Electronics Lab Assignment: Semiconductors and Diode Theory

Note: If you need help with your labs, don't hesitate to reach out to the tutoring center ASAP. They have lots of good resources and are available to work with you to be successful.

Introduction:

Lab is an introduction to semiconductors and diode theory and should be implemented in software (Multisim) only.

In this course, we introduce students to safety when working in a lab with electricity and electrical components. Towards that end, complete the Electrical Safety Mini-Course found in this week's content.

Materials and Equipment:

Materials:
• Simulated Parts (Multisim):
• 1N4001 Diode (To access diodes in Multisim, under the Master Database, go to Group > Diodes > Diode. Any type is fine.)
• Two resistors (2.2 K? and 1.8 K?) with 10% tolerance

Equipment:

• Virtual Instruments (Multisim):
• Agilent Multimeter

Procedure:

Note: If you are new to Multisim or do not know how to do some of the lab activities, please refer to the Tools and Templates section in the left navigation panel.

Part A:

1. Calculate current ‘I' in the circuit shown in Figure 1 with R1 = 2.2 K? and R2 = 1.8 K?. Show work.

2. Calculate the voltage drops across R1 and across R2. Show work.

3. Construct the circuit shown in Figure 1 in Multisim with the resistor values in step 1. Use a 10% tolerance for the resistors. (Refer to the Tools and Templates section if you do not know how to set tolerances for resistors.) To access diodes in Multisim, under the Master Database, go to Group > Diodes > Diode. Any type is fine.

4. Measure the current in the circuit using the Agilent Multimeter. Compare it to your calculated value in Step 1.

5. Using the Agilent Multimeter, measure the voltage drops across R1 and across R2, and compare it to what you calculated in Step 2.

6. Tabulate all your data in the table below using appropriate units. Be sure to capture the screenshots for the circuit and measured values with the date and time stamp (see procedure below). When taking screenshots of your measurements, make sure that the circuit is also visible with connections to the equipment. Multiple screenshots may be necessary to demonstrate the circuit setup and the Agilent multimeter measurements.

Figure 1

Part B:

1. Reverse the polarity of the diode and analyze the circuit. Repeat steps 1) and 2) from Part A.

2. Construct the revised circuit in Multisim and repeat steps 4) and 5) from Part A.

3. Tabulate all your data below using appropriate units. Be sure to capture the screenshots for the measured values with the date and time stamp (see procedure below).

Table 1:

Percent error = (Measured - Calculated)/Calculated x 100

Review Questions:

1. a. Do the simulation results match the calculated values? If not, explain what causes this difference in the measurements. Is this acceptable?

b. Explain how to reduce this difference between calculated and measured values.

c. Would a similar difference be expected in a hardware implementation of the circuit? If so, why?

d. Discuss whether or not you think it is hard for engineers to accept these differences.

e. How do you think you know when the difference is within the range to be expected or is an error?

2. What is the difference between Part A and Part B with respect to the current and voltage drops in the circuit? What accounts for this difference?

Deliverables:

1. Follow the template "Lab Report Template" to compile the report, and make sure to check the report against the grading rubric below. The template can be found in the "Tools and Templates" link in the left navigation panel. The template should provide places for you to include the analysis/calculations, table, screenshots of the measurements, and the answer to the questions.

2. Take screenshots of the measurements obtained from the Multimeter, including the date and time stamp.