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Current time:0:00Total duration:7:23

What is inside a universal remote control?

Video transcript

all right this is a universal remote control we're going to take it apart today see what's inside and what makes it tick there are two different kinds of universal remote controls there are learning remotes and then there are ones that function on code libraries so this one functions on a code library the learning remotes tend to be more expensive but what the learning remotes do is you have our learning remote you can you can put it next to the the original remote and basically use the original remote to program the learning remote and then it will it will function there those like I said tend to be more expensive more complex this one just has a code library built in and so you you enter a certain sequence of numbers and you can pull up a certain code and then that will allow this to trigger whatever device that code goes with so I've already cut the the box apart here let's go ahead and pull the remote out okay so you can see it's got a number of different buttons on here can each perform different functions and there's a little LED a light-emitting diode that lights up there and so let's take the back part of it out and this is a this is a little battery cover and the battery cover is injection molded you can tell that for a number of reasons one is it is very precisely made and the other is that it has a has these little injection ejector pins marks on it so those little circles are pins that were used to push the part out of the mold after it was made and you can see right here it says ABS plastic so it's an ABS plastic part and ABS was selected because it's fairly low cost and impact resistant and we all know that remote controls tend to get beat up and knocked around a lot so that's a good plastic to use so let's see if we can pop this apart usually these these devices have yeah there we go all right this one's molded together alright alright so this device is used uses what's called an interference fit or a snap fit and again the bottom housing and the top housing are made out of ABS plastic you can see that again right here just the ABS symbol there and the plastic recycling symbol and anyway so they these things are called bosses or standoffs and they hold the circuit board in place and these are the little tabs that allow it to snap together now the reason it doesn't have any screws is that it helps to reduce cost so this this remote was very inexpensive and so reducing cost was a key way to be able to produce it for a low amount and still make money selling them ok so you can see we've got a number of different components here these things these Springs right here are what the batteries connect to so there's a springs on the inside here and then other ones here so there looks like it uses triple-a batteries and the power goes through these Springs to the other side of the board and we have a looks like a resistor here maybe a filter of some sort and a capacitor dielectric capacitor and then up here we've got a infrared LED so that shines light in the infrared spectrum so you can't see it with a visible eye if you had an infrared camera you could see it would be shining like a like a flashlight but since we can't see an infrared it looks invisible which is kind of nice because you don't want to constantly be shining a flashlight on your on your TV or your stereo and then there's a little indicator LED here so let's turn that over and we have our printed circuit board and our buttons so the moult another reason for injection molding is it's very precise and so you can get really nice clean fit so these buttons fit nicely into there these buttons are a great way to reduce cost too because they're there's no springs that cause the buttons to return it's actually the material itself so this material is a material called santoprene and and it has a particular resilience and so it causes the button to return to it original location after its pressed and there's no need for Springs and then there's these little conductive contacts down here and those conductive contacts when a button is pressed connect these little conductive are exposed fingers here so there there's these little parts I'm not sure if you can see those very clearly but these little tiny parts here have these these interlocking exposed contacts and so they're shaped like this and so when you push a button it causes the conductor on the back here to come into contact with those exposed fingers and it makes the sends the electrical impulse to this guy which is a little integrated circuit and it it had stores the code library and it also interprets the signals from each of these switches so if you're watching you know channel 4 and you push or you want to watch channel 4 when you push channel 4 and it triggers this connection here then this thing sends tells the tells the batteries to send power to the LED in and it blinks in the infrared LED blinks in a particular pattern and that pattern is interpreted by your stereo or your TV and it causes the stereo TV to to change to that station or channel and you can see on the back this this whole board right here is made out of fiberglass and it's got a thin layer of copper applied to the back you can see in places the copper is etched away and there's just the places where you see the sort of lighter green is where the copper is and the places where it's darker there's no copper so what that does is it allows you to create like wires that connect everything together the copper acts like a wire it's a conductor and the spaces between the copper function like an insulator so you don't you don't have any any shorts but so these little copper connections here are allow for a current to flow and they send signals back to the microprocessor again the microprocessor interprets those and then sends signals to the infrared Leedy which sends the signals off to your TV and if you could see this when with an infrared again if you could see it with an infrared camera you see flat different sequences of flashes coming from this LED and those would be what triggers the the change in in your TV or your stereo and the caught the contacts here are coded so that they don't corrode and also so that that they are insulated somewhat they're coded usually with like a lacquer coating and then this shiny metal here this is called solder and it and it basically fastens connectors like this to the other side of the board and make sure that there's a conductive connection there so that the power from the batteries get sent to the board anyway that's it that's our universal remote