Watt governor

The fly-ball governor was the first known automatic control system. It was installed on Watts steam engine over 200 years ago in 1775. It detected the speed of the rotation of the shaft and automatically opened up the steam supply when a drop was registered in that speed. 

It is the only known monument to Watt that departs from the conventional practice of signifying his achievement through one of three common and easily recognized attributes — a pair of dividers, a steam cylinder or a governor mechanism — and thus relates direcdy to the business of the school to which it is attached.54... 

Thus the production of Z exerts a controlling influence on W-ase, and, reciprocally, the rate of W-ase controls the production of Z. This type of control is called feedback. It is identical in type to the principle of a thermostat on an electric heater, or the governor of James Watt s steam engine nearly 200 years ago. We can represent a reaction sequence with feedback like this... 

Fig. 8. — Newcomen s steam engine as the primary milestone in the novel exploitation of heat and its alternative use other than for effortless getting warmness with the original sketch of cylinder with piston (middle), which can be acquainted with the shared employment of all four elements (where the earth-based construction represents the joining in-form = information transducer). Right it is added by illustrative drawing of the mechanical control torque, factually the first automaton realized through the Watt s innovative governor. ...

We tend to regard automatic control devices as a modem development. However, ingenious feedback control systems for water-level control were used by the Greeks as early as 250 b.c. (Mayr, 1970), with their mode of operation being very similar to that of the level regulator in the modern flush toilet. The fly-ball governor, which was first applied by James Watt to the steam engine in 1788, played a key role in the development of steam power. 

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