SOLUTION

A controller essentially is a Comparator.

Detailed Explanation

Element of control element

Input: The applied signal or excitation signal applied to a control system from an external source in order to produce output is called input.

Error detector or comparator: It is a device where the reference input and feedback signal are compared, and if there is a difference, an error signal is generated. Error signal:

Controller: Controller is a device whose input is the error signal and the output is the actuating signal. It acts to reduce the error to zero by making the actual output equal to the desired output. The controller essentially is a comparator.

The controller is an element that accepts the error in some form and decides the proper corrective action. The output of the controller is then applied to the process or final control element. This brings the output back to its desired setpoint value.

A control system is used to maintain its output within desirable limits by means of a control action or controller. Any deviation of the output from the reference input is detected by an error detector. The error is detected by an actuating signal for control action through a controller. The controller is used to improve the transient and steady-state response of a control system. So we can define a controller as follows. “A controller is a device which is used to get the desired objective as per requirement.