Patents by Inventor Robert E. Schrader

Robert E. Schrader 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).

  • Print hammer coil current control
    Patent number: 5429442
    Abstract: A low cost, integrated circuit compatible, circuit for constantly controlling the current in a print hammer coil is provided. The circuit is suitable for use with a hammer coil driven from the low voltage side (bottom drive) and in series with a sense resistor. A programmable reference that actively compensates the coil current for drift in the hammer coil bias power supply reference generating means is included to allow accurate detection of coil current levels. The control circuit reduces generated noise and has good noise immunity.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: July 4, 1995
    Assignee: International Business Machines Corp.
    Inventor: Robert E. Schrader