källspänning

Källspänning refers to the voltage generated by a power source, such as a battery, generator, or power supply. It is the electrical potential difference between the positive and negative terminals of the source. This voltage is what drives electric current through a circuit when it is connected.

In direct current (DC) circuits, the källspänning is typically constant over time, although it may decrease slightly as a battery discharges. For example, a typical AA alkaline battery has a nominal källspänning of 1.5 volts. In alternating current (AC) circuits, the källspänning varies sinusoidally over time, with a specific frequency and amplitude. The voltage from a wall outlet is an example of AC källspänning.

The value of the källspänning is a fundamental characteristic of a power source and determines the maximum potential difference available to power a circuit. When a load is connected to the source, some of this voltage is "dropped" across the load as it consumes electrical energy. The källspänning is also the voltage that would be measured with a voltmeter connected directly across the terminals of the power source when no current is flowing (open-circuit voltage). Internal resistance within the source can cause the actual voltage to be lower when current is being drawn.