Role of Negative Feedback in a System

Negative Feedback in a System

Negative feedback is a mechanism within a system where the system’s output is used to influence or control its input.
It is so named because the feedback loop counteracts or ‘negates’ any changes to the system.
This feedback process helps to maintain the system’s stability and keep it within a desired range of operation.

The feedback loop starts when a sensor detects a change in the system condition, such as a rise in temperature.
This change is compared to a setpoint or reference value (the desired condition). The difference between the current and the desired condition is called the error signal.
The error signal is then fed back to a controller, which makes adjustments to the input of the system to reduce the error and bring the system back to its setpoint.
By employing this process, negative feedback helps to counteract disturbances and steady the system.

An example of negative feedback is a home heating system. When the room temperature drops below the setpoint, the thermostat sends a signal to switch on the heating, warming up the room until reaching the setpoint again.
Another example can be found in living organisms where negative feedback mechanisms control various physiological systems. For example, the human body maintains a near-constant internal temperature through a negative feedback loop involving the brain, nerves, and skin.

Negative feedback is a crucial mechanism for maintaining dynamic equilibrium in a system.
It increases the overall system stability and can reduce the effects of external disturbances.
Understanding negative feedback is essential for effectively designing, analysing, and working with systems, especially in engineering and biological contexts.