Feedbacksignal

Feedbacksignal refers to the portion of a system’s output that is returned to its input to influence subsequent operation. It is generated by sensing the output variable, possibly conditioning or scaling the sensed signal, and routing it to a summing node at the input. In a closed-loop arrangement, the feedback signal is typically compared with a reference signal to produce an error signal that drives the forward path.

The purpose of the feedbacksignal is to shape the system’s response. In most engineering applications, negative feedback is used to reduce error, improve accuracy, stabilize dynamics, and extend bandwidth, while maintaining linearity and reducing distortion. Positive feedback, by contrast, can increase gain but may lead to instability or self-sustained oscillations if not carefully managed.

The behavior of a system with a feedbacksignal depends on the forward (forward-path) transfer function and the feedback path transfer function. Key concerns include loop gain, phase shift, and time delays, all of which affect stability margins and transient response.

Common examples include electronic amplifiers with negative feedback to set gain, temperature or pressure control loops in which the sensor output feeds back to adjust the actuator, and audio systems where feedback is used or avoided intentionally.

See also: feedback, control theory, transfer function, stability, sensor, actuator.