SGMAH Sigma II Japan YASKAWA 0.637N.m SERVOMOTOR INsB SGMAH-02AAN21

 

 

Unlike dc motors, with servo motors you can position the motor shaft at a specific position (angle) using control signal. The motor shaft will hold at this position as long as the control signal not changed. This is very useful for controlling robot arms, unmanned airplanes control surface or any object that you want it to move at certain angle and stay at its new position.
Servo motors may be classified according to size or torque that it can withstand into mini, standard and giant servos. Usually mini and standard size servo motors can be powered by Arduino directly with no need to external power supply or driver.
Usually servo motors comes with arms (metals or plastic) that is connected to the object required to move (see figure below to the right).

 

 

 

 

The third pin accept the control signal which is a pulse-width modulation (PWM) signal. It can be easily produced by all micro- controllers and Arduino board.
This accepts the signal from your controller that tells it what angle to turn to. The control signal is fairly simple compared to that of a stepper motor. It is just a pulse of varying lengths. The length of the pulse corresponds to the angle the motor turns to.

 

 

 

 

Control Block Diagram of Servo Motors
A pulse signal that is externally applied (when it is the pulse input type) and the rotation detected by the servo motor encoder are counted, and the difference (deviation) is output to the speed control unit. This counter is referred to as the deviation counter.
During motor rotation, an accumulated pulse (positioning deviation) is generated in the deviation counter and is controlled so as to go to zero.
The function for holding the current position (position holding by servo control) is achieved with a position loop (deviation counter).