Autonom robotväckarklocka med trådlös basstation - KTH

Abstract
Annie Gustafsson, M-08 KTH
Fördjupningsarbete i Mekatronik MF106X
This report shows the stepper motors function and their uses. It explains the
differences and similarities between different stepper motors. A permanent magnet
stepper motor can handle high torque and are well damped however not optimal for
high speeds. The variable reluctance stepper motor are good to use at high speeds but
not if the moment is to high. There are also hybrid stepper motors that combine the
best features from the previously mentioned stepper motors, it can handle high speeds
and relatively high torque.
In the report there are also explained a few different ways of making the motor step
forward for example there is full step drive, halfstepping and microstepping. Full step
drive corresponds to the movement of the rotor when a new set of coil windings is
activated. Halfstepping means that the steps will be half the size compared to full step
drive, this because two coil windings can be activated at the same time and then only
one of them. Using microstepping the motor takes even smaller steps and it occurs
when current in the coil windings changes a little bit at the time, the idea is to
approximate a sinusoidal AC waveform.
The report also describes a way to making this practical. A bipolar hybrid stepper
motor, sonceboz model 6540-13-2-9, and two H-bridges, A3953SB-T, are put
together and the H-bridges will control the current flow.
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