Patents by Inventor Henry G. Ansell

Henry G. Ansell 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).

  • Tristate phase-lock loop prevents false lock
    Patent number: 4712077
    Abstract: A phase-lock loop includes a tristate phase detector, a filter and a voltage-controlled oscillator connected in a loop for regenerating clock signals in response to a sequence of data signals applied to the input terminal of the tristate phase detector and the loop. The tristate phase detector opens its output lead whenever a zero is applied to the input terminal of the loop. A resistor is interposed between the tristate phase detector and the loop filter to clamp excursions of a control signal, causing the filter to produce a consistent tuning control signal and forcing the voltage-controlled oscillator to oscillate at a frequency within a preselected frequency range independent of the ones density in the digital sequence applied to the input terminal of the loop.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: December 8, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Bell Labs
    Inventors: Henry G. Ansell, Jeffrey H. Saunders