跟讀練習: Beginner Electronics - 2 - AC vs. DC - 通過影片學習英語口語
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What's going on everyone and welcome back to Electronics Episode 2.
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In this episode, we are going to talk about the two main types of current.
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You have AC or alternating current and you have DC or direct current.
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Now the chances are, if you are watching this video on a computer right now, you're probably using both of these two types of current and we're going to get to that in a little bit.
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But first of all, where in the world can you find these two types of current in your everyday life?
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Well, alternating current can be found most commonly in a wall outlet.
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So in your house, you know, you have the little things on the wall that you plug stuff into.
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It has either two or three little prongs on it.
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You guys all know what a wall outlet is.
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And these wall outlets output alternating current.
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So wall outlets will give off alternating current.
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When you plug something in, it's taking alternating current.
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DC or direct current, however, comes from things, most commonly a battery.
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So of Of course batteries, they have the little plus on them and the minus sign and you got to plug them in the right way.
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You guys all know what a battery is, come on.
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So a battery gives off direct current.
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Now we're going to talk about why these two things are completely different in a little bit
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but let's get some more examples.
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Alternating current powers things like a refrigerator or an electric stove, big appliances.
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So big appliances like that run on alternating current.
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Other electronic devices usually will run on direct current.
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So your cell phone, your computer, all those things, a flashlight, anything that uses a battery is running on direct current.
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Now I'm sure some of you just stopped right there and said, wait a second, I plug my phone into the wall outlet every night to charge it.
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Well, Codemore, you just said that a wall outlet gives off alternating current, but my phone runs on direct current.
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So what's the problem there?
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Well, that brings me to my next point.
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Alternating current can be converted into direct current, and vice versa.
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Direct current can be converted into alternating current with the help of some special electronic devices.
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So when you plug your phone into the wall outlet at night, so you plug your phone into the charger, right, and here's your phone here, phone.
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What the charger actually does is it takes the alternating current coming out of the wall outlet, it converts it into DC current,
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direct current, and then it gives it to your phone to charge the battery in your phone.
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This is the same thing as for your computer.
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You plug your computer or your laptop into the wall to charge it or to run your desktop computer or whatever.
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Well, the computer is actually transferring or taking that alternating current, converting it into direct current,
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and then that direct current is what runs your computer or your phone or anything like that.
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So these two types of current can be converted into one another with the help of other electronic devices, which we'll get to in the far future.
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So now that you guys hopefully understand alternating and direct current and what they're used for, what is the main difference between them?
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Well, let's do this.
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Let me draw a little line here.
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Now, this green line here is going to represent a regular wire.
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So, a wire that electricity is traveling through.
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Now, when alternating current travels through a wire, it's going to be traveling in this direction, right?
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It's going to be traveling that way.
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And then, uh-oh, all of a sudden, it's going to switch directions and it's it's going to begin traveling the other way.
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Then, again, it's going to switch directions and it's going to begin traveling this way again.
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Then, very quickly, it's going to begin traveling the other way.
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It alternates which direction it travels on the wire.
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So alternating current is going to alternate or switch directions in which it's traveling.
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And it happens many, many, many times every single second.
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This electricity is switching directions on which way it's moving.
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Direct current on the other hand is going to move in one direction the whole time.
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It's not going to switch directions.
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It's always going to go in the same direction in which you hooked up your circuit.
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So alternating current switches directions many of times.
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It'll go back and forth across wire.
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Direct current is going to go in one direction only.
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Now of course there's a lot more behind all that stuff that I just said.
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There's a lot more science-y stuff behind all that, but for right now, you guys just need to know that they can be converted into each other, and alternating current switches the direction that it moves in,
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and direct current travels in one direction always.
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Now, for the duration of this electronics tutorial series, we are mainly going to be using direct current.
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We're going to talk about alternating current a little bit throughout the series, but mainly we are going to be working with direct current only,
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And that's because many small electronic components that we're going to be learning run on direct current and not alternating current.
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So hopefully you guys learned a lot about alternating and direct current.
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If you have any questions at all, go down in the below in the comments.
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Post any questions, either I or someone helpful in the comments will hopefully answer your question
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or get you guys to understand something more if you have problems with that.
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Thanks for watching everyone and I'll see you guys in the next electronics episode.
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本課的詞彙與口語要點
這節 B1 級別的口語課以影片“Beginner Electronics - 2 - AC vs. DC”為素材。 影片中反覆出現的詞有：current, alternating, direct, direction, wall。 這段影片共有 67 個句子、973 個單詞可供跟讀。 講話部分時長為 4:56。 說話人語速較快，每分鐘約 197 個詞，會出現較多連讀和弱讀。 87% 的單詞屬於英語最常用的 3,000 詞，詞彙容易理解。
影片中的重點詞彙
影片中最難的 14 個單詞，附發音和釋義：
| 單詞 | 發音 | 釋義 |
|---|---|---|
| outlet 名詞 | /ˈaʊtlɛt/ | 出口 |
| plug 名詞 | /plʌɡ/ | 插頭 /插頭 |
| electronics 名詞 | /ɪˌlɛkˈtɹɑ.nɪks/ | 電子學 /電子學 |
| appliance 名詞 | /əˈplaɪ.əns/ | 器械, 器具 |
| charger 名詞 | /ˈt͡ʃɑɹd͡ʒɚ/ | 充電器 /充電器 |
| flashlight 名詞 | /ˈflæʃˌlaɪt/ | 手電筒 /手電筒, 電筒 /電筒 |
| refrigerator 名詞 | /ɹɪˈfɹɪd͡ʒ.əˌɹeɪ.tɚ/ | 冰箱, 冰櫥 /冰櫥 |
| stove 名詞 | /stoʊv/ | 火爐 /火爐, 爐 /爐 |
| tutorial 名詞 | /ˌtjuːˈtɔːɹɪəl/ | 輔導 /輔導, 教程 |
| desktop 名詞 | /ˈdɛsktɒp/ | 桌面 |
| minus | /ˈmaɪ.nəs/ | 減 /減 |
| duration 名詞 | /dʒʊˈɹeɪ.ʃən/ | 時間 /時間, 長短 /長短 |
| laptop 名詞 | /ˈlæp.tɑp/ | 手提電腦 /手提電腦, 手提計算機 /手提計算機 |
| component 名詞 | /kəmˈpoʊ.nənt/ | 元件, 部件 |
影片中出現的短語動詞
| 單詞 | 發音 | 釋義 |
|---|---|---|
| give off 動詞 | /ɡɪv ɒf/ | 散發 /散發, 發出 /發出 |
| go back 動詞 | 回去, 返回 |
影片中的語法
說話人最常用的結構，並附上影片中的原話：
| 結構 | 影片中的用法 |
|---|---|
| 被動語態 be + 過去分詞 — 強調發生了什麼，而不是誰做的 | can be found · can be converted |
| “going to” 表將來 be going to + 動詞 — 計劃或明顯即將發生的事 | are going to talk · we're going to get · we're going to talk |
| “will” 表將來 will + 動詞 — 決定、承諾或預測 | will give · will run · we'll get |
| 現在進行時 am/is/are + -ing — 此刻或近期正在發生的事 | are watching · is running · is actually transferring |
需要注意的發音
說話人用了 10 次縮略和弱讀形式，例如 we're, I'll, I'm。請按聽到的簡短形式來說。
- “sh” 和 “zh” 音: flashlight /ˈflæʃˌlaɪt/, duration /dʒʊˈɹeɪ.ʃən/
- 長單詞——注意重音位置: electronics /ɪˌlɛkˈtɹɑ.nɪks/, refrigerator /ɹɪˈfɹɪd͡ʒ.əˌɹeɪ.tɚ/
中文母語者容易讀錯的音：
- /v/ — 不要讀成 /w/，上齒輕觸下唇: convert /kənˈvɝt/, stove /stoʊv/
- 詞尾子音 — 要讀清楚，後面不要加母音: alternate /ˈɔl.tɚ.nət/, outlet /ˈaʊtlɛt/, plug /plʌɡ/, convert /kənˈvɝt/, electronics /ɪˌlɛkˈtɹɑ.nɪks/
- /r/ 和 /l/ 的區別: electronics /ɪˌlɛkˈtɹɑ.nɪks/, tutorial /ˌtjuːˈtɔːɹɪəl/
如何用這段影片練習
- 先完整聽一遍影片，不要開口，記下不認識的單詞。
- 先用 0.75 倍速逐句跟讀，熟練之後再回到正常速度。
- 錄下自己的聲音並與原聲對比，特別注意 outlet, plug, electronics 這類單詞。
什麼是跟讀法？
跟讀法 (Shadowing) 是一種有科學依據的語言學習技巧，最初開發用於專業口譯員的培訓，並由多語言者Alexander Arguelles博士普及。這個方法簡單而強大：您在聽英語母語原聲的同時立即大聲重複——就像是一個延遲1-2秒緊跟說話者的影子。與被動聽力或語法練習不同，跟讀法強迫您的大腦和口腔肌肉同時處理並模模擬實的講話模式。研究表明它能顯著提高發音準確性，語調，節奏，連讀，聽力理解和口語流利度——使其成為雅思口語備考和真實英語交流最有效的方法之一。