This is nothing
but a simple electrical
motor,
controlled with the help of servomechanism. If the motor as controlled device,
associated with servomechanism is DC motor, then it is commonly known DC Servo Motor. If the controlled
motor is operated by AC, it is called AC Servo Motor.
Servo
Motor Theory
There are some
special types of application of electrical motor where rotation of the motor is
required for just a certain angle not continuously for long period of time. For
these applications, some special types of motor are required with some special arrangement which makes the
motor to rotate a certain angle for a given electrical input (signal). For this
purpose servo motor comes into picture. This is normally a simple DC
motor which is controlled for specific angular rotation with the help of
additional servomechanism (a typical closed loop feedback control system). Now
day’s servo system has huge industrial applications.
Servo motor
applications are
also commonly seen in remote controlled toy cars for controlling the direction
of motion and it is also very commonly used as the motor which moves the tray
of a CD or DVD player. Besides these, there are other hundreds of servo motor
applications we see in our daily life. The main reason behind using a servo is
that it provides angular precision, i.e. it will only rotate as much we want
and then stop and wait for next signal to take further action. This is unlike a
normal electrical motor which starts rotating as and when power is applied to
it and the rotation continues until we switch off the power. We cannot control
the rotational progress of electrical motor, but we can only control the speed
of rotation and can turn it ON and OFF.
Now we come to the specific answer of the question "what is servo
motor?"
Servo motor is a special type of motor which is automatically operated up to
certain limit for a given command with help of error-sensing feedback to
correct the performance.