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Why is the flying-ball governor an example of negative feedback control?

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Jacquard loom engraving, 1874 — automation At the top of the machine is a stack of punched cards that would be fed into the loom to control the weaving pattern. This method of automatically issuing machine instructions was employed by computers well into the 20th century.

The flying-ball governor is a classic example of a negative feedback control system because it uses the system's own output to regulate its activity and maintain a constant operating level.1

In this mechanism, the governor is mechanically coupled to the engine's output shaft. As the engine's rotational speed increases, centrifugal force causes the weighted balls to move outward. This physical movement is transmitted to a valve, which then reduces the supply of fuel or steam to the engine, thereby slowing it down. Conversely, if the engine load increases and the speed drops, the balls move inward, allowing more fuel or steam to enter and increase the speed.21

By automatically counteracting deviations from the desired speed, the system effectively dampens the process, ensuring the engine remains within stable limits without the need for constant human intervention.21