Thevenin's theorem

Thévenin's theorem holds, to illustrate in DC circuit theory terms,

• Any linear electrical network with voltage and current sources and resistances can be replaced at terminals A-B by an equivalent voltage source V_th inseries connection with an equivalent resistance R_th.
• This equivalent voltage V_th is the voltage obtained at terminals A-B of the network with terminals A-B open circuited.
• This equivalent resistance R_th is the resistance obtained at terminals A-B of the network with all its current sources open circuited and all its voltage sources short circuited.
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