Servo Motor - Types, Construction, Working, Controlling & ApplicationsBefore understanding the working principle of servo motor we should understand first the basics of a servomechanism. A servo system primarily consists of three basic components — a controlled device, a output sensor , a feedback system. This is an automatic closed loop control system. Here instead of controlling a device by applying the variable input signal, the device is controlled by a feedback signal generated by comparing output signal and reference input signal. When reference input signal or command signal is applied to the system, it is compared with output reference signal of the system produced by output sensor, and a third signal produced by a feedback system.
Servo Motor : types and working principle explained.
The figure below shows the schematic diagram for an armature controlled DC servo motor. Basically, servos behave like as actuators which provide precise control over veloci. Servo checks the pulse in every 20 milliseconds? This third signal acts as an input signal of controlled device.There are two types of AC servo motors one is 2 phase and the second is 3 phase. Although these servo motors are not likely to be found, but sometimes you can find them wodking hobby stores where they are used as actuators in higher model airplanes. It is a self contained electrical device, that rotate parts of a machine with high efficiency and great precision. These send electric signals of inconsistent width to the motor.
A servo motor is an electrical device which can push or rotate an object with great precision. Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering. The shaft of this motor is coupled to another shaft with a gear assembly for decreasing the high rpm in to the low rpm revolution per minute at the output side and that shaft is called output shaft shown in figure 4 Figure 4 Servo Motor Control According to the figure a potentiometer is adjust at the voltage adjusting knob and this knob is coupled with another gear assembly at the output shaft. The torque produced at rest time makes the starting time inactive.
A simple servo motor with feedback sensor is shown in figure 1 Servo Motor Mechanism: The servo motor basically composed of three basic parts. Servomotors also find uses in optical rotary encoders to measure the speed of output shaft wworking a variable-speed drive to control the motor speed. The controller has two inputs and one output. This input signal to the device presents as long as there is a logical difference between reference input signal and the output signal of the system.
Here are some applications used to control speed when the servo is overheaded or over rotating:. And, three-phase squirrel cage servo is used for high power systems. The field is controlled below the knee point of magnetizing saturation curve. The basic operating principle of DC motor is the same as other electromagnetic motors.
Servo motor is revolving or linear motion actuator, that allows the precisely control of its linear velocity, acceleration or angular position. This motor is available in market with coupled sensor for feedback control. This motor is control with sophisticated controller or a special kind of module is designed for controlling this motion. Servo motor is not a special class of motor, actually the servo word is used for that motors, which is used for control loop system. Servo motor is usually interfaced with microcontroller for control applications. A simple servo motor with feedback sensor is shown in figure 1. The Servo motor works on the basis of automatic closed loop system, for this system a controller is required, which is composed of a comparator and a feedback path.
Recommended Posts. Moreover the input to its control is a signal either analogue or digital representing the position commanded for the output shaft. This curve denotes high stall torque and a rapid reduction in torque with high speed. High speed force of DC motor is converted into torque by Gears. A servo system primarily consists of three basic components - a controlled device, a feedback system.
A servo motor is an electrical device which can push or rotate an object with great precision. If you want to rotate and object at some specific angles or distance, then you use servo motor. It is just made up of simple motor which run through servo mechanism. We can get a very high torque servo motor in a small and light weight packages. Doe to these features they are being used in many applications like toy car, RC helicopters and planes, Robotics, Machine etc.
Servo motors control position and speed very precisely. Split series motor has a typical torque-speed curve. Continuous rotation servo motor is consteuction related to the common positional rotation servo motor, but it can go in any direction indefinitely.
Frequently these motors have higher designs of tolerance or better bearings and some simple designs also use higher voltages in order to accomplish greater torque. Say at the initial position of servo motor shaft, the position of the potentiometer knob is such that there is no electrical signal generated at the output ans of the potentiometer. That is why dynamic response of armature controlled DC servo motor is much faster than that of field controlled DC servo motor. The motor consists of two bearing on front and back side for the free movement of shaft.