TechStuff plays with R/C

over in my mind ever since. With a shovel. Uh possibly if you know the source of quote, let us know. And if you don't go to a library people. All right, So, um, today we're going to talk about something that that several listeners have requested over the past well probably two years or so, but we've had a lot of people ask

about radio controlled toys. I think RC helicopters is the one that we tend to get the most requests for, but we've also had for r C cars and and and just radio controlled vehicles in general, and they all work at least on the radio side, with the same basic premise. So we're going to cover that and then

maybe we'll get into some specifics. Yes, and oddly enough, I have a little history, and boy do I mean history, because this goes back to eight and one of our old friends who messed around with radio in its very very early days, and who had believe it or not. Actually, you probably believe it if you know who. We're talking about a patent for it. So there was an electrical exhibition in Madison Square Garden and a guy named Nicola Tesla faced off against Marconi in a no whole bar,

two out of three falls match. So not not this time. Madison Square Gardens has a special place in my heart as a wrestling fan. That's go ahead. Uh no, actually, uh, this was a let me see hold on. Oh yes, I wanted to make sure I was right. It was a radio controlled boat, basically a steel boat about four ft long or so. And um, he brought out this radio controlled boat and people thought he was controlling it with his mind powers because you know, radio was still

pretty new at that point. Remember, if a technology is sophisticate enough, it would be indistinguishable from magic. Yes, however, Tesla had his boat powered by several batteries on board. Um. Also, there were like eight guys underneath the water, just pushing it along holding their breath. Uh, this is Tesla we're talking about. You know, he had access to future technology.

Eight robots underwater holding their breath. That's more like it. Um. But yeah, I mean it wasn't in a way, it was not terribly different from from our current r C technology. And there did there so there were switches that were propelling, propowering, powering the propeller, the rudder, and uh running lights. Oh so he could even make the lights go on and off. Yeah. And he even had a coherer, which is a switch

that act that was activated by radio. Um. And uh had it had it set up so that he could power or or control it by radio. And uh people were freaked out by it because again it was magic like to a lot of the people. Yes, he has a U S Patent number six one eight zero nine

for a wireless remote control nine. Yeah. Now, A a reporter from the New York Times was covering this and he said, hey, you know what, you could make this uh, this boat go under water and carry explosives and uh, Tesla basically said no, no, no, no, no no no, this is not a torpedo. It's a robot. They to help humanity not destroy it. Yeah, thanks for the Mitchell and Web fans in the audience. Yeah, but yeah, basically they suggested you, oh, you could use this for a torpedo.

They said, no, no, this this could be used to help people, not destroy people. Um. And then it turns out the military really wasn't interested in it. They were it was too it was too much of a novelty at the time for it to be of course, you know now you know, we've got unmanned aerial vehicles and all sorts of other remote controlled technology less. Um. But yeah, at the time, back in the late late nineteenth century, they weren't interested. Yeah, technology ahead of its time, really

really Tesla and technology ahead of its time Tesla. If Tesla had, if if he had been able to hold onto his patents and his sanity, um, I think I think the world would be would look a little different today. Yeah. Probably. We'd also probably be in fear for our lives whenever we stepped outside about being zapped by some sort of mac huge electronic rays. Anyhow, we're broadcasting power over to New York, stay inside. Well no, no pun intended, I'll

fact you some electricity. Um. And that was a Delbert reference. Um, so, so yeah, it's sort of if you uh, we'll pardon the pun, it's sort of submerged for a while. For for a few decades, it really didn't have a lot

of remote controlled stuff. Um, there were people who were into the technology, I would I would say hobbyists probably more than anything else, who are into different kinds of radio controlled technology, But it really didn't come back again as something that people were interested in until I would say, at least, according to my research, around the nineteen sixties was when you started seeing people with remote controlled cars and planes and and gidsmos for toys. Yeah. Yeah, The

basics behind us are are fairly simple. Uh. The you hold a controller and that controller has inside it a transmitter and uh we actually talked quite a bit about transmitters when we did our podcast about how radio works. But in case you don't remember, the basics behind a transmitter are well, it's all based on on things like magnetic fluctuations and the way that the the relationship between

magnetism and electricity. That's about two thirds of our podcast. Yeah. Yeah, it sounds might sound really familiar to those of you who have been listening to tech stuff for a while. But uh, here's a very basic transmitter. You let's say you've got a battery, and you've got two different lengths of wire, okay, and one length of wire you connect to either end of a some sort of voltage sensor. So you've got a meter there that's going to register

whenever voltage passes through the wire. But it's not connected to anything else, not connected to a power source. And then you've got a battery and another length of wire, and you connect the length of wire to the two ends of the battery. Now, the moment that current begins to flow through that wire, that change in voltage creates a magnetic field. That magnetic field will induce electricity to flow through the second length of wire, the one that's

not connected to a power source. It's only connected to the voltmeter, and the voltmeter will register that there's a change. Now it only will have electricity flow as the magnetic field changes. Yeah, so you can't have a magnetic you can't create a magnetic field, and it just perpetually creates this flow of electricity. It's only whenever the magnetic magnetic

field itself changes. So by connecting and disconnecting the wire from that battery, you are going to change the magnetic field, which will and then induce electricity to flow through that second wire. That's the idea of transmission there. It's the idea of transmitting radio waves is essentially doing the same thing you're really You're You've created a power source and a circuit, and by making the the opening and closing the circuit and a regular but rapid way, you can

create this um this change in magnetic fields. And then if by putting it through an antenna, you can direct it and and even uh amplify it in such a way that you can detect it from a distance. And then depending on how you do this and depending on how you've UH programmed the receiver on the other end,

that's where you get the response. So, for example, if I were to do this with you know, by recording music and then encoding that so that it converts the sound into electricity, the electricity then is essentially converted into uh this this changing magnetic field. A receiver would have would receive this changing magnetic field, convert that into electricity, and then have another encoding device that would convert the electricity back into sound. That's a very high level way

of looking at it. Well, we're not just limited with sound. We can transmit in from other kinds of information this way, including directions essentially to a device. So in this case, we're talking about a controller that let's let's take a very basic controller. Let's say you've got a controller that has a trigger and a wheel, and the trigger is essentially your your your throttle, your accelerator. So if you

pull the trigger, it's sending a series of pulses. It's it's a very specific series of pulses through a very specific frequency. And if your receiver is within range of the whatever your transmitter's power is, uh, the receiver receives this, this series of pulses and then interprets that as that's the accelerator button. Hit the gas. Although it's not necessarily gas. There are r C cars and other vehicles out there

that use gas, but not all of them do. Yeah, many of them will use electricity, but there are others that will rely on some form of fuel besides elect uh, you know, an electrical current. So that's a but. But the the series of pulses from that accelerat ratar is going to be different from the series of pulses. Then if you were to twist the wheel uh to the right, which would tell the vehicle, let's say it's an r C car to turn right, that series of pulses is

going to be a different series. So that way, when the r C car receives that message, it can interpret that as saying, oh, this means turned the wheels to the right, as opposed to hit the gas. Yeah. Now, UM. It's also important to note one of the things from our radio podcast that radio has can take in a number of different forms. I mean, we use there's a broad spectrum of electromagnetic radiation UM, of which radio is apart, and the radio frequencies. It all depends on UM a

number of factors amplitude, wavelength and frequency UM. But just you know, so it sort of depends on the shape of the radio wave basically if you want to get right down to it, and how many there are UM but over a certain period of time. But the there are a couple of frequencies that are specifically in the United States devoted to consumer electronic consumer electronics and UH. This is this is something that's regulated by the Federal

Communications Commission in the United States. The c UH and it's the reason you might wonder why there needs to be such an entity. Uh, the reason for it is that if you had all of your different electronics and it was unregulated, there's a lot of potential for interference.

Because if you've ever had a let's you've had a remote control car before, right, Yeah, If you have a remote control car and your buddy has a remote control car and they're both running on the same frequency and there's no way of differentiating it, then you can't race your car against your buddy's car because every time you press up on your control both cars start to move because they you know, they can't differentiate between two signals

sent along the same frequency. So imagine that multiplied by an astronomical number. If all devices were unregulated. I mean, there's all you could have the argument of, well, if it's unregulated, what are the odds that the frequency you chose it's going to be the same as someone else. Those odds are pretty good. Actually, if you look at the entire breadth of radio, everything that relies on radio transmissions, because it's not just radio, it's television, it's all these

other sort of devices. Um, So that's why you had to have a some sort of of body that would regulate this and say, all right, we are dedicating this part of the spectrum of the radio frequency spectrum to consumer electronics. Yeah we can. Uh, I mean there are a number of of real world non RC examples. Uh. You know, it's the reason why, um, wireless hubs in your house have the ability to change channels to ensure

that you don't interfere with the neighbors and vice versa. Um. You know, their their tales of pilots being able to hear baby monitors. I don't know if that's the old wireless phones. Yea, the wireless phones to uh, they've they've changed the frequencies on which they broadcast simply to avoid all the radio transmissions in the home. Now that they're people have wire wireless networks and things, um, the interfere

with one another. Yeah. I remember having a wireless phone where if you turned it on, sometimes you can hear other people's conversations, like like not not conversations that were happening in your home. Yes, but you know you turned it out, you turned it on, you Yeah, you like, I don't know if I can even make a phone call, and I don't know if I want to, because if I do, then maybe someone else is hearing what I'm saying. Yeah, So yeah, that that's the reason for the regulation. And

I remember to our conversation about the remote controls. They used to use sound to change the channel, and I used to, uh, I would drop magnets on this toy that I used to play with at my grandmother's house. She had one of those early TVs with or TVs with early remote control, and I could change the channel simply by uh the magnetic or actually it was a sound thing, so it was the sound of the magnets falling. It was an ultrasonic system as opposed to infrared or

radio waves. Yeah, I had the same thing with a slinky. But you happen to have that say that that interference, and it was a sound interference, not an electromagnetic interference. But it's it's funny when those little things happen. And this is uh their courting off so that that people can enjoy their radio controlled stuff and uh not interfere

with other people in and vice versa. Right, And a lot of the the RC toy uh toys out there are at least the older ones anyway, are dedicated in either the twenty seven mega Hurts or the forty nine Mega Hurts ranges. Some of them are actually capable of doing either, so that you know, if you have a whole bunch of friends together and you all want to race your vehicles, you can switch from one frequency to the other, so that way, you know, you you avoid

this interference problem. And also you can get more specific within a frequency. So let's say that I'm say twenty seven mega hurts is what my my vehicle runs on. Like that, that's it doesn't can't accept information from the

forty nine mega hurts spectrum or frequency range. But I could possibly if you this is all up to the manufacturer, but you could create a device that could accept different channels within the twenty seven mega hurts frequency range, so twenty seven point one, twenty seven point two, twenty seven point three, so you might have multiple channels that you can switch on and that way, um, if you do have a bunch of friends and you want to raise

your vehicles, you can all try different channels to make sure that you know your signals aren't uh uh conflicting with someone else's UM. And this is you know, that's of course really important if you're in a competition, because there are plenty of actual events out there where people are building our C cars or our c whatever's and competing them against each other in various races or obstacle courses that kind of thing, um, And some of them are kit based, and a lot of them now are

really you buy. You spend a lot of money from a particular manufacturer and buy a racing our vehicle. But of course skill comes into play too, So just because you have the fastest car doesn't mean you're gonna be the best driver automatically, that's true. Yeah, I mean there has to be a receiver, of course, on board the

device that you're controlling. That's that's the second part of this, Right, You've got the transmitter in your hand, but the vehicle itself has to have a receiver, and of course it will. The receiver will be attached to a micro controller of some type that operates the servos on board the remote controlled thing. Um. So you know, and it gets more and more complex. Like for a car, you might have ford in reverse and you know the wheels turning left

and right. That's that's pretty simple, you know, when you get into something like a remote controlled airplane. Then you've got other servos and other control surfaces. You've got uh, the you know, the engine or engines you've which of course you're going to have to maintain speed to keep the airflow going over the wing and keep the plane moving.

But you've also got the rudder controls, you've got the you know, the control surfaces on the wing to help you go up and down, not not necessarily left and right. And you've got to operate all of those things. Um. For a submarine, you might have the same type of thing where you have control surfaces that that move the sub up or down, left or right through the water. Um. Yeah, So the stuff that that you know, servos and motors are very important in these devices. Yes. And this is

stuff that takes electrical energy and converts it into mechanical energy. Yes, so we really the fascinating thing to me about an r C car is seeing how many different types of energy are being used. Yes, you know how many. And it's relying on several different things. It's relying on uh, it's relying on electricity, on magnetic changes in magnetic um states. It's relying on radio frequencies, it's relying on on mechanical energy. Uh, it's a great lesson in basic physics really when you

look at it that way. And when I said that, you know, the older ones run on twenty seven Mega Hurts and four nine Mega Hurts. There are radio controlled vehicles now that are in have our work in the giga Hurts range because the gig Hurts also opened up for some of the gig Hurts range open up for consumer devices. So some of the professional I guess what you can call it professional, some of the sports enthusiast ones, the r C racing ones are in the Giga Hurts range,

not in the Mega Hurts range. Yeah, of course this is This is yet another one of those hobbies that you can get into for a fairly reasonable cost if you have have some money squirreled away. But you can also really get into things, build things yourself, more complex devices, more expensive devices. You can move, say from a propeller plane to a ducted fan, which is what people use to sort of simulate a jet the appearance of a jet basically the fans inside the engine, and so it

appears to be to work on jet. Also, I think you can now buy jet engine real jet engines for these aircraft, which I imagine need quite a bit of space. And you know, we've even seen this sort of technology used in actual vehicle vehicles, not model vehicles. Mean the MythBusters have done it. Yeah, where where they were trying to recreate a stunt that was too dangerous to have a human behind the wheel of a vehicle or behind

the helm of a vehicle, whatever you want to call it. Um, And so they would rig up a robot that would be remote controlled and they would uh use that to manipulate the vehicle. And you know, so, yeah, it's there are a lot of different applications to this beyond the typical I want, you know, I've got little little remote control four by four and I want to drive it around the neighborhood. You know. Well, battle bots, you know, that was another type of remote controlled vehicle that uh

required things. Well, I mean that that actually is sort of another illustration too, because say you have a bot that has crawler treads on it, so you have your left tread and your right tread, plus you might have one,

two or even more weapons on the battle bot. Then you have to have um your controller and you you'd have a couple of people on some of those crews where somebody would drive the bot, so they would be in charge of making sure it got where it needed to go or got away from the other body if their weapons were disabled. And then you had somebody operating

the weapons. So that required several different frequencies UM and the receivers and controllers, the transmitters and controllers to manipulate them, and the receivers and controllers on the device itself to handle all those different things. They can get quite complex UM and again costly, because you know, those machines cost thousands of dollars. It's it can be uh, it can be a lot of fun, and it can be very expensive. Well.

And I mean I've also seen them in uh it's it's not unusual to see it in applications like UM puppetry. You know, the the Hinson Company has used remote controlled servos for some of their more advanced puppet characters in movies like Labyrinth and uh, you know, so that they could have more articulation in the character's face, but operating

under the same principles as the remote control car. UM. It's just you have like a remote control goblin face, which I think it's pretty awesome, and unfortunately I don't know anywhere where you can buy it. It's UM, it's really funny that you know that's something that's ubiquitous is actually fairly fairly easy to accomplish UM. And of course there are many different kinds of hobby stores UM. Some may be local to you depending on where you live.

Others are online and pretty easy to access UM and they offer all kinds of different things. One of the big toys I saw for this this past holiday season, the one we just uh finished up since we're recording this we actually we're recording it before this happens, but we're publishing in early were the UH air Swimmers line of inflatable toys that have remote control. The it makes the there's a fish and a shark that can it looks like they're swimming through the air, which is kind

of an actually pretty cool effect to see. But I mean they're they're using the same kinds of remote controls that we've had for decades more or less, just different frequencies maybe on the transmitter and receiver. Yeah, And I've been I've been kind of UM searching since Chris is wondering why I've been staring at my computer. I've been trying to figure you were just on YouTube again now. No, but I've been trying to find a specific UM toy because I owned one, and I can't remember what it

was called. But it was essentially a little toy battling robot. They I think there was something like six different types of this, these battling robots, and they all had different

colors and um uh. It was a robot that was remote controlled and you would you would battle it against someone else's robot, and it had things like a little infrared transmitter and an infrared receiver, so it's kind of like a laser tag type thing where you could shoot at another person's robot and also could do physical attacks like an actual knock a robot over. Um. I totally

don't remember this toy it was. It was in a way it was a really a brilliant kind of move, although I don't know how well it did in the market. But it also had a sort of a card game element to it. You could purchase packs of cards that would give your robot different stats, so in other words, your robot would be limited at how fast it could go based upon the card that you could scan to give it a speed, and the cards were ranked I think one through five, So if you had a speed

of three, you're right there in the middle. If you found a speed of five, your robot could actually move at a faster pace, and you would also have armor as well, so that would let it withstand more hits before it registered an actual hit. Uh. It was a neat idea, and I got one, and my buddy Oz got one, and we maybe had one fight and that was it. And my lovely life has endured the fact that I have this battle robot in a closet, this little bitty thing. It's not like the ones that were

in the Robot Wars or anything like that. Um but and all of its accessories that I went on and bought, not to mention, a deck of cards where I was trying to get like those those weapons and those abilities that would make them better. And some of the cards were specific only to particular robot models. So you've got cards for robots you didn't know exactly, the idea being that you would trade them for someone else's cards, where they might have ones that are useful to you but

not to them. That kind of thing it's brilliant, brilliant marketing. But it was all based on this same technology, and each robot worked on its own part of the frequency band the robots all belonged to, so that way you didn't have to worry about your UM your controls interfering with theirs. And there are also some r C vehicles

that are not really radio controlled. There's some that are infrared controlled, so it's more like a remote control for a typical television set, although some of those are now using radio frequencies in the form of WiFi, so that you know, you could have the the cable unit or uh DVD player or Blu ray player or whatever it is, you could have it out of view. And because it's using radio frequencies which aren't blocked, they don't need a line of sight. Yeah. The disadvantage of using the R

for that, yeah, you can't. That's the thing about it and I ARE vehicle or an I R anything, is that you have to maintain a line of sight in order for it to be UM controllable. Once it gets like if you if you were to make something that you're directing by I R go around the corner, then you'd suddenly lose contact with it and it wouldn't it would just stop or go on a killing rampage whatever it's default settings. Right. So, but from the RC range, you know, you you don't have to necessarily have a

line of sight. Now there is a only a you know, a useful broadcast range that's going to be dependent upon the power supply and the kind of antenna you're using. Um. If so, if you were to say, fly a remote controlled helicopter around and it's sort to get outside of that rage, you might quickly have a search and rescue operation on your hands. Mm hmm. Yeah, I thought I was thinking back to some of the other stuff I had that sort of emulated remote control, but not really.

I had a car UM that had a cam system on it, uh, and it came with a series of plastic cams. It was actually a replica of a Porsche nineventeen race car, and you would stick a cam on top and it would do whatever the cam had and the cam would rotate and so the car would basically you know, would go forward and then reverse and do whatever, but it would do that according to the shape of

the cam. UM. And then of course I had the big track which sort of appears to be remote controlled, but you're really programming it before you even press go and then it does what it does. And um so I mean they're there are other ways of doing similar things, but it's just not the same like the old remote controlled toys that would still have a wire attack them. I had one of those two press up or down and that would make a go forward or backward. But

it's all wired. It's not so you're tethered to it. Yeah. The parent a r drone, which is something I saw it CS a few years ago. It's been it's been for a while. Yeah, it's been out for a while. It's a four rotor copper copter chopper and it's uh it doesn't look like a helicopter because it doesn't have that one uh blades up at the top. Yeah, it's got it's got four sets of them and uh it looks like a weird hovering drone thing. But you can

control those through a smartphone device usually. I think it's only um iOS. Actually, I don't think they have an Android based system yet, but they they actually maybe they do. I'm looking at their website and they have a little Android icon on it. Yes, a new Android app, so they do in fact have Android now. When I first saw it, it was only for the Apple iPhone. But in this case, it's using WiFi to to let you control the the device, and you do it through an

interface on your smartphone. And uh, it's similar to what we've been talking about, except that you know it's it's a a WiFi frequency, not the same as the old direct radio frequencies. So uh, we're seeing lots of kind of experimentation with this this older technology, I mean technology that dates back to the nineteenth century. Um, and it's really neat to see the kind of toys that are coming out. I was always a big fan of remote

control cars. I owned a few. Um, haven't played with one in a long time because it drives my dogs crazy. I would have figured you'd play with one specifically because it drives your dogs crazy. They don't last so long, the toys, not the dogs. The last all day long. But no, they will like I had. I think it was a remote control Plymouth Prowler, a purple Plymouth prowler, because that's the only color they came in originally. And uh, the dogs didn't seem to like those classic lines. The

same way I did. They're not roadster fans. On the other hand, I do have a remote controlled mouse that I use with my cats, and you know, so it's it's it sort of works. It's a very uh low end mouse, right, you plug it in, squeak mouse, not a mouse, right, and it it stays charged for maybe about five minutes of play. And by play that I mean I play with the mouse and the cats stare at it, like, what is that thing moving around on the floor. Never mind, I'm going to take a bath now.

That's the thing that looks almost, but not exactly completely unlike an actual mouse. Yes, that's pretty much how it works. So we have fun, the humans have fun playing with the remote controlled mouse, and the cats and sit there, which is pretty much the way cats work anyway. You know. We we worked for their amusement and they just sit there and watch. So yeah, that's the that's the basics behind the whole r C toy thing. It's you know,

like it is. It is simple, but it's it's relying on some very basic, uh foundations for the way energy and works, in the way the different kinds of energy interact and influence one another. It's a it's neat stuff if you want to learn more. We actually have an article on how stuff works dot com about how r C toys work and it has some useful information in

there so you can learn more about it. And there are a lot of sites, like I said, online that cater to people who are into this in a hobbyist level where they will learn more about building their own and there are lots of kits that you can get. Um there you can also find out about competitions if you want to try and hone your skills as an RC driver and go up against other drivers. And it's

neat stuff. Yeah, if you can. If you can find a hobby store near you, um, they're probably gonna know about things like competitions and good places to go because of course, actually that's something else. Uh. You know, we were talking about the FCC regulating radio frequencies here in the United States. Uh. You know, it's good to stay aware of the laws in your area. UM, maybe not

necessarily as far as you know. If you can buy a remote controlled car in your local store, chances are it's probably legal, but you also want to make sure that you are operating these devices in places that are okay, especially things like planes, because the planes need quite a bit of space um to operate, and there may be areas that are specifically off limits to stuff like that for safety reasons, or you might be near a residential neighborhood. You also want to operate them in a safe place,

um you know, for obvious reasons. You don't want to hurt somebody or yourself or destroy your your brand new RC car. Yeah. Yeah, so it's uh when your RC car met up with a real life car. Yeah and uh, you know, so you definitely want to to do that, especially if you're investing some some real money into these hobbies, um you know. And plus you don't want to run a foul with the law and end up with a happy ticket na Um, Johnny Law might have some words with you. So so yeah, I keep that in mind.

You want to operate these things safely and uh and responsibly. Yes. And if you guys have requests for any other sort of topic you think would be interesting for us to cover, let us know on Facebook or Twitter. Are handled. There is tech stuff h s W. 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 House 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