Rückkopplungsschaltung

Rückkopplungsschaltung, also known as feedback circuit, is a fundamental concept in electronics and control systems. It involves feeding a portion of the output signal of a system back to its input. This feedback can be either positive or negative, significantly altering the system's behavior.

Negative feedback, the more common type, typically works to stabilize a system, reduce distortion, and improve linearity. By feeding a portion of the output that opposes the input signal back, it counteracts changes and deviations. This is crucial in amplifiers to maintain a consistent gain and in control systems to keep a process variable at a desired setpoint, such as maintaining a constant temperature or speed. Examples include operational amplifiers and cruise control systems.

Positive feedback, conversely, amplifies the input signal and can lead to instability or oscillation. It works by feeding a portion of the output back in phase with the input, reinforcing the signal. While often avoided in control systems, it is intentionally used in oscillators to generate waveforms and in certain types of memory circuits. Latching mechanisms also utilize positive feedback to maintain a state.

The design of feedback circuits involves careful consideration of the feedback factor, which determines how much of the output is fed back, and the phase relationship between the input and feedback signals. Understanding these parameters is key to achieving the desired performance from a feedback system.