Electronic instrumentation
Download
1 / 35

Proj2f03 - PowerPoint PPT Presentation


  • 214 Views
  • Uploaded on

Electronic Instrumentation. Project 2 1. Optical Communications 2. Transmitter Circuit 3. Receiver Circuit 4. Signal Reconstruction 5. Project Report 6. Practical Questions. Optical Communications. Transmitting an audio signal using light. Transmitter Circuit. audio signal.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Proj2f03' - RexAlvis


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Electronic instrumentation l.jpg

Electronic Instrumentation

Project 2

1. Optical Communications

2. Transmitter Circuit

3. Receiver Circuit

4. Signal Reconstruction

5. Project Report

6. Practical Questions


Optical communications l.jpg
Optical Communications

ENGR-4300 Electronic Instrumentation


Transmitting an audio signal using light l.jpg
Transmitting an audio signal using light

Transmitter Circuit

audio signal

Receiver Circuit

ENGR-4300 Electronic Instrumentation


Modulation l.jpg
Modulation

  • Modulation is a way to encode an electromagnetic signal so that it can be transmitted and received.

  • A carrier signal (constant) is changed by the transmitter in some way based on the information to be sent.

  • The receiver then recreates the signal by looking at how the carrier was changed.

ENGR-4300 Electronic Instrumentation


Amplitude modulation l.jpg
Amplitude Modulation

http://cnyack.homestead.com/files/modulation/modam.htm

ENGR-4300 Electronic Instrumentation


Frequency modulation l.jpg
Frequency Modulation

http://cnyack.homestead.com/files/modulation/modfm.htm

ENGR-4300 Electronic Instrumentation


Pulse width modulation l.jpg
Pulse Width Modulation

http://cnyack.homestead.com/files/modulation/modpwm.htm

ENGR-4300 Electronic Instrumentation


Pulse position modulation l.jpg
Pulse Position Modulation

http://cnyack.homestead.com/files/modulation/modppm.htm

ENGR-4300 Electronic Instrumentation


Optoisolators l.jpg
Optoisolators

  • Optoisolators use light to transfer a signal between two devices rather than a direct electrical connection.

  • You can buy computer cards with optoisolating connectors that protect the computer from devices connected to it. Good for industrial applications.

ENGR-4300 Electronic Instrumentation


Servo motor control l.jpg
Servo-motor control

  • The servo-motors are controlled by the computer through an optoisolating card.

  • The low voltage DC computer is protected (isolated) from the high voltage AC power needed to turn the motors.

ENGR-4300 Electronic Instrumentation


Transmitter circuit l.jpg
Transmitter Circuit

ENGR-4300 Electronic Instrumentation


555 timer in astable mode l.jpg
555-Timer in Astable Mode

ENGR-4300 Electronic Instrumentation


Input and modulated output l.jpg
Input and Modulated Output

ENGR-4300 Electronic Instrumentation


Special capacitors l.jpg
Special Capacitors

DC Blocking

Capacitor

(High Pass Filter)

Bypass Capacitor

(Low Pass Filter)

ENGR-4300 Electronic Instrumentation


Sample input and output l.jpg
Sample Input and Output

  • As input rises, pulses are longer

  • As input falls, pulses are shorter

ENGR-4300 Electronic Instrumentation


Your signal is what l.jpg
Your signal is what?

  • Called pulse position modulation in .pdf file

  • Also looks like pulse frequency and pulse width modulation

ENGR-4300 Electronic Instrumentation


Sampling frequency l.jpg
Sampling Frequency

  • The pot (used as a variable resistor) controls your sampling frequency

  • Input frequency in audible range (0-4K Hz)

  • Sampling frequency should be between 8KHz and 48K Hz to reconstruct sound

  • Input amplitude should not exceed 1V

ENGR-4300 Electronic Instrumentation


Receiver circuit l.jpg
Receiver Circuit

ENGR-4300 Electronic Instrumentation


Receive light signal l.jpg
Receive Light Signal

ENGR-4300 Electronic Instrumentation


Inverting amplifier pre amp l.jpg
Inverting Amplifier (Pre-Amp)

ENGR-4300 Electronic Instrumentation


Audio amplifier l.jpg
Audio Amplifier

ENGR-4300 Electronic Instrumentation


Audio amplifier details l.jpg
Audio Amplifier Details

increases

gain 10X

(optional)

386 audio

amplifier

high pass

filter

volume

low pass filter

ENGR-4300 Electronic Instrumentation


Special capacitors23 l.jpg
Special Capacitors

DC Blocking

Capacitor

Bypass

Capacitor

ENGR-4300 Electronic Instrumentation


Signal reconstruction l.jpg
Signal Reconstruction

  • The signal is reconstructed well enough by this design that it will be audible.

  • In order to improve the quality of the signal, you will add an integrator, which will more exactly reconstruct it.

  • Types of integrators

    • passive integrator (low pass filter)

    • active integrator (op amp integrator circuit)

ENGR-4300 Electronic Instrumentation


Passive integration l.jpg
Passive Integration

Integration works only

at high frequencies

w >> wc. Unfortunately,

your amplitude will also

decrease.

ENGR-4300 Electronic Instrumentation


Active integration l.jpg
Active Integration

Integration does not work at frequencies below wc.

Your gain goes from -Rf/Ri to -1/RiC

ENGR-4300 Electronic Instrumentation


Signal reconstruction27 l.jpg
Signal Reconstruction

  • integration

    • pulse on = + slope

    • pulse off = -- slope

    • ratio determines rise and fall

  • design parameters

    • sampling frequency

    • type of integrator

    • integrator components

ENGR-4300 Electronic Instrumentation


Comparing output of blocks l.jpg
Comparing Output of Blocks

  • location of points A-H are indicated in the project write-up

  • function of each block you should be able to determine from these notes and the experiments

  • take two measurements at a time

    • A on channel 1 and B on channel 2

    • B on channel 1 and C on channel 2

  • take all measurements relative to ground

ENGR-4300 Electronic Instrumentation


Project report l.jpg
Project Report

  • Introduction

    • Application Goals

    • Educational Goals

  • Basic Design

    • Identify function of each block

    • Identify input frequency and amplitude

    • Circuit diagram

    • Circuit built and witnessed

    • Take data at specified points

ENGR-4300 Electronic Instrumentation


Final design l.jpg
Final Design

  • What type of integrator?

    • What components?

    • Calculations

  • Circuit Diagram

  • Testing Plan

  • Design Changes

  • Problems Encountered

  • Take data at specified points

  • Have changes improved audio quality?

ENGR-4300 Electronic Instrumentation


Analysis and comparison l.jpg
Analysis and Comparison

  • Analyze each block

    • PSpice or hand analysis

    • Show calculations or explain plot output

  • Compare experimental with theoretical results

    • How are they different?... the same?

    • Why are they different?

  • Compare basic and final design

    • signal reconstruction

    • sound quality

ENGR-4300 Electronic Instrumentation


Personal responsibilities l.jpg
Personal Responsibilities

  • Make a list of all tasks to be completed as part of this project

    • Testing plan

    • Keep everyone on task

  • Assign responsibility for each task to one person (tasks cannot be shared)

  • Have task assignment list checked out

ENGR-4300 Electronic Instrumentation


Appendices l.jpg
Appendices

  • Useful data or results from experiments

  • Information resources

    • From the web

    • From the library or other sources

  • Only attach useful information

    • Useless information will result is a loss of points

    • Explain the purpose of each piece of info

ENGR-4300 Electronic Instrumentation


Practical questions l.jpg
Practical Questions

The participation points for this project will be determined based on practical skills. To test practical skills, students will be asked to perform simple practical tasks related to this project in a timely fashion. The instructor or the TA will assign the points.

Please notice that the practical questions are meant to be answered individually.

ENGR-4300 Electronic Instrumentation


Sample practical questions l.jpg

describe the goal and the methodology

identify components and parts of each circuit

debug the circuit

connect the circuits to the power supply and to the ‘scope

use PSpice traces and cursors.

draw Capture circuit

set up ‘scope to compare the output of two blocks

set function generator to get a signal comparable to an audio signal

capture the ‘scope signal both as a picture and data, using Agilent Intuilink

adjust sampling frequency

choose integrator component values

Sample Practical Questions

ENGR-4300 Electronic Instrumentation


ad