Patents by Inventor Per Ingvar M. Back

Per Ingvar M. Back has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method and apparatus for controlling the magnitude and direction of a current through a winding
    Patent number: 4908562
    Abstract: The invention relates to a method and a controlling apparatus for controlling the magnitude and direction of a current (I) through a winding (L). The method and controlling apparatus are based on a drive circuit (TR.sub.1, D.sub.1, TR.sub.2, D.sub.2, TR.sub.3, D.sub.3, TR.sub.4, D.sub.4) which is controllable such as to enter into three different types of operational state. In a first type of operational state the current is normally increasing in magnitude. In a second type of operational state the current is normally decreasing in magnitude comparatively slowly. In a third type of operational state the current magnitude is normally decreased comparatively rapidly.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: March 13, 1990
    Assignee: Telefonaktiebolaget L M Ericsson
    Inventor: Per Ingvar M. Back