Thevenin's theorem is a fundamental concept in circuit analysis that states that any linear two-terminal circuit can be replaced by an equivalent circuit consisting of a single voltage source, a single resistor, and a load resistor.
Thevenin's theorem deals with replacing a complex circuit with a voltage source and a resistor, while Norton's theorem replaces the same circuit with a current source and a resistor. Thevenin's theorem is useful for analyzing circuits with many voltage sources, while Norton's theorem is more useful for circuits with multiple current sources.
To determine the Thevenin equivalent circuit, you must find the open-circuit voltage (Voc) and the equivalent resistance (Req) of the original circuit. Voc is the voltage measured across the terminals of the open-circuited circuit, and Req is the resistance seen when looking into the circuit from the load terminals. The equivalent circuit will consist of a voltage source with a value of Voc and a resistor with a value of Req.
Thevenin's theorem allows for a complex circuit to be simplified into a single voltage source and resistor, making it easier to analyze and understand. It also allows for the use of superposition, where the effects of each individual source can be analyzed separately and then added together to find the total response of the circuit.
No, Thevenin's and Norton's theorems can only be applied to linear circuits. Non-linear elements like diodes and transistors do not follow the same rules as linear elements and therefore cannot be analyzed using these theorems.