Lab 5 - thevenin equivalents

Thevenin Equivalents

Objectives:

1. Model a Power System with multiple sources and loads to evaluate how an individual Load (titled #2) impacts the rest of the system designed.
2. Apply the Thevenin process to designed circuit using resistors as the load and cables in the System. Also, specify regulated power supplies to be independent voltage sources.

Process:

1. Problem
          Determine the smallest equivalent Load #2 resistance that can be successfully used and its power consumed, given voltage across Load #2. What voltage will exist at the terminals of Load #2 if we remove it (open-circuit/highest voltage) and what short-circuit current will flow if we replace Load #2 by a short?

2. Given Assumptions
          R_c1 = 1000 ohms
          R_c2 = R_c3 = 39 ohms
          R_L1 = 680 ohms
         V_s1 = V_s2 = 9 volts
         V_Load2min = 8 volts

3. Circuit Calculations
            A: Establish open circuit voltage

            B. Compute Thevenin reistance

            C. Determine R_load2

4. Built Circuit
            A. Thevenin Equivalent Circuit

            B. Original Circuit

5. Data Collected
            A. Thevenin Equivalent

            B. Original Circuit

6. Data Analyzed

Conclusion:

          The electrical circuit equivalent of the power system was given and used for analysis in identifying the impingement of R_Load2 illustrating Objective 1. To demonstrate Objective 2, R_Load2 was isolated using the Thevinin process by reducing the network down to an equivalent source and series resistance. Intermittently, nodal analysis was used to calculate the Vth that coupled the Rth for the Thevenin circuit. Measurements were taken to test the validity of the calculated values and yielded between 8 and 14 percent error. A second circuit was built to extract the value of R_Load2 and test the maximum power effect.