Thevenin's theorem for
electrical networks states that any combination of
voltage sources and
resistors with two terminals is electrically equivalent to a single voltage source
V and a single series resistor
R. The theorem was first discovered by German scientist
Hermann von Helmholtz in 1853, but was then rediscovered in 1883 by French telegraph engineer M. L. Thévenin (
1857-
1926).
See also: Norton's theorem.