Parallel LC Resonant Circuit Calculator

Calculation of the resonant frequency of a parallel LC resonant circuit

An LC resonant circuit is a circuit consisting of an inductor and a capacitor that are connected in parallel. When the capacitive and inductive resistances are equal, the circuit has a resonant frequency.

This calculator will help you calculate the third value if you know the other two parameters: inductance, capacitance, or resonant frequency.

The resonant frequency of the circuit is determined by the formula:

$f = \frac{1}{(2\pi\sqrt{LC})}$

An oscillatory process occurs in the circuit when the energy of the electric field is converted into the energy of the magnetic field and vice versa. The reactivities of the inductance and capacitance depend on the frequency of the alternating current.

As the frequency increases, the reactance of the inductor increases, and the capacitance decreases. When the frequency decreases, the opposite is true: the inductive resistance decreases, and the capacitive resistance increases.

At a certain frequency, the capacitance of the capacitor becomes equal to the inductive resistance of the coil. This is called current resonance.

The reactivities of the inductor and capacitor can be calculated using the formulas:

$X_L = 2 \pi f L$

$X_C = \frac{1}{(2 \pi f C)}$

The resonant effect of LC circuits has many important applications in the processing of analog and radio frequency signals. For example, it is used in notch filters, bandpass filters, and generators.