Chapter 20 Electromagnetism in the Middle Ages

To make electricity, you need to understand electromagnetism. In the history of modern earth, on October 17, 1831, Faraday discovered the phenomenon of electromagnetic induction for the first time, and then obtained the method of generating alternating current, which is regarded as an important achievement of electromagnetism.

The so-called electromagnetic induction phenomenon is that when a magnet passes through a closed circuit, a current will be generated in the circuit.

Taking advantage of this phenomenon, keep the closed circuit stationary and keep turning the magnet. Let the closed circuit cut the magnetic field lines emitted by the magnet in a static state, then the current will be continuously generated in the circuit, and the mechanical energy will be converted into electrical energy, thus becoming a simple generator. This is the knowledge in high school physics textbooks. It is not very advanced, but some troubles are the realization of basic materials and basic parts.

To make this engine run continuously, it is impossible to rely on manpower, which is inefficient and prone to errors. It can only rely on natural resources, either wind or water. Richard chose wind power, so he designed a windmill to make it for craftsmen.

However, craftsmen can only make some simple parts, such as complex rotors, energy storage devices, rotating shafts, etc., which are very troublesome. That's why I don't want to do it unless I have to.

But now that it's decided, it's only going to be done.

The first is the production of the rotor.

The main material of the rotor is a magnet, such as NdFeB magnet, SmCo magnet, AlNiCo magnet, FeCrCo magnet. But at present, this world is within the territory of the Blue Lion Kingdom, and there is no magnet of any kind at all, and it can only be made by oneself. The type that you choose to manufacture is the simplest and most common one-iron tetroxide (Fe3O4) magnet.

To make a ferric oxide magnet, you need to get the material of ferric tetroxide.

In order to obtain this material, there are many methods, such as the hydrogen reduction method of α-iron oxide, the slow oxidation method of ferrous hydroxide, the Harber method, the addition method, the alkali addition method, etc. The addition method is one of them. The two most critical reaction substrates for this method are elemental iron (iron filings, Fe) and iron oxide (rust powder, Fe2O3)…

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Taking a deep breath, Richard washed his hands, put on a dust mask to prevent powder from entering his mouth and nose, and started to operate.

First, Richard put iron filings into sulfuric acid. It can be seen by the naked eye that as soon as it is put into the beaker, a large number of air bubbles will appear in the beaker, and the reaction will be violent. In this process, ferrous sulfate (FeSO4) will be formed.

After the reaction, Richard began to add caustic soda (NaOH) and iron oxide (Fe2O3). Then, it is heated to 95-105°C, and the addition reaction is carried out in the solution to finally produce ferric tetroxide.

However, the ferric oxide was not pure at this time, so Richard transferred the solution to a funnel with filter paper and started filtering. After filtering, the filtered solid matter was dried, and then a series of operations were carried out. Finally, with a lot of effort, pure ferric oxide was finally produced.

Then through magnetization, the iron tetroxide becomes a real magnet, a piece of black paint. Repeat this step to make a sufficient number of magnets and fix them in the ring-shaped mold, and then the most important part of the generator - the rotor is made.

After doing this, Richard did not rest, and started to make energy storage equipment. After all, windmills can generate electricity, but the electricity has to be stored before it can be used. This requires a real rechargeable battery, not a fruit battery, nor a capacitor like a Leiden jar.

What Richard is going to make is a lead-acid battery, which is the cheapest and most common electric vehicle battery on the modern earth.

It was chosen on the one hand because the material is easy to collect, and on the other hand because of its simple structure, consisting of only four parts: positive plate group, negative plate group, electrolyte and container.

In addition to sulfuric acid as an electrolyte, there is actually only one, or two, substances required:

The first,

Lead, used to make the negative plate group.

The second, lead oxide in the air, is used to make the positive plate group.

In the current medieval world, many things may be lacking, but lead alone cannot be lacking. Because according to the development of the modern earth, in the 2000 years of AD, human beings began to extract a large number of metals such as iron, copper, silver and lead.

So, without much effort, Richard let people get enough lead and lead oxide.

Taking a deep breath, Li Cha's eyes became a little dignified.

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

In the ancient Roman era of the modern earth, the ancient Romans did not know the harm of lead. They used lead pipes as water pipes for a long time and used lead as a drinking container, which led to chronic lead poisoning of a large number of people and became an important reason for the decline of ancient Rome.

Richard knew this, and he didn't want to repeat the same mistakes, and he didn't want to be seriously ill before he became a wizard, so he did sufficient protective work before conducting experiments.

Put on a dust mask first, then put on a bird's beak mask outside, put on a tight-fitting black protective suit that covers all your skin, and finally put on gloves made of cow bladders.

When he was ready, Li Cha took a deep breath and felt the air pass through the herbal sac in the bird's beak mask and poured into his lungs. With a certain gaze, he moved his hands.

The first is to pour enough sulfuric acid into the prepared container as a solution. Then insert the gray velvet lead plate as the negative electrode into the container and fix it. Next, put the brown lead oxide plate as the positive electrode and fix it.

Between the positive and negative electrodes, a separator is placed to prevent contact of the electrodes. After that, this step is repeated continuously, inserting a lead plate and a lead oxide plate into the container in the order, and finally the entire container is full.

The reason for this is that multiple groups of positive and negative plates are placed in series to increase the voltage of the lead-acid battery.

After doing this, Li Cha breathed a sigh of relief, knowing that the main work of the lead-acid battery was completed, and the next step was to set up the external wires and other trivial details.

Pieces and pieces, until the evening, Richard finally finished all.

"Bang bang" made two soft sounds, and put the prepared lead-acid battery and rotor on the wooden frame. Li Cha turned around and took off his gloves, took off his beak mask, took off his dust mask, and took off his protective clothing. Only then did he find his whole body. all soaked.

After all, it was a hot summer, and even working in a relatively cool palace for an entire afternoon was extremely painful. I didn't notice it when I was working, but after finishing it, Li Cha felt the underwear clinging to the skin, and the whole body was extremely sticky.

Frowning, Li Cha pushed the door and walked out of the independent laboratory.