feedback
<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)
Nearby terms:
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Theft Limited « Fedora « feedback » feedback control
» feed-forward » Feel
