ELECTRONICS-PROJECT

1

ECE 321 Final Project

This project is for individual student and is NOT a team project.

HOWEVER, collaboration among team members (i.e., ECE322 team) is strongly

encouraged and should be properly acknowledged in the final project report.

Final Project Report Due: May 4, 2015 to be uploaded onto Evaltools

Project Demo:

Tues., 5/5/15, 1:30 - 3:30 For TTH Classes that meet at 3:00 pm (ECE 322_01)

Wed., 5/6/15, 1:30 - 3:30 For MWF Classes that meet at 3:00 pm (ECE 322_02)

Objective

1. To design an “analog computer” to fulfill the following requirement

Vout = 25*(A*V1in + B*V2in)

where V1in = V2in = 10 mVpp @ 1 kHz, is the input sinusoidal (sine) signal to the analog

computer, which can be generated from a function generator; Vout is the output of the

computer; and A is a constant of your birth month mod 10 (divide by 10 and take the

remainder) and B is a constant of your birth day mod 10 (divide by 10 and take the

remainder).

e.g., If your birthday is November 7, A = 11 mod 10 = 1 and B = 7 mod 10 = 7.

If your birthday is February 26, A = 2 mod 10 = 2 and B = 26 mod 10 = 6.

2. To verify the circuit design with the help of contemporary software 3. To build and test the final design on breadboard

Instructions and Related Information

Figure 1 shows an illustrative block diagram of the analog computer.

Figure 1. Block diagram of an “analog computer”

2

DC dual-polarity power supply:

1. It should be able to provide a stable ±12V dc power. 2. 7812 and 7912 voltage regulators are available (datasheets are available at

AllUser U:\ECE Component Library on lab workstations). If you are using your

own laptop, you need to type \\ECEVault\AllUser\ECE Component Library.

3. Refer to the figure below (read Chapter 17 of your textbook):

Pre-amplifier:

1. Pre-amplify the input signal by a value of AV = 40. 2. Realize this pre-amplifier using an OP amp.

Main amplifier (Op-Amp):

1. Implement the summing and multiplying operations 2. LM741 general purpose op-amplifiers are available. 3. Refer to Chapter 13.2 of your textbook on summing amplifiers

Input:

Vin = 10 mVpp @ 1 kHz

Other available components:

Resistors, capacitors, diodes

3

Procedure

1. Design the circuits block by block. Determine the values of the resistors and capacitors in the circuits based on the overall design requirement and the local

operation requirement (dc bias, voltage gain, input and output impedance, dc and

ac equivalent circuit, etc.).

2. Simulate your design with PSpice software. Record corresponding waveforms and values. Verify your design and if needed redesign or modify your design.

3. Setup your design on the breadboard block by block. Test each subsystem and then integrate all subsystems. Record corresponding waveforms and

measurements.

Hint:

1. Understand how breadboards get connected underneath. The bigger breadboard is disconnected half way through the vertical panel. Remember to use jumper wires

to make the entire breadboard a unit.

2. Color-code your breadboard setup. For example: red for +12V, white for -12V, black for ground, yellow for input and output signals, green and blue for local

network.

3. Be aware that the packages for the 7812 and 7912 are different. Pay attention to their spec sheets.

4. Test your circuit block by block. Set up the DC power supply, pre-amp, and summer/multiplier at separate locations. Make sure each block works fine when

activated individually. Save input and output waveforms for each individual

block. Finally connect them together.

5. If the function generator cannot provide a stable Vin = 10 mVpp @ 1 kHz, try to increase the signal magnitude (For example to 500 mVpp) in order to get a stable

signal. Then use a voltage divider to get the low magnitude input signal you need.

6. If the DC power supply you have designed has high frequency noise (up to 1 MHz), try to fix it by adding proper filter capacitors. In order to speed up your

test, you can use the standard DC power supply to power the rest of your circuit.

7. Ask another group member to double-check your circuit before turning the power on. Usually it is impossible to get the circuit right the first time.

8. Remember to turn off the power before you rewire the circuit, plug in or pull out components.

The Deliverables

1. PSpice source files in one zip file for your final circuit design and simulation verification results (i.e., plots).

2. Final breadboard setup and test (lab demo). 3. Final Project Report.

4

Final Project Report

Refer to the Formal Report guidelines (from ECE 322 Electronics I Lab). Under the

guidelines, it should include the following:

1. Title Sheet

2. Abstract

3. Acknowledgements

4. Table of Contents

5. List of Tables

6. List of Illustrations

7. Introduction (including the objective(s) of the project)

8. Theory

9. Experimental Apparatus 10. Experimental Results and Discussion

(Include both breadboard test and simulation results from each individual blocks

as well as the overall design)

11. Conclusion

12. List of References or Bibliography

13. Appendices

Grading policy of the final project

The final project will be graded based on

PSpice design and simulation 20%

Breadboard design and measurement 30%

Final project report 40%

Project demo (and familiarity with equipment) 10%