A stepper motor is an electromechanical device which converts electrical pulses into discrete mechanical movements. The shaft of a stepper motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence.
Stepper motors are the easiest devices for precise positioning control. They are wildly being used in various application for position and speed via all kinds of control signals such as digital, analog, communication etc.
Features
Precise Positioning Control
A stepper motor rotates with a fixed step angle, just like the second hand of a clock. This angle is called “basic step angle.” MOONS’ offers several types of “basic step angle” as standard motors: 2-phase stepping motors with a basic step angle of 0.9° and 1.8° and 3-phase stepping motors with a basic step angle of 1.2°.
Besides the standard motor, MOONS’ also has stepper motors available with other “basic step angle.” They are 0.72°, 1.5°, 3.6° and 3.75°, these motors are not listed in this catalogue, please contact MOONS’ for details.
Easy Control with Pulse Signals
A system configuration for high accuracy positioning is shown below. The rotation angle and speed of the stepping motor can be controlled accurately using pulse signals from the controller.
What is a Pulse Signal?
A pulse signal is an electrical signal whose voltage level changes repeatedly between ON and OFF. Each ON/OFF cycle is counted as one pulse. A command with one pulse causes the motor output shaft to turn by one step.
The signal levels corresponding to voltage ON and OFF conditions are referred to as “H” and “L,” respectively.
The length of Rotation is Proportional to the Number of Pulses
The length of rotation of the stepping motor is proportional to the
number of pulse signal (pulse number) given to the driver.
The relationship of the stepper motor’s rotation (rotation angle of the
motor output shaft) and pulse number is expressed as follows:
θ =θs X A
θ: Rotation angle of the motor output shaft [deg]
θs : Step angle [deg/step]
A : Pulse number [pulses]
The Speed is Proportional to the Pulse Frequency
The speed of the stepper motor is proportional to the frequency of
pulse signals given to the driver.
The relationship of the pulse frequency [Hz] and motor speed [r/min]
is expressed as follows:
N＝ 60θsf/360
N : Speed of the motor output shaft [r/min]
θs : Step angle [deg/step]
f : Pulse frequency [Hz]
(Number of pulses input per second)
Generating High Torque with a Compact Size
Stepper motors generate high torque with a compact size. These features give them excellent acceleration and response, which in turn makes these motors well-suited for torque-demanding applications where the motor must be started and stopped frequently.
To meet the need for greater torque at low speed, MOONS’ also has geared motors option.
The Motor Holds Itself at a Stopped Position
Stepper motor has full torque at stand-still as long as the windings are energized. This means that the motor can be held at a stopped position without using a mechanical brake.
Motor with Electromagnetic Brake
Once the power is cut off, the self-holding torque of the motor is lost and the motor can no longer be held at the stopped position in vertical operations or when an external force is applied. In lift and similar applications, an electromagnetic brake type motor is required.
Closed Loop Servo Control Stepper Motors
The Step-Servo is an innovative revolution for the world of
stepping motor, it enhances the stepping motor with servo
technology to create a product with exceptional feature and
broad capability.
The Step-Servo greatly improves the performance to be much
more Intelligent, Efficient, Compact, Accurate, Fast and
Smooth.
