江蘇春晨電纜有限公司生產YFFB扁電纜YFFB行車扁電纜拖鏈扁電纜，
其實嚴格來講，這個“插頭”叫開關電源適配器，目的是將電網傳來的交流電轉換為直流電傳輸進電子設備中。筆記本電腦的電源適配器更大，冬天暖手更方便~
In fact, this "plug" is called the switch power adapter, the purpose is to convert the alternating current from the power grid to the direct current transmission into the electronic equipment. The power adapter of the laptop is bigger, and the warm hand is more convenient in winter.
那為啥要把交流電換成直流電呢?讓我們從頭講起。
Why do you want to change the AC to DC? Let's talk about it from the beginning.
電是一種自然現象。電荷靜止或移動會產生很多有意思物理現象，比如雷雨天氣中會看到的閃電、冬天脫毛衣的時候噼里啪啦的火花。后來，科學家們從各種電效應中發現規律，于是發明出了電池、發電機、電動機。
Electricity is a natural phenomenon. The charge or mobile will have a lot of interesting physical phenomena, such as thunderstorms will see the lightning in the winter, when the crackling sparks off a sweater. Later, scientists discovered laws from various electrical effects and invented the batteries, generators, and motors.
先用直流電，還是先用交流電?YFFB扁電纜YFFB行車扁電纜拖鏈扁電纜
First use direct current, or the first use of alternating current?
220伏/50赫茲交流電是我國的供電標準，所以很多人都以為家用電器用的都是交流電。至于直流電，大概除了那句廣告中會念叨的“直流變頻空調”，想不到其他的了吧。
220 volt /50 Hertz alternating current is the power supply standard of our country, so many people think that the household appliances are all alternating current. As for the direct current, it may not be possible except for the "DC frequency conversion air conditioning" that will be said in the advertisement.
其實，直流電應用很廣泛，你肯定見過，也用過。比如：
In fact, the use of direct current is very wide, you must have seen, also used. For example:
定義
Definition
直流電，是指方向不隨時間發生變化的電流。YFFB扁電纜YFFB行車扁電纜拖鏈扁電纜
Direct current refers to the current that does not change with time.
交流電，是指大小和方向都發生周期性變化的電流。
Alternating current (AC) refers to a current that changes periodically in size and direction.
從示波器觀測，一個是直的，一個彎的……
From the oscilloscope, one is straight, a curved one...
反正都是電，感覺差別不大?
It's all electricity anyway, and it doesn't feel very different?
No~No~No~
No~No~No~
讓我們翻開歷史，講點八卦!
Let's turn over the history and tell the gossip!
直流電，是電力革命急先鋒。在早期的電磁學實驗中，人們總是想方設法把產生的電能轉變為直流電。
Direct current is the pioneer of the electric power revolution. In the early electromagnetics experiment, people always tried to transform the generated electric energy into DC.
1879年，托馬斯˙愛迪生制成只碳絲白熾燈，吸引了大量投資。此后，小愛同學一路順風順水，1882年的一個夜晚，110伏的直流電輸送到紐約曼哈頓整個街區……大家終于可以扔掉煤油燈啦~
In 1879, Thomas Edison, made the first carbon filament incandescent lamp, attracted a lot of investment. Since then, Edward I wish you a happy voyage. smooth, one night in 1882, DC electricity to New York Manhattan the whole block of 110 volts...... You can finally throw away the kerosene lamp.
然而，直流輸電的弊端也隨著使用范圍的擴大而逐漸顯現：電壓不變的情況下，供電距離的增加和用戶的增長加劇了線路損耗。小型直流中心電站供電區域于2公里不到的方圓內。
However, the drawbacks of HVDC are also increasing with the expansion of the scope of application. Under the condition of constant voltage, the increase of power supply and the growth of users aggravate the line loss. The power supply area of a small DC central power station is limited to the square of less than 2 kilometers.
因為損耗量=電流電阻，所以減小電流就能減少損耗。
Because of the loss of current = - resistance, so reducing the current can reduce the loss.
在傳輸功率保持不變的情況下，電流和電壓成反比，所以，提高電壓就能減小電流，減小損耗。
When the transmission power remains constant, the current is inversely proportional to the voltage, so increasing the voltage can reduce the current and reduce the loss.
當時高壓直流技術尚不成熟，直流電變壓比較復雜。這時候，塞爾維亞小青年尼古拉˙特斯拉背著書包，跨越大洋奔向偶像愛迪生。他有一個不太成熟的小建議——交流輸電。交流電機比直流電機結構更簡單，容易變壓，可以簡單、經濟、可靠地解決提高輸電電壓的問題。
At that time, the high voltage DC technology was not yet mature, and the DC voltage was more complex. At this time, the Serbia youth Nicola Tesla back schoolbag, across the ocean to the idol Edison. He has an immature little suggestion - AC transmission. AC motor is simpler than DC motor and easy to change pressure. It can solve the problem of increasing transmission voltage simply, economically and reliably.
可是，這個建議被霸道總裁拒絕了。有人說是因為小愛同學沒上過幾天學，不懂高數，交流電對他來說有點抽象。為了阻撓交流電發展，愛迪生除了當眾做交流電電死動物實驗、發動媒體報道交流電事故，還促成電椅的發明——用交流電執行死刑。
However, the proposal was rejected by the overlord. Some people say that is because the students love not in a few days, do not understand the high number of alternating current for him a