What Is Negative Feedback in Homeostasis?

Negative feedback regulation: bringing the ecosystem to or maintaining equilibrium or steady state, with the result that it inhibits and attenuates changes in the component that originally changed.

Negative feedback regulation

The characteristics of negative feedback can be well understood from the "negative" word, it mainly acts on other parts of the control system through the difference between input and output. This difference reflects the difference between the required output and the actual output. The control strategy of the controller is to continuously reduce this difference to make the difference smaller. The system formed by negative feedback has high control accuracy and stable system operation. We illustrate the working process of negative feedback by introducing examples used in the principle of automation. When a person intends to hold a water glass on the table, the person must first see the distance between his hand and the glass, and then determine the direction of movement of his hand, and the hand starts to move toward the water glass. At the same time, the human eye constantly observes the distance between the hand and the cup (the distance is the difference between input and output), and the role of the human brain (controller) is to constantly control the movement of the hand to eliminate this difference. Until the cup is in your hand, the whole process is over. From the above example, it can be seen that the deviation formed by negative feedback is the key for people to accurately complete the cup-taking action. If this difference cannot be obtained, the entire action cannot be completed. This is why a person with blind eyes cannot get a cup. Negative feedback is generally obtained after the output value is measured by the measuring element and then sent to a comparison element to compare with the input value.

The main significance of negative feedback regulation is to maintain the steady state of the internal environment of the body. In the case of negative feedback,

Negative feedback is widely used in electronic circuits. In the amplifier circuit, negative feedback can be used to stabilize the static operating point and the amplification factor, which can reduce non-linear distortion, expand the frequency band, and also change the input impedance and output impedance of the amplifier.

Negative voltage feedback can stabilize the output voltage of the amplifying circuit, so the output impedance is reduced compared to when there is no negative feedback. Negative current feedback can stabilize the output current of the amplifying circuit, so the output impedance is larger than without the feedback. The feedback branch is connected in series, so the input impedance is increased; the input impedance of the parallel negative feedback input is reduced because the feedback branch is connected in parallel.

After the amplifier circuit introduces negative feedback, the amplification factor is reduced, but it has an important effect on improving the performance of the amplifier circuit.