What is an On-Off Controller?
What is an On-Off Controller?
On-Off Controller Definition
An on-off controller is defined as a control system that fully opens or closes the control element when the process variable crosses a preset level.
Working Principle
The on-off controller works by fully opening or closing the output value, causing the process variable to change direction and cycle continuously.
Example of Application
A typical example is the cooling fan control in transformers, which activates based on temperature levels.
Actual response curve
Dead Time
Practical systems experience a delay, known as dead time, between the control signal and the action.
Ideal vs. Actual Response
The actual response curve of an on-off control system differs from the ideal due to the presence of dead time.
