1. Thévenin’s Theorem

2. Thevenin’s Theorem
Thevenin’s theorem simplifies the process of solving for the unknown values of voltage and current in a network by reducing the network to an equivalent series circuit connected to any pair of network terminals.
Any network with two open terminals can be replaced by a single voltage source (VTH) and a series resistance (RTH) connected to the open terminals. A component can be removed to produce the open terminals.

3. Thevenin’s Theorem Determining Thevenin Resistance and Voltage
RTH is determined by shorting the voltage source and calculating the circuit’s total resistance as seen from open terminals A and B.
VTH is determined by calculating the voltage between open terminals A and B.

4. Circuit Schematic: Thévenin’s Theorem

5. Definitions for Thévenin’s Theorem
Linear circuit is a circuit where the voltage is directly proportional to the current (i.e., Ohm’s Law is followed).
Two terminals are the 2 nodes/2 wires that can make a connection between the circuit to the load.

6. Steps to Determine VTh and RTh
Identify the load, which may be a resistor or a part of the circuit.
Replace the load with an open circuit .
Calculate VOC. This is VTh.
Turn off all independent voltage and currents sources.
Calculate the equivalent resistance of the circuit. This is RTH.
The current through and voltage across the load in series with VTh and RTh is the load’s actual current and voltage in the original circuit.

7. Thevenin’s Theorem =

8. Thevenin’s Theorem

9. Thevenin’s Theorem

10. Thevenin’s Theorem

11. Thevenin’s Theorem
Note that R3 does not change the value of VAB produced by the source V, but R3 does increase the value of RTH.

12. QUESTIONS???