His motor has 6 wires (unipolar) but he is only using 4 so he still has to energize two windings at all times.
http://www.nmbtc.com/pdf/motors/17PM-K.pdf
I looked at the attached datasheet and I couldn't find any stepper motor application examples in the datasheet.
@Robin2,
I'm having a hard time wrapping my head around the idea of driving a stepper motor by reversing coil polarity. Perhaps because I am only looking at the electronics and not the magnetics. Is the principle that by reversing polarity the motor will turn by magnetic repulsion as opposed to attraction or vice versa ? I thought that a stepper motor could only work by attraction.
LMD18200.pdf (338 KB)