Patents Assigned to Touch Tec International
  • 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
  • Patent number: 5142183
    Abstract: A piezoelectric switch assembly and method of manufacture. A piezoelectric module is provided which is comprised of a carrier disk and a wafer of piezoelectric material disposed thereon, with electrical leads connected thereto. The piezoelectric module is disposed inside a hollow recess formed in a switch plug, with the periphery of the carrier disk supported on a rim thereof. A disk of compressible material is disposed between the body of the plug and the piezoelectric module. The switch plug is inserted into a hollow chamber formed in a switch insert, said switch insert having a pressure receiving front wall. A front member is provided which is formed with an aperture for receiving the switch insert. Pressure on the pressure receiving front wall of the socket causes deformation of the piezoelectric wafer to generate an electrical signal which is received by circuitry attached to the electrical leads to effect one or more preselected switch functions.
    Type: Grant
    Filed: August 26, 1991
    Date of Patent: August 25, 1992
    Assignee: Touch Tec International
    Inventors: James P. Burgess, Thomas Walker