Name: parallel rlc tuning at resonance
Uploaded: 2024-07-08T13:20:02.000Z
Duration: 1 min 23 s
Channel: JoVE

Considere un sintonizador de radio AM que comprende una conexión en paralelo de una resistencia, un condensador y un inductor, que colectivamente contribuyen a la admitancia de entrada del circuito.
En la resonancia, la parte imaginaria de la admitancia es cero, lo que hace que la frecuencia de resonancia varíe inversamente con la raíz cuadrada del producto de la inductancia y la capacitancia.
A la frecuencia de resonancia, la combinación en paralelo del inductor y el condensador actúa como un circuito abierto. Como resultado, la resistencia consume una corriente mínima y la energía oscila entre el campo magnético del inductor y el campo eléctrico del condensador.
La respuesta de frecuencia indica que la magnitud de la corriente disminuye inicialmente, alcanza un mínimo en la frecuencia de resonancia y aumenta a medida que aumenta la frecuencia.
En las frecuencias de media potencia, la corriente es 1,4142 veces la corriente mínima.
El ancho de banda se calcula determinando la diferencia entre las frecuencias de media potencia más altas y más bajas.
El factor de calidad, que indica la nitidez de la curva de resonancia, se puede expresar en términos de reactancias.
Un factor de calidad más alto produce frecuencias de media potencia distribuidas simétricamente alrededor de la frecuencia de resonancia y un ancho de banda más estrecho.

respuesta de frecuencia

El circuito RLC en paralelo es una disposición en la que la resistencia (R), el inductor (L) y el condensador (C) están conectados a los mismos nodos y, como resultado, comparten el mismo voltaje entre ellos. El circuito RLC paralelo se analiza en términos de admitancia (Y), que refleja la facilidad con la que puede fluir la corriente. La admisión está dada por:
<img alt="Equation 1" src="/files/ftp_upload/15145/15145_Equation_1.svg" style="height: 30px;">
La resonancia en un circuito RLC paralelo ocurre cuando la reactancia neta es cero, lo que significa que los efectos capacitivos e inductivos se cancelan entre sí. Esta condición se logra cuando:
<img alt="Equation 2" src="/files/ftp_upload/15145/15145_Equation_2.svg" style="height: 30px;">
Resolviendo la frecuencia de resonancia se obtiene:
<img alt="Equation 3" src="/files/ftp_upload/15145/15145_Equation_3.svg" style="height: 34px;">
Esta frecuencia resonante es donde el circuito exhibirá un comportamiento puramente resistivo y la corriente a través de la resistencia será máxima. La potencia disipada en el circuito es máxima en resonancia debido al flujo máximo de corriente. En las frecuencias del punto de media potencia, la corriente es aproximadamente 0,707 de la corriente máxima, lo que lleva a la mitad de la disipación de potencia máxima. El ancho de banda del circuito RLC paralelo es la diferencia entre estas frecuencias de media potencia y se encuentra usando:
<img alt="Equation 4" src="/files/ftp_upload/15145/15145_Equation_4.svg" style="height: 30px;">
El factor de calidad (Q) es un parámetro adimensional que compara la frecuencia de resonancia con el ancho de banda, indicando la selectividad o nitidez del pico de resonancia. En circuitos de alta calidad donde Q≥10, las frecuencias de media potencia se pueden aproximar usando:
<img alt="Equation 5" src="/files/ftp_upload/15145/15145_Equation_5.svg" style="height: 30px;">
<img alt="Equation 6" src="/files/ftp_upload/15145/15145_Equation_6.svg" style="height: 30px;">
 Un factor Q más alto significa que el circuito es altamente selectivo y resuena fuertemente en un rango estrecho de frecuencias alrededor de la frecuencia de resonancia. Esta propiedad es particularmente beneficiosa en las comunicaciones por radio, ya que permite filtrar frecuencias no deseadas y minimizar las interferencias. Los circuitos de resonancia paralelos son particularmente útiles en aplicaciones de filtrado que actúan como filtros de banda eliminada o de muesca, bloqueando un rango de frecuencia específico y permitiendo el paso de otros. Esto los hace valiosos en el procesamiento de señales para eliminar frecuencias o ruidos no deseados.

Respuesta de frecuencia

Considere un sintonizador de radio AM que comprende una conexión en paralelo de una resistencia, un condensador y un inductor, que colectivamente contribuyen a la ...

Education

Educación

JoVE Core

Electrical Engineering

Ingeniería Eléctrica

Unit 1

Unidad 1

Frequency Response

Respuesta en frecuencia

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Parallel Resonance

parallel rlc tuning at resonance

A parallel RLC circuit uses a resistor, inductor, and capacitor connected to the same nodes. Because they share the same voltage, the circuit is analyzed with admittance, which describes how easily current can flow. In a parallel RLC circuit, admittance helps show how the circuit responds as the frequency changes.

Resonance happens when the net reactance is zero. At that point, the capacitive and inductive effects cancel each other out. The resonant frequency is found from this condition. At resonance, the circuit behaves as a purely resistive circuit, and the current through the resistor reaches its maximum.

Power dissipation is also greatest at resonance because the current is highest. The half-power point frequencies are the points where the current is about 0.707 of the maximum current. At those frequencies, the power dissipation is half of its maximum value. The bandwidth of the parallel RLC circuit is the difference between the two half-power frequencies.

The quality factor, or Q, compares the resonant frequency with the bandwidth. It shows how sharp or selective the resonance peak is. For high-quality circuits where Q is 10 or greater, the half-power frequencies can be approximated with a simpler method. A higher Q means the circuit responds strongly to a narrow range of frequencies around resonance.

This selective behavior is useful in radio communications. It can help filter unwanted frequencies and reduce interference. Parallel resonance circuits are also used as band-stop or notch filters. In these filters, a specific frequency range is blocked while other frequencies pass through, which is useful for removing unwanted signals or noise.

Parallel RLC Tuning at Resonance

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parallel resonance

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Explore how a parallel RLC circuit behaves at resonance, including admittance, bandwidth, Q factor, and its use in radio tuning and notch filtering.

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electrical engineering

Parallel RLC Tuning at Resonance

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