A series resonant circuit is a type of circuit that includes an induction coil and a capacitor connected in series with an energy source. In such a circuit, voltage resonance is possible. At resonance, the phase shift between the input current and voltage is zero, the complex input resistance is pure resistance, the current reaches its maximum value, and the reactance is equal to each other:
Where p is the characteristic resistance of the circuit.
To determine the resonant frequency, we are equal to the reactance of the series resonant circuit:
The ratio of the voltage amplitude of the reactive element of a circuit at the resonant frequency to the voltage amplitude at the input of the circuit is called the quality factor of the circuit:
The quality factor of resonant circuit Q can be represented by the parameters of its elements:
Usually, the quality factor of resonant circuits in electronic devices ranges from tens to hundreds. Therefore, in resonant mode, the voltage on the reactive elements of the circuit can be many times higher than the voltage applied to the circuit.