What is the Difference Between Positive Feedback and Negative Feedback?

The main difference between positive feedback and negative feedback lies in their response to change. Positive feedback amplifies change, while negative feedback reduces change. Here are some key differences between the two:

• Amplification: Positive feedback enhances or amplifies changes, moving a system away from its equilibrium state and making it more unstable. On the other hand, negative feedback dampens or buffers changes, tending to hold a system to some equilibrium state, making it more stable.
• Phase Relationship: In positive feedback, the input and output signals are in-phase, meaning they have the same phase. In negative feedback, the input and output signals are out-of-phase, meaning they have opposite phases.
• System Stability: Positive feedback systems are generally less stable compared to negative feedback systems. Negative feedback systems are more stable and widely used in control systems.
• Examples: Positive feedback examples include contractions in childbirth and the ripening of fruit. Negative feedback examples include the regulation of blood glucose levels and osmoregulation.

In summary, positive feedback amplifies changes and tends to make a system more unstable, while negative feedback reduces changes and helps maintain system stability. Both types of feedback are essential in various applications and play crucial roles in control systems, process control systems, oscillators, amplifiers, and traffic control systems.

Comparative Table: Positive Feedback vs Negative Feedback

Here is a table summarizing the differences between positive feedback and negative feedback:

Positive feedback amplifies the deviation of a system from its set point or equilibrium, while negative feedback attenuates it. Positive feedback results in more of a product or response, whereas negative feedback results in less of a product or response. In control systems and biological systems, both positive and negative feedback mechanisms play crucial roles in maintaining stability and homeostasis.