Patents Examined by G. Dobeck
  • Patent number: 4028598
    Abstract: A DC motor having a permanent magnet rotor and two Hall effect elements relatively displaced 90.degree. for switching the currents in the stator windings as a function of the rotor position. The stator includes at least two windings. An output transistor for each winding controls the current flow therein and the base currents thereof are supplied from a common source of constant current. First and second control transistors have their base electrodes connected to the output terminals of the Hall elements and their output electrodes coupled to the base electrodes of the output transistors. In any position of the rotor only one output transistor can conduct and each winding can be fully energized at most over an angle of 120.degree..
    Type: Grant
    Filed: January 7, 1974
    Date of Patent: June 7, 1977
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik Jan Bergmans