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Alright today we're going to take a look at the

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Conair 1875 hair dryer.We're going to look at the different systems

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and functions inside of it, how it was made and

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how it works.

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And we're also going to take a look at how they

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were able to produce a hair dryer for less than

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$8.00 and still make a profit and still stay in

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business as a company because that's a very low

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price and the way low price. And the way they've

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done that is they've reduced a lot of cost and

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complexity and we'll take a look at how they've

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done that. So the first thing I want to take a look at is

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the plug here. This is called a "ground fault

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interruptor circuit plug" and it has two different

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sized prongs right here. There's a larger prong and

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a smaller prong. And that's very important.

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The larger prong is the neutral prong and that

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means you can't plug this in incorrectly, it has to go in

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in only one way. And that means that the power

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is grounded properly. So the power always goes

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to ground and that's a critical thing in a circuit

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like this. So what this plug does it's actually pretty

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smart it can tell if there's a power difference

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between these two prongs. And that power difference

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might occur when the hair dryer was, say, dropped

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in water or there was some sort of short that

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happened. Inside the hair dryer there are open

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electrical contacts that if they're put into water

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or some other conductive fluid they'll short out.

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And it will cause the, you know, it'll electrify the fluid.

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And in the past that was a huge problem because

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people would get schocked or electrocuted and now

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it's not as big a deal because we have these ground

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fault interruptor circuits. So let's take a look at what's

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inside of that. And I've already popped this apart to

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some degree. I'm going to see if I can get it the rest

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of the way here. Now I want to say one thing really

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quick here from a safety stand point:

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It's absolutely critical that you DON'T take apart

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any plugs ever without a professionnal! And if you do

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have a professional and you do end up taking apart

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a plug like this make sure that you never ever

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plug it in! It's totally unsafe. So this is a plastic

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moulded housing it was injection moulded.

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There were two pieces of steel that came together

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and the molten plastic was injected and you can see

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there are little pin marks right here. And pins came in

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inside the mold and pushed this part out.

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And then there's a little plastic piece here with a

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spring and that's for the test switch.

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So the test switch pushes on this part right here

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on the printed circuit board and the reset switch

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is right here. So you push on the reset switch

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and it will reset it so if it gets triggered you can still

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use your hair dryer again later.

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So one thing I want to take a look at here is the

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printed circuit board here. So we've got a lot of

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really cool things happening on this printed circuit

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board. It is made out of fiberglass.

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It's got a thin layer of copper applied to it.

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And then on top of the copper is a layer of lacquer.

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(The copper) Before they put the copper layer down

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they actually etch away parts of the copper. So

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there's places where there is no copper and there's

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places where there is. And those places where the

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copper exists are called traces and they function

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like little tiny wires. They're supper flat and compact

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and allow you to get a lot of stuff in a very

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small space. Which is why we use a little

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printed circuit board like this. And you can see on

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here we've got a little tiny capacitor that's called a

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surface mount capacitor and a little resistor.

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Remember a capacitor stores a charge and then

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releases it and a resistor will resist current flow

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and that can be used to protect different parts of the

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circuit. And this right here is

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this part right here is called and integrated circuit.

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And it actually takes commands from things on the

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back takes information from things on the back

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and decides what to do with it.

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So this thing right here is called a toroidal ring

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or a copper coil and it basically can sense the

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difference between these two lines.

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And so when there's a significant voltage difference

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a few milliamps even

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it can tell and it sends information to the

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integrated circuit here. And then the integrated circuit

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tells this guy which is called a solenoid

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it's a linear solenoid.

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But it sends electricity to this and it causes this pin

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to pop. And when the pin pops, it breaks the circuit

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the electrical contact, the connection in the circuit.

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So there's no chance that you can get shocked there.

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And there's a couple of really neat interesting parts

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on this board. We've got a

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this is a dialectric capacitor.

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And then we have another capacitor right here.

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And you can see right here this is a ceramic

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capacitor this little sort of rust colored one.

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I'll take this out so you can see it better.

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And this is called a transistor so it can function

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like a switch in a circuit. And this is called a

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varistor or a variable resistor and it can protect the

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circuit from high voltages and things like that.

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It's a non-linear resistor in other words as the

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current flow changes the resistance changes and so

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it can protect your circuitry there.

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And if you look on the inside you can see the

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back side of the plugs or the prongs I should say.

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And those are just brass pieces with wires that

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go to the circuit soldered on.

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And then this part of the switch housing

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or I should say the plug is also made out of injection

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moulded plastic. And then we have the wire that

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comes down here and there's this protective rubber

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piece on the wire so that the wire can flex back-and-

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forth inside of the housing without wearing out.

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And if you look right here here's a warning. It says:

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unplug it do not remove this tag.

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They still want to warn you that it's definitely not safe

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to drop a hair dryer into water.

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This is a safety precaution but it's not a good idea

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to ever put the hair dryer near water because

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it is an electrical device with open contacts

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on the inside.