Theveninlähteen

Thevenin's theorem, often referred to as Theveninlähteen in Finnish, is a fundamental concept in electrical engineering that simplifies complex linear electrical networks. It states that any linear electrical network, regardless of its complexity, can be reduced to an equivalent circuit consisting of a single voltage source and a single series resistor. This equivalent circuit, known as the Thevenin equivalent, behaves identically to the original network at its terminals.

The Thevenin equivalent voltage, denoted as Vth, is the open-circuit voltage across the terminals of the original network. To calculate Vth, one must remove any load connected to the terminals and then determine the voltage difference between these terminals. The Thevenin equivalent resistance, denoted as Rth, is the resistance seen looking back into the network from the terminals, with all independent voltage sources short-circuited and all independent current sources open-circuited.

The significance of Thevenin's theorem lies in its ability to simplify circuit analysis. By reducing a complex network to its simplest equivalent form, engineers can more easily determine the behavior of the circuit when different loads are connected. This is particularly useful in power distribution systems and when analyzing the output of electronic circuits. The theorem applies only to linear networks, meaning that the relationship between voltage and current is always proportional, and components do not exhibit nonlinear behavior.