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.