Voltage or current?

電壓還是電流？

You may have heard the saying, it's not the volts that kill you, it's the amps.

你可能聽說過這樣一句話：殺死你的不是電壓，而是安培數。

In one way that's true.

從某種程度上來說，這是真的。

But as you'll see, that's not the complete story.

但正如你將看到的，這並不是故事的全部。

You can't have amps without volts.

沒有伏特就沒有安培數。

And resistance plays a part too.

阻力也是原因之一。

What are current and amps?

什麼是電流和安培數？

Current is just a measure of how much charge passes a point over a period of time.

電流只是衡量一段時間內通過某一點的電荷量。

It's in units of amps.

組織、部門是安培。

In this example you can see negatively charged electrons.

在這個例子中，你可以看到帶負電的電子。

The amount of current, or amps, is the amount of the negative charge of the electrons passing this point every second.

電流（或安培數）就是每秒鐘通過這一點的電子負電荷量。

Here's a table used in a few government's health and safety documents, telling you what happens to your body when different amounts of current flow through it.

下面是一些政府健康和安全文件中使用的表格，告訴你不同電流流經人體時會發生什麼情況。

It's for both 50 and 60 hertz alternating current, or AC.

它適用於 50 赫茲和 60 赫茲交流電，即交流電。

That's what you get from your wall socket in many countries.

在許多國家，牆上的插座都是這樣的。

For direct current, or DC, the current has to be higher, but the numbers are still in the milliamps.

對於直流電（DC），電流必須更大，但數字仍以毫安為組織、部門。

According to the documents, at 1 milliamp, or 0.001 amps AC, the feeling is barely noticeable.

文件顯示，在 1 毫安或 0.001 安培交流電時，這種感覺幾乎不明顯。

But above 16 milliamps AC, or 88 milliamps DC, your muscles are stimulated to extend and flex.

但交流電超過 16 毫安或直流電超過 88 毫安時，肌肉就會受到刺激而伸展和彎曲。

But when the flexing dominates, you can no longer let go.

但是，當彎曲佔據主導地位時，你就不能再放手了。

At 20 milliamps AC, your respiratory muscles, the ones responsible for breathing, are paralyzed.

交流電 20 毫安時，負責呼吸的呼吸肌就會癱瘓。

That of course leads to death.

這當然會導致死亡。

The heart's pumping is controlled by electrical stimulation.

心臟泵血由電刺激控制。

At 100 milliamps AC, or 300 to 500 milliamps DC, if the current runs through the heart, then that is interfered with.

在 100 毫安交流電或 300 至 500 毫安直流電條件下，如果電流通過心臟，就會對心臟造成干擾。

This causes what's called ventricular fibrillation.

這就是所謂的心室顫動。

The heart quivers instead of beating properly, and also leads to death.

心臟不能正常跳動而顫抖，也會導致死亡。

So far, it does look like it's the amps that kills you.

目前看來，要命的是放大器。

But current doesn't move on its own.

但是，電流不會自己移動。

That's where voltage comes in.

這就是電壓的作用。

The current needs energy in order to move, and it's the voltage that supplies that energy.

電流需要能量才能移動，而電壓正是提供這種能量的源泉。

Voltage can be defined as the amount of energy for each unit of charge.

電壓可以定義為每組織、部門電荷的能量。

The volt is just a unit for voltage.

伏特只是一個電壓組織、部門。

A little energy applied to each charge would mean a lower voltage, and a lot of energy applied to each charge would mean a higher voltage.

每個電荷的能量越小，電壓就越低，而每個電荷的能量越大，電壓就越高。

When traveling through the body, to go to and from the heart, most of the charge passes through the blood vessels.

當電荷在體內往返於心髒時，大部分電荷都會通過血管。

The bloodstream is a relatively good electrical conductor.

血液是一種相對較好的電導體。

The big barrier is the outer layer of skin, made up of dead skin cells.

大屏障是由死皮細胞構成的皮膚外層。

That skin layer resists the flow of charge.

這層皮膚會阻擋電荷的流動。

It plays a part of a big resistor in the body's electrical circuit.

它在人體電路中扮演著一個大電阻器的角色。

As the name implies, resistors resist the flow of electricity.

顧名思義，電阻器能阻止電流流動。

Let's look at an analogous electrical circuit.

讓我們來看看一個類似的電路。

This motor represents the heart, these wires are the blood vessel, and these resistors are the dead skin that provides most of the resistance to the flow of current.

這個電機代表心臟，這些電線是血管，而這些電阻器則是死皮，為電流提供了大部分阻力。

The values of these resistors add up to 100,000 ohms.

這些電阻的阻值加起來為 100,000 歐姆。

That's the same resistance that a body with dry skin has.

這與皮膚乾燥的人體所具有的抵抗力是一樣的。

We use household electricity, which here is 120 volts AC.

我們使用家庭用電，這裡是 120 伏交流電。

When I plug in the electricity, the motor doesn't turn.

插上電源後，電機不轉。

That's good, that's analogous to the heart being protected by the skin resistance.

很好，這就好比心臟受到皮膚抵抗力的保護。

The general rule is anything above 30 volts may be hazardous.

一般來說，超過 30 伏的電壓都可能有危險。

But the skin resistance doesn't stay constant.

但皮膚的抵抗力並不是一成不變的。

The higher the voltage is, the lower the skin's resistance is.

電壓越高，皮膚的電阻就越低。

And at only around 450 to 600 volts, the skin will break down altogether and allow electricity to easily pass.

而在只有 450 至 600 伏特左右的電壓下，皮膚就會完全崩潰，讓電流輕易通過。

It will no longer act as much of a resistor at all.

它將不再是一個電阻器。

And voltage isn't the only thing that affects skin resistance.

電壓並不是影響皮膚電阻的唯一因素。

So does wetness.

潮溼也是如此。

If the skin is wet, from water poured on it, from sweat, or from high humidity in the air, the body's overall resistance drops from around 100,000 ohms to around 1,000 ohms.

如果皮膚是溼的，被水澆過、出汗或空氣溼度過高，人體的整體電阻就會從約 100,000 歐姆降至約 1,000 歐姆。

So here I replace the resistors so that the resistance adds up to only around 1,000 ohms.

是以，我在這裡更換了電阻器，使電阻加起來只有大約 1,000 歐姆。

Now when I plug it in, the motor turns.

現在，當我插上電源時，電機就會轉動。

That's analogous to more current flowing through the heart.

這就好比有更多的電流流過心臟。

So with wet skin, the resistance is lower, causing more current to flow.

是以，在皮膚溼潤的情況下，電阻會降低，從而產生更多電流。

More amps.

更多安培數

How long the current flows also has an effect.

電流流過的時間長短也有影響。

At 50 milliamps, if you manage to let go within 2 seconds, then you'll be okay.

在 50 毫安的電流下，如果能在 2 秒鐘內鬆手，就不會有問題。

But if the current is 500 milliamps, then you have just 0.2 seconds, 2 tenths of a second, to let go and still be okay.

但是，如果電流是 500 毫安，那麼你只有 0.2 秒，也就是萬分之二秒的時間來放手，並且仍然沒事。

What about when you get a shock by rubbing your feet on carpet and then touching a metal door handle?

當你的腳在地毯上摩擦，然後接觸到金屬門把手時，你會受到電擊嗎？

There could easily be a few thousand volts there, enough to break down your skin's resistance.

那裡很可能有幾千伏電壓，足以破壞你皮膚的電阻。

But while there is enough voltage, there isn't a lot of charge in this case.

不過，雖然有足夠的電壓，但在這種情況下電荷量並不多。

However, since it's all being dumped at once, it can result in a high current, or amps, but only for a brief amount of time, around 1 millionth of a second, or 1 microsecond.

不過，由於所有電流都是一次性傾倒，是以可能會產生高電流或高安培數，但只能持續很短的時間，約為百萬分之一秒，或 1 微秒。

So the fact that it doesn't last long makes it harmless.

是以，它持續時間不長的事實使它變得無害。

The same applies to this small homemade wind service machine.

這臺自制的小型風力服務機也是如此。

The voltage can be in the thousands, but the current is small and lasts for only a short time.

電壓可達數千伏，但電流很小，持續時間很短。

That's not to say that a brief shock can't cause some harm, like a moment of pain as it burns your skin.

這並不是說短暫的電擊不會造成一些傷害，比如灼傷皮膚時的片刻疼痛。

I wouldn't want to get a shock from this big Van de Graaff generator, or from my homemade high voltage power supply.

我可不想被這臺大型範德格拉夫發電機或我自制的高壓電源電擊。

Or worse yet, from the high voltage, high current coil on this microwave oven transformer.

更有甚者，可能是微波爐變壓器上的高壓大電流線圈造成的。

Well thanks for watching.

謝謝觀看。

See my YouTube channel, rimstarorg, for more informative videos like this.

請查看我的 YouTube 頻道 rimstarorg，瞭解更多類似的資訊視頻。

That includes one on how to make the homemade wind service machine I showed, another on how fast an electron or electricity flowed down a wire, and for a variety, one on how to use a Fresnel lens from a rear projection TV as a solar cooker, or just to have fun burning stuff.

其中包括如何製作我展示過的自制風力服務機、電子或電能在導線上流動的速度，以及如何使用背投電視機的菲涅爾透鏡作為太陽能灶具，或者只是為了享受燒東西的樂趣。

And don't forget to subscribe if you like these videos, or give a thumbs up or leave a question or comment below.

如果您喜歡這些視頻，別忘了訂閱，或豎起大拇指，或在下面留言或提問。

See you soon!

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