What is the diffrence between a positive feedback loop and a negative feedback loop?

Answer 1

Click on this

http://en.wikipedia.org/wiki/Positive_feedback

Answer 2

An example of a negative feedback loop occurs for many hormone levels, where a hormone acts directly or indirectly on the gland where it was produced, impeding its own production. This acts to keep the hormone within normal levels. A positive feedback loop of the body is male sperm production, where the more that is produced acts to stimulate increased production, and vice versa - the less it is required, the lower the production. (Use it or lose it!)

Answer 3

In a negative feedback, a perturbation feeds the inverse of the perturbation back to the input, causing it to cancel out. In positive feedback, the perturbation is amplified and then fed back to the input, so that it will grow without limit. You have probably noticed the squeals from an improperly adjusted public address system which are an example of this.