|n.||1.||the process in which part of the output of a system is returned to its input.|
|2.||response to an inquiry or experiment.|
|Noun||1.||feedback - the process in which part of the output of a system is returned to its input in order to regulate its further output|
|2.||feedback - response to an inquiry or experiment|
|(electronics)||feedback - 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.