Action of the Controller In Automatic Control Systems Flashcards
Why is it necessary to have an adjustable set point signal?
To set the process variable at different requirement values
What is the function of a controller?
A controller compares the set point signal with the feedback to determine the error signal. It also raises the power level of the error signal to operate the actuator.
What two signals does the comparator use to determine error signal?
- Set point signal
- Feedback signal
What is the difference between positive and negative feedback?
In positive feedback, the output of the comparator is the sum of the set point and feedback signals. In negative feedback, the output of the comparator is the difference between the set point and feedback signals
Which of the two types of feedback is desirable for an automatic control system?
Negative feedback
Identify two modes of control used in automatic control systems
ON-OFF and proportional
What is the typical characteristic of a proportional control mode with regard to its error?
It always has some error
What typical adjustment could be used to minimize error of a proportional control mode?
Increasing system gain
