The Negative feedback reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Negative feedback

Negative feedback is a type of feedback, during which a system responds so as to reverse the direction of change. Since this process tends to keep things constant, it is stabilizing and attempts to maintain homeostasis. When a change of variable occurs within a stable negative feedback control system, the system will attempt to establish equilibrium.

Open systems (ecological, biological, social) contain many types of regulatory circuits, among which are positive and negative feedback systems. 'Positive' and 'negative' do not refer to desirability, but rather to the sign of the multiplier in the mathematical feedback equation. The negative feedback loop tends to slow down a process, while the positive feedback loop tends to accelerate it.

Following is a list of negative feedback systems:

• Circulatory control
• Erythrocyte concentration

Table of contents

1 See also 2 Non-Engineering Links 3 External links

See also

• stability criterion
• Nyquist
• Closed Loop

Non-Engineering Links

• Donella Meadows' twelve leverage points to intervene in a system

External links

• http://www.biology-online.org/4/1_physiological_homeostasis.htm