The Thevenin Equivalent Circuit is a simplified representation of a complex electrical circuit. It consists of a single voltage source in series with a resistor, and is used to replace a portion of a circuit that has two terminals with a simpler circuit that produces the same voltage-current characteristics at those two terminals.
The purpose of finding Thevenin Equivalent Circuit is to simplify complex circuits and make them easier to analyze and design. It allows us to reduce a complex circuit to a single voltage source and a resistor, which can greatly simplify calculations and analysis.
The Thevenin Equivalent Circuit is calculated by finding the open-circuit voltage (Voc) and the equivalent resistance (Req) of a circuit. Voc is the voltage across the two terminals when they are disconnected from the circuit, and Req is the resistance seen at those two terminals. The equivalent circuit is then constructed by placing the voltage source (with voltage equal to Voc) in series with the resistor (with resistance equal to Req).
A Norton Equivalent Circuit is another simplified representation of a complex electrical circuit. It consists of a single current source in parallel with a resistor, and is used to replace a portion of a circuit that has two terminals with a simpler circuit that produces the same voltage-current characteristics at those two terminals.
The Norton Equivalent Circuit is related to the Thevenin Equivalent Circuit through the principle of duality. The Norton Equivalent Circuit can be obtained from the Thevenin Equivalent Circuit by converting the voltage source and resistor into a current source and resistor, respectively. Similarly, the Thevenin Equivalent Circuit can be obtained from the Norton Equivalent Circuit by converting the current source and resistor into a voltage source and resistor, respectively.