Name: ac circuit response: impedance and admittance
Uploaded: 2024-04-11T12:48:49.000Z
Duration: 1 min 23 s
Channel: JoVE

In Wechselstromkreisen werden die passiven Elemente - der Widerstand, die Induktivität und der Kondensator - durch die Phasenspannung und den Phasenstrom charakterisiert.
Die Impedanz ist das Verhältnis der Phasorspannung zum Strom und stellt den Widerstand gegen den sinusförmigen Stromfluss in einem Wechselstromkreis dar.
Bei Gleichstromquellen mit Nullfrequenz funktioniert die Induktivität wie ein Kurzschluss mit null Impedanz, während der Kondensator als offener Stromkreis mit unendlicher Impedanz fungiert.
Bei hohen Frequenzen wirkt die Induktivität jedoch wie ein offener Stromkreis, und der Kondensator wird zu einem Kurzschluss.
Die Impedanz ist eine komplexe Größe, die in rechteckiger Form ausgedrückt werden kann, wobei der reale Teil den Widerstand und der imaginäre Teil die Reaktanz darstellt.
Die Reaktanz kann positiv oder negativ sein. Eine positive Reaktanz impliziert eine induktive Impedanz, bei der der Strom hinter der Spannung zurückbleibt. Umgekehrt bedeutet eine negative Reaktanz die kapazitive Impedanz, bei der der Strom die Spannung leitet.
In polarer Form kann die Impedanz durch ihre Größe und ihren Phasenwinkel charakterisiert werden.
Die Admittanz, der Kehrwert der Impedanz, kann auch in rechteckiger Form ausgedrückt werden, wobei die realen und imaginären Komponenten den Leitwert bzw. die Suszepptive darstellen.

impedanz und admittanz

Impedances and Admittance

Im Bereich der Wechselstromkreise nehmen passive Schaltungselemente wie Widerstände, Induktivitäten und Kondensatoren einen anderen Charakter an, wenn sie durch Zeigerspannung und -strom charakterisiert werden. Ihr Verhalten wird durch die Impedanz ausgedrückt, ein wichtiges Konzept bei der Analyse von Wechselstromkreisen. Die Impedanz ist ein Maß für den Widerstand gegen den sinusförmigen Stromfluss in einem Wechselstromkreis. Anders als ihr Verhalten in Gleichstromkreisen, wo Induktivitäten als Kurzschlüsse und Kondensatoren als offene Stromkreise erscheinen, ist das Verhalten dieser Komponenten in Wechselstromkreisen frequenzabhängig. Bei hohen Frequenzen wirken Induktivitäten als offene Stromkreise, während Kondensatoren zu Kurzschlüssen werden. Die Impedanz ist eine komplexe Größe mit einem Realteil für den Widerstand und einem Imaginärteil für die Reaktanz. Die Reaktanz kann entweder positiv oder negativ sein und zeigt eine induktive Impedanz an, wenn der Strom hinter der Spannung zurückbleibt, und eine kapazitive Impedanz, wenn der Strom der Spannung voraus ist. Die Impedanz kann auch in Polarform dargestellt werden, wobei ihre Größe und ihr Phasenwinkel hervorgehoben werden. <img alt="Equation1" src="/files/ftp_upload/15109/15109_PT_Equation_1v2.svg" style="text-align: center; height: 18px;"> <img alt="Equation2" src="/files/ftp_upload/15109/15109_PT_Equation_2.svg" style="text-align: center; height: 15px;"> Der Kehrwert der Impedanz ist die Admittanz, die in Siemens (S) gemessen wird. Die Admittanz gibt die Leichtigkeit an, mit der Strom durch einen Stromkreis fließt. Sie besteht aus Leitwert (Realteil) und Suszeptanz (Imaginärteil). Die Admittanz ist ebenso wie die Impedanz ein wertvolles Werkzeug bei der Analyse von Wechselstromkreisen, das es Ingenieuren ermöglicht, elektrische Schaltkreise zu verstehen und zu manipulieren, die unter sinusförmigen Bedingungen arbeiten.

Impedanz und Admittanz

In Wechselstromkreisen werden die passiven Elemente - der Widerstand, die Induktivität und der Kondensator - durch die Phasenspannung und den Phasenstrom charakterisiert.
Die Impedanz beträgt ...

Education

Lehre

JoVE Core

Electrical Engineering

Elektrotechnik

Unit 1

Einheit 1

AC Circuit Analysis

Analyse von Wechselstromschaltungen

KEY TERMS AND CONCEPTS

ZENTRALE BEGRIFFE UND KONZEPTE

ac circuit response: impedance and admittance

AC circuit response changes with frequency, and impedance describes how resistors, inductors, and capacitors affect sinusoidal current flow. In phasor form, voltage and current are used to show this behavior in a clear way. Impedance is a key idea in AC circuit analysis because it measures opposition to current in an alternating circuit.

These components behave differently in AC than in DC. In DC circuits, inductors act like short circuits and capacitors act like open circuits. In AC circuits, their behavior depends on frequency. At high frequencies, inductors act like open circuits, while capacitors become short circuits.

Impedance is a complex quantity. Its real part is resistance, and its imaginary part is reactance. Reactance can be positive or negative. Positive reactance shows inductive impedance, where current lags behind voltage. Negative reactance shows capacitive impedance, where current leads voltage.

Impedance can also be written in polar form. This form shows both magnitude and phase angle. The reciprocal of impedance is admittance, which is measured in Siemens, or S. Admittance shows how easily current flows through a circuit.

Admittance also has two parts. Its real part is conductance, and its imaginary part is susceptance. Like impedance, admittance helps engineers analyze AC circuits under sinusoidal conditions. It gives another useful way to study and shape circuit behavior.

AC Circuit Response: Impedance and Admittance

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Learn how impedance and admittance describe AC circuit behavior in resistors, inductors, and capacitors, including reactance, phase, and frequency effects.

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JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

AC Circuit Response: Impedance and Admittance

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