Electrical Engineering ⇒ Topic : Q-Factor of Series Resonant Circuit

Q-Factor of Series Resonant Circuit

At series resonance, the voltage across L or C (the two drops being equal and opposite) builds up to a value many times greater than the applied voltage V (= *I_rR).

The ratio V_L / V or V_C / V at resonance is a measure of the quality of a series resonant circuit.

This is called the Q-factor (Q stands for quality) of the circuit. It is also known as the voltage magnification factor.

Since the coil resistance is often the only resistance in a series resonant circuit, the Q is sometimes refered to as the Q-factor of the coil. Therefore, we use the expression X_L / R for Q in series resonant circuit.

The Q-factor of a series resonant circuit can also be expressed in terms of L and C.

The series resonant circuit is also called an acceptor circuit because such a circuit accepts currents at one particular frequency (i.e., f_r) but virtually rejects currents of other frequencies. Such circuits are used in radio and television receivers