Patents by Inventor Tom Roche

Tom Roche 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).

  • Weighted transducer and driving circuit with feedback
    Patent number: 5181019
    Abstract: A sound generating device which increases the effectiveness of the sound generated by mechanically coupling a weight to a piezoelectric element. This sound generating device may find particular application in a combination backup light and sound generating device utilized in an automotive vehicle. Also, circuitry for driving a piezoelectric element at its resonant frequency when the driving signal is applied to the piezoelectric element across a step-up transformer. The circuitry features a feedback signal which detects the frequency at which the piezoelectric element is vibrating. This feedback signal is then subjected to low-pass and high-pass filtering to remove any phase shifts resulting from applying the driving signal across the step-up transformer. This filtered feedback signal is then utilized to control the driving signal.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: January 19, 1993
    Assignee: Designtech International, Inc.
    Inventors: Mark Gottlieb, Tom Roche