Name: matching load impedance for maximum power
Uploaded: 2024-07-08T13:19:54.000Z
Duration: 1 min 20 s
Channel: JoVE

Considere um circuito CA linear conectado a uma carga, representado por seu equivalente de Thevenin.
A corrente que flui através da carga é determinada usando a forma retangular da Thevenin e a impedância da carga.
A potência média fornecida à carga é obtida a partir da expressão da corrente.
Para determinar a resistência de carga para potência máxima, a derivada da potência em relação à resistência para potência máxima é definida como zero.
Da mesma forma, a reatância de carga para potência máxima é obtida.
Assim, para a transferência de potência média máxima, a reatância da impedância de carga é o negativo da reatância da impedância de Thévenin, e sua resistência é igual à resistência da impedância de Thévenin.
Ao substituir esses valores, a potência máxima é obtida.
De acordo com o teorema da potência média máxima, a impedância de carga é igual ao conjugado complexo da impedância de Thevenin.
Para cargas puramente resistivas, a transferência de potência média máxima ocorre quando a impedância da carga é igual à magnitude da impedância de Thevenin.
Nas comunicações sem fio, a impedância da antena é combinada com a impedância da linha de transmissão ou do circuito receptor, maximizando a transferência de energia, garantindo a intensidade ideal do sinal e melhorando a qualidade e o alcance da comunicação.

o teorema de transferência de potência máxima

Considere um circuito linear equivalente AC Thevenin conectado a uma impedância de carga.
<img alt="Equation 1" src="/files/ftp_upload/15125/15125_Equation_1.svg" style="height: 18px;">
A carga conectada consome a corrente e o circuito fornece energia para a carga. A corrente alternada que flui através da carga é determinada usando a forma retangular de tensões, correntes, impedância de rede e impedância de carga. A potência média entregue à carga é obtida a partir do produto do quadrado da corrente pela resistência da carga.
<img alt="Equation 1" src="/files/ftp_upload/15125/15125_Equation_1.svg" style="height: 18px;">

<img alt="Equation 2" src="/files/ftp_upload/15125/15125_Equation_2.svg" style="height: 18px;">
A transferência máxima de potência entregue à carga é determinada calculando a derivada de potência em relação à resistência da carga. A derivada é então igualada a zero para a condição máxima. Assim, para transferência de potência média máxima, a reatância da impedância de carga é o negativo da reatância da impedância de Thevenin, e sua resistência é igual à resistência da impedância de Thevenin. Quando estas condições são satisfeitas, a impedância de carga é considerada o conjugado complexo da impedância de Thevenin do circuito. A potência máxima é obtida quando a impedância da carga atende às condições acima mencionadas.
<img alt="Equation 3" src="/files/ftp_upload/15125/15125_Equation_3.svg" style="height: 46px;">

<img alt="Equation 4" src="/files/ftp_upload/15125/15125_Equation_4.svg" style="height: 38px;">

<img alt="Equation 5" src="/files/ftp_upload/15125/15125_Equation_5.svg" style="height: 18px;">
De acordo com o teorema da potência média máxima, a impedância de carga é igual ao conjugado complexo da impedância de Thévenin. Para cargas puramente resistivas, a transferência máxima de potência média ocorre quando a impedância da carga é igual à magnitude da impedância de Thevenin.
Nas comunicações sem fio, a impedância da antena é compatível com a linha de transmissão ou com a impedância do circuito receptor, maximizando a transferência de energia, garantindo a intensidade ideal do sinal e melhorando a qualidade e o alcance da comunicação.

O Teorema de Transferência de Potência Máxima

Considere um circuito CA linear conectado a uma carga, representado por seu equivalente de Thevenin.
A corrente que flui através da carga é determinada usando o ...

Education

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Electrical Engineering

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Unit 1

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AC Steady State Power

Potência de Regime Permanente CA

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

The Maximum Power Transfer Theorem

matching load impedance for maximum power

Maximum power transfer in an AC circuit depends on matching the load impedance to the Thevenin equivalent of the source network. The load draws current, and the circuit delivers power to that load. To analyze the current, the voltages, currents, network impedance, and load impedance are written in rectangular form.

The average power delivered to the load comes from the square of the current multiplied by the load resistance. To find the condition for maximum power, the power is differentiated with respect to the load resistance. That derivative is then set equal to zero.

For maximum average power transfer, the load reactance must be the negative of the Thevenin reactance. The load resistance must also equal the Thevenin resistance. When both conditions are met, the load impedance is the complex conjugate of the circuit's Thevenin impedance.

For a purely resistive load, maximum average power transfer occurs when the load impedance equals the magnitude of the Thevenin impedance. This idea is used in wireless communications, where an antenna is matched to a transmission line or receiver circuit. Good matching improves power transfer, signal strength, communication quality, and range.

Matching Load Impedance for Maximum Power

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the maximum power transfer theorem

Maximum power transfer in an AC circuit depends on matching the load impedance to the Thevenin equivalent of the source network. The load draws current, and the circuit delivers power to that load. To analyze the current, the voltages, currents, network impedance, and load impedance are written in rectangular form. The average power delivered to the load comes from the square of the current multiplied by the load resistance. To find the condition for maximum power, the power is differentiated...

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Learn how AC load impedance matching and complex conjugate conditions help maximize power transfer in Thevenin equivalent circuits and wireless communication.

Matching Load Impedance for Maximum Power | JoVE K12

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

Matching Load Impedance for Maximum Power

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