Jännitelähteillä

Jännitelähteillä, known in English as voltage sources, are fundamental components in electrical circuits. They are devices that provide a constant electrical potential difference, or voltage, across their terminals, regardless of the current drawn from them. This constant voltage is the defining characteristic of an ideal voltage source. In reality, however, all voltage sources have some internal resistance, which causes the output voltage to decrease slightly as the current increases.

Voltage sources can be categorized into two main types: direct current (DC) voltage sources and alternating current (AC) voltage sources. DC voltage sources, such as batteries and DC power supplies, provide a voltage that remains constant in polarity over time. AC voltage sources, like generators and AC adapters, produce a voltage that periodically reverses its polarity, typically in a sinusoidal pattern.

The primary function of a voltage source is to drive electric current through a circuit. When connected to a load, the voltage source pushes charge carriers, creating an electrical current. The magnitude of this current depends on the voltage provided by the source and the resistance of the load, as described by Ohm's Law. Understanding voltage sources is crucial for analyzing and designing all types of electrical and electronic systems.