servomotor

device

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The Information Architects of Encyclopaedia Britannica

Last updated

July 13, 2026

Quick Summary

A servomotor is a power-driven mechanism that amplifies a weak control signal to produce a controlled torque. It's essentially a small induction motor designed for precise control of torque and direction.12

Key features include:
* Two Stator Windings: Displaced by 90 degrees, one receives a constant supply, while the other gets a controllable voltage from an electronic amplifier.1
* Controlled Torque: The motor's torque is proportional to the voltage on the second winding, allowing for precise adjustments based on the input signal.1
* Low Inertia Rotor: Some designs use a low-inertia rotor for rapid acceleration, making them suitable for position-control systems.1

Servomotors are typically used in small power ratings due to their lower efficiency and are integral to position-control systems.1

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electric motor
Servomotors
A servomotor is a small induction motor with two stator windings displaced 90° with respect to each other around its periphery. The rotor is usually of the squirrel-cage type but made with relatively high resistance conductors. The purpose of the motor is to provide…
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A servomotor is a small induction motor with two stator windings displaced 90° with respect to each other around its periphery. The rotor is usually of the squirrel-cage type but made with relatively high resistance conductors. The purpose of the motor is to provide…
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turbine
Axial-flow machines
…controlled by an oil-pressure operated servomotor, usually mounted in the rotor hub with the oil fed through the generator and turbine shaft. The servo-control system, which also drives the gates through a cam or rocker arrangement, is designed to adjust angles and inlet flows to match the electrical load while…
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…controlled by an oil-pressure operated servomotor, usually mounted in the rotor hub with the oil fed through the generator and turbine shaft. The servo-control system, which also drives the gates through a cam or rocker arrangement, is designed to adjust angles and inlet flows to match the electrical load while…
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servomechanism
…any necessary error corrections (the servomotor). In the controlled device, that which is being regulated is usually position. This device must, therefore, have some means of generating a signal (such as a voltage), called the feedback signal, that represents its current position. This signal is sent to an error-detecting device.…
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…any necessary error corrections (the servomotor). In the controlled device, that which is being regulated is usually position. This device must, therefore, have some means of generating a signal (such as a voltage), called the feedback signal, that represents its current position. This signal is sent to an error-detecting device.…
Read More