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5 Design, system overview and function
Irrespective of which sensor is operated, the basic principle of regulation is always the
same:
The basic principle of regulation is continuous:
measurement - comparison - adjustment
A control circuit serves to set a specified physical variable (control variable) to a desired
value (nominal value) and to maintain it at this value, regardless of any malfunctions which
may occur. To perform the control task, the control variable's momentary value - the actual
value - must be measured and compared with the nominal value. If variances occur,
readjustment must be carried out in a suitable manner.
External malfunction
Sollwert
Feststellung einer
Abweichung
Korrekturmaß-
nahmen
Messung des
Ist-Wertes
Äußere Störung
Ist-Wert
Measuring the actual value
Nominal value
Ascertainment of a variance
Correction measures
Actual value