Servo Motor - What is A Servo Motor?

Servo Motor - What Is It?

In this article I will do some introductions on servo motor. There are many definitions that you can find about servo motor. According to otherpower.com , servo motor is a motor used for motion control in robots, hard disc drives, etc. Generally designed more like an alternator than a standard motor, most servo motors need special control circuitry to make them rotate electrically and some servo motors can be used in reverse to generate alternating current.

According to hdtvprimer.com , servo motor is a small motor in a C-band dish feed assembly. A servo motor selects whether vertical or horizontal polarization is to be received.

But according to earthlink.net, servo motor is a small motor with many applications; for ecample: In a hard drive, it moves the read/write heads, on command, to specified locations above the spinning data-storage media (disks). A servo motor moves a Satellite Dish's Feed Horn so that it can be oriented to the polarity of the satellite signal for capture and channeling of the signals to the LNB amplifier located in the front-end of the satellite system.

And according to the famous wikipedia.com, a servomechanism, or servo motor is an automatic device which uses error-sensing feedback to correct the performance of a mechanism. The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position or other parameters. For example an automotive power window control is not a servomechanism, as there is no automatic feedback which controls position—the operator does this by observation. By contrast the car's cruise control uses closed loop feedback, which classifies it as a Servomechanisms.

Servomechanisms may or may not use a servo motor. For example a household furnace controlled by thermostat is a servomechanism, yet there is no closed-loop control of a servo motor.

A common type of servo motor provides position control. Servo motor is commonly electrical or partially electronic in nature, using an electric motor as the primary means of creating mechanical force. Other types of servo motor use hydraulics, pneumatics, or magnetic principles. Usually, servos operate on the principle of negative feedback, where the control input is compared to the actual position of the mechanical system as measured by some sort of transducer at the output. Any difference between the actual and wanted values (an "error signal") is amplified and used to drive the system in the direction necessary to reduce or eliminate the error. An entire science known as control theory has been developed on this type of system.

Servomechanisms were first used in military fire-control and marine navigation equipment. Today servomechanisms are used in automatic machine tools, satellite-tracking antennas, automatic navigation systems on boats and planes, and antiaircraft-gun control systems. Other examples are fly-by-wire systems in aircraft which use servos to actuate the aircraft's control surfaces, and radio-controlled models which use RC servos for the same purpose. Many autofocus cameras also use a servomechanism to accurately move the lens, and thus adjust the focus. A modern hard disk drive has a magnetic servo system with sub-micron positioning accuracy.

Typical servo motor gives a rotary (angular) output. Linear types are common as well, using a screw thread or a linear motor to give linear motion.

Another device commonly referred to as a servo motor is used in automobiles to amplify the steering or braking force applied by the driver. In this form this device is not a true servo, but rather a mechanical amplifier.

In industrial machines, servo motor is used to perform complex motion.

Basically these are the definitions that you can find about servo motor.

Servo Motor