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• If we apply an AC voltage, the frequency of the voltage affects the amount of current that will flow.

如果我們施加交流電壓，則電壓的頻率會影響將流動的電流量。

• Inductors, capacitors, and resistors all react differently to AC voltage.

電感、電容和電阻對交流電壓的反應都不同。

• But, in all three cases, the frequency of the AC current will be exactly equal to the frequency of the voltage.

但是，在所有三種情況下，交流電流的頻率將完全等於電壓的頻率。

• Let us call the voltage at this point the "Input Voltage".

讓我們將此時的電壓稱為「輸入電壓」。

• This is the voltage that we control.

這是我們控制的電壓。

• In the case of an ideal resistor,

在理想電阻的情況下，

• the current that flows is always proportional to the difference in the voltage values at the two sides of the resistor.

流過的電流總是與電阻兩側電壓值的差值成正比。

• This means that if the only components in our circuits are ideal resistors,

這意味著如果我們電路中的唯一元件是理想電阻，

• then the amplitude of the current that flows is independent of the voltage's frequency.

那麼流過的電流幅度與電壓頻率無關。

• Now, suppose we replace the resistor on the right with a capacitor.

現在，假設我們用電容替換右側的電阻。

• Once the capacitor is charged, both sides of the resistor will have the same voltage, and no current will flow.

一旦電容充電，電阻兩端的電壓相同，沒有電流會流動。

• Current flows only if we change the value of the input voltage.

只有當我們改變輸入電壓的值時，電流才會流動。

• The amount of current that flows depends on the difference in the voltage values of the two sides of the resistor.

流動的電流量取決於電阻兩側電壓值的差異。

• If we change the value of the input voltage slowly,

如果我們慢慢改變輸入電壓的值，

• then the voltage values of the two sides of the resistor will tend to stay at about the same voltage.

那麼電阻器兩側的電壓值將趨於保持在大約相同的電壓。

• This means that only a small amount of current will flow through this circuit at low frequency.

這意味著只有少量電流以低頻流過該電路。

• At high frequency, a larger amount of current will flow.

在高頻率下，將流過更大量的電流。

• This is because if we vary the input voltage quickly as shown,

這是因為如果我們如圖所示快速改變輸入電壓，

• the capacitor never has enough time to charge, and the voltage across it always stays close to zero.

電容沒有足夠的時間充電，並且它兩端的電壓始終保持接近零。

• Having a voltage across the capacitor that is always close to zero

若電容器兩端的電壓始終接近零，

• allows a larger voltage difference between the two ends of the resistor, allowing more current to flow.

電阻兩端之間的電壓差較大，從而允許更多電流流動。

• Since the voltage across the capacitor does not have the ability to change instantaneously,

由於電容兩端的電壓無法瞬間改變，

• the voltage across the capacitor changes after the current changes.

電流變化後，電容兩端的電壓會發生變化。

• Let's turn off the input voltage.

我們關閉輸入電壓。

• Now let's replace the capacitor with an inductor.

現在讓我們用電感替換電容。

• An inductor exerts a force preventing the current flowing through it from changing instantaneously.

電感器施加力防止流過它的電流瞬間改變。

• If the input voltage is constant, then the inductor will not exert any forces, and it will therefore not impede the flow of current.

如果輸入電壓恆定，則電感器不會施加任何力，因此它不會阻礙電流的流動。

• If the input voltage changes, the inductor will initially try to keep the current through it at the same value as before.

如果輸入電壓發生變化，電感首先嘗試將電流保持在與之前相同的值。

• After we change the voltage, we need to wait for the current to change.

在我們改變電壓後，我們需要等待電流改變。

• After the current changes, the inductor then wants to keep the current at this new value.

在電流變化之後，電感器希望將電流保持在這個新值。

• If we change the input voltage very rapidly as shown, the current will not have enough time to change.

如果我們如圖所示非常快速地改變輸入電壓，則電流將沒有足夠的時間來改變。

• This means that only a small amount of current will flow through the inductor at high frequency.

這意味著只有少量電流將以高頻流過電感。

• At low frequency, more current will flow.

在低頻率下，會有更多電流流過。

• In this sense, an inductor has the opposite behavior of a capacitor.

從這個意義上講，電感具有與電容相反的特性。

• Also, whereas the voltage across a capacitor can't change instantaneously,

而且，電容兩端的電壓不能瞬間改變，

• for an inductor it is the current that can't change instantaneously.

對於電感來說，電流是瞬間無法改變的。

• This means that for an inductor, the current changes after the voltage changes.

這意味著對於電感，電流在電壓變化後會發生變化。

• The frequency of the input voltage is only one of the factors that determines how much the inductor will impede the flow of current.

輸入電壓的頻率只是決定電感阻礙電流流動的因素之一。

• Another factor is the amount of inductance the inductor has.

另一個因素是電感的電感量。

• If the inductor has a higher inductance, then a smaller amount of AC current will flow through it.

如果電感具有更高的電感量，那麼少量的交流電流就會流過它。

• This is because with a higher inductance,

這是因為電感量更高，

• the inductor will exert a greater force trying to keep the current flowing through it constant.

電感會發揮更大的作用力，試圖保持流過它的電流不變。

• In this example, even though we have a low frequency,

在這個例子中，即使我們的頻率很低，

• we still have a small amount of AC current flowing due to the fact that the value of the inductance is high.

由於電感值很高，我們仍然會有少量的交流電流流過。

• Increasing the capacitance of a capacitor has the opposite effect of increasing the inductance of an inductor.

增加電容的電容量具有增加電感的電感量的相反效果。

• If a capacitor has a higher capacitance, then a larger amount of AC current will flow through it.

如果電容具有更高的電容量，則會有更大量的交流電流流過它。

• This is due to the fact that with a higher capacitance, the capacitor charges and discharges more slowly.

這是因為電容量更高，電容的充電和放電速度更慢。

• Therefore, in this case, the voltage across the capacitor stays close to zero,

因此，在這種情況下，電容兩端的電壓保持接近零，

• thereby allowing a larger difference in voltage to develop at the two ends of the resistor,

從而允許在電阻兩端產生更大的電壓差，

• thereby allowing more current to flow.

從而允許更多的電流流動。

If we apply an AC voltage, the frequency of the voltage affects the amount of current that will flow.

# 交流電阻抗-電感和電容的交流電壓

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thpss100230 發佈於 2020 年 10 月 09 日