Patents by Inventor Barrett Karr

Barrett Karr 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: 5170087
    Abstract: An electronic circuit for a contactless, piezoelectric switch assembly. The piezoelectric switch assembly includes a piezoelectric module which generates voltages under manual pressure and electronic circuit operative to perform a predetermined switch function upon receipt of these electrical signals. The electronic circuit performs a variety of switching functions, such as: toggle on and off; dimmer setting; momentary on. The sensing means of the electronic circuit is coupled to the piezoelectric module via a reference voltage and a negative current source that pulls one terminal of the piezoelectric module toward the reference voltage. A slew rate limited buffer amplifier drives a comparator with hysteresis achieved by changing the comparison voltage. This hysteresis serves to reduce detection of jitter and noise in the initial application of pressure.
    Type: Grant
    Filed: August 26, 1991
    Date of Patent: December 8, 1992
    Assignee: Touch Tec International
    Inventors: Barrett Karr, Thomas Walker