Editing Negative feedback (section)

=== Mechanical engineering ===
{{See also|Control systems|Control engineering}}
[[File:Ballcock.svg|thumb|The [[ballcock]] or float valve uses negative feedback to control the water level in a cistern.]]
An example of the use of negative feedback control is the [[ballcock]] control of water level (see diagram), or a [[pressure regulator]]. In modern engineering, negative feedback loops are found in [[Governor (device)|engine governor]]s, [[fuel injection]] systems and [[carburettor]]s. Similar control mechanisms are used in heating and cooling systems, such as those involving [[air conditioners]], [[refrigerators]], or [[freezers]].