How does a stepper motor work?
How does a robotic arm in a manufacturing
facility repeat the exact same movements over and over?
How does an automated milling machine move
with such precision?
It`s all because of the stepper motor.
What`s special about the stepper motor is
that it can control the angular position of the rotor without a closed
feedback. It is a simple accurate and open-loop system.
Let`s first understand how the variable
reluctance type of stepper motor works. Which is the simplest one late on we
will move to a highly accurate and commonly used motor type.
This motor has six stator teeth and can be
energized with three separate DC power sources. The rotor is made of a stack of
steel laminations, it has a different number of teeth than the rotor for in
this case. This is done intentionally so that only one pair of rotor teeth is
aligned with the stator at a time.
If you de-energize coil A and energize B,
it becomes clear that the rotor will rotate as shown from the geometry. It is
clear that the one step size is 30 degrees to get the next step the energized
coil B and energized C. After that coil A becomes energized again in short the
rotor moves to the position with the least reluctance, the step size of this
motor is 30 degrees, you can improve the accuracy to 15 degrees with a small
trick.
If you have any questions about motor, feel free to contact Gold Crown Micromotor, we are 24 hours online to support you.