Patents by Inventor John P. Andersen

John P. Andersen 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).

  • Automatic transfer switch
    Patent number: 5070252
    Abstract: An automatic transfer switch having two sets of phase switches, one set for connection between a normal source of power and a load, and the other set for connection between an emergency power source and the load. The transfer switch includes two pairs of neutral switches, one pair for connection in parallel between the normal source neutral and the load neutral, and the other pair for connection in parallel between the emergency source neutral and the load neutral. The phase switches can operate to provide an "open transition" transfer, wherein the phase switches connecting the load to one source open before closing of the phase switches which connect the load to the other source, or a "closed transition" transfer, wherein the phase switches connecting the load to one source open after closing of the phase switches which connect the load to the other source.
    Type: Grant
    Filed: April 3, 1990
    Date of Patent: December 3, 1991
    Assignee: Automatic Switch Company
    Inventors: Rene Castenschiold, John P. Andersen