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Governors, feedback amplifiers and PID control.

Watt’s centrifugal governor and proportional droop (1788)

Watt's centrifugal governor and proportional droop (1788)

Minorsky’s PID controller for ship steering (1922)

Minorsky's PID controller for ship steering (1922)

Black’s negative-feedback amplifier (1927)

Black's negative-feedback amplifier (1927)

Ziegler and Nichols tune a PID from the edge of instability (1942)

Ziegler and Nichols tune a PID from the edge of instability (1942)