Armature Control Patents (Class 388/853)
By voltage or current modification (Class 388/854)
By selectable or variable impedance (Class 388/855)
  • Speed control arrangements for electric motors
    Patent number: 5387856
    Abstract: In a speed control arrangement for an induction motor or an a.c. permanent magnet motor in which any one of a number of power frequencies may be selected for application to the motor, there is provided circuitry to control the rate of change of frequency from one selected power frequency to another to control the acceleration or deceleration of the motor.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: February 7, 1995
    Assignee: Plessey SemiConductors Limited
    Inventor: David P. Gilbert