Introduction and working of stepper motors

2.  A stepper motor is an electromechanical
device which converts electronic pulses into
mechanical movements.
 The shaft or spindle of a stepper motor
rotates indiscrete step increments when
electrical command pulses are applied to it in
the proper sequence.
 The motor’s rotation has several direct
relationships to these applied input pulses.

3.  There are three basic types of stepper motors
 Variable-Reluctance motors
 Permanent Magnet Motors
 Hybrid Motors
Construction Of variable reluctance motor

4. Permanent magnet
stepper motor
Hybrid stepper
motor

5.  A stepper motor can be a good choice
whenever controlled movements is required.
These motors can be used as advantages in
applications where you need to control
rotation angle, speed, position and
synchronism.
 Because of inherent advantages listed,
stepper motor has its own very advantageous
applications.

6.  These are the constant power5 devices
 Torque decreases as in the increase in the
speed
 Exhibits more vibrations than the other
motors
 Vibrations can be very bad at some speeds
which can cause to loose the torque

7.  When a phase wiring of a stepper motor is
energized with current, a magnetic flux is
developed in the stator. The direction of this
flux is determined by the “Right Hand Rule”

8.  Excellent response to
starting/stopping/reversing
 It is possible to achieve very low speed
synchronous rotation with a load that is
directly coupled to the shaft
 The motor response to the digital input
pulses provide open-loop control, making the
motor simpler and less costly to control.
 Motor has full torque at stand-still

9.  Resonance can occur if not properly
controlled
 Not easy to operate at high speeds

10.  Used in closed loop servo systems
 Multi-axis lathe machines
 Use for precession positioning equipments
like linear actuators, linear stages, rotation
stages
 Used in floppy disk drives, flatbed scanners,
computer printers, plotters and slot machines
 In some places, it is used in generators in
homemade wind turbines for generating
electricity

11.  THANKYOU…….