Chapter 020 Medieval Electromagnetism

```

To create an electric current, one needed to understand electromagnetism. In the history of modern Earth, on October 17, 1831, Faraday first discovered the phenomenon of electromagnetic induction, thereby obtaining the method to generate alternating current, which was considered a significant achievement in electromagnetism.

The so-called phenomenon of electromagnetic induction meant that when a magnet passed through a closed circuit, an electric current would be generated within the circuit.

Using this phenomenon, by keeping the closed circuit stationary and continuously rotating the magnet, the closed circuit, in its static state, cut through the magnetic field lines emitted by the magnet. This caused a continuous generation of electric current within the circuit, converting mechanical energy into electrical energy, thus becoming a simple generator. This was high school physics textbook knowledge, not considered very profound, though the realization of basic materials and components was somewhat troublesome.

To keep this engine running continuously, relying on manpower was not feasible, as it was inefficient and prone to errors. Only natural resources could be utilized, either wind power or water power. Richard chose wind power and thus designed a wind turbine to be made by the craftsman.

But the craftsman could only make some simple parts, such as the complex rotor, energy storage devices, and shafts, which had to be done by Richard himself, which was quite laborious. Because of this, Richard didn't want to do it unless absolutely necessary.

However, since the decision was made, he had to proceed.

First was the fabrication of the rotor.

The main material for the rotor was magnets. Neodymium iron boron magnets, samarium cobalt magnets, aluminum nickel cobalt magnets, and iron chromium cobalt magnets would all do. But currently, in the Blue Lion Kingdom, there was no type of magnet available, so he had to make them himself. The type he chose to make was the simplest and most common one—iron oxide (Fe3O4) magnets.

To make iron oxide magnets, he needed to obtain iron oxide material.

And to obtain this material, there were many methods, such as the hydrogen reduction method of α-ferric oxide, slow oxidation method of ferrous hydroxide, Haber method, addition method, and alkaline addition method. He chose the addition method. The two most critical reactants in this method were pure iron (iron filings, Fe) and iron oxide (rust powder, Fe2O3)…

Richard took a deep breath, washed his hands, put on a dust mask to prevent powder from entering his nose and mouth, and began the procedure.

First, Richard placed the iron filings into sulfuric acid. Visually, as soon as they were added, the beaker immediately bubbled a lot, reacting violently. In this process, ferrous sulfate (FeSO4) would be generated.

After the reaction was complete, Richard began adding baking soda (NaOH) and iron oxide (Fe2O3). He then heated it to 95-105°C to allow the solution to undergo an addition reaction, ultimately producing iron oxide.

However, the iron oxide at this time was not pure. Richard transferred the solution to a funnel equipped with filter paper to begin filtration. After filtering, the solid material obtained was dried, followed by a series of operations. After a considerable effort, he finally produced pure iron oxide.

Then, through magnetization, the iron oxide became a real magnet, a pitch-black piece. By repeating this step, he made a sufficient number of magnets to fix them in an annular mold, thus completing the most important part of the generator—the rotor.

After finishing these, Richard did not rest but began making the energy storage device. After all, the turbine generated electricity, but electricity needed to be stored to be used. This required a real rechargeable battery, not a fruit battery, much less a Leiden bottle-type capacitor.

What Richard prepared to make was a lead-acid battery, which was the cheapest and most common electric vehicle battery on modern Earth.

The reason for choosing it was twofold: materials were easy to collect, and the structure was simple, consisting of only the positive plate group, negative plate group, electrolyte, and container.

Aside from the sulfuric acid used as the electrolyte, practically only one material was needed, or rather two:

Firstly, lead, used to make the negative plate group.

Secondly, lead oxide in air, lead oxide, used to make the positive plate group.

In the current medieval world, perhaps many things were lacking, but lead alone would not be missing. Because according to modern Earth's development, by the year 2000, humans had begun massive extraction of metals such as iron, copper, silver, and lead.

Therefore, without much effort, Richard obtained sufficient lead and lead oxide.

Taking a deep breath, Richard's gaze became somewhat solemn.

Both lead and lead oxide were toxic. Excessive inhalation or ingestion would cause heavy metal poisoning, ranging from physical discomfort to death.

In the ancient Roman era on modern Earth, the Ancient Romans did not know the dangers of lead and thus used lead pipes for water delivery and lead containers for drinking, resulting in widespread chronic lead poisoning, becoming an important reason for Ancient Rome's decline.

Richard was aware of this and did not want to repeat the same mistakes, not wanting to be afflicted with illness before becoming a wizard, so he took ample protective measures before conducting the experiment.

He first put on a dust mask, then added a bird-beak mask over it, changed into a black protective suit that covered his entire skin snugly, and finally donned gloves made from ox bladders.

With preparations complete, Richard took a deep breath, feeling the air pass through the herbal pouch in the bird-beak mask and fill his lungs. He focused his gaze and began the work.

First, he poured a sufficient amount of sulfuric acid into the prepared container as the electrolyte. Then, he inserted the gray fluffy lead plates, serving as the anode, into the container, securing them. Next, he placed the brown lead oxide plates, serving as the cathode, securing them.

Between the anode and cathode, he placed a separator to prevent the electrodes from contacting each other. Then came the continual repetition of this process, sequentially inserting lead plates and lead oxide plates into the container until the entire container was completely filled.

The reason for doing so was to allow multiple groups of anode and cathode plates to act in series, thereby increasing the lead-acid battery's voltage.

After completing these tasks, Richard exhaled slightly, knowing that he had finished the main work of the lead-acid battery. What followed were the trivial details of setting up the external wires, etc.

Piece by piece, until evening, Richard finally completed everything.

With two light "thump thump" sounds, placing the completed lead-acid battery and rotor on the wooden frame, Richard turned to take off his gloves, removed the bird-beak mask, took off the dust mask, and shed his protective suit, realizing that his whole body was soaked through.

After all, it was a hot summer; even in the relatively cool palace, working an entire afternoon was extremely taxing. He hadn't noticed it while working, but upon completion, Richard felt the inner clothing clinging to his skin, and the stickiness all over his body.

Frowning slightly, Richard pushed open the door and walked out of the independent laboratory.

```