How Much Information Do You Know About the Stepper Motor?

A stepper motor or step motor or stepping motor is a brushless DC electric motor that divides a full rotation into a number of equal steps. The motor’s position can then be commanded to move and hold at one of these steps without any position sensor for feedback (an open-loop controller), as long as the motor is carefully sized to the application in respect to torque and speed. Switched reluctance motors are very large stepping motors with a reduced pole count, and generally are closed-loop commutated. Switched reluctance motors are very large stepping motors with a reduced pole count, and generally are closed-loop commutated. To make the motor shaft turn, first, one electromagnet is given power, which magnetically attracts the gear’s teeth. When the gear’s teeth are aligned to the first electromagnet, they are slightly offset from the next electromagnet.

This means that when the next electromagnet is turned on and the first is turned off, the gear rotates slightly to align with the next one. From there the process is repeated. Stepper motor for sale effectively has multiple “toothed” electromagnets arranged around a central gear-shaped piece of iron. The electromagnets are energized by an external driver circuit or a micro controller. Each of those rotations is called a “step”, with an integer number of steps making a full rotation. In that way, the motor can be turned by a precise angle. Motion Control, in electronic terms, means to accurately control the movement of an object based on either speed, distance, load, inertia or a combination of all these factors. There are numerous types of motion control systems, including; Stepper Motor, Linear Step Motor, DC Brush, Brushless, Servo, Brushless Servo and more.

Dual Shaft Nema 34 CNC Stepper Motor 8.5Nm (34HS46-5004D) 5A 86x114mmThis document will concentrate on Step Motor technology. Permanent magnet and hybrid stepper motors are two types of the most commonly used stepper motors. Sometimes, it’s difficult to know which type of stepper motor is the best choice for your project. For this reason, we have provided detailed information to help engineers determine the best motor for their application requirements. Follow our convenient step motor guide to learn the basics of hybrid stepper motor engineering and find out why this type of motor can be so beneficial to your project. Typically, step angles for a hybrid stepper motor range from 200 to 400 steps per revolution. This type of motor provides a combination of the best features available on both the PM and VR types of stepper motors.

A motor that has known detent positions where the rotor will stop with the proper control in some cases. The digitally controlled motor moves the head positioner from track to track in small, step-like motions. And the hybrid stepper motor provides excellent performance in areas of torque, speed, and step resolution. The word Hybrid means combination or mixture. The shaft of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence. HB Stepper motors are the easiest devices for precise positioning control. They are widely being used in various applications for position and speed via all kinds of control signals such as digital, analog, communication etc. HB motors come in different types including the basic type, encoder type, IP65 type, Integrated type with drive and controller, brake type and geared type.

Working of a Variable Reluctance Stepper Motor

A four phase or (4/2 pole), single stack variable reluctance stepper motor is shown below. Here, (4/2 pole) means that the stator has four poles and the rotor has two poles.


Variable Reluctance Stepper Motor fig 1

The four phases A, B, C and D are connected to the DC source with the help of a semiconductor, switches SA, SB, SC and SD respectively as shown in the above figure. The phase windings of the stator are energized in the sequence A, B, C, D, A. The rotor aligns itself with the axis of phase A as the winding A is energized. The rotor is stable in this position and cannot move until phase A is de-energized.

Now, the phase B is excited and phase A is disconnected. The rotor moves 90 degrees in the clockwise direction to align with the resultant air gap field which lies along the axis of phase B. Similarly the phase C is energized, and the phase B is disconnected, and the rotor moves again in 90 degrees to align itself with the axis of the phase

Thus, as the Phases are excited in the order as A, B, C, D, A, the rotor moves 90 degrees at each transition step in the clockwise direction. The rotor completes one revolution in 4 steps. The direction of the rotation depends on the sequence of switching the phase and does not depend on the direction of the current flowing through the phase. Thus, the direction can be reversed by changing the phase sequence like A, D, C, B, A.

The magnitude of the step angle of the variable reluctance motor is given as




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