In control systems, what does a proportional controller adjust based on?

A proportional controller is fundamentally designed to adjust its output based on the difference between a desired set-point and the actual process variable, which is referred to as the deviation. The main function of this controller is to reduce the deviation by applying a correction proportional to the magnitude of the error.

When the deviation from the set-point is large, the controller produces a significant output to bring the process variable back to the desired level. Conversely, as the process variable approaches the set-point, the output adjustment becomes smaller. This proportional relationship allows for a smooth and efficient response in maintaining the desired conditions of the system.

In this context, choices related to integral time and temperature change are not the primary focus of a proportional controller, as they involve different aspects of control mechanisms or processes. Meanwhile, change in energy does not directly correlate to the operation of a proportional controller, since the controller's primary function is to respond to the deviation from a set-point.