Name: finding voltage and impedance in circuit a
Uploaded: 2025-05-22T09:06:14.000Z
Duration: 1 min 18 s
Channel: JoVE

Il sistema di distribuzione dell'energia domestica, che comprende linee di distribuzione e trasformatori, può essere considerato la rete di origine.
All'interno della casa, vari apparecchi elettrici possono essere rappresentati come impedenze di carico.
Il teorema di Thévenin semplifica questo complesso sistema di distribuzione in un circuito equivalente di Thévenin.
Trovare il circuito equivalente di Thévenin richiede la conoscenza di due parametri: la tensione di Thévenin e l'impedenza di Thévenin.
Per comprendere il processo di determinazione, si consideri un circuito RLC semplificato collegato a una sorgente di tensione.
Per calcolare l'impedenza di Thévenin, sostituire la sorgente di tensione con un cortocircuito e determinare l'impedenza equivalente del circuito.
La tensione di Thévenin è uguale alla tensione a circuito aperto, equivalente alla caduta di tensione attraverso il ramo parallelo del circuito.
Inizialmente, viene calcolata la corrente che scorre attraverso la maglia chiusa del circuito. Quindi, utilizzando la legge di Ohm, viene determinata la caduta di tensione attraverso il ramo parallelo, che fornisce la tensione di Thévenin.
Se il circuito ha sorgenti che operano a frequenze diverse, il circuito equivalente di Thévenin e le impedenze del condensatore e dell'induttore devono essere determinate separatamente per ciascuna frequenza.

circuiti equivalenti di thévenin

Il sistema di distribuzione elettrica domestica, che comprende linee di distribuzione e trasformatori, funge da rete primaria. Gli apparecchi elettrici all'interno di una casa, possono essere rappresentati come impedenza di carico. Per semplificare questo intricato sistema di distribuzione, può essere applicato il teorema di Thévenin per creare un circuito equivalente di Thévenin. Se un circuito CA è suddiviso in due parti (circuito A e circuito B), collegate da un'unica coppia di terminali come mostrato nella Figura 1.

<img alt="Figure1" src="/files/ftp_upload/15113/15113_PT_Figure_1.svg" style="text-align: center; height: 140px;">
Figura 1: Circuito suddiviso in due parti

<img alt="Figure2" src="/files/ftp_upload/15113/15113_PT_Figure_2.svg" style="text-align: center; height: 150px;">
Figura 2: Circuito A sostituito dal suo circuito equivalente di Thévenin

 La sostituzione del circuito A con il suo circuito equivalente di Thévenin (una sorgente di tensione in serie con un'impedenza), non altera la corrente o la tensione di alcun elemento nel circuito B (mostrato nella Figura 2). I valori delle correnti e delle tensioni di tutti gli elementi del circuito nel circuito B, saranno gli stessi indipendentemente dal fatto che il circuito B sia collegato al circuito A o al suo equivalente Thévenin. Per trovare il circuito equivalente di Thévenin sono necessari due parametri: la tensione di Thévenin e l'impedenza di Thévenin. La Figura 3 mostra un circuito aperto collegato ai terminali del circuito A per determinare la tensione a circuito aperto Voc , mentre la Figura 4 indica che l'impedenza di Thévenin Zt è l'impedenza equivalente del circuito A*.

<img alt="Figure3" src="/files/ftp_upload/15113/15113_PT_Figure_3.svg" style="text-align: center; height: 96px;">
Figura 3: Circuito equivalente di Thévenin con Voc .

<img alt="Figure4" src="/files/ftp_upload/15113/15113_PT_Figure_4.svg" style="text-align: center; height: 96px;">
Figura 4: Circuito equivalente di Thévenin che mostra Zt.

Il circuito A* è costituito dal circuito A in cui tutte le sorgenti di tensione indipendenti sono state sostituite con cortocircuiti e tutte le sorgenti di corrente indipendenti con circuiti aperti. Generalmente, l'impedenza di Thévenin Zt può essere determinata sostituendo ripetutamente impedenze in serie o in parallelo con impedenze equivalenti.

Circuiti Equivalenti di Thévenin

Il sistema di distribuzione dell'energia domestica, che comprende linee di distribuzione e trasformatori, può essere considerato la rete di origine.
All'interno della casa, ...

Education

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Electrical Engineering

Ingegneria elettrica

Unit 1

Unità 1

AC Circuit Analysis

Analisi dei circuiti in CA

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

Th&#233venin Equivalent Circuits

finding voltage and impedance in circuit a

The household power distribution system can be simplified with Thevenin's theorem. In this system, distribution lines and transformers form the main network. Electrical appliances can be treated as load impedance, which makes the circuit easier to analyze.

An AC circuit can be split into two parts, circuit A and circuit B, with a single pair of terminals between them. Circuit A can then be replaced by its Thevenin equivalent circuit. That equivalent has a voltage source in series with an impedance.

Replacing circuit A with its Thevenin equivalent does not change the current or voltage of any element in circuit B. The values in circuit B stay the same whether it is connected to the original circuit A or to the Thevenin equivalent. This is why the method is useful for studying connected circuits.

Two values are needed to build the Thevenin equivalent circuit. The first is the Thevenin voltage, which is found from the open-circuit voltage across the terminals of circuit A. The second is the Thevenin impedance, Zt, which is the equivalent impedance of circuit A*.

To form circuit A*, all independent voltage sources are replaced with short circuits. All independent current sources are replaced with open circuits. Then series or parallel impedances can be combined repeatedly to find Zt.

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Finding Voltage and Impedance in Circuit A

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