-
Alright today we're going to take a look at the
-
Conair 1875 hair dryer.We're going to look at the different systems
-
and functions inside of it, how it was made and
-
how it works.
-
And we're also going to take a look at how they
-
were able to produce a hair dryer for less than
-
$8.00 and still make a profit and still stay in
-
business as a company because that's a very low
-
price and the way low price. And the way they've
-
done that is they've reduced a lot of cost and
-
complexity and we'll take a look at how they've
-
done that. So the first thing I want to take a look at is
-
the plug here. This is called a "ground fault
-
interruptor circuit plug" and it has two different
-
sized prongs right here. There's a larger prong and
-
a smaller prong. And that's very important.
-
The larger prong is the neutral prong and that
-
means you can't plug this in incorrectly, it has to go in
-
in only one way. And that means that the power
-
is grounded properly. So the power always goes
-
to ground and that's a critical thing in a circuit
-
like this. So what this plug does it's actually pretty
-
smart it can tell if there's a power difference
-
between these two prongs. And that power difference
-
might occur when the hair dryer was, say, dropped
-
in water or there was some sort of short that
-
happened. Inside the hair dryer there are open
-
electrical contacts that if they're put into water
-
or some other conductive fluid they'll short out.
-
And it will cause the, you know, it'll electrify the fluid.
-
And in the past that was a huge problem because
-
people would get schocked or electrocuted and now
-
it's not as big a deal because we have these ground
-
fault interruptor circuits. So let's take a look at what's
-
inside of that. And I've already popped this apart to
-
some degree. I'm going to see if I can get it the rest
-
of the way here. Now I want to say one thing really
-
quick here from a safety stand point:
-
It's absolutely critical that you DON'T take apart
-
any plugs ever without a professionnal! And if you do
-
have a professional and you do end up taking apart
-
a plug like this make sure that you never ever
-
plug it in! It's totally unsafe. So this is a plastic
-
moulded housing it was injection moulded.
-
There were two pieces of steel that came together
-
and the molten plastic was injected and you can see
-
there are little pin marks right here. And pins came in
-
inside the mold and pushed this part out.
-
And then there's a little plastic piece here with a
-
spring and that's for the test switch.
-
So the test switch pushes on this part right here
-
on the printed circuit board and the reset switch
-
is right here. So you push on the reset switch
-
and it will reset it so if it gets triggered you can still
-
use your hair dryer again later.
-
So one thing I want to take a look at here is the
-
printed circuit board here. So we've got a lot of
-
really cool things happening on this printed circuit
-
board. It is made out of fiberglass.
-
It's got a thin layer of copper applied to it.
-
And then on top of the copper is a layer of lacquer.
-
(The copper) Before they put the copper layer down
-
they actually etch away parts of the copper. So
-
there's places where there is no copper and there's
-
places where there is. And those places where the
-
copper exists are called traces and they function
-
like little tiny wires. They're supper flat and compact
-
and allow you to get a lot of stuff in a very
-
small space. Which is why we use a little
-
printed circuit board like this. And you can see on
-
here we've got a little tiny capacitor that's called a
-
surface mount capacitor and a little resistor.
-
Remember a capacitor stores a charge and then
-
releases it and a resistor will resist current flow
-
and that can be used to protect different parts of the
-
circuit. And this right here is
-
this part right here is called and integrated circuit.
-
And it actually takes commands from things on the
-
back takes information from things on the back
-
and decides what to do with it.
-
So this thing right here is called a toroidal ring
-
or a copper coil and it basically can sense the
-
difference between these two lines.
-
And so when there's a significant voltage difference
-
a few milliamps even
-
it can tell and it sends information to the
-
integrated circuit here. And then the integrated circuit
-
tells this guy which is called a solenoid
-
it's a linear solenoid.
-
But it sends electricity to this and it causes this pin
-
to pop. And when the pin pops, it breaks the circuit
-
the electrical contact, the connection in the circuit.
-
So there's no chance that you can get shocked there.
-
And there's a couple of really neat interesting parts
-
on this board. We've got a
-
this is a dialectric capacitor.
-
And then we have another capacitor right here.
-
And you can see right here this is a ceramic
-
capacitor this little sort of rust colored one.
-
I'll take this out so you can see it better.
-
And this is called a transistor so it can function
-
like a switch in a circuit. And this is called a
-
varistor or a variable resistor and it can protect the
-
circuit from high voltages and things like that.
-
It's a non-linear resistor in other words as the
-
current flow changes the resistance changes and so
-
it can protect your circuitry there.
-
And if you look on the inside you can see the
-
back side of the plugs or the prongs I should say.
-
And those are just brass pieces with wires that
-
go to the circuit soldered on.
-
And then this part of the switch housing
-
or I should say the plug is also made out of injection
-
moulded plastic. And then we have the wire that
-
comes down here and there's this protective rubber
-
piece on the wire so that the wire can flex back-and-
-
forth inside of the housing without wearing out.
-
And if you look right here here's a warning. It says:
-
unplug it do not remove this tag.
-
They still want to warn you that it's definitely not safe
-
to drop a hair dryer into water.
-
This is a safety precaution but it's not a good idea
-
to ever put the hair dryer near water because
-
it is an electrical device with open contacts
-
on the inside.