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Visit：4154   Date：2019-12-26

Impedance In circuits with resistance, inductance, and capacitance, the blocking effect on alternating current is called impedance. Impedance is often represented by Z. Impedance consists of resistance, inductive reactance, and capacitive reactance, but they are not simple additions. The unit of impedance is Euro. In direct current, the effect of an object on current obstruction is called resistance. All substances in the world have resistance, but the difference in resistance value is just the difference. Substances with very low resistance are called good conductors, such as metals; substances with very high resistance are called insulators, such as wood and plastic. There is another type of conductor between them called a semiconductor, and a superconductor is a substance with almost zero resistance. However, in the field of alternating current, in addition to resistance, which obstructs current, capacitance and inductance also hinder the flow of current. This effect is called reactance, which means the effect of resisting current. The reactance of a capacitor and an inductor is called a capacitive reactance and an inductive reactance, respectively, referred to as capacitive reactance and inductive reactance. Their unit of measurement is the same as the resistance, and the value is related to the frequency of the alternating current. The higher the frequency, the smaller the capacitive reactance and the larger the inductive reactance. The lower the frequency, the greater the capacitive reactance and the smaller the inductive reactance. In addition, the capacitive reactance and the inductive reactance also have the problem of the phase angle, which has the relationship on the vector, so it will be said that the impedance is the sum of the resistance and the reactance on the vector. For a specific circuit, the impedance is not constant, but changes with frequency. In a series circuit of resistance, inductance and capacitance, the impedance of the circuit is generally greater than the resistance. That is, the impedance is reduced to a minimum. In a parallel circuit of an inductor and a capacitor, the impedance increases to a maximum value at resonance, which is the opposite of a series circuit.