ECE 201L Circuit Analysis Laboratory
Lab 2

This lab provides experience with

Attachment: lab2.zip.

Video Clips: lab2

Do the following exercises. Report your results by editing the attached Word document and submitting it in Isidore. Submit one report per group, but each individual is responsible for having copies of the report and any additional documentation.

  1. Build a circuit consisting of a switch, 200-ohm resistor, and red LED. Use proper breadboarding technique: connect power to power rails, connect flat (short lead) of LED to negative side. Demonstrate to one of the instructors, and obtain signature.

    The red LED must be connected with the longer lead toward the positive side of the battery. There is also a flat area on the rim of the LED marking the negative end of the LED.

  2. Measure the voltage across your 9-v (nominal battery) and the voltage drop across the resistor and the red LED. Verify whether Kirchoff’s Voltage Law (KVL) is satisfied for this circuit. Measure the resistance and calculate the current through the circuit.

  3. Build (modify) circuit consisting of LED, micro-lamp and bi-pin lamp controlled by three switches. Demonstrate to one of the instructors, and obtain signature.

  4. Insert the multimeter probes between the positive power rail and the switch (see below) Measure the current through the circuit for the eight possible combinations of the three switches. Verify whether the total current if more than one switch is closed equals the sum of currents measured when only one switch is closed. (KCL)

  5. Connect a 1000-2000 ohm resistor to the HP 3630A power supply and HP 34401 multimeter as follows:

    Record the voltage and current for at least five evenly-spaced, input voltage levels from 1 to 6 volts. The voltages do not have to be exact round numbers. Record the values on a spreadsheet and plot current vs. voltage. Ohm’s law says that the data should lie on a straight line whose slope is the conductance (1/R). Find the resistance from your data and compare the value to that obtained by using the DMM.

    Paste a copy of your Excel plot in your lab report. A plot of the difference between the fitted line and the data points is often informative and you should include that plot as well.

  6. Connect the motor in place of the resistor in the above figure. Vary the voltage from 1 to 6 volts, measure the current for the unloaded motor and the stalled motor. To stall the motor, grab the shift tightly with your fingers so that it can not rotate. Do not stall the motor for longer than needed to measure the current. Fasten a small piece of paper on the motor to observe the speed of the motor as a function of the voltage.

Maintained by John Loomis, last updated 1 Sept 2010