A.C. Fundamentals - Key Points About Parallel Resonance
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Parallel resonance, also known as anti-resonance, is a phenomenon that occurs in electrical circuits containing inductors, capacitors, and resistors. Here are the key points about parallel resonance:
Definition: Parallel resonance is a condition in an electrical circuit where the impedance of the circuit becomes minimum at a certain frequency. At this frequency, the circuit exhibits a high current response to a given applied voltage.
Components: A parallel resonance circuit consists of components arranged in parallel, typically an inductor (L) and a capacitor (C), along with a resistor (R) that represents the circuit's inherent resistance.
Resonant Frequency (Ďr): The resonant frequency is the frequency at which the parallel resonance occurs. It is determined by the values of the inductor and capacitor and is given by the formula: Ďr = 1 / â(LC), where Ďr is the angular resonant frequency in radians per second, L is the inductance in henries, and C is the capacitance in farads.
Impedance at Resonance (Zr): At the resonant frequency, the impedance of the circuit becomes purely resistive and is minimum. The formula for impedance at resonance is Zr = R, where R is the resistance of the circuit.
Current Response: Due to the low impedance at resonance, the circuit allows a high current to flow through it when operated at the resonant frequency. This can be advantageous in certain applications like filter circuits.
Voltage Response: The voltage across the circuit is determined by the applied voltage and the impedance of the circuit. At resonance, the voltage across the resistor is equal to the applied voltage, and the voltage across the inductor and capacitor cancels out, leading to a drop in voltage across these components.
Phase Angle: At resonance, the phase angle between current and voltage across the circuit is zero. This means that the current and voltage are in phase, and the circuit behaves resistively.
Power Factor: At resonance, the power factor of the circuit is unity (1), indicating maximum power transfer from the source to the circuit. The power factor is a measure of the efficiency of power utilization in the circuit.
Bandwidth: The bandwidth of a parallel resonance circuit is the range of frequencies around the resonant frequency for which the impedance remains relatively low. It is determined by the Q factor (Quality factor) of the circuit.
Applications: Parallel resonance has various applications in electronics, such as in filter circuits, impedance matching networks, and tuning circuits in radio and communication systems.
Damping: Damping in a parallel resonance circuit refers to the degree of resistance in the circuit that affects how sharp or broad the resonance peak is. Higher damping reduces the sharpness of the peak.
It's important to note that while parallel resonance has its benefits in certain applications, it can also lead to issues like voltage magnification and excessive current at the resonant frequency if not properly controlled or designed.
Definition: Parallel resonance is a condition in an electrical circuit where the impedance of the circuit becomes minimum at a certain frequency. At this frequency, the circuit exhibits a high current response to a given applied voltage.
Components: A parallel resonance circuit consists of components arranged in parallel, typically an inductor (L) and a capacitor (C), along with a resistor (R) that represents the circuit's inherent resistance.
Resonant Frequency (Ďr): The resonant frequency is the frequency at which the parallel resonance occurs. It is determined by the values of the inductor and capacitor and is given by the formula: Ďr = 1 / â(LC), where Ďr is the angular resonant frequency in radians per second, L is the inductance in henries, and C is the capacitance in farads.
Impedance at Resonance (Zr): At the resonant frequency, the impedance of the circuit becomes purely resistive and is minimum. The formula for impedance at resonance is Zr = R, where R is the resistance of the circuit.
Current Response: Due to the low impedance at resonance, the circuit allows a high current to flow through it when operated at the resonant frequency. This can be advantageous in certain applications like filter circuits.
Voltage Response: The voltage across the circuit is determined by the applied voltage and the impedance of the circuit. At resonance, the voltage across the resistor is equal to the applied voltage, and the voltage across the inductor and capacitor cancels out, leading to a drop in voltage across these components.
Phase Angle: At resonance, the phase angle between current and voltage across the circuit is zero. This means that the current and voltage are in phase, and the circuit behaves resistively.
Power Factor: At resonance, the power factor of the circuit is unity (1), indicating maximum power transfer from the source to the circuit. The power factor is a measure of the efficiency of power utilization in the circuit.
Bandwidth: The bandwidth of a parallel resonance circuit is the range of frequencies around the resonant frequency for which the impedance remains relatively low. It is determined by the Q factor (Quality factor) of the circuit.
Applications: Parallel resonance has various applications in electronics, such as in filter circuits, impedance matching networks, and tuning circuits in radio and communication systems.
Damping: Damping in a parallel resonance circuit refers to the degree of resistance in the circuit that affects how sharp or broad the resonance peak is. Higher damping reduces the sharpness of the peak.
It's important to note that while parallel resonance has its benefits in certain applications, it can also lead to issues like voltage magnification and excessive current at the resonant frequency if not properly controlled or designed.