Name: series and parallel impedance rules
Uploaded: 2024-04-11T12:48:49.000Z
Duration: 1 min 21 s
Channel: JoVE

Considera una serie di luci natalizie, in cui ogni lampadina rappresenta un'impedenza. Questa disposizione in serie di impedenze garantisce una corrente uniforme su ciascun componente.
Applicando la legge della tensione di Kirchhoff, l'impedenza equivalente è uguale alla somma delle singole impedenze, in modo simile ai resistori in serie.
La tensione della sorgente viene distribuita proporzionalmente tra più componenti in base alle rispettive impedenze, aderendo al principio della divisione della tensione.
In un collegamento in serie, il malfunzionamento di una singola lampadina innesca un circuito aperto, interrompendo il flusso di corrente.
Quindi, le luci di Natale sono solitamente cablate in una configurazione parallela, garantendo una tensione costante su ciascun componente.
Applicando la legge della corrente di Kirchhoff a questo circuito parallelo si scopre che il reciproco dell'impedenza equivalente è uguale alla somma dei reciproci delle singole impedenze, in modo simile ai resistori in parallelo.
Quindi, l'ammissione equivalente è data dalla somma delle singole entrate.
La corrente della sorgente si divide tra i componenti in modo inversamente proporzionale alle loro impedenze, dimostrando il principio di divisione della corrente.
In questo caso, ogni componente stabilisce un percorso indipendente verso la fonte di alimentazione, consentendo un flusso di corrente isolato.

combinazione di impedenza

Considera una serie di luci di Natale, ciascuna lampadina simboleggia un elemento di impedenza. In questa configurazione in serie, il flusso di corrente elettrica rimane uniforme in ogni componente. Questo comportamento è in linea con la legge sulla tensione di Kirchhoff (KVL), che afferma che l'impedenza totale in una tale configurazione è uguale alla somma delle impedenze individuali, similmente ai resistori in serie. Ne consegue che la tensione proveniente dalla sorgente di alimentazione viene distribuita proporzionalmente tra questi componenti, rispettando il principio di divisione della tensione.

<img alt="Equation1" src="/files/ftp_upload/15569/15569_PT_Equation_1.svg" style="text-align: center; height: 48px;">

Tuttavia, l'inconveniente di questo collegamento in serie è evidente quando una sola lampadina si guasta, provocando un circuito aperto che interrompe l'intero flusso di corrente. Le luci di Natale sono generalmente disposte in configurazione parallela per garantire un'alimentazione continua e costante. Questa configurazione garantisce una tensione costante su ciascuna lampadina, secondo la legge della corrente di Kirchhoff (KCL), dove il reciproco dell'impedenza equivalente corrisponde alla somma dei reciproci delle impedenze individuali, similmente ai resistori in parallelo. Ne consegue che l’ammettenza equivalente è la somma delle ammettenze individuali.

In questa disposizione parallela, la corrente della sorgente si divide inversamente in base alle impedenze delle singole lampadine, esemplificando il principio di divisione della corrente. In particolare, ciascuna lampadina stabilisce un percorso indipendente verso la sorgente di alimentazione, consentendo un flusso di corrente isolato e ininterrotto.

<img alt="Equation2" src="/files/ftp_upload/15569/15569_PT_Equation_2.svg" style="text-align: center; height: 48px;">
<img alt="Equation3" src="/files/ftp_upload/15569/15569_PT_Equation_3.svg" style="text-align: center; height: 40px;">

Inoltre, in circuiti più complessi con impedenze sia in serie che in parallelo, le trasformazioni delta-stella e stella-delta possono essere impiegate anche per circuiti di impedenza, offrendo preziosi strumenti di analisi e progettazione dei circuiti. Queste trasformazioni facilitano la conversione tra diverse configurazioni di impedenza, migliorando la versatilità dei circuiti basati sull'impedenza.

Combinazione di impedenza

Considera una serie di luci natalizie, in cui ogni lampadina rappresenta un'impedenza. Questa disposizione in serie delle impedenze garantisce una corrente uniforme ...

Education

Didattica

JoVE Core

Electrical Engineering

Ingegneria elettrica

Unit 1

Unità 1

AC Circuit Analysis

Analisi dei circuiti in CA

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

Impedance Combination

series and parallel impedance rules

Impedance in series and parallel circuits follows the same rules used for resistors. A string of Christmas lights is a simple example. Each bulb represents one impedance element. In a series connection, the current stays the same through every component.

This series behavior matches Kirchhoff’s Voltage Law, or KVL. The total impedance in the circuit is the sum of the individual impedances. The source voltage is then divided among the components based on their values. This is the voltage division principle. One weak point of a series circuit is that one failed bulb can open the circuit and stop current flow.

Christmas lights are often wired in parallel to avoid that problem. In a parallel circuit, each bulb keeps its own path to the power source. The voltage across each bulb stays constant. This matches Kirchhoff’s Current Law, or KCL. For parallel impedance, the reciprocal of the equivalent impedance equals the sum of the reciprocals of the individual impedances.

The equivalent admittance is the sum of the individual admittances. Admittance is the inverse of impedance. In this setup, the source current splits according to the impedances of the branches. This is the current division principle. Because each bulb has an independent path, current can keep flowing even if one branch fails.

For circuits that mix series and parallel impedances, delta-to-wye and wye-to-delta transformations are useful. These methods let students convert one impedance network into another form. They make circuit analysis and design more flexible.

Series and Parallel Impedance Rules

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Impedance in series and parallel circuits follows the same rules used for resistors. A string of Christmas lights is a simple example. Each bulb represents one impedance element. In a series connection, the current stays the same through every component. This series behavior matches Kirchhoff’s Voltage Law, or KVL. The total impedance in the circuit is the sum of the individual impedances. The source voltage is then divided among the components based on their values. This is the voltage...

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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

Series and Parallel Impedance Rules

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