(smooth, futuristic music)
(classical string music)
(chalk board writing)
- I'm Jonathan, and
welcome to Brain Stuff.
Now, have you ever been in your bathroom
brushing with an electric toothbrush
(electric motor)
and wondered to yourself, "Wait a minute.
"How the heck is this
thing working anyway?"
Well, don't worry, your toothbrush
isn't running on uranium.
No.
Our electric toothbrushes
recharge their batteries
through a process called
wireless charging.
See, electricity already exists
all around us, binds us,
(dramatic, adventure music)
it penetrates us...
(dramatic, adventure music)
Actually, it exists as magnetic fields
in the atmosphere, and wireless charging
just harnesses those fields
in all kinds of devices,
from toothbrushes, to cell
phones, and even cars.
Depending on the size of the device,
and its distance from a transmitter,
there are three ways to
wirelessly charge it.
For low-power devices that stay within
30 feet or 10 meters of their transmitter,
there's something called radio charging.
(radio static)
Now, this method is used with small things
like medical implants, hearing
aids, and some watches.
A transmitter sends a
low-powered radio wave
(electronic pulsing)
through the air to the receiver
that converts the wave into pure energy.
But for something a little
larger than a watch,
like your toothbrush, the most
common method is called
inductive charging.
So instead of radio
waves, inductive charging
uses electromagnetic
fields to transfer energy
(electric crackling)
from a transmitter to a receiver.
In the toothbrush's case, it forms
a two-part transformer with
the base it's mounted on.
The primary transmitter is housed
in the toothbrush's base,
producing the magnetic field.
Now, this field is picked up by
the secondary receiving coil
inside the toothbrush itself,
which induces electricity
and charges the device.
(device charging)
Now, remember when I said that
your toothbrush didn't run on uranium?
Joke's on you!
No, no, no, it doesn't,
at least, it shouldn't.
But the magnetic field
of inductive charging,
it generates something called
non-ionizing radiation,
which we're 99.9% sure is
harmless.
(abrupt rewinding)
Perfectly safe.
Well, while is inductive charging is great
for toothbrushes and
phones, what if you wanted
to charge something larger
like, say, your car?
Well, for this kind of application,
(bell chime)
we use resonance charging.
This is a similar principle
to the toothbrush.
It uses a coil and a magnetic field.
But the difference is that it can deliver
way more energy: somewhere
around 3000 watts.
Scientists envision a future where
vehicles using resonance charging
actually recharges while
you're driving around.
A receiving coil resting under the vehicle
would resonate with a grid
directly under the road.
(car speeding by)
Even while moving, this car would move
through these magnetic fields.
It would induce electricity to
flow and charge its own battery.
It's pretty awesome.
So, if wirelessly charging is so easy,
why do I still have to
fight for the one seat
in the cafe, next to an electric socket?
Well, unfortunately, the
companies that produce
our phones, tablets, laptops, and cars
have yet to agree on a common standard,
so all these devices can charge
with the same basic technology.
Once we all agree on how
to charge wirelessly,
we won't constantly be
on the lookout for places
to plug our phones or
our toothbrushes into.
So now that you know how to
charge a device wirelessly,
how would you start using this process?
Let us know in the comments below,
and make sure you like and
subscribe to this channel,
because they're right offscreen right now
threatening me with
pitch forks and torches.
(smooth, futuristic music)
