Introduction to EE 212 Lab

The goal of this lab course is to illustrate principles from the circuits and signals classes and teach the use of electronic test equipment.

The general format for your lab notebook:

• Keep all lab work in a quad-rule bound notebook with numbered pages.
• Include a table of contents at the beginning and record in it the titles and page numbers of each lab.
• Date each page as you use it.
• Data, schematics, and final work should go on the right side. Use the left side for scratch work and possibly for annotation should you leave something out and need to add it later. Do not do scratch work on scratch paper - everything you write in the lab should go in your lab notebook.
• Hand-written entries should be in ink rather than pencil. Cross out bad work with a single line through it, rather than blacking it out. When you review your work, it is sometimes useful to see what mistakes you made, and why.
• For each experiment, tape the lab handouts in your notebook.
• The lab notebook should be neat, but not formal.

The general format for recording steps in the lab:

• Briefly record information on your procedure. There should be enough information so that an engineer not familiar with our lab could reproduce your work.
• Draw schematics and block diagrams as you design and build circuits. Show on schematics the points where measurements were taken.
• As you take data, put it neatly in tables and make simple hand-drawn plots of results near tables if necessary.
• Add sketches or printouts of oscilloscope traces where appropriate. Leave space for computer-generated plots if you want to add these later.
• Be sure to include units with all data and all plots.
•  Include a summary giving a brief conclusion of what was accomplished and learned.
• Answer questions posed in the lab.

Hints:

• Often, you will not be asked a specific question about a part of the lab, but you are expected to explain and comment on each section. You should look for key words in the lab handout. One key word is measure. If you are asked for a measurement, your instructor will expect to see the measured value in your write-up. If appropriate, the measurements should be presented in a table. If you make more than one measurement, you should almost always plot the result, even if you are not explicitly asked to do so. Also, a measurement should not be presented without an explanation. You could write "I measured the voltage across the resistor to be 5.13 Volts. This is close to the value of 5.00 Volts calculated using the voltage divider formula. The 2.6 % difference is probably due to the 5 % tolerance of the resistors we use in this lab.'' Or it can be better to show on a schematic what is being measured and record the measured value, "VR1=5.15 V, expected 5 V, 5 % tolerance of the resistors accounts for difference". The latter is briefer and there is enough information for reproducing the result. Also, the latter is quicker to understand than a long description. However, some times long description are better as well. You choose what gives all the information needed.
• Another key word is plot. If you are asked to plot something, you are also expected to comment on the plot --- for example, do the points fall on a straight line? If so, why? Be sure to include units with all data and all plots.
• Compare is another key word that requires an explanation. For example, in Lab 1 you are asked to compare a measured resistance value to the labeled value of a resistor. It is not sufficient to say "The measured value of 22.7 kohm is close to the labeled value of 22 kohm.'' Instead, you should say something like "The measured value of 22.7 kohm is 3 % different from the labeled value of 22 kohm. This is within the 5 % tolerance of the resistors we use in this lab.''
• When you start a lab, your work area will be neat and clean. When you finish, it is expected that you will leave with your work area neat and clean. Return any components you used in the lab to the parts bin. Remove all wires you put on the breadboard, and return them to the wire bin. Make sure multimeter and scope probes are untangled and placed neatly in the work area. If you consistently leave your area messy, points will be deducted from your lab grade.