EE2073 Project Manual - EE2073 INTRODUCTION TO EEE DESIGN...

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EE2073
INTRODUCTION TO EEE
DESIGN AND PROJECT
PROJECT MANUAL
School of Electrical and Electronic Engineering

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Project Title: Automatic Volume Control for Audio
Amplifier System
1. Introduction
This project illustrates the use of the various principles covered in this course for
solving practical electrical/electronic system design and implementation problems.
The objective is to design and develop an automatic volume controller for an audio
amplifier system. It is a practical example of the digital control system based on the
use of data acquisition (DAQ) modules and the LabVIEW software development
platform for implementing a discrete-time, sampled-data system. The physical process
for the controller is the audio amplifier system with Volume Unit (VU) meter as
output level sensor and front-end Voltage Controlled Amplifier (VCA) stage as gain
control block (the actuator) followed by a Power Amplifier (PA) stage. Students will
gain experience in modeling the physical process and the feedback control system,
designing the audio amplifier system and the sensor/actuator interfacing electronics,
power supplies, etc. The system block diagram is shown in the following figure:
2. The System Design and Development Process
All projects, regardless of their levels of complexity, generally follow a well-defined
design and development process characterized by the following project stages
(phases) and milestones (for project reviews):
VCA
Volume Unit (VU) Meter
(Sensor)
PC Platform
DAQ modules
LabVIEW
Physical Process
Controller Model
Set Point
Voltage Controlled Amplifier (VCA)
Control Interface
(Actuator)
Automatic Volume Control for Audio Amplifier System
Controller Parameters
PA

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i. Explore strategies to solve application problem (Requirement/Strategy
Review)
ii. Propose and evaluate design options (Preliminary Design Review)
iii. Design, test and build subsystems (Design Review)
iv. Integrate subsystems into working system (Critical Design Review)
v. Test and evaluate system performance (Project Readiness Review)
3. Project Overview
As an automatic volume controller for an audio amplifier system, the objective is to
design a controller that automatically adjusts the gain of the audio amplifier system so
as to give a constant audio output at the preset level for a dynamically changing input
audio signal. Since the loudness of the audio volume is eventually perceived by the
reasonably adaptive human ear, very tight or fast control of the audio volume is not
the primary requirement and hence controller designs using fairly simple control
algorithms are applicable.
The project is to be designed and implemented as a digital control system (a discrete-
time, sampled-data system) based on the use of data acquisition hardware modules
and the PC-based LabVIEW graphical programming environment. The VCA, PA and
VU Meter subsystems of the audio amplifier system are to be designed, fabricated,
integrated and tested. Data acquisition is used as the basis for the design, development
and implementation of the automatic volume control for audio amplifier system.