The most common style of stepper motors used today have permanent magnets. These magnets are always "pulling" and will try to orient the rotor to one of the 50 pole positions even when the stator coils are not energized.
When the two coils of the stator are energized, the poles of the rotor orient to the peak magnetic field of the mating polarity generated by the coils. This peak field can be in one of 4 locations based on the polarity of the current in each of the two coils. If the current in the coils is varied with respect to each other, the peak can be moved part way between the normal locations. This is how "microstepping" works. A good description in more detail can be found at: http://www.hsi-inc.com/ResourcesandDownloads/StepperMotorTheory/tabid/192/De fault.aspx Steve Stallings > -----Original Message----- > From: Andy Pugh [mailto:a...@andypugh.fsnet.co.uk] <snip> > > Presumably because the poles retain the magnetic polarity > from last time they were energised? > > -- > atp > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
