Method of Testing a Bifilar-Wound Permanent Magnet Step Motor
Original Publication Date: 1984-Aug-01
Included in the Prior Art Database: 2005-Feb-04
A four-phase permanent magnet step motor has windings 10 and 11 wound in opposite directions on a first bobbin and windings 12 and 13 wound in opposite directions on a second bobbin. Neither bobbin has significant mutual coupling with the other. The four phases are produced by utilizing a switching arrangement to connect the windings 10 and 12, the windings 12 and 11, the windings 11 and 13, and the windings 13 and 10 in sequence. This continuously changes the polarity to cause the rotation of the motor in steps. To detect if there is a short circuit between the windings 10 and 11 or between the windings 12 and 13, a connection 14 is made between the junction of the windings 10 and 12 and the junction of the windings 11 and 13.