电容器阻抗计算器

Overview

Our capacitive reactance calculator helps you determine the impedance of a capacitor if its capacitance value (C) and the frequency of the signal passing through it (f) are given. You can input the capacitance in farads, microfarads, nanofarads, or picofarads. For the frequency, the unit options are Hz, kHz, MHz, and GHz.

方程

$$X_{C} = \frac{1}{\omega C} = \frac{1}{2 \pi fC}$$

地点:

$$ x_ {c} $$ =欧姆（ω）中的电容器电抗

$$ \ omega $$ = rad/s的角频率= $$ 2 \ pi f $$，其中$$ f $$是hz中的频率

$$ c $$ =法拉德的电容

Reactance (X) conveys a component's resistance to alternating current. Impedance (Z) conveys a component's resistance to both direct current and alternating current; it is expressed as a complex number, i.e., Z = R + jX. The impedance of an ideal resistor is equal to its resistance; in this case, the real part of the impedance is the resistance, and the imaginary part is zero. The impedance of an ideal capacitor is equal in magnitude to its reactance, but these two quantities are not identical. Reactance is expressed as an ordinary number with the unit ohms, whereas the impedance of a capacitor is the reactance multiplied by -j, i.e., Z = -jX. The -j term accounts for the 90-degree phase shift between voltage and current that occurs in a purely capacitive circuit.

以上方程使您可以电容器的电抗。要将其转换为电容器的阻抗，只需使用公式Z = -JX即可。电抗是一个更直接的价值。它告诉您电容器在一定频率下的电阻。但是，需要阻抗进行全面的交流电路分析。

As you can see from the above equation, a capacitor's reactance is inversely proportional to both frequency and capacitance: higher frequency and higher capacitance both lead to lower reactance. The inverse relationship between reactance and frequency explains why we use capacitors to block low-frequency components of a signal while allowing high-frequency components to pass.

Further Reading

教科书 - 交流电容器电路

教科书- Series Resistor-Capacitor Circuits

Worksheet - Capacitive Reactance

Clean Power for Every IC: Understanding Bypass Capacitors