Patents Assigned to Smith-Johannsen Enterprises
  • Self limiting electric heating element and method for making such an element
    Patent number: 5057674
    Abstract: This invention relates to a self-limiting electrical heating element comprising resistance components having a positive temperature coefficient and a zero temperature coefficient, arranged in a layered structure with two electrodes placed diagonally within or in contact with two ZTC layers separated by a PTC layer.
    Type: Grant
    Filed: August 8, 1990
    Date of Patent: October 15, 1991
    Assignee: Smith-Johannsen Enterprises
    Inventor: Robert Smith-Johannsen