Labs: TA's and Overview

What will you need for the lab?  See Syllabus

Please go to your regularly scheduled lab section.  If for some reason you are not able to attend that lab section (being ill, on travel, etc.), you may attend a different section if there is space.  If you do attend a different lab section, you must let both TAs know.  Turn in your work to your regular, assigned TA before your next regular, assigned lab.  (Keep the same TA and due dates.)

If you need to change your lab section permanently, please send a permission code request form (2nd link) Links to an external site.  to the ECE office for waiting list or permission code.

About the Labs:

Electrical Engineering is about 'what can you do to a voltage or current'? Throughout the semester, we will be learning about many different ways to control the voltage and current in a circuit.  For example, voltage and current dividers split (or add) voltages and currents, amplifiers increase (or decrease) them, inverters reverse their polarity (multiply by -1) and more.  Each lab will provide you with a set of skills (such as how to measure V,I,R, design and specify the correct parts, build and test circuits, and more).  The overall labs this semester will focus on resistive and capacitive sensors.  Resistance and capacitance can be used to measure temperature, pressure, proximity, moisture, and more. They basically take data from the outside world.  The circuits we connect them to will give information back to us (such as turning on a light if something gets too hot).  At the end of the semester, you will be ready to build a resistive or capacitive sensor system of your own design, and the last few weeks of lab will be a Rube Goldberg Links to an external site. design to build a sensor to do SOMETHING, anything!  You choose, you design, you build.  This can be relatively simple, using the concepts from the labs in class (and yes, that is sufficient to do well in the lab).  Or, this can be as advanced as you would like to make it.  So, as you move throughout the labs this semester, start to think about ways you might use the circuits and concepts from each lab and combine them into a sensing system for SOMETHING....

Let's get started: (NOTE: the labs are being upgraded and changed, so these descriptions are only approximate, and subject to change)

Lab 0 - Get equipment, install software

Lab 1 - Measuring Voltage, Current & Resistance

In this lab you will:

ECE 1245: (week 1, attend both ECE1050 and 1245 sessions, but complete all of the 1245 lab)

• Measure resistance, voltage, and current using a digital multimeter.
• Classify resistors based on standardized color coding.
• Calculate and measure resistors combined in series and parallel, and the voltages (voltage difference and node voltage) and currents in these circuits.
• Use a breadboard (protoboard) to prototype your circuits.
• Measure a potentiometer (pot).

ECE 1050: (week 2, do this at home/on your own)

• Complete the Matlab OnRamp online interactive tutorial to learn the basics of Matlab.
• Use Matlab to write a program to find the total resistance, and the voltages and currents in series and parallel resistive circuits.

Lab 2 - Resistor Networks, Voltage and Current Dividers

In Lab 2, we are going to design and build a circuit where an LED will turn on/off depending on the value of a variable resistor, R1. In a future lab, this variable resistor will be a resistive sensor for physical parameters such as temperature, light, or moisture.

• ECE 1050:
  • Design a circuit that turns on an LED (light) when a resistor is below a certain value. In future labs, the variable resistor can be a resistive sensor that changes resistance with temperature, light, or moisture.
  • Learn the basics of how to use an LED.
  • In this design you will use voltage dividers and KVL/KCL.
• ECE 1245:
  • Build and test the design.

Lab 3: R-2R Ladder Digital to Analog Converter

• ECE 1050:
  
  • Plot a waveform and its quantized version
  • Solve a matrix equation for a 2-bit D/A converter circuit
  • Run an LTspice simulation of the 2-bit D/A converter circuit
• ECE 1245:
  • Build an R-2R ladder Digital-to-Analog converter for converting binary numbers to analog voltages.

Lab 4 - Thevenin Equivalent Circuits

In this lab you will build simple linear circuits consisting of v-sources and resistors, measure the output voltage of the linear circuit with various load resistances,find an equivalent Thevenin circuit consisting of a single voltage source and resistance that has the same output characteristics as the linear circuit,design a voltage reference whose Thevenin equivalent matches given specifications.

Lab 5 - Resistive Sensors

In this lab you will simulate and build a comparator circuit that will turn an LED on or off depending on the resistance of a sensor. The sensor you will use is a photoresistor which changes resistance with light.

Lab 6 - Non-inverting Op Amp

Lab 7 - Digital Gates

In this Lab you will simulate and measure basic logic gates (NAND, XOR, NOT, OR) and design a control circuit for a 7-segment display display.   This lab introduces digital logic gates that are the basis for computer circuits.  You will learn about basic types of gates, and you will design a simple circuit for summing one-digit binary numbers. Logic gates will also be useful in your final project if you need to turn on an LED or motor when a certain combination of sensor inputs occurs, such as "the output of sensor 1 is low AND the output of sensor 2 is high." 

EXTRA CREDIT Lab 6.5 - Level Shifters

In this Lab you will:

• Build several level-shifter circuits that shift voltages coming out of a comparator to voltages appropriate for the inputs to logic gates.
• Calculate the output voltages of various level-shifter circuits.
• Measure the output voltages of various level-shifter circuits.
• Design a level shifter circuit.
• Plot the output voltage of a level shifter circuit.

In your final project, you will have an analog voltage from a resistive or capacitive sensor, and may want to convert it to a digital voltage so you can work with it in the digital domain.  This lab deals with the problem of changing voltages from analog (the output of your op amp comparator) to digital levels appropriate to drive digital logic gates.  Circuits that map voltages from one range to another are called level-shifters.  It is common for different parts of a circuit to have different power supply levels, and some voltage translations are so common that special level-shifter IC's are designed for them.  In this lab, we will see how to design several kinds of level-shifters.

Lab 8 - Capacitors & Capacitive Sensors

In our previous labs, you have used resistors as sensors.  In this lab, we will use capacitors instead.  You have measured DC voltage, and current, but in this lab, you will measure voltages and currents that change with time using a function generator and an oscilloscope.

Lab 9 - Final Project - Week 1 (PDR)

Lab 9 - Final Project - Week 2 (CDR)

Lab 9 - Final Project - Week 3 (FDR)

Lab 9 Extra Credit -- Post a video of your final project

Invent, design, simulate, and build a sensor system of your own devising.  Choose and/or build an R or C sensor. Build the circuit to have this sensor do something.  It can turn on a light, motor, or buzzer, for instance.