Experiment 9 Lab Manual
© Dept. of EEE, Faculty of Engineering, American International University-Bangladesh (AIUB) 1
American International University- Bangladesh
Department of Electrical and Electronic Engineering
Introduction to Electrical Circuits Laboratory
Title: Transient Analysis of RC Series and RL series using PSPICE
Introduction:
In this experiment we apply a pulse waveform to the RC and RL series circuit to analyze the
transient response of the circuit by using PSPICE simulating tool. The pulse width relative to
a circuit’s time constant determines how it is affected by an RC and RL circuits.
The purpose of this experiment is to
1. simulate the circuits by using components from the PSPICE library and,
2. analyze obtained graphs and results.
Theory and Methodology:
Time Constant (τ): A measure of time required for certain changes in voltages and currents in
RC and RL circuits. Generally, when the elapsed time exceeds five time constants (5τ) after
switching has occurred, the currents and voltages have reached their final value, which is also
called steady-state response.
The time constant of an RC circuit is the product of equivalent capacitance and the Thevenin
resistance,
τ = R×C (1)
The time constant of an RL circuit is the equivalent inductance divided by the Thevenin
resistance,
τ = L/R (2)
Time Period (T): Time required to complete one cycle is called Time Period or the length of
each cycle of a pulse train is termed its time period (T).
Pulse width (tp): The pulse width of an ideal square wave is equal to half of the time period.
Figire-1: RC circuit Figire2: RL circuit
8UF
8K
V PULSE
V1 = 0 V
V2 = 10V
TD = 0 S
TR = 0S
TF = 0S
PW = 1S
V1 = 0 V
V2 = 10V
TD = 0 S
TR = 0S
TF = 0S
PW = 1S
8K
V PULSE
50H
