What is a Feedback and Types of Feedback?

Feedback is a process whereby some proportion of the output signal of a system is passed (fed back) to the input. This is often used to control the dynamic behaviour of the system.

Types of Feedback:

  • Negative feedback:

This tends to reduce output (but in amplifiers, stabilizes and linearizes operation). Negative feedback feeds part of a system’s output, inverted, into the system’s input; generally with the result that fluctuations are attenuated. Negative Feedback have advantages over Positive Feedback.

  • Positive feedback:

This tends to increase output. Positive feedback, sometimes referred to as “cumulative causation”, is a feedback loop system in which the system responds to perturbation (A perturbation means a system, is an alteration of function, induced by external or internal mechanisms) in the same direction as the perturbation. In contrast, a system that responds to the perturbation in the opposite direction is called a negative feedback system.

  • Bipolar feedback:

which can either increase or decrease output.

Example for Negative Feedback and Positive Feedback