onoffsäätöelementti

An onoffsäätöelementti, often translated as an on-off control element or simply an on-off controller, is a fundamental component in control systems. Its primary function is to regulate a process by switching a controlled variable between two distinct states. These states are typically "on" and "off," or "high" and "low." The controller operates based on a setpoint, which is the desired value for the controlled variable. When the controlled variable deviates from the setpoint by a predetermined amount, known as the differential or hysteresis, the onoffsäätöelementti activates or deactivates the actuator.

For example, in a simple heating system, an onoffsäätöelementti might control a heating element. If the room temperature (the controlled variable) drops below the setpoint minus the differential, the heating element is switched on. Once the temperature rises above the setpoint plus the differential, the heating element is switched off. This continuous cycling ensures that the temperature remains within a desired range, although it may experience some fluctuation due to the inherent nature of the on-off control.

The simplicity and low cost of onoffsäätöelementti make them suitable for a wide range of applications where precise control is not critical. Common examples include thermostats in buildings, simple temperature regulators in appliances like ovens and refrigerators, and level controls in tanks. While they can lead to overshoot and undershoot in the controlled variable, their straightforward operation and reliability contribute to their widespread use. More complex control strategies, such as proportional or PID control, are employed when tighter regulation is required.