🚀 go-pugleaf

In article <AZvKRje00WBLQ1zFUy@andrew.cmu.edu> tf0z+@andrew.cmu.edu (Todd Andrew Ferrante) writes:
>I have a number of small stepper motors I want to use for a robotics
>project.

SGS-Thompson's "Industrial and Computer Peripheral IC's" databook describes
such a beast. Their rep in NY is at (516) 935-3200.

Four-wire stepper motors are not hard to use ! First, take a beeper to find
which 2 windings are 'paired' ( There are 2 separate windings). I'll describe
how to make it turn. Call one set of windings A-B; the other C-D. For brevity,
the term 'AB' means that wire 'A' is at (say) + 5 volts, and 'B' is 0. 'BA'
means 'B' is at +5 and 'A' is 0. Here we go !!!!

	The pattern is AB,CD,BA,DC,AB,CD,BA,DC.... If, perchance the motor
just vibrates, one winding is open. To reverse rotation, apply :

	AB,DC,BA,CD,AB,DC,BA,CD  (ie, reverse the pattern)

	This gives coarse stepping. You can get smoother stepping by using
more sophisticated patterns which energize both windings simulataneously
and use 1/2 current, etc.

NOTE, NOTE, NOTE : If you concoct discrete drivers, USE REVERSE-BIASED DIODES
to conduct-away the inductive energy. It WILL destroy your transistors. Enjoy!