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Advantages of stepper motors:
i) They can be directly controlled by computers, micro-processors and
programmable controllers.
ii) Precision control of speed without using closed loop feedback.
Applications:
i) Operation control:
Such motors used for operational control in computer peripherals, textile
industries, IC fabrications and robotics etc.
ii) Incremental motion:
Applications requiring incremental motion are typewriters, line printers, tapedrivers,
floppy disk drivers, numerically controlled machine tools, process-control
systems and X-Y plotters.
Others:
It includes commercial, military and medical applications where these motors
perform functions as mixing, cutting, striking, metering, blending and purging.
They also take part in manufacture of packed food stuffs, commercial endproducts
and even the production of science fiction movies.
Permanent Magnet Stepper motor:
It has wound stator poles and permanently magnetized rotor poles. It has a
cylindrical rotor. Its direction of rotation depends on the polarity of stator current.
The stator has projecting poles. Rotor has 2 poles whereas stator has 4 poles and
the two stator poles are energized by one winding, the motor has two windings or
phases.
Working :
When a particular stator phase is energized, the rotor magnetic poles move into
alignment with excited stator poles. The stator wdgs. A and B can be excited with
either polarity current (A+ refers to the +ve current i+
A in phase A and A- to
negative current (i-
A). Fig, shows condition when phase A is excited with the
current i+
A. Here = 0o. If excitation is now switched to phase B, the rotor rotates
by a full step of 90o clockwise direction. When phase A is excited with –ve
current i-
A, the rotor turns through another 90o in clockwise direction. Similarly
excitation of phase B with i+
B further turns rotor through another 90o in same
direction. After this excitation of phase A with i+
A makes rotor run through one
complete revolution of 360o.
gregorymasila answered the question on February 22, 2018 at 16:50
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