Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!noc.near.net!howland.reston.ans.net!wupost!csus.edu!netcom.com!carice
From: carice@netcom.com (Chuck Rice)
Subject: Stepper motor wiring
Message-ID: <cariceC84BK4.DyE@netcom.com>
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Date: Fri, 4 Jun 1993 22:24:03 GMT
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While waiting for my Miniboard (thanks for the status Greg)
I decided to begin gathering other parts to play with till it
arrives. I dropped by the Weird Stuff Warehouse and found several
Stepper Motors. I bought four (two pair) for $3 a piece.
Unfortunately, there is no doc on them.

One type has 4 wires and the other has 5 wires. The 4 wire motor
says that it is an Astrosyn stepper, 12 volt 75 ohm, 17bb-h132-11
made by Minebea Co.,LTD. It is sealed shut so I could not open it
without trashing it.  I hooked it up to an ohm meter and discovered
that there appears to be two separate circuits. Then I tried
attaching two wires to a nine volt battery and the motor turned a
step. I tried the other two wires and it turned back a step. From
this I surmised that to get this motor to turn, I will have to send
the following signals:

        +        -      +        -     \
        +        -      -        +      \  Repeate thes signals
        -        +      -        +      /  over and over?
        -        +      +        -     /

        o        b      r        y     <--- The four motor wire colors
        |        |      |        |
        |        |      |        |
        |        |      |        |
        +-666666-+      +-666666-+
          coil-1          coil-2


Is this correct? If so does this mean that I will need to use 2 of
the available four motor driver circuits an the miniboard for each
motor? 

The other motor has even fewer markings on it. It says that it is a
Type KP4MA-029 P/N 1298216 E/C 775551F made by Japan Servo Co. (It
was sold as a stepper, but junk parts are often mislabeled.) It has
5 wires on it. Black, Red, Tan, Green, and White. Its case is held
together by four screws, so I opened it up for a look see (bad
habit that I have had since I was a child --- love to take things
apart). The wires go into the coil in two places. The Black and Tan
wires were together on one side and the other three were on the
other. Put it back together and got the following from my ohm
meter:

        B-R - 76 ohm
        B-T - 76 ohm
        B-G - 74 ohm
        B-W - 77 ohm
        R-T - 153 ohm
        R-G - 151 ohm
        R-W - 153 ohm
        T-G - 151 ohm
        T-W - 153 ohm
        G-W - 151 ohm

From this, I would guess that it is hooked up something like:


        B-------+---666666-----R
                |   Coil-1
                |
                +---666666-----T
                |   Coil-2
                |
                +---666666-----G
                |   Coil-3
                |
                +---666666-----W
                    Coil-4

Experimenting with my 9-volt battery with one terminal connected to
Black and touching R,T,G, and W in sequence caused it to step
though it would miss sometimes. Does this sound right? Does this
mean that I will need all 4 motor drivers for one motor?

Sorry if these are basic questions, I searched a lot of places for
info on steppers, but I must not be looking in the right ones. I
even went by Computer Literacy but only found a couple of books
with minimal references. Although I started off as an EE-wanabee,
some fool taught me how to write a program and I got sidetracked
for 15 years. Trying to get my feet wet again. Any help would be
appreciated. -Chuck-



