Otaku Engineer in Great Tang Dynasty

"There is another way to convert alternating current into direct current!"

In the workshop, Mo Lingwei's laboratory, Li Zexuan put down the pen and paper in his hand and spoke.

When Mo Lingwei and Wang Ji heard this, they couldn't help being surprised. Mo Lingwei said, "Shanchang, how can this alternating current be transformed into direct current?"

Li Zexuan smiled and said: "Whether it is AC or DC, they are all electricity, and of course they can be converted into each other! With a rectifier circuit, you can convert AC to DC, and with an inverter circuit, you can convert DC to AC! But The rectifier circuit needs a new electronic component rectifier diode. This diode has unidirectional conductivity and can only pass current in one direction. With it, we can build a rectifier circuit!"

Mo Lingwei immediately became interested when she heard the words, and she quickly asked, "Zhang Chang, what should I do with this rectifier diode? Can you teach me?"

In the eyes of others, the knowledgeable first female professor of Yanhuang Academy, at this moment, like an ignorant student, is absorbing knowledge frantically from Li Zexuan.

Li Zexuan pondered for a moment, and said, “This rectifier diode can be divided into electronic diodes and crystal diodes according to different materials. According to our current conditions, we can try to make some electronic diodes! Miss Mo, Mr. Wang, I will use this today. To teach you how to make electronic diodes, you have to promise me never to leak, otherwise not only the workshop will suffer losses, but Datang will also suffer losses!"

In the end, Li Zexuan solemnly charged Mo Lingwei and Wang Ji.

Electronic diodes, also called vacuum diodes, are widely used in voltage stabilizing and rectifying circuits because of their unidirectional conductivity. Throughout the entire history of human integrated circuit development, the invention of electronic diodes can be regarded as the starting point of the human electronics industry, so Li Zexuan can't help being serious.

In the previous life, after the invention of the electronic diode, the American inventor De Forest cleverly added a grid plate between the diode filament and the plate, making the world's first electronic triode. Since then, the electronic components sealed in "small glass bottles" have been widely used in various electronic product fields. Electronic products such as televisions, radios, amplifiers, etc., are all inseparable from diodes and transistors!

However, the shortcomings of electronic diodes and electronic triodes are also obvious: high power consumption, large heat generation, large volume, and short life span, so people are always looking for new electronic devices to replace them. It was not until the birth of transistors and the arrival of the era of solid electronic technology that electron tubes were completely replaced!

In the 21st century, the diodes and triodes used in countries all over the world are actually transistors. Of course, there is also another name called semiconductor tube, because they are all made of semiconductor material silicon or germanium. With Datang's current industrial foundation, firstly, purification of silicon or germanium is a problem, and secondly, the production of the key structure pn junction in semiconductor diodes is also a considerable problem.

The so-called pn junction is the use of different doping processes, through diffusion, p-type semiconductor and n-type semiconductor are fabricated on the same semiconductor substrate, and a space charge area is formed at their junction, which is called pn junction. The pn junction has Unidirectional conductivity. Among them, n-type semiconductor is silicon crystal (or germanium crystal) doped with a small amount of impurity phosphorus element, and p-type semiconductor is silicon crystal (or germanium crystal) doped with a small amount of impurity boron element.

Li Zexuan currently does not have boron on hand, so he temporarily gave up this plan of manufacturing crystal diodes!

"The mountain leader can rest assured, Wang will never say a word to outsiders what the mountain leader said here today, even if he is drunk!"

Wang Ji was the first to bow his hand, but the second half of the sentence was a bit dumbfounding.

Even though this old guy is a drunkard, he doesn't speak nonsense when he is drunk, which is reassuring.

"Shanchang, I won't leak what you said, I... I promise with my life!"

Hearing what Li Zexuan and Wang Ji said was very solemn, Mo Lingwei also became serious and said to Li Zexuan.

Li Zexuan nodded and said, "That's good! Next I will tell you how to make this electronic diode!"

As he said, Li Zexuan picked up paper and pen, and while drawing a sketch, he explained: "First of all, we seal two metal sheets in the vacuum glass tube. Of course, we can also use the method we used to make electric lights to put the glass in the glass tube. If the oxygen is exhausted, a complete vacuum is not required. After that, after we add alternating current to the anode plate, a constant current with the same direction will appear on the other plate!"

Mo Lingwei was a little puzzled: "Shan Chang, what is the principle?"

Li Zexuan thought for a while and explained: "Look, when the anode potential is higher than the cathode, the electrons emitted by the cathode move toward the anode to form an electron flow under the action of the electric field. When the cathode voltage is higher than the anode, the electric field the electrons experience The force pulls the electrons back to the cathode and cannot generate current, so this electronic diode has unidirectional conductivity and can be used for circuit rectification!"

In fact, this effect was called the "Edison effect" in the previous life.

In 1883, in order to find the best filament material for electric bulbs, Edison placed a section of copper wire near the carbon filament inside the vacuum bulb, hoping to prevent the carbon filament from evaporating. Although he failed, he accidentally discovered that the copper wire that was not connected to the circuit generated a weak current due to the hot electrons emitted by the carbon wire. Although Edison did not study this phenomenon carefully, he applied for a patent for the "Edison effect~www.readwn.com~ years. When Fleming was researching and improving the detector in the radiotelegraph receiver, he envisaged the use of the Edison effect. Detection. He encapsulated two metal sheets in a vacuum glass tube and applied a high-frequency alternating voltage to the anode plate. After the Edison effect appeared, the alternating current was converted into direct current when the alternating current passed through the device. Fleming put this equipment A tube with two electrodes is called a vacuum diode. It has two functions: rectification and detection. This is the first electronic device in human history.

What Li Zexuan has to do now is this kind of vacuum diode! Although he knew the principle, he was really not sure whether it could be done in the end.

"Shanchang, I understand! Generally speaking, the structure of this electronic diode is not complicated. Although it takes a lot of work, it is not impossible to make it. Let me try it a few times!"

After listening to Li Zexuan's explanation, Mo Lingwei thought alone for a long time, and finally nodded.

Wang Ji also said, "Wang probably understands it too! I will definitely assist Miss Mo to make the electronic diode!"

Mo Lingwei's progress is directly related to whether his electrolysis workshop can proceed normally, of course he is more concerned than anyone else!

Li Zexuan nodded and said, "That's a lot of hard work! But in my opinion, DC generators and electronic diodes can be manufactured at the same time! Whichever is made first, put into use first, and the electrolysis workshop can start earlier!"

To be on the safe side, Li Zexuan decided to have both hands hard and grab both hands!

"Yes! The mountain is long!"

The two clashed in response.

Li Zexuan nodded in satisfaction, and said in his heart: With diodes, the triode is not far away. By then, many electrical appliances can be made, and Datang will soon enter the electronic age!

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