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  • Hi. Why do we ever use AC to power homes instead of DC?

    嗨,為什麼我們總是用交流電為家庭供電,而不是直流?

  • Haven't I showed you that AC is typically more dangerous than DC?

    我沒有告訴過你交流電通常都比直流電危險嗎?

  • [Painful Gurgle]

    我們能在直流電上運行所有的東西嗎?

  • Can we run everything on DC?

    沒錯!事實上家裡的每台裝置都必須在使用電以前

  • Yes! In fact pretty much every device at home has to rectify AC into DC

    先將交流電整流成直流電。所以我為什麼生氣?

  • first before it can use it so why? Why am I angry?

    原因是很基本的。曾經,一個叫尼古拉·特斯拉的人與交流電和湯瑪斯·愛迪生的直流電發生爭執

  • The reason is elementary. Once there was a fight between a guy named Nikola Tesla being AC and Thomas Edison

    因特斯拉贏得了他雇主西屋公司的契約,從而生產交流電

  • being DC and Tesla won the contract on his employer Westinghouse company to provide power with AC

    無論愛迪生如何透過在公共場合電擊

  • no matter how hard Thomas Edison tried to expose the dangerous nature of AC by

    狗和大象來揭露交流電的危險性

  • electrocuting dogs and elephants in public.

    WOW~

  • Wow

    現在我想起我為何生氣了。這個愛迪生傢伙其實是隻動物!他還發明了用交流電驅動的電動椅

  • Now I remember why I'm angry; this Edison guy was an animal! He even invented the electric chair to execute with AC

    並不是因為那是一種更簡單或更好的方式,而是因為他想透過將交流電和死亡連結起來來汙衊交流電。

  • --not because it was a cleaner or better way to execute--because he wanted to deface AC by forever associating it with death.

    尼古拉·特斯拉理所當然的贏得了這場戰役

  • Nikola Tesla very rightfully won this battle.

    沒錯,交流電可能比同等級的直流電還危險,

  • Yes, AC can be more dangerous than the same level DC but a higher level DC can be as dangerous

    但高一點的直流電也會一樣危險

  • if not more and just because something is dangerous

    我們並沒停止使用它。舉例,如果你住在高樓,

  • we don't stop using them like for example if you live in a high-rise

    你不會想冒著跳下窗戶的風險。但交流電在這裡有優勢嗎?

  • you are not in a constant risk of jumping off the window. But is there an advantage of using AC?

    我的意思是,當時他們只想使用鎢絲燈而不關心是交流或直流電

  • I mean, back then all they wanted was light using incandescent lights and those don't care about AC or DC.

    現在我像平常一樣在直流電上運行一般的燈泡

  • Here I'm running a regular light bulb on AC as usual

    然後我...

  • and here I

    S**t

  • S**t

    S**t

  • S**t

    我弄壞了它。

  • I killed it.

    不要造成短路 S**t

  • Don't short s**t.

    無論如何,我正在把交流轉換成直流電藉由FUUUL

  • Anyways with this I'm converting the AC into DC using

    它只是一個二極體,但也能使用,如果我測量它的輸出電壓

  • It's a single diode, but it will do and if I measure the voltage at the output

    F**k

  • F**k

    S**t

  • S**t

    f**k 這個電容

  • Holy f**k the capacitor

    啊 f**k

  • Ah f**k

    F**king piece of s**t

  • F**king piece of s**t

    反正我讀到差不多

  • Anyways i'm reading around

    170伏特的直流電,就算一樣很危險

  • 170 volt DC and although it's still quite dangerous

    我還是可以觸摸它,而且不像觸摸120伏特的交流電一樣痛苦

  • I can still touch it and it's not as remotely as painful as touching the 120 volt AC

    然後這個燈泡

  • and the lightbulb

    也運行得很正常

  • Runs on it just fine

    甚至更亮一點 因為它是連續的170伏特

  • And it's even a little brighter because it's 170 volt continues

    除了燈光,電動馬達也在家裡越來越受歡迎

  • Beside the lights the electric motors were becoming more popular in home

    像是絞肉機或風扇等 但也可以製作成無刷的

  • Appliances like meat grinders or fans and such, but even those could be made into brushless

    直流或是有刷的交流,像是我從老微波爐取下的

  • AC or brushed DC for example, of course a brushless AC motor like this one that I took from an old

    無刷交流馬達可以使用比有刷直流馬達更久...

  • microwave oven can last much longer than a brushed DC...

    (S***,F***)

  • (S***,F***)

    記得小心凌亂的電線。有刷直流馬達裡的碳刷最終還是會磨損

  • Loose wires, avoid them anyways brushes in DC brushed motors wear out eventually

    這就是為什麼交流馬達都可以使用更久 除此之外,交流和直流似乎沒有太多的差別

  • And that's why AC motors can last longer, but beside that fact there doesn't seem to be much preference between AC and DC

    但交流電的真正優勢並不在家裡

  • But the real advantage of AC is not at home

    是在電還沒送到家裡時的傳送過程

  • It's before electricity even gets to home in transmission lines

    這就是為何愛迪生的直流配電系統最終會消失的原因

  • And that's why Edison's DC power distribution system eventually died away, here

    我在這用細的電線當成傳輸線

  • I made a transmission line using thin wires and using my supply

    並用我的電源供應器試著在1歐姆負載上輸出10伏特10安培的電

  • I'll try to place 10 volts across my 1 ohm load for 10 amps of current

    然後我會測量負載的電壓,讓我們來試試

  • And I'm measuring the voltage across my load. Let's try it

    看這電壓

  • See the voltage is like

    只有7.5伏特,而且我的傳輸線

  • seven and a half and you see my

    已經開始冒煙和變熱,且電壓持續地降低,看經過負載的

  • Transmission line is starting to smoke and heat up and the voltage continues to drop see the line resistance is so much that the voltage

    線路電阻是如此的大且還到不了10伏特

  • Across the load doesn't even get to ten volts

    像是只有7伏特7安培通過負載,且由於高電阻,它加熱得非常快

  • It's at seven volts for seven amps through the load and because of the high resistance. It's heating up so much

    同樣的,因為愛迪生在傳輸線上傳輸低電壓,所以有大量的電流通過這些線路

  • Similarly because Edison was passing low voltage across the transmission lines a ton of current was passing through the lines

    且在電線撐不住自身重量下或變得太貴之前,電線的細度有限

  • And there is a limitation to how thick you can make the wires before they break under their own weight or become too expensive

    通過線路電阻的高電流將會在長距離傳輸上導致大量壓降

  • Huge currents through the resistance of the wire would result in large voltage drops over longer distances

    這就是為什麼愛迪生的系統只能將電力傳輸到大約一英里至兩英里的地方

  • And that's why Edison's system could only transmit power to around a mile or two from the power source

    否則功率損耗將會超過太多

  • Otherwise the power loss would be so much over the lines

    那會導致巨大的反效率,當然愛迪生知道他很ㄌ*ㄢˋ的系統

  • That would cause huge inefficiency, of course Edison was aware of his s**tty system

    所以他決定他的天才員工來解決這問題,也就是我們親愛的尼古拉·特斯拉(Tesla)

  • So he decided to let one of his genius employees to take care of the problem, who was our beloved Nikola Tesla

    Tesla當時也在愛迪生(Edison)底下工作。 根據Tesla所說,Edison承諾他

  • He was working for Edison at the time. according to Tesla Edison promised him

    如果Edison的DC系統有很大的改進的話,可以得到(當時的)50,000美元報酬

  • $50,000 which was a lot of money back then, if Tesla was able to make great improvements to Edison's DC system

    Tesla在幾個月之後做到了,當去要報酬的時候

  • Which Tesla did in a few months and when he went to Edison to ask for the money?

    他卻說:哈哈,開玩笑地。 看來你並沒有注意到我們的

  • He said "Haha. I was joking obviously you're not aware of our

    美式幽默。 Tesla說:F*** you,我不幹了!!!

  • American humor," which Tesla said "F*** you, I quit !!!"

    之後Tesla想到不錯的系統並在西屋公司研發出來

  • Later Tesla came up with his genius system and developed it for Westinghouse company

    就是讓電力傳輸更方便。他利用交流電(AC)傳輸,所以可以利用變壓器改變電壓

  • What he did was to transmit power much smarter. He used AC so he could change the voltage level using transformers, here

    我用一台自耦變壓器(Auto Transformer)來生產10V AC,可以讓1Ω的負載產生10A電流

  • I'll use my auto transformer to generate 10 volt AC which would result in 10 amp AC through my 1 ohm load

    但在傳輸之前,我先利用

  • But before I send it through the transmission line, first

    微波爐的變壓器讓電源電壓上升,然後

  • I'll step the voltage up using my microwave transformer

    如果我有變壓器的話,我會在另外一端讓電壓下降

  • and then I would step the voltage down after the line if I had a transformer

    Well,我應該可以跟我們的微波爐"借"一下

  • Well, guess I can borrow the one from our microwave

    F**k,他們使用特殊螺絲(tamper proof screws)讓我沒辦法拆開

  • F**k. They're using tamper proof screws to stop me

    他們不知道這並沒辦法阻止我。 只是拖時間罷了。

  • What they don't know is that nothing can stop me. They are just postponing the inevitable

    搞定了...

  • There we are...

    在拿出來之前先拍一張接線圖。我不想等等就把它炸飛了

  • I'll just take a picture of the wiring before I pull it out. I don't want to blow it up later

    拿出來了

  • There we are

    OK,接好線了。 在接上負載之前先量一下電壓

  • Ok, now we have both transformers connected. Let's do some voltage measurements before I connect the load. At the input

    輸入有大概10V,不錯。 在線路上...

  • We have close to 10 volts so that's good. On the transmission line

    有大概190~200V。 在輸出部分...

  • We get around 190-200 volts. And at the output

    也有大概10V,非常好。 現在把負載接上去

  • Again we have close to 10 volts so that's pretty good. Now, let's connect a load

    現在負載的電壓...

  • Ok. And the voltage across the load is

    1.6V?這垃圾發生什麼事? 線路上的電壓呢

  • 1.6 volts? That's garbage. What happened? The transmission line voltage

    118V?(電壓)都掉下來了

  • 118 volts? Everything dropped

    這比DC傳輸還差。Tesla發生什麼事了? 量一下變壓器次級圈的電阻好了

  • This is worse than the DC system. What's going on Tesla? Let's measure the transformer secondary winding resistance

    大概100Ω。難怪

  • Around hundred ohms. No wonder

    次級圈電阻太大以至於電壓降太多了,所以這些變壓器並不是這個用途的

  • There's too much drop over the large resistance of the secondary, so these transformers are not made for this purpose

    這不是好得範例。不管它了。我還是要傳輸電力

  • That was a bad example. It doesn't matter. I'm gonna transmit power. No matter what

    2V...3V...

  • 2 volts. 3 volts

    4. 5. 6. 7

  • 4. 5. 6. 7

    8. 9

  • 8. 9

    好了,現在負載有10V

  • And 10 volts across the load. We did it

    線路沒有冒煙所以接著試驗

  • And our transmission line is not burning so that's always a plus

    沒有東西炸掉。現在線路電壓多少?

  • Nothing is exploding. What is the transmission line voltage now?

    820V!!!

  • 820 volts!!! Well anyways, although

    雖然這是很糟糕的實驗,但是我用

  • This is a pretty bad example, you can see that

    比DC廢電的方式傳輸電力

  • I'm transmitting more power than the DC system

    但是線路沒有燒起來。 所以這算是某方面的成功?

  • But my transmission lines are not burning. So, that's sort of a success?

    在這系統中看到了

  • See in this system

    我可以在不把線路變粗的情況下 傳送大約100W的電力

  • I can transmit a lot of power in this case around hundred watts without having to thicken the transmission line wires

    如果變壓器效率高一點可以送更大的電力

  • And if the Transformers were better the efficiency would be higher, too

    事實上,在這個系統中,你可以使用更高的電壓來讓傳輸的距離更遠

  • In fact, in this system, the higher you convert the voltage to, the easier it is to transmit power over greater

    當然在有限制的情況下。 這就是為甚麼外面電線通常都有一萬伏(10kV)或十多萬伏(數百kV)

  • distances, with some limitations, of course. That's why in real life, they convert it to 10 kilovolt or hundred kilovolts

    為甚麼? 因為就在變壓器,理想上輸入跟輸出的功率是相等的

  • Why? Because in transformers, the input and output power is

    雖然實際上並不是,總是會有損耗, 而且 功率=電壓X電流(P=VI)

  • ideally the same, although not really, because there's always some power loss as you saw, and power is voltage times current

    所以舉例來說,如果我升壓20倍,

  • So, for example, if I increase the voltage by

    為了同樣功率,所以變壓器和線路電流也

  • 20 times, in order to have the same power, the current has to drop by 20 times at the output of the

    下降了20倍 。又因為 電阻上產生的功率會等於電阻X電流平方(P=R*I^2)

  • transformer and over the transmission lines. And because the power through a resistor is equal to resistance times current squared

    所以在他X的線路上的功率會降低400倍

  • The power would be 400 times less wasted on f**king wires

    F**k

  • F**k

    高壓電又有另一個需要做的就是

  • And with high voltage comes great responsibility

    兩條線路距離要足夠遠才不會有電弧產生

  • The transmission lines have to be placed far enough so no arcing happens

    並沒有簡單的方法可以處理這Edison的

  • There is no easy way to do the same thing with Edison's stupid

    笨DC系統。 為了要改變電壓,必須要把DC變成AC

  • DC system. In order to change the voltage, you would have to convert DC to AC,

    然後升壓,再把AC變回DC,過程中又會損失一堆能量

  • increase the voltage, and then convert the AC back to DC, and lose a lot of power in the process

    Edison仍然不知道因為他只看到會丟失供電這個商機

  • Edison still couldn't see this. All he saw was that his company was losing the contract of his life to power the world

    所以他就開始攻擊

  • So all he did was to grab the fact that

    Tesla的方法。高壓電例如10kV或100kV,對人體非常危險

  • Tesla's system was running on super high voltage, like 10 kilovolt or 100 kilovolt, and say that it's super dangerous to people

    並在世人面前用一萬伏電死動物

  • by electrocuting animals with 10 kilovolt in public

    湯瑪斯·愛迪生。他對科學和科技貢獻了非常多,但他也是個視錢如命(a$$hole)商人

  • Thomas Edison. He contributed a lot to science and technology what he was also an a$$hole

    他可以下去了(不會翻)

  • businessman, and that bit him in the lower back area

    道德上來說,別當視錢如命(a$$hole)的人

  • the moral of the story, don't be an a$$hole

    送~禮~時~間~

  • GIVEAWAY TIME!!!

    CircuitSpecialists非常的讚,它們常常提供我所有基本工具和零件還有一堆東西

  • You know, CircuitSpecialists has been quite nice to me providing all my basic tools and components and everything

    我希望你也可以去他們網站看看你想要甚麼

  • And I really hope you find what you need In their website too

    我很高興他們送我一台電表,這是一台LCR表 可以測量電感量(L)、電容量(C)

  • And, I'm quite happy with the multimeter they sent me, which is an LCR meter. It measures inductance, capacitance

    電阻(R)、電壓、電流和一堆功能 感謝CircuitSpecialists

  • resistance, voltage, current, and a bunch of more stuff. So thanks to CircuitSpecialists

    我要在patreon.com送出5台這個給我的patrons

  • I'm gonna give away five of these to my patrons at patreon.com

    以及觀眾(你)。 此外如果你開始學電子而且需要一台電源供應器的話

  • and you the viewers. Also, if you want to start electronics you would need a lab power supply

    這邊也會送出4台這個,當然我的patrons會自動被加入抽獎。至於其他人

  • And I'll give away four of those too. As usual, my patrons are automatically in the draw. For everyone else

    請在下方說明的Google表單中,填入你想要甚麼然後我就會把你加入抽獎

  • please follow the link to the Google Form in video description and let me know which one you need and I'll draw your name

    然後就這樣 Unibrow out(不會翻)

  • and that's it. Unibrow out

Hi. Why do we ever use AC to power homes instead of DC?

嗨,為什麼我們總是用交流電為家庭供電,而不是直流?

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B1 中級 中文 美國腔 電壓 愛迪生 傳輸 電流 功率 電力

為甚麼要在家裡使用交流電(AC)來代替直流電(DC)??(Why Use AC Instead of DC at Home??)

  • 9 1
    施廷叡 發佈於 2021 年 07 月 18 日
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