What is a defining feature of a proportional control system?

A defining feature of a proportional control system is its ability to adjust the output based on the measured offset from a desired setpoint. This method continuously modulates the control signal in proportion to the difference between the actual conditions and the target conditions, allowing for smoother and more accurate control over the system being managed. For instance, in a temperature control system, if the temperature deviates from the setpoint, the proportional control system will adjust the cooling or heating output in line with the degree of deviation, rather than just switching the device on or off.

This contrasts with systems that rely solely on binary operations, which simply toggle between states without providing intermediate control based on the conditions. Additionally, a proportional control system does not require constant manual adjustments, as it is designed to automatically respond to variations in the measured variable. This automatic feedback mechanism is crucial for maintaining desired levels without constant human intervention.