Stepper Motor: how it works and what it is used for

How a stepper motor works:

　　　In common ,the rotor of motor is permanent magnet, when current flows through the stator windings, it will produce a vector magnetic field. This field will cause the rotor rotating by an angle,which drives the direction of stator and rotor in the same direction. When stator’s vector magnetic rotates by an angle, it will cause rotor rotating. As long as inputting an electrical signal, the motor rotates an angle. The displacement of output angle is proportional to the pulse, the speed of rotatory is proportional to thefrequency of pulse.Changing the order in which the windings are energized,the motor will reverse. Therefore, controlling the number of pulse,frequency and the order that windings are power-on in each windings can achieve the goal of rotatory of motor.

A stepper motor is used to:

　　(1)Application in electrical clock and watch

　　Quartz clock and watch consists of quartz resonator, integrated circuit ,stepper motor,liquid crystal display, watch battery or ac power. Also it contains conductive rubber,padder,light bulb,buzz,er etc.

　　In the indicating quartz electronic wristwatch,for the goal of converting the electrical signal into the rotation of pointer which indicates time,it uses the miniature stepper motor and gear transmission system which plays the role of transducer.

　　(2)Application in the hands of industrial machines

　　Industrial manipulator is a mechatronics automation device which can imitate the behavior of hands .according to the program, trajectory and requirements it achieve of goal of replacing hand’s grasp,moving or manipulating

　　Stepper motor is an actuator that converts pulse signal into linear and angle displacement.the output of displacement is proportional to the input of the number of pulse signal, and it’s speed is proportional to the the number of input pulse (input frequency) in per unit time, and it’s steering is related to the phase sequence which is inputted into winding. Therefore, as long as controlling the number and frequency of signal pulse and phase sequence of motor winding, the displacement of output,speed and direction can be controlled.

　　(3)Application in packaging machinery

　　By controlling gear pump,Stepper motor can achieve the goal of exact measurement.In transporting viscous body, it is widely used in many places, such as syrup,bean paste,liquor,oil,tomato juice etc.

　　The measurement of gear pump is achieved by a pair of gear meshing,the material from inlet is forced into outlet。The power comes from stepper motor,it’s location and speed can be controlled by programmable controller.