Page 45 - basic control system
P. 45
BLOCK DIAGRAM OF CLOSED-
LOOP CONTROL SYSTEM
Error Detector
Error Detector/Comparator
❏ Also known as comparison element. Its function is to
compare the reference value with the measured value
and produces an error signal.
Feedback/Measurement Element
❏ This produces a signal related to the variable condition
being controlled and provides the signal feedback to
error detector to determine if there is an error.
❏ Negative feedback is necessary for control to be
achieved.
❏ Positive feedback occurs when the signal fed back is
added to the reference value.
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