[Repost] Direct current is more suitable for home use, so why is civilian electricity alternating current?[Copy link]
The civil electricity in my country is 220v 50Hz alternating current. Although the voltage and frequency in other countries in the world are not exactly the same as those in my country, they all use alternating current without exception. Alternating current is so popular, but in daily life we will find that, except for appliances with motors and pure resistance, other household appliances basically cannot use alternating current directly, but must be converted into direct current first, such as computers, televisions, microwave ovens, induction cookers, chargers, etc. From this point of view, direct current seems to be more suitable for home use, so why does civil electricity use alternating current? This is about the war of currents 100 years ago. At that time, there were two genius scientists - Edison and Tesla. Edison became a successful entrepreneur and world-renowned inventor because of his invention of the electric light. He was a staunch supporter of direct current, while Tesla was an employee under Edison. He was more optimistic about the prospects of alternating current. Later, due to economic conflicts, Tesla and Edison parted ways and jumped to Westinghouse Electric Company in the United States to focus on the research and development of alternating current systems. In the following years, Edison and Tesla staged a war of currents, and finally ended with Tesla's victory in alternating current. The main reason why AC power can win the battle is that it can easily increase and decrease the voltage through transformers, and the loss of long-distance transmission is small, and the economic benefits are higher. Although DC power is more suitable for home use, it cannot be increased and is not suitable for long-distance transmission, so it is gradually eliminated. Seeing this, some people may say, what is the current UHV DC transmission? In fact, UHV DC still relies on AC to complete transmission. The AC from the power plant is first boosted by the transformer, and then converted into UHV DC by the converter. After long-distance transmission, it is converted into AC by the inverter station and input into the AC power grid. In UHV DC transmission, AC plays an irreplaceable role. Finally, to sum up, the fundamental reason why AC can replace DC and become the world's mainstream is that it is easier to boost and reduce voltage. What do you think about this issue? Welcome to leave your views in the comment area.
The key to this question is that both geniuses have been proven by their strength and real talent. One has to admire genius. There is also a video about Tesla. Of course, when talking about this genius, Edison is indispensable.
I don’t know who or why translated “westinghouse” into “西屋”. “Westing” originally means “towards the west” or “facing the west”. According to Chinese custom, a house facing west should be called “东屋”.
maychang posted on 2019-1-30 14:46 I don’t know who or why translated “westinghouse” into “西屋”. “Westing” originally means “towards the west”, “towards the west”…
There are basically two ways to translate foreign languages into Chinese, one is transliteration and the other is free translation. In principle, China uses free translation for free translation and transliteration for free translation. Typically, names of people and places are transliterated, and others are free translation. Westinghouse was originally a surname. Westhouse was an engineer who invented the air brake for railway vehicles. Later, he started a company and named it after his surname. So it should be transliterated as "Westinghouse Company" here. Another company name that uses a surname is Goodyear. Goodyear is the inventor of the rubber vulcanization method. The company was transliterated as "Goodyear" instead of "Good Years". So it is correct to translate it as "Westinghouse Company". There is also a similar translation in the electronics industry. Fairchild is also a surname. Some translations are "Xiantong" and some are "Fairchild". I think "Fairchild" is more appropriate.
maychang posted on 2019-1-31 10:18 There are basically two ways to translate foreign languages into Chinese, one is transliteration and the other is free translation. In principle, Chinese people use free translation if it can be translated, and use free translation if it cannot be translated...
Mr. Zhang is really knowledgeable, I admire him! The translation name I dislike the most is STARBUCKS - "星巴克" mixed translation, although I have never drunk it, I think it should be called "星达巴克" more appropriately.
cruelfox posted on 2019-1-31 10:28 Mr. Zhang is really knowledgeable. I admire him! The translation I dislike the most is STARBUCKS——“星巴克” mixed...
There are too many such ambiguous translations. In addition to electronic technology, there are also many in physics, chemistry and other subjects. Let's talk slowly when we have time.
cruelfox posted on 2019-1-31 10:28 Mr. Zhang is really knowledgeable, I admire you! The translation name I dislike the most is STARBUCKS——“星巴克” mixed...
When chemical knowledge was first translated, gold, silver, copper, iron, and tin, which have existed in China since ancient times, were completely translated. But hydrogen was originally translated into "light gas" because of its low density. Oxygen was originally translated into "nourishing gas" because it is necessary for any animal. Nitrogen was originally translated into "light gas" because it diluted oxygen. Chlorine was originally translated into "green gas" because it is light green. It can be seen that these gases were also translated into meaning at the time. But later they couldn't stand it anymore, and helium, neon, argon, krypton, xenon, and radon had to be translated phonetically. From this we can infer that any noun that is transliterated must not have existed in ancient China. This is a proposition. But the converse of this proposition does not hold. Things that did not exist in ancient China may not be transliterated but translated.
maychang published on 2019-1-31 18:51 When chemical knowledge was first translated, gold, silver, copper, iron, and tin were all in China since ancient times, and they were completely translated. But hydrogen was originally translated as "light gas" because of its low density. Oxygen is the most...
Helium, neon, argon, krypton, xenon, and radon - did Chinese have these characters before? If it is a new word created specifically for naming elements, it seems more accurate to call it "naming" than "translation", because the naming uses homophony. Naming also has the function of unifying standards, and the translator has more decision-making power in translation. For example, the translation of names cannot be forced. In the books I read before, Fourier was translated as Fourier, Fourier, and Fourier. The terminology is not always the same. One of my teachers translated convolution as "convolution" instead of the commonly used "convolution" in his book. He even specifically said in class that this is folded, not rolled up. The trouble is that when filling in the blanks in the middle school exams, you must use the translation in the textbook, otherwise it will be counted wrong
In terms of safety, AC is obviously better than DC. Note that the safety mentioned here is not as simple as the feeling of electric shock. From the perspective of power relay protection, the overcurrent and disconnection performance of high-power DC equipment is obviously weaker than AC power supply. Do you want to use your electric water heater in your home under DC power supply for a long time? Don't even think about it. Under the effect of mA-level leakage current, the life of the electric heating tube will be significantly shorter than that of AC power supply.
cruelfox posted on 2019-1-31 20:39 Helium, neon, argon, krypton, xenon, radon - did Chinese have these characters before? If they are newly created characters specifically for naming elements, calling them "naming" seems more complicated than "translation..."
It is difficult to unify the translation of scientific and technical names. Now there are many differences in the translation of science and technology between the mainland and Hong Kong and Taiwan. We say integrated circuits, Taiwan says integrated circuits. The mainland calls it laser, Taiwan calls it laser (by the way: laser is a literal translation, laser is a transliteration).
"In the following years, Edison and Tesla staged a war of currents, and Tesla's alternating current finally won." It should be said that Morgan was the one who finally decided to use alternating current. For this reason, Edison and Morgan fell out, sold all the stocks of the newly established General Electric Company in his hands, and announced that he would never set foot in General Electric Company in his life. Edison did this, but how big is General Electric now?
PowerAnts published on 2019-1-31 21:11 In terms of safety, AC is obviously better than DC. Note that the safety mentioned here is not as simple as the feeling of electric shock. It should be considered from the perspective of power relay protection, ...
"Is high-power AC switched at zero crossing?" The phase angle of high-power AC switching is almost random. Only voltages below 1kV can use electronic devices to achieve zero-crossing switching. Cutting off high-voltage and high-power electricity in the power industry is a difficult point. The difficulty is mainly the arc extinguishing ability. In order to extinguish the arc, transformer oil is usually used between the contacts, and the contacts need to have a considerable operating distance.
shuangchafeng published on 2019-2-2 22:49 I think it is advantageous to use AC for long-distance power transmission, and it is more convenient to use DC for household power supply.
"I think it is advantageous to use AC for long-distance power transmission, and it is more convenient to use DC for household power supply." Then the power department needs to convert the industrial frequency AC into DC at the household entrance, which is not cheap. Your washing machine and other equipment also need to use DC motors, but it is not as convenient for DC motors to change the direction of rotation as AC motors. Your electronic equipment, such as desktop computers, still need to convert hundreds of volts of DC into DC of voltage levels such as 12V and 5V, which is not more convenient than AC.
shuangchafeng posted on 2019-2-2 22:49 I think it is advantageous to use AC for long-distance power transmission, and it is more convenient to use DC for household power supply.
It is precisely because of the above reasons. No place in the world adopts the DC household power supply plan. There are only a few electrified railways in the world that use DC power supply.
For AC circuits, no matter at what phase angle the switch is disconnected, the arc is easily extinguished when the AC current passes zero. You will experience this by playing with AC and DC welding machines.
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