Hey everyone, Jacob from Make Science Fun thanks for joining me today. Today is
essentially a coffee machine teardown, to see what makes it tick, how do they work. Ahh this is my old faithful. About a month ago
the heat wasn't, it wasn't producing as much heat, the coffee wasn't as hot
there was not as much steam and that sort of thing and then just last week the
electricity in the house just kept like tripping out for no apparent reason it
was a lot of effort to find out what was actually tripping it and it turned out
that it was this machine. I've got a suspicion why it was tripping out the
power but I'll talk about that a bit more as we open it up. So I guess every
coffee machine needs water. You put water in here and then the water comes out
here. Now it's not coming out at the moment but when you put it in the back
there's a little probe I guess that pushes up, and it lets the water out. See
that, whoaaaa. I don't want water everywhere. Get rid of that, get rid of that. The filter, it has just got like a piece of cloth but it has
also got charcoal in here. Now charcoal is a great filter because it absorbs,
absorbs chemicals. Oh! There it is. That's it there, and I bet if i cut it open
we'll have like charcoal.
And, you can see all this granulated charcoal, see that see that granule, see
that granulated charcoal there. Ewwww it's not coffee. Oh disgusting hmm like cockroach
poo. Now this is where the cockroaches grow, I mean where the hot water goes when you
overflow the thing. The hopper, it's where the coffee beans go and they get ground
up inside the machine there. Let's get these bad boys off. Make sure you don't have this plugged in. Let's see if I can work out what's going on in this beast!
Umm I don't want to fix it. I just want to see how it works.
Ummm firstly, in comes the power now the top one is basically positive and the
other one is negative. It's alternating current so it goes backwards and
forwards. But the bottom one is what's called the earth lead and the earth lead is
this green wire which is attached to the middle base which we'll call the earth.
And, if I fire this wire, this wire through my house it goes to the circuit
board and then goes to a wire outside to a pole deep down into the ground and
that's called the earth. And what that's for is that if, if there's something that
goes wrong in the machine and maybe the live power touches the case and because
the case is made out of metal well that can conduct electricity to the user and
electrocute them. And so if something goes wrong rather than electrocuting the
user it sends electricity down the earth outside to be safe. But! here's the catch.
There's a new thing in our circuit boards, a residual circuit device, I think
it's an RCD, and it actually measures the current in the earth circuit and if there's any
current in the earth circuit like any current whatsoever, it actually trips the
whole house. Now I think that's what's been happening. Often in heating units they
leak a little bit of electricity especially as they get old and so that's
what I think's been happening I think it's leaking electricity down that earth
wire. So I could be really really naughty and like cut that earth wire and I won't
trip the RCD anymore, but, I could end up getting electrocuted if
something really does go wrong. So I better not do that! Get rid of that. Click, break you off.
and pull you out. So what the heck does this do? Open it up, ah ha ha ha ha look at this as the water goes through it, it
spins and I bet those two little things are magnets,
click. Oh, so that's got a little rotating waterwheel in it, it's a tiny little
rotating wheel, oooo it spins so nice, well look at that, it spins so easy,
and there must be a little magnetic sensor that's what that does it measures, this
measures the flow rate of the water going into the coffee machine, boom good.
This red thing here has to be the water pump, there we go.
That's the water pump that's the water pump, 48 watt water pump, brrrrrr
Some type of diaphragm pump, but man it's it's a it's a it's a sealed it's a
sealed unit there's no opening this thing up.
That's the water heater, cold water comes in here and the hot water comes out
there, it's quite heavy actually weighs probably about two three hundred grams
and it's got sensors there is quite a few sensors on here. This one detects if it
gets like really hot on the outside then it actually clicks off. I suggest it's
another temperature sensor. I said I think this is what actually senses how
hot the hot water is because it's at the bottom, would take time for this to heat up and
this would let the computer know when it's hot enough. Speaking of the computer,
water pump, heater, need a computer to drive all this stuff. This machine won't be making
coffee in the near future, and, that's what makes a perfect coffee
and you know what, I'm looking at it, I don't know if you can see this, but there
is some discoloration in this area here, something is cooked, yeah there's some
definitely heat damage in this area here and somehow that green earth wire is
connected to this somehow and I bet that's what's causing the circuit to
keep tripping. Okay, and that, that is the grinding unit itself
beautiful little Universal motor it will actually run on DC and AC and
they're fairly talky motor for something like this. That goes from the
big wheel, to the small wheel, to the big wheel, the big gear and
so that's what probably for every, I don't know, 20 turns, turns that big gear once. Beautiful!
Well, thanks for joining me today, that's about, that's about it, and I've got a bit
of a picture of what's in a coffee machine and now I know that what cooked it was
probably a heated resistor has ended the life of my poor, departed, coffee machine.
Thanks for joining me, and I'm sure I'll see you again soon, bye for now.