In an automatic control system, the controller output signal changes the position of which element?

In an automatic control system, the controller output signal specifically targets the final control element. This element is responsible for executing the necessary adjustments to the system’s output based on the controller's commands.

The final control element interfaces with the operational components of the system, such as valves, motors, or other actuators, enabling it to deliver the correct changes that influence the process being controlled. For example, if the system aims to control the temperature, the final control element might adjust a valve that regulates the flow of heating or cooling media.

Understanding this function is crucial because while other components, such as recorders and transmitters, play supportive roles in monitoring and communicating data, they do not directly implement changes in the system’s performance. The sensing element also plays a vital role by measuring a particular parameter and allowing the system to assess its status, but it does not execute physical changes in the process itself. Therefore, the final control element is vital for the functioning of automated control systems, executing the precise adjustments needed to maintain desired performance levels.