lähtöimpedanssi

Lähtöimpedanssi, or output impedance, is a fundamental concept in electrical engineering that describes the impedance seen at the output terminals of an electronic device or circuit. It represents the internal resistance of the source to the flow of alternating current. When a load is connected to the output, the source's output impedance, along with the load's impedance, determines how much voltage and current are delivered to the load.

A low output impedance generally means that the source can deliver current to varying loads with minimal change in voltage. This is often desirable in applications where consistent voltage delivery is crucial, such as in audio amplifiers. Conversely, a high output impedance can lead to significant voltage drops when a load is connected, especially if the load impedance is low.

The output impedance of a real voltage source can be modeled as an ideal voltage source in series with an impedance. For a real current source, it can be modeled as an ideal current source in parallel with an impedance. Understanding and controlling output impedance is critical for efficient power transfer and signal integrity in many electronic systems, including power supplies, amplifiers, and signal generators.