At 18:02 1998-03-15 +0000, you wrote:
>Hi folks!
>
>Having got myself a step motor from an old
>printer, I have identified that it has 2 split
>coils and now I need to know the sequence in which
>the coils need to be energized to rotate the
>motors in one direction and in the other. Is there
>a standard way of doing it?
>
>I would be grateful if you can enlighten me on how
>to do it.
>
>I'm using a non-inverting driver (L293D) and a PIC
>16C84.
>
>Francesco Cembrola
>
Briefly:

BIPOLAR DRIVE:
For bipolar drive igneore center taps
C1: coil 1; C2 = Coil 2
Each coil driven by H stage
+ = positive current, - = neg current

Step    Coil(s) and polarity
 1      C1+
 2      C1+ & C2+
 3      C2+
 4      C2+ & C1-
 5      C1-
 6      C1- & C2-
 7      C2-
 8      C2- & C1+

Use every step to do half step
Odd numbers to do full step low power
Even numbers to do full step double power


UNIPOLAR DRIVE:
Connect each coil center to plus
C1A: Coil 1 one end
C1B: Coil 1 other end
C2A: Coil 2 one end
C2B: Coil 2 other end

Step    Connections grounded
 1      C1A
 2      C1A & C2A
 3      C2A
 4      C2A & C1B
 5      C1B
 6      C1B & C2B
 7      C2B
 8      C2B & C1A

Use every step to do half step
Odd numbers to do full step low power
Even numbers to do full step double power



If you first do not get it to work, try to swap ends of one of the coils.
To reverse swap both coils ends.

/Morgan
/  Morgan Olsson, MORGANS REGLERTEKNIK, SE-277 35 KIVIK, Sweden \
\  mrt@iname.com, ph: +46 (0)414 70741; fax +46 (0)414 70331    /