Patents by Inventor Louis Chi Hoi Cheng

Louis Chi Hoi Cheng 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).

  • Mimic high pass filter in a protective relay
    Patent number: 6473723
    Abstract: A mimic filter which can be implemented in analog or digital circuitry, and which removes dc offset or other noise from an input signal using a pseudo-differentiation technique. The input signal is adjusted by a feedback value, and the adjusted signal is amplified by a proportional gain factor to generate an output signal. The feedback value is determined by integrating the output signal and multiplying the integration by an integration gain factor. The mimic filter avoids the generation of false signal spikes.
    Type: Grant
    Filed: March 17, 1999
    Date of Patent: October 29, 2002
    Assignee: General Electric Company
    Inventor: Louis Chi Hoi Cheng