Patents by Inventor Keith Van Patten

Keith Van Patten 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).

  • Patent number: 5319295
    Abstract: A digital current regulator for controlling the operation of an inductance device such as an AC motor. A plurality of independently controllable insulated gate bipolar transistors are selectively enabled to vary the instantaneous phase and magnitude of current applied to an AC motor. To minimize induced back EMFs during current switching operations, a number of safeguards are utilized. Switching between adjacent states only is provided to minimize the magnitude of instantaneous current changes. A "ready blocking" function limits the maximum switching frequency to avoid significantly derating the switching device capabilities, while a "time out" feature assures system operation above at least a minimum switching frequency to further minimize the magnitude of instantaneous current changes. A time hysteresis function is provided to avoid switching device response to false feedback control signals.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: June 7, 1994
    Assignee: Unico, Inc.
    Inventors: Keith Van Patten, William S. Hammel, Ramdas M. Pai