Short video spoiler history: The beginning of modern warfare

Chapter 137 Vacuum Triode

[A friend in the comment area asked, are solar cookers really that magical?]

[This is Gansu, my hometown in the northwest. The magic tool for boiling water on the Loess Plateau is the solar stove]

[In the villages of our Loess Plateau, almost every household has such a unique water-boiling device. You can see that it is a bit like a pot, which gathers light together for heating.]

[However, because the sun moves, there is an angle adjustment function at the bottom of the solar cooker, and it will not affect the bracket in the middle, which we usually use to place the pot.]

[Some people say this looks a bit like the old satellite TV dish, and it really does look a bit like it]

[Solar stoves do not require gas, oil, electricity or fire. As long as there is sunshine, you can boil water and cook. You can boil water and cook on any sunny day, roast potatoes and make steamed buns, regardless of spring, summer, autumn or winter. It is purely green and pollution-free.]

[In sunny weather like this, it takes about 5-6 minutes to boil with a little water. Today, I will make our Gansu specialty food, potato paste, on the solar stove.]

[When I was a child, the solar cooker in my memory was very magical. Some people say that there is a solar cooker in my grandmother's house in the elementary school textbook. I have never seen it in real life. Maybe you have never been to the Northwest. This thing is very common in our rural area and sells for more than 200 yuan.]

Jinling City, in front of Fengtian Palace.

Zhu Yuanzhang and others' eyes lit up. This was a good thing that did not require burning firewood or coal. But then they thought of most of the Ming Dynasty that could not use it due to insufficient light intensity, and they felt helpless.

The principle of this pot is very simple, which is to concentrate the light to one point, and then boil the water through the heat energy of the sunlight. Everyone can see this clearly.

"The most valuable things here are these shiny stainless steel plates. Can they be sold for more than 200 yuan?"

"This is steel! Steel! Not iron," someone corrected. As the saying goes, steel is made through a hundred tempering processes. The steps from mining a piece of iron ore to making steel and then selling it are extremely complicated.

"This thing is very useful in the north, and it can save some fuel costs throughout the year." Zhu Yuanzhang commented that boiling water, cooking, and heating are always daily needs of the people. With this solar stove that can utilize solar energy, the burden on the people will be reduced a lot.

An item as simple as this one can basically be used for several years.

However, the invention of these items can only be manufactured, sold and traded spontaneously by the people, and the court will not interfere in these trivial matters.

"Why does this place feel so little changed and is almost the same as it is today?" Everyone looked at the sky. There were almost no modern buildings or facilities around. Instead, it looked like a rural scene from ancient times to the present, with dry land, dead weeds, and dead trees, and the hills in the distance looked a little dark.

The low house is also one-story, but it appears to be made of iron sheets.

"It's too far from the beach, and transportation is inconvenient."

Zhu Yuanzhang and many others have been to the northwest region and know that these places are bitterly cold, with insufficient rainfall to grow crops and inconvenient transportation. Just like in the video, even after more than 600 years, other rural areas that have been seen have been turned upside down, but the rural areas there have not changed much, and are similar to the rural areas in the countryside today.

Since the Song Dynasty, the southeastern coastal areas have developed well, and the same is true in later generations. However, areas such as Gansu and the Northwest are indeed not well developed.

"Wow! I finally saw solar energy mentioned in the elementary school textbook. I didn't understand why they said you can just put a pot in it to cook rice, but now I understand."

"This has to be done in an empty space. It won't work in Guangdong. There are so many buildings that you might accidentally set fire to someone else's house."

"Forget about cooking if you're dying of the sun, maybe you can simmer the soup over low heat [covering face]"

"There are many in Tibet, especially in pastoral areas. This thing is very effective and pollution-free. It's not as slow as you think."

"Using nuclear energy to cook mung bean soup"

《Concave mirror focuses light, the temperature is very high》

[Light bulbs use electricity to heat carbon filaments to emit light. After a long time of use, the glass on the positive side will always turn black. This is because the United States used direct current at the time. The current is the directional movement of electrons, and the temperature of the carbon filament is extremely high when the power is turned on.]

[High temperature will cause thermionic emission of electrons. Electrons will escape from the carbon filament and fly to the positive electrode. During this process, a small number of electrons will hit the glass, so the side close to the positive electrode will turn black. If it is alternating current, you will find that both sides will turn black.]

[Later, another physicist, Fleming, used a similar structure and placed a positively charged metal plate next to it. When the temperature rose and thermal electron emission occurred, the electrons would be attracted by the positively charged metal plate, which was equivalent to forming a closed loop from the filament to the metal plate, and the current would be conducted.]

[On the contrary, if the metal plate is negatively charged, like charges will repel each other and the electrons cannot pass through, which means that this route is in a cut-off state]

[When the current is forward-directed, the current is conducted; when the current is reverse-directed, the current is cut off. This is the earliest vacuum diode. The vacuum diode mainly has the functions of detection and rectification. It can also be used as a switch for high-frequency switching of electronic components, that is, a rectifier diode, a switching diode, etc.]

[With the vacuum diode, represented by the diode symbol, four diodes can be used to build a rectifier bridge and add a capacitance wave, we get direct current. This is the principle of the diode rectifier bridge to convert AC to DC]

[The mobile phones and computers we use are weak electronic products, which means they use direct current]

In front of Fengtian Hall.

Everyone quickly started transcribing again. The previous part was the background story, and even the principle and function of the entire diode were basically understandable.

"The role of rectification is understandable, but what is detection? How do high-frequency switching electronic components work?" Everyone in the science department felt like their brains were about to explode. Tianmu explained the principles, but some parts were indeed difficult to understand.

"Except for converting AC into DC, it seems that there is no other use in reality." One person frowned and said. In fact, it seems that there is no need to convert AC into DC. At least for now, there is no related electronic equipment that can be used.

"That's true. Let's copy it down first."

"This vacuum diode requires the use of electron emission phenomenon. Does that mean that the filament needs to be powered on all the time to generate heat?" Du Ping from the Science Department asked puzzledly.

Everyone was stunned for a moment. It was obvious. Yes, then this would bring about another problem. That is, the service life of today's carbonized bamboo filaments is insufficient, and secondly, the vacuum technology is not up to standard.

The vacuum technology used in light bulbs now uses heating to expel the air inside, but this method is obviously not so reliable. Another way is to fill it with other gases to replace the air inside.

In any case, the service life of carbonized bamboo silk was insufficient before tungsten ore was discovered.

"Switching diode? It sounds like the principle is the same, but the specific design details seem to be different from the rectifier diode."

Zhu Yuanzhang, Liu Ji and others all understood the principle of the diode, but they did not understand its application scenarios, so they felt it was very abstract. Even if they wanted to say something, they could not say it. This vacuum diode was like an extremely unfamiliar person. [Later, another great god, Forrest, upgraded it again on this basis and put a hollow metal mesh in the middle, called a grid]

[When a positive voltage is applied to the gate, the electrons flying out of the filament are attracted, and then pass through the hollow gate to the right side, so the current is conducted along this path]

[On the contrary, applying a negative voltage to the gate will repel electrons from flying through, so the current in this path is cut off. Assuming that a certain positive voltage is applied to the gate, only the left and right positive and negative poles are in a slightly conductive state.]

[Then input a small AC signal to the gate. Assuming it is a positive wave, it is superimposed on the gate to increase its voltage, so the on-current will increase.]

[Similarly, if the secondary wave is superimposed on the gate, its voltage will be weakened and the conduction current will be reduced. That is, the input signal causes a slight change in the gate, resulting in a strong change in the current conducted between the left and right sides.]

[By building a simple circuit, it can be converted to output a larger voltage signal, which is equivalent to amplifying the input signal several times. This is the principle of vacuum triode signal amplification]

[Because electrical signals will attenuate as they are transmitted over distance, this also promoted the development of telephone calls at the time, and for the first time enabled telephone calls to be made across the United States. With vacuum triodes that amplify signals, electrical signals can be transmitted over long distances.]

[Vacuum diodes and vacuum triodes also promoted the explosive development of electronics. After just over 100 years, it evolved into the various high-techs we see today.]

In front of Fengtian Hall.

Everyone suddenly realized that adding a mesh gate in the middle of the vacuum diode is the so-called vacuum triode.

The problem of telephone signal attenuation with distance is manifested as unclear sound at both ends of the phone and constant "hissing" sound of electric current noise. This problem is the same as long-distance transmission of telegraph and requires other technologies to solve.

The first thing everyone thought of was a relay, but it was completely useless.
Because relays can only transmit long-distance signals through electromagnetic generation, causing the switch to be connected and closed, thus achieving long-distance transmission, that is, only 0-1 signals (telegrams) can be transmitted.

But the current generated by the telephone is continuous, but the strength fluctuates. This signal is called an analog signal. So the relay cannot solve this problem, which is also a problem that everyone is worried about.

"Great! Although I don't quite understand the principle yet, we will know if it works after verifying it." Zhu Biao and others carefully copied down the circuit diagram given by Tianmu.

"The filament and the grid of the vacuum triode require direct current to control the positive and negative poles to maintain stability. Generally speaking, batteries are used to solve this problem, but this method is too troublesome. After all, the battery power will eventually run out."

"So we can use the rectifier bridge mentioned above to convert AC into DC, or use a DC generator to generate DC, which perfectly avoids this problem."

Everyone analyzed the structural diagram bit by bit, and put forward all the ideas they could think of one by one. Soon, all the difficult parts of the transistor were solved one by one, although they were not very difficult in themselves.

"I don't know how far the signal can be transmitted this time?"

"Judging from the east and west of Country M, this distance should be enough."

What would happen if I added a grid in the middle of the triode?

《The amplification factor is slightly larger than that of the triode, and it is used for high-frequency, audio amplification, oscillation, etc. It was later replaced by the pentode》

"Horrible upright ape. What the hell are you talking about? . ?"

"I always thought that a diode is a PN junction and a transistor is an NPN/PNP junction"

"The pn junction is the transistor, which was invented after the vacuum tube."

"Vacuum diodes and triodes generate a lot of heat and have high power consumption, so they are all replaced by transistors."

Jinling City Electrical Appliance Store.

The faces of the owners and servants became increasingly ugly.
No, what are you talking about? Why did Tianmu say that it was a good talk? Are the differences between people so big?
Hexing Tea and Snack Shop.

Shopkeeper Wan put down his pen with some boredom. On the paper was a transistor structure diagram that he had just copied. Unfortunately, he didn't understand it.

"Is the threshold for this thing so high?"

"It's high-tech after all. Show some respect!" Many diners said with a wry smile. In fact, everyone wanted to get a piece of the pie from the various technologies mentioned by Tianmu.
However, the technologies mentioned are either various minerals, or special products from overseas, or simple objects, but the market has been divided up. What is left now are hard nuts to crack, and most people can't even understand them.

This is really sad and helpless. Because more than 9% of the people in Jinling City are illiterate and can't even read words, it is really difficult to expect them to make vacuum triodes.

This is not a simple mechanical structure that can be learned at a glance. The twists and turns, electromagnetic conversion, signal transmission, etc. are like a mystery to most people.

Besides, everyone is just here to relax on the day when the sky lights up, and they don’t have time to study on weekdays, so most people are definitely here to join in the fun, and what they like most is definitely the commentary of various movies and TV series and the beautiful fairies dancing various dances.
The amount of talent this thing requires is extremely terrifying. Look at the explanation in the comments section. This is just one of the technologies. There is another technology above it called PN junction.

Same principle, two different techniques.
How did they find out?

"Dog Head Recorded in the Yongle Encyclopedia"

"I seem to have memorized it before. In 1906, American scientist De Forest invented the triode, which marked the beginning of the electronic age for mankind."

Tang Dynasty, Chang'an City.

Li Shimin was already used to being a hands-off boss, so he smiled knowingly when he saw the mockery of the Yongle Encyclopedia.

According to the information mentioned by Tianmu, he specifically calculated the time. The Ming Dynasty was founded in 1368, with the reign title of Hongwu. In the 1403th year of Hongwu (), Zhu Di invaded the capital and successfully pacified the rebellion.

This triode is a product after 1900.
"Can this triode also amplify the sound?" Fang Xuanling and others were all stunned, looked at each other, and found a new direction.

"It seems. It really works!" They are all signals anyway, so why not.

"But what is the structure of this triode?"

"Well, you can try them one by one. As long as the circuit is built correctly, the sound will become much louder."

(End of this chapter)