feedback (redirected from Fb control)

feedback /feed·back/ (fēd´bak) the return of some of the output of a system as input so as to exert some control in the process; feedback is negative when the return exerts an inhibitory control, positive when it exerts a stimulatory effect.

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feed·back (fdbk)

n.

1. 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.

2. The portion of the output so returned.

3. The return of information about the result of a process or activity.

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feedback

Etymology: AS, faedan + baec

, (in communication theory)

1 information produced by a receiver and perceived by a sender that informs the sender of the receiver's reaction to the message. Feedback is a cyclic part of the process of communication that regulates and modifies the content of messages.

2 the return of some of the output so as to exert some control in the process.

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feedback,

n the constant flow of sensory information back to the brain. When feedback mechanisms are deficient because of sensory deprivation, motor function becomes distorted, aberrant, and uncoordinated.

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feedback

the return of some of the output of a system as input so as to exert some control in the process.

Feedback controls are a type of self-regulating mechanism by which certain activities are sustained within prescribed ranges. For example, the serum concentration of oxygen is affected in part by the rate and depth of respirations and is, therefore, an output of the respiratory system. If the concentration of oxygen drops below normal, this information is transmitted as input to the respiratory control center. The control center is thereby stimulated to increase the rate of respirations in order to return the oxygen concentration in the blood to within normal range.

This series of events is an example of negative feedback, which always causes the controller to respond in a manner that opposes a deviation from the normal level (setpoint). It is, therefore, a corrective action that returns a factor within the system to a normal range. Positive feedback tends to increase a deviation from the setpoint. In other words, positive feedback reinforces and accelerates either an excess or deficit of a factor within the system. See also homeostasis.