Jännitelähdettä

Jännitelähdettä (Finnish for "voltage source") is a fundamental electrical component in circuit theory that provides a voltage to drive current through a circuit. It serves as the primary source of electrical energy, supplying the potential difference required for current flow.

In practical applications, voltage sources include batteries (direct current, DC) and generators (alternating current, AC). An ideal voltage source maintains a constant output voltage regardless of the load, with zero internal resistance. Real-world voltage sources have finite internal resistance, causing their output voltage to decrease under load.

Jännitelähdettä is essential for powering devices, ranging from simple resistive loads to complex electronic systems. The concept has been central to the development of electrical engineering, enabling circuit analysis and design through principles like Ohm's law and Kirchhoff's laws. Its role in energy conversion—transforming mechanical, chemical, or other forms of energy into electrical energy—makes it a cornerstone of modern technology.