- Where does our electricity come from?
Well, most of our electricity come from power plants
that use generators to generate our electricity.
How do the generators create electricity?
Well, they spin electromagnets near coils of wire.
Wait, how does that work?
And how did anyone figure that out in the first place?
Well, I'll tell you in the video, ready?
Let's go.
♪ Electricity ♪
It all started in 1832.
That's when Michael Faraday wrote a paper
about the many ways to create
or induce electricity with magnets.
Faraday wrote, that moving a magnet
into or out of a coil, would create bursts of current
and spinning a copper disc near a magnet,
made a constant but very weak current.
A French instrument maker
with a nearly unpronounceable name of Hippolyte Pixii,
read Faraday's paper and combined their features
into one single machine where he spun the U shaped magnet
near coils of wire.
When Pixii spun the magnet,
an interesting thing occurred.
The current would go one way and then half a turn later,
the current would swing back the other way.
By spinning the magnet faster,
he could get more current,
but also make the current swing back and forth faster.
Pixii created alternating current or AC.
Now, at the time, that seemed like a negative result.
He went to France's leading electrician,
a man named Andre Ampere who suggested
he could fix this problem with a funny device,
we call a commutator.
The commutator had brushes that connected to the coils
so that sometimes the wires were connected one way
and sometimes they were connected the opposite way.
The result of all this,
is that it changed the alternating current
into a current that pulsed but only went in one direction.
Even with the commutator,
this generator was not useful for telegraphs
as the signal was too bouncy.
Poor Pixii died in an accident two years later at age 26.
And as far as we know,
never made a dime of his invention.
Not much of importance happened for another 16 years
until a Brussels professor named Floris Nollet
made a generator with more and more coils,
eventually creating a behemoth machine
with 40 magnets and 16 coils
that he called the Alliance
that could produce around 50 volts of potential.
At the time,
the only electrical lamp was called an arc lamp
and was made with creating a very bright spark
between carbon rods.
The Alliance machine would light up an arc lamp
but it was not practical
for commercial use because the commutator
would spark and break with all brushes rubbing
against the rapidly spinning machine.
After seven years,
and basically as a random act of frustration,
they tried using it without the commutator at all.
They found to their shock,
that the alternating current would light up an arc lamp.
This was the first instance of using the current
that went back and forth alternating or AC,
instead of forcing the current
to be a one direction, direct current or DC.
This was the first use of AC to create light.
The most important invention
in generators happened around this time
and it has to do with the electromagnet.
Way back in 1831,
an American scientist named Joseph Henry,
experimentally demonstrated
that you can make the strongest magnet per weight
with a simple battery
by wrapping insulated wire tightly
around the metal core and putting current in that wire.
In the 1850s, two men said that independently thought
of using electromagnets in their generator.
Samuel Varley was a 35 year old English telegraph operator
and disciple of Michael Faraday
who had been playing with generators for fun on his own
since he was 17 years old.
In 1856, he invented a generator with electromagnets
although it took him 10 years to file for a patent.
Varley might've been the first,
but he was mostly ignored as he was not well connected.
And he had a bitter falling out
with his older brother, Cromwell Varley
who was well-connected and apparently worked
to obscure his younger brother's accomplishments.
Another Englishman named, Henry Wilde was well-connected
and his siblings didn't work against him.
In 1864, he wrote about how he used electromagnets
to create a generator.
Also, why he thought of it.
Wilde stated that since electromagnets demonstrated
that electricity could produce a very strong magnet
and generators demonstrated that magnets
and spinning could produce a lot of electricity,
it seemed logical to basically nestle these effects.
His idea was to use a generator
with magnets to create electricity
and then use that electricity to make electromagnets
to generate even more electricity.
Wilde found his results to be most splendid.
He had ecstatic descriptions
of how his compound generator would produce great amounts
of electricity that could produce brilliant lights
or even melt metal bars.
Notice, you can't get something for nothing.
It will produce more electricity
but it's also correspondingly harder to rotate.
Wilde's paper was a hit
and then two other scientists credited his work
with giving them the idea of creating a generator
with electromagnets powered by the generator itself.
The idea is to siphon some of the electricity produced
by the generator back into the wires
of the electromagnets so that the current
that the generator produce creates the magnetism.
This is called self excitation.
If you just spin wires near other wires,
you don't generate any electricity.
You need some magnetism to kickstart it.
Both men found that you could either kickstart it
by using a little bit of electricity from a battery
or even rubbing it with a magnet
or even using the magnetic field of the earth.
So in other words,
electromagnets are given a little magnetism
and then the coils are spun near these weak magnet.
This causes current to be induced in the coil.
Some of this current is then siphoned off
to the electromagnet increasing its magnetism.
This causes more current to be induced
in the coil to be fed back to the electromagnet.
This feedback loop is what makes these generators
so very powerful.
Self excitation and electromagnets was the key
to making powerful generators
to light up whole cities with electricity.
One of the men to discover self excitation in 1866,
was a German scientist named Werner Von Siemens.
Siemens had started a company 20 years earlier
called Siemens & Halske
to manufacture long distance telegraph lines in Germany.
Siemens became the first company
to manufacture self excited generators,
which they called dynamos
for the Greek word for power, dunamis.
A name used for most DC generators for the next 50 years.
Just to give credit where it was due,
Samuel Varley, the guy with the pissed off brother,
discovered self excitation in the 1850s
and even patented it before either Siemens
or the other scientists, Wheatstone wrote about it.
However, he was mostly ignored
by the scientific community at the time.
With dynamo, suddenly companies were springing up
all over to produce electricity,
to light up cities and even homes.
However, most people used a commutator
to make pulsed DC current instead of AC current.
Why?
Well, there was the mistaken belief
that AC was more dangerous than DC.
Also, you couldn't use self excitation with the AC
because the electromagnets needed direct current.
So you needed a side exciter like while view.
Siemens himself said that, "Nothing whatsoever
in alternating current, it is pure humbug."
In the late 1800s,
there were only a few brave visionaries
who wanted to use AC.
One of those visionaries was named Nikola Tesla.
In 1887, Tesla invented what is called,
a multi-phase AC generator
and a corresponding multi-phase AC motor.
In this system, you spend multiple separate coils
around the electromagnets.
The idea is that,
the different coils get the same alternating current
but the current is out of step with each other.
The alternating current is then transmitted over more wires
but with significantly more power.
For example, the three phase motor needs three wires
instead of the traditional two.
However, has three times the power.
In addition, multi-phase current can be used
to make stronger motors
as each coil pushes the motor at different phases.
For that reason, we use three phase generators
in our power plants today.
After the invention of the diode
which is a one-way switch,
we had a way of producing AC and using self excitation,
which is what we do today.
This is how we mostly generate electricity.
Think of a power plant,
coal plants burn coal
and then have the steam spin electromagnets
near coils of wire.
Nuclear plants use nuclear reactions to heat water
so that the steam will spin electromagnets
near coils of wire.
Dams block a river and then have the pressurized water
spin electromagnets near coils of wire.
Windmills use wind to spin electromagnets
near coils of wire.
They almost all work this way.
So this is where electricity comes from.
Thanks for watching my video.
Please remember to give it a thumbs up.
If you liked it, you might like the previous one
on how Faraday discovered induction in the first place.
I will also make a video about Edison and Tesla
and Westinghouse and the whole fight over AC and DC.
But first I wanna tell you one of my favorite stories
in the history of electricity,
the invention of the telephone.
It's a story about a shy teacher for deaf students
and how his love of his deaf student,
inspired him to invent the telephone.
That story is next time
on the secret history of electricity.
♪ Electricity ♪
(instrumental music)