Patents Represented by Attorney Frederick W. Powers, II
  • Patent number: 4201938
    Abstract: A tap changer voltage regulator permits a tap changer switch selector contact to engage an open circuited new tap without arcing and has a half-tap voltage auxiliary winding which permits halving the voltage being interrupted and doubling the number of steps and also has an auxiliary switch with a first movable contact which initially connects the selector contact on the new tap in series with a circulating current limiting inductor and the load to prevent load circuit interruption and is provided with a second movable contact in series with a pair of normally closed contacts through which flow the load current and the current which circulates while the selector contacts bridge adjacent taps during the tap change. The normally closed contacts are shunted by a pair of inverse parallel thyristors.
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: May 6, 1980
    Assignee: Siemens-Allis, Inc.
    Inventor: Manfred E. Neumann