Patents by Inventor David A. Schaffner

David A. Schaffner 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).

  • Single level D.C. output voltage power supply
    Patent number: 4864488
    Abstract: A power supply for producing a single level D.C. output voltage in response to a 110 or 220 A.C. input voltage is disclosed. The power supply automatically selects a full wave diode bridge or voltage doubler configuration and provides series capacitors to filter the D.C. output voltage. The selection is controlled by a switch which responds to the charge on one of the output capacitors. Latching means are also provided to prevent the power supply from switching to the voltage doubler configuration once 220 volts is applied.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: September 5, 1989
    Assignee: NCR Corporation
    Inventors: David J. Bulmahn, David A. Schaffner