# Lab 12: PSpice: Time Domain Analysis

## Objectives

• Use PSpice Circuit Simulator to simulate circuits containing capacitors and inductors in the time domain.Use PSpice Circuit Simulator to simulate circuits containing capacitors and inductors in the time domain.
• Practice using a switch, and a Pulse & Sinusoidal voltage source in R-L and R-C circuits.

## Equipments

• PSpice Program

## Background

The inputs to an electric circuit have generally been independent voltage and current sources. PSpice provides a set of voltage and current sources that represent time varying inputs. “Time Domain (Transient)” analysis using PSpice simulates the response of a circuit to a time varying input. Time domain analysis is most interesting for circuits that contain capacitors or inductors. For the capacitor, the part properties of interest are the capacitance and the initial voltage of the capacitor (the “Initial Condition”). For the inductor on the other hand, the part properties of interest are the inductance and the initial current of the inductor (the “Initial Condition”).

In this lab we consider three examples. The first example illustrates transient analysis of a R-L circuit with s single switch; the second and third circuits analyzed are the response of an R-C circuit to a Pulse voltage source and a sinusoidal voltage source.

We will again use a five-step procedure to organize circuit analysis using PSpice.

## Questions

1. The circuit is at steady state before the switch is thrown at t = 0. 1. Determine and plot the voltage across the capacitor vC(t) and the current i2kΩ(t) through the 2 kΩ resistor for t > 0. PSpice does not let you plot current and voltage simultaneous since they have different units.
2. Simulate the circuit, print out the plots and explain (using short concise sentences) the behavior of the capacitor and 2 kΩ resistor using your plots.
2.  Turn in Exp #1, Exp #2 and Exp #3 of the PSpice lab. Make sure that you show your work for verifying the simulation results!