How Automatic Control Works ?
What ever may be the type of control system, the automatic process will be of the closed loop type; that is to say, it includes both the measuring means as well as the controlling means within the process itself, thereby completing the loop.
These are the steps followed in the automatic control system :
Step 1 :
A detection (measuring) means to sense the value of the process variable known as "primary element ".
Step 2 :
A transmission means of the measured signal to the measuring element .
A measuring element to reckon the actual process variable and display it called as "secondary element ".
A comparison means to detect error with reference to the desired set value .
A computation means to convert the error signal to a proportionate controller output (in phase and magnitude).
Step 6 :
A corrective (regulating) means by which the controller output signal is transmitted by the control medium to the final control element.