll also really help you. Anyway, I say this as a guy that used to have a car like that, but never mind that. Got married, sold it, had to sell it. Never mind that, it's a sad story. Moving on. And I mean, the sad story was selling the car, not getting married. Oh, my God. Standing versus sitting height changes the distance between you and the antenna. Stationary target, standing there, kid never going to do that. You know, obviously, that's far worse than you travel past at 40 to 60 miles an hour, 100 to 120 kilometers an hour, whatever it works out to. You know, you're traveling past, you're going to get exposure for a matter of a few seconds at most. Now, I thought, OK, you're in a traffic jam, possibly. Okay, that would be an exception. Traffic jam through the free flow tolling point. That is unfortunate. The final nail in the coffin for this calculation, the power output and the power output and the antenna gains from those transponders are not clearly defined anywhere that I could see. It varies from model to model. I guess you could take the maximum theoretical limits that are permitted by the regulations, but here's the next problem. The regulations vary from country to country, don't they? So I really would have loved to have done that calculation, but there's too many variables for me to have a reasonable stab at it. So I had to do the respectful thing and give up. Moving on. So that's microwaves. Ultimately, to summarise, microwaves for transmitting power, they are bad because one, yeah, they're going to cause... Essentially, they're going to cause thermal effects in living tissue. Yeah. People are going to be very sensitive to that. Second problem is you can't transmit a hell of a lot of energy. You just can't because you need to focus the microwave energy to get the maximum power transfer over a longer distance. Ultimately, it's just not going to be a hell of a lot of energy. So and of course, I didn't talk about the efficiency, the efficiency is also not particularly great. So, transmitting bulk amount of energy over microwave, just not going to happen. Too many compromises, too many issues. If we didn't have... If there were no thermal effects, maybe it would be a bit more acceptable. But that's a big stumbling block to overcome. And the more power you transfer, the worse those effects are. So, imagine trying to beam microwave energy from somewhere out in the street into the home so you didn't have to use a wire to get power into the house or from a central point in every room. What are you going to do? Drown the room in microwave energy? Slowly cook everyone sitting in the room? But this is so good. No, it's definitely a negative. OK, so now that we've agreed that microwave is dumb when it comes to transferring power. Let's look at the most commonly used methodology for higher power consumption transfer, because etal, technically RFIDs, they all work. Okay. But they're very low power. Now let's think about induction, inductive coupling. And again, we talked about this a little bit on episode 38, watch this time and space, go back and listen to that episode. I did talk about this in a lot more depth than I'm going to now, But just a quick refresher, inductive charging is extremely limited in range, microwave much longer distances, but inductive charging is through magnetic induction and that is only effective at short distances. So I'm talking, you know, like less than a foot, half a foot, so like 15 to 30 centimetres close. In fact, you want it closer than that because the closer you get, the better the efficiency. So I had a look at when I did the episode for the research for that episode. So I'm going to shamelessly reuse my research because why not? Larger than, OK, so you look at 86% efficiency, that was the best that I could find. Now, in a portable device, that's worse because you also make it heavier in so doing because it's heavier than it's heavier than just a connector and a cable. Right. Oh, yeah, that's right. Remember, we're talking about wireless power versus cables. So just mentioning, yes, we are still considering this as a comparative. So anyway, so it's lossy, it's inefficient, you know, and frankly, when you go that up against a cable, a cable has essentially no loss. There's virtually no contact losses in your connections. You know, a fraction of a percent of loss in efficiency using a cable versus a perfect power transfer. There's no argument from a loss point of view. Induction loses from that point of view. So, you know, anyone that says inductive charging is better because it takes up less physical space, again, shut that down. That's simply not the case. So anyway, OK, I had this crazy thought, what if we got rid of all the PowerPoints in our house, all the general purpose outlets, got rid of them all. Clean, flat walls, but behind the walls, we had inductive coupling coils in the walls. So you could hang a picture on the wall and it would pick up power from an inductive strip behind the wall. Or power. That sounds cool. Oh, it's got a high cool factor. Now, imagine TVs are getting low and low power. Do you agree? Definitely. Yeah. Getting thinner, lighter. Some of them even have curved screens. Yay. Like that's something. Got to pass on that one. I completely, absolutely need curvature in my television. Thank you to everyone that's adding curvature where none was required previously. Yeah, that was a feature of CRTs. The curve was the other way around. We didn't pay extra for them. Anyhow. OK. And you want me to pay more for your curve just because it's concave? Yeah. Anyway, all right, whatever. OK. Sometimes you just can't add more sarcasm. This sarcasm detector is off the charts. Classic Simpsons before it went to hell. OK, so imagine hanging a TV on the wall and there's no wires connected at all because it's getting all of the all of the data via Wi-Fi and it's getting all of its power via an inductive charging loop in the wall. You know, and it's light enough now that you can hang it on the wall with, you know, with stick on clips. Mind you, would you trust a thousand, two thousand dollar television with stick on clips? But you know, no, well, but I mean, I'll tell you what I've hung up some relatively heavy things that these it's a 3M thing. They I forget the name of it off the top of my head, but you know, those it's like they're surprisingly strong. Yeah. High density Velcro, you know, and you strip off both sides, you clean it and you put them up against each other. I put up huge whiteboards with six of those strips. And they don't fall down, so it's surprisingly good. All right. So I thought, yeah, that's a cool idea. You know, obviously, though, you've got other issues because the more of these induction coils you put around the house, you're creating magnetic interference. So what's that going to mean? You need more shielding because otherwise devices are going to get magnetic interference now because you're putting it everywhere. It's over a much wider area. You know, I mean, you're going to have weird stuff happening, like stuff being attracted to the walls. It sounded like such a good idea. It's also not as efficient. We already talked about that, but it's technically possible to do it without wires for smaller televisions that don't have big power drawers, I would suspect. But at some point inside the wall, there's still a wire. You haven't really gotten away from wires exactly. You've just replaced a wire in the last few centimeters or last few inches. That's all you've done. And how often do you really move your television? How often do you unplug and unplug the power cable, your television? What exactly are you saving? You can tuck and hide that away behind it if you want to. It just makes it look a bit cleaner. Refer to my statement regarding keyboards and mice and USB cables. OK, so if you're going to go with inductive charging, the only way that I think inductive charging makes much sense at all is getting back to the I have a built in battery. And one of the other reasons for having it on a watch, for example, like an Apple watch, is that it'll prevent water ingress through the connection point, through the physical connection point. That is, you know, obviously a big benefit. So yeah, I think people just need to accept that for larger devices, anything with anything that has a reasonable amount of power consumption. And I mean, that's a hard line to draw. But you know what I mean, a reasonable amount of power consumption, whether it's continuous power consumption, or simply devices that aren't required to be portable, it's never going to be cost effective, it's never going to be more efficient. You know, it's not going to be there's not gonna be no there's gonna be no point to it. So for smaller portable devices, absolutely go rechargeable batteries coupled with inductive charging that solves the disconnect, connect disconnect problem with the connectors. It makes a hell of a more robust as a product. But ultimately, the compromise is you're going to make the device bigger, and it's going to be heavier, but that's your tradeoff. You know, that's the price of portability. Yeah. Okay. So that's enough of wireless. Last section I've got here has nothing to do with wireless. It's got to do with the last thing about that article. That I mentioned earlier. If we if we are resigned to the fact that we have to have a cable connecting in to provide power to the device. then why not have a combination cable? In other words, overload the cable. And I don't mean overload from a power point of view. I'm using that in the software programming parlance. You overload a function by providing multiple features depending upon which flags are enabled, you're overloading it so that you're, through a single access point, you are providing more than just a single function. So other than just power, let's piggyback stuff along with the power, either on the same wires as the power, or on multiple wires bundled together in the same cable. This is not a new idea. In fact, there are a bunch of ideas. The first one I'm aware of, and I'm sure there's others that I've missed, but one that'll be familiar to longer time Apple users is the Apple Desktop Bus, ADB. You familiar with this one? - I am not. I think it's a little before my Mac time. - Okay, well, the first Macs that I used, used ADB, and I thought, ooh, that's a funny little dinky-die connector. Anyway, the point is it was one of Steve Wozniak's babies and not literally. In 1986 was when it was first released and they still build up to 1998. So it had a good run. What's that 12 years? Yeah, 12 years. See, I did that without a calculator. Anyway, why is it engineers are told we can't do math without a calculator? And that's math or maths. I've given up caring about that one by the way. So I'm just going to call it MathMaths and that way I offend both parties. Anyway, it supported five volts at 500 milliamps and that five volts, 500 milliamps was enough to power as well as to communicate with devices. Now you compare that with equivalent standards at the time, older standards, mind you, but equivalent standards like parallel or serial ports, they were running RS232 standards. Now they were only for data. They were never designed to carry power. So ADB was an example where you carried power as well. and you could power low-powered devices using it, which was cool. USB started using the same idea that came out in 1996, a couple of years before they cut the cord on ADB. And again, it started out with 500 milliamps, sound familiar? Subsequent versions bumped that up to 900 milliamps, charging devices can now support up to five amps at five watts. So from a power point of view, that's five, five, so 25 watts, that's significant. So you're able to carry a reasonable amount of power plus a reasonable amount of data on these things, especially with USB 3. So USB is an example of, I guess what I call an overloaded cable, you know, a combination cable, can provide power and data. There are lots more examples. So let's talk about power over Ethernet. That's another good one. That bumps that well beyond the five volts. In fact, it actually works out depending upon the standard, 'cause there's a couple of versions of the power over Ethernet standard, you get 44 to 57 volts. Now, some people know this, some people don't. For those that don't, the current on power over ethernet is very similar to the ranges that you've got with ADB and USB. 350 milliamps for first power over ethernet standard, but PoE+ can handle up to 600 milliamps. Need a better quality cable though. Now why? And the answer is, all the cables that are used have a very small cross-sectional area because they are primarily envisaged for carrying data. The cross-sectional area of the cable determines the amount of current that it can carry. The more, the higher the diameter, larger the diameter of the cable, the more current it can carry. And if you put a bunch of cables together and you bundle them together in strands, individual strands bundled together, then again, you're increasing your effective cross-sectional area. And that's how you can figure out the amount of current it can carry. - Yeah. It's not a simple equation though, there's skin effect and a whole bunch of other things that I'm not going to go into but that's the rough equation. Now because all these cables are about the same size and they need to be flexible and so on there is a practical limit to how much current they can carry. So on USB they really beefed it up to handle the 5 amps plus they use multiple wires so it's a form of indirect bundling I guess you could call it that I believe. I'm going to, I've actually overstepped that, I'm not entirely sure if they use multiple cables. But the bottom line is that that's the most current I've seen. And I'm pretty sure that there are very few devices that support the full five amps. So the 12 watt chargers, which is the biggest iPad charger, for example, that you can get, they started coming out with that with the iPad Air, those 12 watt chargers at five amps, obviously, you can figure that's about 2.1, 2.2 amps. Okay, over a single USB cable. Yeah, that's a fair bit of current. Anyway, so power over Ethernet gets whether by increasing the voltage because the insulation on Ethernet is higher rated so they can get away with that on the power of Ethernet cables. There was one thing, okay so where is it used, Chori? It's becoming more common in control systems these days because some instrumentation draws the power, it's Ethernet based industrial Ethernet and it'll draw its power from the power of Ethernet, so you have to run a power cable out there as well, it's not a bad idea. IP based desk phones, very, very common use of power over Ethernet. IP based cameras, another example. Yeah, that's what I was going to say, CCTVs in my warehouse at work, they use it. Yeah, exactly. It's gone from being obscure to being very popular because from a data comms point of view, you just got to run the one cable. You don't have to worry about running separate power to it and that's a big deal, big cost saving as well. So I think it's fantastic. And that's where this conversation is going. So hold that thought. When I was... I linked to Wikipedia a lot and I've had a few people saying, "Gee, you really like Wikipedia, don't you?" Well, Wikipedia is convenient, but let's be honest, it's not always correct. And I'll give you an example of that right now. What? There's a link... Is that heresy? I don't know what to say. You don't know what to say? You've shattered everything. I've shattered your faith in the font of all knowledge. Uh-huh. Okay, well, I got the book of knowledge. Here's one to chew over. Okay. Again, not literally. There's the Wikipedia page on Power over Ethernet. There's a line in there that reads like this made me chuckle. DC power is inherently less efficient than AC power due to the lower voltage. Let that sink in for a second and then track down the author and give him a hard slap. So DC power and AC power have nothing at all to do with voltage. Yeah. If you talk about peak to peak voltage on AC, meaning your peak voltage is higher, that affects your installation. That has nothing to do with efficiency. In fact, AC is less efficient because of coupling. AC coupling is a big problem. DC coupling is no problem. It's so small, it's immeasurable. And DC, if you've got a DC device drawing DC power, chopping up DC is much cleaner than chopping up AC. So it's more efficient. So what the actual hell are they on about? That's fine. I'm not going to correct it because that would be helpful. No, actually, I don't know. Maybe I should correct it actually. I'll flag it. Come back, I'll correct it at some point. because that just jumped out at me as being ridiculous. You can't make that kind of statement. And besides which, a statement like that adds no value whatsoever. That is a person's opinion as to why... The context of the statement was, the reason that Power of Wreathenet has not become the runaway success of blah, blah, blah, blah, blah is because, you know, DC is less inherently less efficient. Okay, that's such BS. No, no, no, no, no. Yeah, and Power of Wreathenet is becoming much more popular. You go back 5-10 years ago, Power over Ethernet existed, it wasn't popular back then, now it is because it's being built into Cisco Ethernet switches and all you got to do is run a slightly more expensive cable and hey presto, you've got IP based phones that cost you nothing to run. Everywhere is using them. Why? Because they're cheap and in fact, you count up all the damn desk phones and all the buildings I've worked in for the last 6 years, they've all been IP based phones, every single damn one of them. a lot of power over Ethernet. So don't tell me that that is not becoming popular because DC is less efficient. What? Anyway, sorry author who wrote that. You didn't do enough research. Okay, Powerline Ethernet. Moving on from my rant. MIMO technology, that's pushing it towards gigabit speeds. Now that's starting to get interesting. Now, you know what I mean when I I say power line Ethernet, right? Cool. It's becoming a big thing. I remember the first time I heard about it, I'm like, oh, that'll never work because transformers, because circuit breakers and sub circuits and blah, blah, blah, blah, blah. But you know what, actually it's got, oh yeah, it was slow as all hell in the beginning, but now it's getting respectable. To the point at which you always wanted to run that networking around the house, either go fiber, cause that's what the cool kids use, or a gigabit Ethernet these days or 10 gig Ethernet. Well, you know what, If I can get gigabit out of Powerline Ethernet, suddenly I'm interested. Yeah. Or you turn your whole your whole grid into a network. Exactly. That's cool. Because I've got, you know, I got four kids. Eventually, they're a few years away getting a laptop through school. And I'm faced with a problem with Wi-Fi because I've got three Apple TVs, four iPads, three iPhones, you know, between everyone in the household. There's a lot of Wi-Fi. I got a Wi-Fi pea soup going on, going through my head. And it's... Anyway, that's an image. Anyway, the point is that, you know, what am I going to do? Keep adding Wi-Fi routers? I guess so. Or I could switch to, you know, when they get laptops and I'll do more work on their laptops and then when their iPads, I imagine. Anyway. I don't know if that's actually true. I'm presuming that that's true. Anyway, point is that Powerline Ethernet at Gigabit becomes interesting. So laying no cables, plug a plug in one and plug a plug in the other one away you go. Your household as you said, your household is your now your network. So the downsides as I alluded to before of course is that if you trip a circuit breaker and you've got multiple circuits then you're stuffed. Your ethernet signal will not bridge between them. So each circuit is its own independent network. Or of course you know I'm assuming you've got a circuit breaker most places do these days maybe you've got a fuse if you blow a fuse. I don't mean you, I mean the switchboard blows a fuse. Anyway, so yeah, but then again, if you've got a device that's, you know, needs power to work, let's say that it's a device that doesn't have a battery in it, it's not battery backed like a laptop. Well, you know, let's say you're plugging it into a local Ethernet switch on your desktop and using that for data. If you've got no power, you're screwed anyway. Right, because you can't power the device to get the data off the power. So, you know, by and large, you know, it's not that big a deal if you trip something. And how often do you really trip something? I mean, I do, unfortunately, sometimes because I've got an overloaded GPO circuit. I mean, I say overloaded, it's not overloaded all the time. But if I have the microwave toaster and grinder running at the same time, then it's gone. Yeah, it's the grinder, baby, that's the problem. Damn it. I need to get back to hand grinding. That's that will solve all my problems and introduce new problems. Anyway, so I just careful not to have them all running at the same time. I need to install another subcircuit. That might happen. OK, because my house has two lighting circuits and two GPO circuits. Yeah. OK, so that's Powerline Ethernet, and it's also coming down in price, still a little bit pricey, but, you know, getting better. So I thought to myself, you know, why not combine that into your power adapter on your laptop charger or into your iMac. Don't make me go and buy a separate power line, Ethernet adapter, build it in. That would be pretty cool. It's not that hard. All you do is you have a high pass filter and you strip off your AC, your mains power, and then you extract the data and convert it to Ethernet and you're done. The costly part is the filtering, but you're already doing that if you've got a switch mode converter. So why not do it? Yes, it would cost a little bit more, but just think. Think about the possibilities. You've got Wi-Fi, you've currently got an Ethernet plug in the back. What say you get rid of that Ethernet plug and now you're getting it through the power cable? You just eliminated a port. What do you think? I think I see where this is going. Next logical step. I have a time capsule. I have a Wi-Fi base station. You do the same thing on there. Once you buy a Wi-Fi base station, you've got a power line ethernet adapter built in. You don't buy a separate one anymore. It's all integrated. You get a laptop, same deal. Suddenly, you just freed up a heck of a lot of bandwidth on your Wi-Fi. You need power. You're not going to get away from that. You are always going to have a power cable going into your computer, so long as it is a high current demand device. That's unavoidable at this point in time. And I really can't see that changing. It'll always be more efficient. The only devices that can get away with not needing that are extremely low power devices. You can put a battery in a rechargeable battery in, and then you can look at inductive charging. But that's not what I'm talking about. It's about high current devices. Now, TVs, monitors, computers, you know, any appliance you can think of, they're all going to have cables. I mean, here's another thing. What about fridge intelligent fridges? Why do they have to be on wifi? You're already connecting it to the power. All it takes is for someone to bite the bullet and say, we're going to support this. Apple, are you listening? That would be great. It'd be a great addition to the home kit. You want to- Yeah, exactly. Yeah. Build it into Apple TV. So anyway, I have no doubt there is a lab somewhere that has got this product in R&D within Apple, no doubt whatsoever. and I'm sure other manufacturers are trying it. But at the moment it's a cost problem. So they're saying, "Why do I add additional components to add cost?" Well, the cost of adding those components is at the moment is greater than putting an RJ45 socket on there, you know, and an ethernet transceiver on there. You know, I'm sure there'll be common costs between them and so on and so forth, but it's the filter, the high pass filter and the components you got to use, it'll be more expensive. But you know what? One cable, man, one cable. So in conclusion, I think that eliminating cables only really makes sense for data for most devices, because, you know, but the problem is, I guess, bandwidth is a precious resource and cluttering it up with more and more junk isn't really smart in the longterm. If everything has a wifi interface or everything's got Bluetooth, you're just getting more and more and more RF soup. So it makes sense for devices, you know, when you try to seal them, fine, that's cool. You know, if it's mobile, in which case, you know, fully sealed non-replaceable batteries are better with inductive charging, you know, and that's fine. That makes sense. It's a trade-off. Yes, we know it's not remotely efficient. When you add up the inefficiencies, you're looking at 15 to 20% worse overall efficiency than, you know, by using inductive charging with, you know, with rechargeable batteries. Okay, we accept that, but that's the trade-off. And that's the trade-off most people are willing to make. These are low power devices. It's not gonna hurt your hip pocket that much. But from a strictly electron point of view, it's not going to be as good. But if you are resigned to the fact with a high power device that you're going to need to have a wire, then overload those wires with more than just power. Put the data on them if you can. And bundle it with an optical cable if you can, I guess, because optical rocks. And that's it. What do you think? I think it's good. Did I miss anything? I don't believe so. Well then, if you'd like to talk more about this, you can reach me on Twitter @johnchedgie That's J-O-H-N-C-H-I-D-G-E-Y and my writing and this podcast and others I've made are hosted at my site If you'd like to get in touch with Vic, what's the best way to get in touch with you Vic? They can find me on Twitter @vighudson1 And there's a podcast that you do as well, it's called Apps something or other? or other? AppStory Podcast. You can find that at Fantastic. And if you'd like to send any feedback about this or any other episode, please use the feedback form on the website. That's where you'll also find the show notes for this episode under Podcasts Pragmatic. You can follow Pragmatic Show on Twitter to see show announcements and other related stuff. And a final thank you to our two sponsors for this episode. First of all, to Igloo, an intranet you'll actually like. Built with easy to use apps like file sharing, blogs, calendars, task management and much, much more. Make sure you visit this URL to get started today. It's free to use for up to 10 people. No credit card required. Just sign up and start playing today. I'd also like to thank for sponsoring this episode. If there's anything that you'd like to learn about and you're looking for an easy and affordable way to learn, then can help you out. Instantly stream thousands of courses created by experts in their fields of business software, web development, graphic design, and lots and lots more. Kickstart your new year and challenge yourself to learn something new. Visit to get a free 10 day trial today. There's something for everyone. So, if you ever wanted to learn something new, what are you waiting for? Thank you, everyone, for listening once again. And always, thanks again to you, Vic. Thank you. [MUSIC PLAYING] [MUSIC PLAYING] (upbeat music) [music] (upbeat music) (upbeat music) (upbeat music) (upbeat music) (upbeat music) (upbeat music) (upbeat music) (upbeat music) ♪ ♪ [Music] catch on the flip side I don't know like of what flip side of something how much coffee have you had John? I have had none maybe that's the problem at least ten minutes no I'm just kidding okay it's half past midnight I stopped my coffee ran out an hour and a half ago mate I'm on water I'm down to water
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Vic Hudson

Vic Hudson

Vic is the host of the App Story Podcast and is the developer behind Money Pilot for iOS.

John Chidgey

John Chidgey

John is an Electrical, Instrumentation and Control Systems Engineer, software developer, podcaster, vocal actor and runs TechDistortion and the Engineered Network. John is a Chartered Professional Engineer in both Electrical Engineering and Information, Telecommunications and Electronics Engineering (ITEE) and a semi-regular conference speaker.

John has produced and appeared on many podcasts including Pragmatic and Causality and is available for hire for Vocal Acting or advertising. He has experience and interest in HMI Design, Alarm Management, Cyber-security and Root Cause Analysis.

Described as the David Attenborough of disasters, and a Dreamy Narrator with Great Pipes by the Podfather Adam Curry.

You can find him on the Fediverse and on Twitter.