feedback feed·back (fēd'bāk')
n.
The return of a portion of the output of a process or system to the input, especially when used to maintain performance or to control a system or process.
The portion of the output so returned.
The return of information about the result of a process or activity.
feedback (fēd'bāk') The supply of an input to some process or system as a function of its output. See more at negative feedback, positive feedback. |
A process in which a system regulates itself by monitoring its own output. That is, it “feeds back” part of its output to itself. Feedback is used to control machines; a heating system, for example, uses a thermostat to monitor and adjust its output. Feedback is also used by the human brain to control various muscles and joints.
Note: By extension, “feedback” is any response or information about the result of a process.
Note: Feedback is usually a feature of automation.
Response, esp information and opinion: We'll wait for feedback before we try anything else
[1950s+; fr the portion of output fed back to the input in an automatic control circuit or system]
electronics
Part of a system output presented at its input. Feedback may be unintended. When used as a design feature, the output is usually transformed by passive components which attenuate it in some manner; the result is then presented at the system input.
Feedback is positive or negative, depending on the sign with which a positive change in the original input reappears after transformation. Negative feedback was invented by Black to stabilise vacuum tube amplifiers. The behaviour becomes largely a function of the feedback transformation and only minimally a function of factors such as transistor gain which are imperfectly known.
Positive feedback can lead to instability; it finds wide application in the construction of oscillators.
Feedback can be used to control a system, as in feedback control.
(1996-01-02)
in biology, a response within a system (molecule, cell, organism, or population) that influences the continued activity or productivity of that system. In essence, it is the control of a biological reaction by the end products of that reaction.