Growing up, you may have heard
that you should never stick a knife in a toaster,
and today, we want to try and do a few tests
to find out why that is.
What is going to happen
if you put a knife in a toaster
while it's turned on?
[Captions by Judy V. at Y Translator] [Music]
[Music]
Many years ago, when I was a child,
I actually did stick a knife in a toaster.
I had never been told that this was a bad idea,
and I don't know the exact circumstances behind what I did,
but I remember getting one heck of a jolt through my body.
It wasn't comfortable,
and I want to avoid doing that, or anything potentially fatal today.
Here's the basic idea.
We're going to test a few different methods
of seeing what happens if you do stick a knife in a toaster.
We'll try and measure the current flowing through it,
and we'll try and create an analog
to see what would happen
if the current were flowing through a person.
So here's what I'm going to be doing to avoid getting shocked.
First off, my knife will be attached to a stick
using some plastic zip ties.
This should allow me to have some distance
away from the toaster,
and to not have the current of the knife
traveling through my hands.
Second, the hand holding the stick will be wearing a thick leather welding glove.
This does not conduct electricity well at all,
so, that should prevent even more current getting to me,
even if it manages to travel up through the stick.
I'll be wearing these strange slippers
that I made out of Proto-Putty in a different video,
and I'm going to be standing on a block of insulation foam.
My left hand, the one not holding the stick
will be behind my back, or in a pocket the whole time.
So, there's very little chance of any electricity conducting
from one hand through my chest and my heart
into the other hand.
If any electricity does get conducted,
it's much more likely to go through my arm
and down out of my feet,
and finally, in case there are any really bright sparks,
I'll be wearing a welding mask.
Let's get all of our safety gear ready,
plug in our toaster,
turn it on,
and then see what happens if we start poking around in there.
First, I'm going to try and touch one of the nichrome heating coils
without touching any of the other metal in there.
This is on a stick, so, my dexterity may be a little limited.
But, that's the goal.
[Music]
Well, I managed to make the knife warm.
So, that's your first danger.
If you leave the knife in too long while you're holding it,
it's going to get hot, and then you'll burn your fingers.
Now, let's see if I can touch one of the nichrome wires
while touching the metal sides of the toaster,
see if that does anything different.
[Music]
I thought maybe I would get a couple of sparks,
something like that.
Maybe the circuit breaker would trip,
but a knife not connected to anything isn't really completing a circuit.
It's just poking at stuff,
and I presume the toaster's already built in such a way
that if something metal touches those nichrome wires,
it's not going to short anything out.
So, we may have to force the issue.
I want to see if I can get the knife connecting from one wire onto another,
but since my knife is very straight,
I'm gonna have to try, and wrap a little bit of wire
around some of the nichrome in the toaster,
to give me a sort of access point, so I can see what happens if the two connect.
Right.
That wire is now definitely in contact with some of the nichrome.
So I'm gonna try two different things, I'm going to try touching that wire,
and the copper wire connecting those with the knife,
and I'm going to try touching that nichrome element in the wire
at the same time.
Let's give this a shot.
Oh, I saw a spark!
[Music]
So not only Is that sparking, but it's actually like sticking.
it's like welded the knife onto the nichrome wire.
You can also see that the whole toaster
lights up a lot more when I'm making this connection.
[inaudible] the copper wire is actually attached to the steel knife now.
All right, we tried one side, we got some cool sparks,
the knife started welding itself onto the nichrome wire and the copper wire,
so, that's not something you want happening while you're making toast.
Your knife welding itself down in place...
Let's see what happens on the other side.
Will it be the same effect?
[Music]
Oh, yep!
That's that same look we got before, sparking, welding, glowing extra bright,
Check this out.
where I've been connecting,
the copper wire has heated enough
that where it touches the plastic housing of the toaster,
it started melting into it.
The coils inside the toaster have been heating up way hotter
than I'm pretty sure they're supposed to.
I want to see just how much electricity starts flowing through these things.
What we want to do now is take a voltmeter,
and connect the leads to the two different sides
to see how much energy is flowing through these things.
Plug it in and I'll just touch the knife to one of the wires,
and we can see what shows up on our voltmeter.
It looks like while these are connected,
we have about 50 volts running from one nichrome wire to the other.
Another test I want to try is to see what happens
if we touch the knife to one of the coils,
and at the same time to something that is grounded.
We're going to take an extension cord,
fit a wire into the grounding port of the end of the extension cord,
and then see what happens if we touch one of the nichrome wires
to that grounded wire.
[Music]
That popped the toaster up immediately.
And I believe I popped the toaster up
because there's no longer electricity to the toaster,
which means almost certainly we have tripped the breaker.
We have a GFI in the kitchen,
and we just had to hit reset on that,
took us a few minutes to find it.
It's possible that if something less conductive than a knife
had this current running through it though,
it could get a good jolt of electricity without resetting the breaker.
I have an idea of how we can test that.
We've now got wire running from the knife down into the hot dog.
At the other end of the hot dog is a wire
that's connected to the ground wire in our extension cord.
And we have both of these plugged in, and we touch the knife to the nichrome,
we'll see if it conducts electricity through the hot dog well enough to trip the breaker
or if it starts frying the thing.
[Music]
Oh!
Popped it immediately.
That's probably good for security.
Now, we have our knife connected to our hotdog.
Our hotdog is connected to one end of the voltmeter,
and the other end of the voltmeter is going into our ground wire.
[Music]
109 volts traveling through that hot dog right now.
This is pretty interesting.
I didn't see this coming,
and that's possibly just because I don't know everything
about how toasters work.
But every different segment of nichrome wire that I touch
gives a different readout on the voltmeter.
Once again, I've hooked the knife up to the hot dog,
and the hot dog up to the ground.
However, this time our toaster is not plugged into an outlet with the GFI.
Now, our toaster is plugged into an outlet that only has a breaker switch
to turn it off if something goes wrong.
So, we might see some difference in what's happening to our hot dog
[Music]
And our hot dog is starting to cook,
Random fact,
the first electrical toaster was invented in Scotland in 1893,
35 years before sliced bread started being sold in stores.
[Music]
Parts of our hotdog got a little bit scorched by electricity there.
It was burning,
you can see the steam coming out--
This part's actually quite hot in fact.
By connecting our hotdog to a circuit that doesn't have a GFI on it,
we were allowing over a hundred volts of electricity to run through this hot dog,
which as you may remember,
is an analog for
what would happen if you held the knife in your bare hand?
Based on this set of experiments,
we learned that if you stick a knife into a toaster,
not too much really happens.
Unless some part of your body is electrically grounded as you do,
in which case, you're going to get a real shock that could potentially kill you.
if the toaster is plugged into a switch on a GFI circuit,
you'll likely get a little shock,
but the GFI should trip instantly and save your life.
But why take the chance?
Don't stick knives in toasters.
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