Patents Assigned to ETA SA Fabriques d'Ebaches
  • Method of controlling a bi-directional stepping motor and a bi-directional stepping motor adapted to be controlled by this method
    Patent number: 5028857
    Abstract: A method for improving the efficiency of a stepping motor (1) comprising a rotor (15) having a permanent magnet (16) producing a first magnetic field, as well as a first coil (13) and a second coil (14) for supplying to the magnet (16) respectively a second magnetic field (18) and a third magnetic field (19) symmetrical to one another in relation to an axis of symmetry (7) intersecting the axis of rotation (15a) of the rotor (15).
    Type: Grant
    Filed: May 10, 1989
    Date of Patent: July 2, 1991
    Assignee: ETA SA Fabriques d'Ebaches
    Inventor: Daho Taghezout