utgångsresistansen

Ugångsresistansen, often translated as output impedance or source impedance, is a fundamental concept in electrical engineering. It refers to the internal resistance of an electrical source, such as a battery, amplifier, or signal generator, as seen from its output terminals. This resistance opposes the flow of current when a load is connected.

The output impedance plays a crucial role in how power is transferred from a source to a load. According to the maximum power transfer theorem, maximum power is delivered to a load when the load's impedance is equal to the source's output impedance. However, in many applications, particularly in audio amplifiers, a low output impedance is desired to ensure that the voltage delivered to the load remains relatively constant regardless of the load's impedance. This minimizes distortion and maintains signal integrity.

Conversely, some circuits, like radio frequency transmitters, might be designed with a specific output impedance (often 50 ohms) to match transmission lines and antennas, optimizing signal propagation and minimizing reflections. A high output impedance can lead to voltage division, where a significant portion of the source voltage is dropped across the output impedance itself, leaving less voltage for the load. Understanding and controlling the output impedance is therefore essential for designing efficient and well-performing electronic circuits.