Lab 2 Prelab Help Sheet

This help sheet is not going to be as comprehensive as the prelab help sheet for lab 1, and next week will be even less thorough. Part of the goal of this class is for you to be able to devise prelab activities on your own. So if you’re running out of ideas for things to do, please review last week’s help sheet.

Think carefully about which group members you want to complete each section. Many of the topics here are interconnected, so it often helps to make sure everyone does them (or, at minimum, that you meet and share out what you learned during prelab.) We especially encourage everyone to do the reading and watch the videos.

Reading and Reference

• Watch lecture videos.
• Watch op-amp videos 1 & 2.
• Read the lab.
• Flag parts of the lab that didn’t make sense for discussion with your team or a prof.
• Read the submission sheet and notice:
  1. What are the deliverables?
  2. What are the specifications on those deliverables?
• Read the “Additional Information about Accuracy in Multimeters” article
• Read “Auntie Sparks Guide to Breadboarding”

Software

• Test compile matlab_logging.ino
• Make sure you have access to and understand the use of matlablogging.m (Why can’t we give it a test run?)

Teensy Measurements

• How are you going to find the sample rate of the Teensy?
• How are you going to find the size of one Teensy unit?
• What do you expect to happen with the 175kHz input signal? Why would we ask you about it?

Divider Measurements

• Look up all necessary impedance values and uncertainties.
• Have you calculated your expected output voltage for each entry in the table?
• Do you know whether you’ll get a RMS or peak-peak measurement for each experiment?
• Lay out your breadboard ahead of time using a breadboard simulator like fritzing or Tinkercad
• Are you sure you understand and accounted for instrument loading? Consult the videos or a Prof. if you’re not confident you got this right.
• Are you clear on how to change a channel setting between 1x and 10x modes?
• How are you going to quickly calculate your VOPC, ERRI and ERRC values in the lab? Would making a spreadsheet or a Matlab script help?
• How does error propagation work?
• Are you accounting for error in every component in your experiment, including your instruments?

Op-Amp Divider Measurements

• Have you calculated your expected output voltage for each entry in the table?
• What do op-amp followers do and why are we using them in this context?

Results

• Make a plan for how your team will split its time in lab.
• Write up the math parts of your submission sheet so that you can just paste in results in lab.