Understanding the Types of Stepper Motors

What is a Stepper Motor?

A stepper motor can be an electromechanical device which turns electro-mechanical pulses into discrete mechanical motions. The spindle or shaft of the stepper motor rotates in discrete step increments when electrical control pulses are put on it in the proper series. The motor's rotation has numerous direct associations to these applied type pulses. The series of the applied pulses is straightforwardly related to the path of electric motor unit shafts rotation. The acceleration of the motor unit shafts rotation is immediately relevant to the rate of recurrence of the type pulses, and the amount of rotation is straightaway related to the number of source pulses applied.

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Types of a Stepper Motor

The three basic types of Stepper Motors are:

1. Variable reluctance
2. Permanent magnet
3. Hybrid

Variable-reluctance (VR)

This sort of stepper motor has been around for an extended period of time. It really is probably the easiest to comprehend from a structural perspective. This kind of motor includes a soft flat iron, multi-toothed rotor, and a wound stator. Once the stator windings are energized with DC (direct current) the poles, they become magnetized. Rotation occurs when the rotor teeth are drawn to the energized stator poles.

Permanent Magnet (PM)

Permanent Magnet (PM) is also known as a "tin can" or "can stock" stepper motor unit. The permanent magnet step motor is an inexpensive and low-resolution type step motor unit with precise step angles of 7.5° to 15°. As the name implies, PM step motors have permanent magnets put into the motor framework. The rotor no more has teeth much like the VR stepper motors. Instead, the rotor is magnetized with the alternating south and north poles located in straight lines, parallel to the rotor shaft. These magnetized rotor poles offer an increased magnetic flux strength, and as a result of this, the PM step motor unit exhibits improved torque features when weighed against the VR type.

Hybrid (HB)

The hybrid type stepper motor is more expensive than the PM stepper motor but provides better performance with added value to step resolution, torque, and acceleration. The unique measure angles for the HB stepper motor range between 3.6° to 0.9° (100 - 400 steps per revolution. The hybrid type stepper motor syndicates with the best and the top features of both the PM and VR types of stepper motors. The rotor is multi-toothed like the VR motor unit and consists of an axially magnetized concentric magnet around its shaft. The teeth on the rotor offer an even better route which helps guide the magnetic flux to preferred locations in the air gap. This further escalates the detent, positioning and dynamic torque features of the electric motor when compared with both PM and VR types.

The two most used types of stepper motors are a permanent magnet and the hybrid types of stepper motors. In case a designer is uncertain which kind will best fit his applications requirements he should first check out the PM type as it is several times less costly. If not then your hybrid motor unit may be a good choice.

Shiva Kushwaha is a lead blog writer, blogger & content marketer, he publishes and manage the contents on many blogs. Shiva writes about lifestyle, technology, travel, health and more.