UNIVERSITY OF WEST ATTICA
SCHOOL OF ENGINEERING
DEPARTMENT OF COMPUTER ENGINEERING AND INFORMATICS

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Circuit Theory

RLC Components, Transient Response

Vasileios Evangelos Athanasiou
Student ID: 19390005

GitHub · LinkedIn

Nikolaos Katsos
Student ID: 21390084

Supervisor: Christos Kampouris, Laboratory Teaching Staff

UNIWA Profile

Co-supervisor: Georgios Antoniou, Laboratory Teaching Staff

UNIWA Profile

Athens, May 2022

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Project Overview

This project, titled "RLC Components, Transient Response" (Project 2), was conducted as part of the Circuit Theory course at the University of West Attica (UNIWA), within the Department of Informatics and Computer Engineering.

The primary objective of the project was to analyze and observe the transient response of RC and RL circuits through:

• Theoretical analysis
• Software simulation using Multisim
• Physical laboratory experimentation

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Table of Contents

Section	Folder	Description
1	assign/	Assignment material for the Circuit Theory course (DC RLC circuits)
1.1	assign/circuit theory rev2021_EXERCISE_2nd.pdf	Assignment description in English
1.2	assign/θεωρία κυκλωμάτων rev2021_ΑΣΚΗΣΗ_2η.pdf	Assignment description in Greek
2	docs/	Documentation on RLC components transient response (DC analysis)
2.1	docs/RLC-Components-Transient-Response.pdf	English documentation
2.2	docs/RLC-Εξαρτήματα-Μεταβατική-Απόκριση.pdf	Greek documentation
3	multisim/	Multisim simulations for DC RLC circuits
3.1	multisim/Q2.ms14	RLC transient response simulation
3.2	multisim/RC.ms14	RC circuit transient analysis
3.3	multisim/RL.ms14	RL circuit transient analysis
4	README.md	Repository overview and usage instructions

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Project Structure

The report is organized into the following main sections:

• 1.2.1 – RC Component
  Analysis of the transient response of an RC circuit, including theoretical derivations, Multisim simulations, and experimental laboratory results.

• 1.2.2 – RL Component
  Analysis of the transient response of an RL circuit through theoretical and simulated solutions.

• 1.3 – Questions
  Discussion and answers to specific theoretical and practical questions related to the observed circuit behaviors.

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Key Components and Equipment

The following equipment and tools were utilized during the laboratory session:

• Hardware

  • Breadboard
  • Connection cables
  • Digital multimeter
  • Resistors (various values)
  • Capacitors

• Power Sources

  • DC voltage source set to 12 V
  • Square pulse voltage source at 30 Hz

• Software

  • Multisim for circuit simulation

• Measurement Tools

  • Oscilloscope (for capturing voltage waveforms)
  • Timer (for recording capacitor charging times)

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Key Findings

RC Transient Response

• When fully charged, a capacitor behaves as an open circuit, since the current flowing through it approaches zero.

• The charging time is directly proportional to the resistance value.
  An increase in resistance increases the time constant
  
  $$\tau = RC$$

  resulting in a longer time required for the capacitor to reach full charge.

• A phase difference was observed between the input source signal and the capacitor voltage during simulation.

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RL Transient Response

• When the current in an RL circuit reaches its maximum value, the inductor (coil) behaves like a short circuit.
• The transient response is characterized by an exponential increase or decrease of current following a switching event, consistent with theoretical expectations.

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Installation & Setup Guide

This repository contains laboratory simulations and analysis for Circuit Theory, focusing on RLC series and parallel circuits and their resonance behavior.

All simulations are implemented in NI Multisim.

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Prerequisites

Required Software

• NI Multisim 14 (or later)
  Ensure your system meets the requirements for running .ms14 files.
  Download from NI Multisim.

Optional Software

• PDF Viewer for documentation: RLC-Components-Transient-Response.pdf / RLC-Εξαρτήματα-Μεταβατική-Απόκριση.pdf

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Installation Steps

1. Clone the Repository

git clone https://github.com/Circuit-Theory/RLC-DC.git

2. Navigate to Project Directory

cd RLC-DC

Ensure the following folder structure exists:

assign/
docs/
multisim/

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3. Open a Simulation in Multisim

• Launch NI Multisim.
• Select File → Open.
• Navigate to the multisim/ folder.
• Open the desired .ms14 file (series or parallel circuit).
• Wait for the circuit topology to load.

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Open the Documentation

1. Navigate to the docs/ directory
2. Open the report corresponding to your preferred language:
   • English: RLC-Components-Transient-Response.pdf
   • Greek: RLC-Εξαρτήματα-Μεταβατική-Απόκριση.pdf