A servo drive is an automatic device that takes a command signal and compares it with the feedback from a servomechanism in order to provide the required voltage to a servo motor to correct any deviation from the commanded status.
Servo Drive History
The concept of the servomechanism is much older than the use of the current terms. The Greeks used wind-driven servo-motors to continuously adjust the heading of their windmills so the blades always faced into the wind. The history of these systems is difficult to trace as the terms governor, regulators and follow-up device proceeded the use of servo motor and servo drives.
The Industrial Revolution marked a major turning point in human social history. The development of windmills, furnaces, boilers and at last the steam engine that could not be regulated by an operator required automatic control. James Watt developed his fly-ball governor for regulating speed of steam engines long before the term servo-motor came into use and Nikola Tesla experimented with “wireless control” of model ship on the Potomac River using electric contactor “servo-motors” to steer the models remotely.
During World War I, Layrence Sperry filed a U.S. patent application for an aerial torpedo in which a “servo-motor” moved the rudder to steer the course. By 1915, the serm “servo motor” was firmly entrenched within the language of America’s community of electrical engineers.
Later during this century companies like GE, Westinghouse and Northrup further developed this technologies introducing DC and AC servos.