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Thevenin's theorem
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Any linear network is equivalent to a voltage source and a resistor.
Any linear two-terminal network is equivalent to a voltage source V_th (open-circuit voltage) in series with a resistance R_th (the resistance seen with sources turned off).
Simplifies analysing the effect of different loads.
Replace voltage sources by shorts and current sources by opens.
In more detail
Thevenin's theorem states that any linear network can be replaced by a single voltage source in series with a resistance, which simplifies analysis of a particular load.
Real-world uses
- Engineers simplify complex networks for load analysis.
- Power electronics designers use Thevenin equivalents to test circuits.
- Electrical engineers replace a complicated network with a single source and resistor to analyse how a load behaves.
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Frequently asked questions
How do I find the Thevenin voltage?
Calculate the open-circuit voltage across the terminals of interest.
How do I find the resistance?
Switch off the independent sources and find the resistance seen from the terminals.
What is the Thevenin voltage?
The open-circuit voltage between the two terminals of the network, found with the load removed.
Related topics in Current Electricity & Circuits
Galvanometer · Multimeter · Maximum power transfer · Norton's theorem · Superposition theorem · Delta–star conversion