electronics A control system which monitors its effect on
the system it is controlling and modifies its output
accordingly. For example, a thermostat has two inputs: the
desired temperature and the current temperature (the latter is
the feedback). The output of the thermostat changes so as to
try to equalise the two inputs.
Computer
disk drives use feedback control to position the
read/write heads accurately on a recording track. Complex
systems such as the human body contain many feedback systems
that interact with each other; the homeostasis mechanisms that
control body temperature and acidity are good examples.
(1996-01-02)