AC Components and Circuits
RLC Circuit Analysis

Section 8-1 Series RLC Circuits

Series RLC Circuit

 When XL is greater than XC, the phase is positive. When  XL is less than XC, the phase is negative When XL = XC the impedance (ZT) is the same as R, and there is no phase angle.

Procedure

Analysis of a series RLC circuit, given the values of VT, XL, XC, and R

Step 1: Calculate the total impedance

 ZT = Ö R2 + (XL - XC)2

Step 2 Calculate the total current

 IT = VT ZT

Step 3 Determine the current for each component

IR = IL = IC = IT

Step 4 Calculate the voltage for each component

VR = IT x R
VL = IT x XL
VC = IT x XC

Step 5 Determine the phase angle for each component and the total phase angle

qR = 0º
qL = 90º
qC = 90º
 qT = XL - XC R

Examples

Endless Examples & Exercises



 When VL is greater than VC, the phase is positive. When  VL is less than VC, the phase is negative When  VL = VC the voltage across the resistor (VR) is dental to the source voltage VT)

Voltage phasors for RLC circuits are identical to those for impedance.

The special point where where the reactances are equal (and the reactive voltage is zero