Other Stepper Motors
Other Stepper Motors

There are two stages to sorting out which wire is which in a 5- or 6-wire unipolar stepper motor:

  1. Isolate the Common Power wire(s) by using an ohmmeter to check the resistances between pairs of wires. The Common Power wire will be the one with only half as much resistance between it and all the others.

     coils

    This is because the Common Power wire only has one coil between it and each other wire, whereas each of the other wires have two coils between them. Hence half the resistance.

  2. Identify the wires to the coils by supplying a voltage on the Common Power wire(s) and keeping one of the other wires grounded while grounding each of the remaining three wires in turn and observing the results.

    Select one wire and ground it

    Assume it's connected to coil 4

    Keeping it grounded, ground each of the other three wires one by one
    Grounding one wire should make the rotor turn a little clockwise

    That'll be the wire connected to Coil 3

    Grounding one wire should make the rotor turn a little anticlockwise

    That'll be the wire connected to Coil 1

    Grounding one wire should do nothing

    That'll be the wire connected to Coil 2

    Note:
    The numbering of the coils as above is purely arbitrary - it's the order they are in that's important.

Now you just need to generate the stepping sequences

 Examples

  Stepper Motors Index  

last updated: 10-Sep-98 Ian Harries <ih@doc.ic.ac.uk>