Quality Factor of Parallel RLC Circuit:
Consider the Quality Factor of Parallel RLC Circuit shown in Fig. 8.16.
In the circuit shown, the condition for resonance occurs when the susceptance part is zero.
Admittance
The frequency at which resonance occurs is
The voltage and current variation with frequency is shown in Fig. 8.17. At resonant frequency, the current is minimum.
The bandwidth,
For Parallel RLC Circuit, to obtain the lower half power frequency,
From Eq. 8.26, we have
If we simplify Eq. 8.27, we get
Similarly, to obtain the upper half power frequency
From Eq. 8.29, we have
Bandwidth
The quality factor is defined as
In other words,
In the case of an inductor,
The maximum energy stored = 1/2 LI2
Energy dissipated per cycle = (I/√2)2 x R x T
The quality factor
For the capacitor, maximum energy stored = 1/2 (CV2)
The quality factor