Thévenin’s Theorem allows one to replace a complicated circuit with a simple equivalent circuit containing only a voltage source and a series connected resistor.
According to Thevenin's Theorem, the linear circuit in the figure a can be replaced by that in figure b. The circuit to the left of the terminals a-b in figure b is known as the Thevenin equivalent circuit.
Thevenin's Theorem states that a linear two-terminal circuit can be replaced by an equivalent circuit consisting of a voltage source Vth in series with a resistor Rth, where Vth is the open-circuit voltage at the terminals and Rth is the input or equivalent resistance at the terminals when the independent sources are turned off.
In order to find the Thevenin equivalent circuit we have steps to consider:
1. Turn off sources (current or voltage source). Short the voltage source, open the current source.
2. Make an open circuit
3. Determine Rth
4. Turn-on sources and solve for Vth
5. Draw for Thevenin's equivalent circuit.
1. Turn off sources (current or voltage source). Short the voltage source, open the current source.
2. Make an open circuit
3. Determine Rth
4. Turn-on sources and solve for Vth
5. Draw for Thevenin's equivalent circuit.