Name four negative feedback configurations.


Q.) Name four negative feedback configurations.

Subject: Electronic Devices and Circuits
  1. Negative Feedback with Fixed Set Point:
  • Description: In this configuration, the controlled variable is maintained at a constant set point. Any deviation from the set point triggers a corrective action to bring it back.
  • Examples:

    • Temperature regulation: The thermostat in a heating or cooling system compares the room temperature to a set point and adjusts the heating or cooling accordingly.
    • Blood glucose regulation: The pancreas releases insulin when blood glucose levels rise above a set point, promoting glucose uptake and lowering blood glucose levels.
  1. Negative Feedback with Variable Set Point:
  • Description: In this configuration, the set point itself is adjusted based on external conditions or internal factors.
  • Examples:

    • Sweating: When body temperature rises, the sweat glands are activated to release sweat, which evaporates and cools the body. As the body cools down, sweating is reduced.
    • Osmoregulation: The kidneys adjust the amount of water reabsorption based on the concentration of solutes in the blood.
  1. Derivative Negative Feedback:
  • Description: In this configuration, the rate of change of the controlled variable is used to generate a corrective action.
  • Examples:

    • Car suspension: The shock absorbers in a car suspension system respond to the rate of change of the car's vertical movement, providing a smoother ride.
    • Aircraft flight control: The autopilot system in an aircraft adjusts the control surfaces based on the rate of change of the aircraft's position and attitude.
  1. Integral Negative Feedback:
  • Description: In this configuration, the accumulated error between the controlled variable and the set point is used to generate a corrective action.
  • Examples:

    • Process control: In industrial processes, integral control is often used to eliminate steady-state errors and maintain a constant process variable.
    • Home heating system: The thermostat in a home heating system integrates the temperature difference between the current temperature and the set point over time to adjust the heating output accordingly.