Lab Assignment: THEVENIN'S THEOREM (Hard-wire)

OBJECTIVES: The objectives of this laboratory exercise are to verify the validity of a Thevenin equivalent circuit, and to compare calculated current and voltage values with measured values

PROCEDURE:

Construct the circuit shown in Figure 1 on your breadboard. Make sure that you confirm the values of all resistors (always do this).

Figure 1

1. Measure the open circuit voltage between terminal "A" and "B". This is the Thevenin voltage.

2. Disconnect the source voltage from the circuit and replace it with a short. Measure the resistance between terminals "A" and "B". This is the Thevenin resistance.

3. Reconnect the source voltage and connect four different load resistors, one at a time, between terminals "A" and "B" on your breadboard, as shown in Figure 1. Use load resistor values of 0.1 k?, 1.0 k?, 2.0 k? and 3.0 k?. For each resistor, measure and record the load voltage and the load current.

4. Construct the Thevenin equivalent circuit on your breadboard. Use an appropriately adjusted potentiometer for the Thevenin resistance, and make sure to reset the source voltage to the Thevenin value.

5. Connect the same four load resistors to the Thevenin equivalent circuit, one at a time, as used in step 4, above. For each resistor, measure and record the load voltage and the load current.

DATA ANALYSIS:(Steps 1 through 3 were completed in the course of Lab Exercise #9)

1. Create a Table of calculated I_L and V_L for the original circuit in Figure 1 and for the Thevenin Equivalent Circuit.
2. Create a Table of simulated I_L and V_L for the original circuit and for the Thevenin Equivalent Circuit.
3. Create graphs of I_L vs. R_L and V_L vs. R_L for the original circuit and for the Thevenin Equivalent Circuit.
4. Create a Table of measured I_L and V_L for the original circuit as well as for the Thevenin Equivalent Circuit for all values of RL.

SUBMITTAL:

Write a full formal report (see ‘Format of a Technical Report' on Blackboard) summarizing this experiment. IN YOUR OWN WORDS, your report must include the following:

• A LAB COVER SHEET

• A TITLE PAGE

• OBJECTIVE - Paragraph form using complete sentences

• PROCEDURE- Use your own words. This may be a bulleted or numbered item section

• DATA - includes the following information (but may not be limited to):

o Sample Calculations (IL and VL from original circuit, IL and VL from Thevenin Equivalent circuit)
o Circuits
o Tables
o Graphs

• DISCUSSION - Paragraph form using complete sentences.

• CONCLUSION - Paragraph form using complete sentences.