TREA

Stephen P. Johnston

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  • Detroit Lakes, MN, US
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Patents Grantslast 30 patents

  • Information Patent Grant

    Sphere-actuated float switch
    • Patent number 5,142,108
    • Issue date Aug 25, 1992
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS
  • Information Patent Grant

    Sphere-actuated float switch
    • Patent number 5,087,801
    • Issue date Feb 11, 1992
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS
  • Information Patent Grant

    Alternator circuit arrangement useful in liquid level control system
    • Patent number 4,652,802
    • Issue date Mar 24, 1987
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • G05 - CONTROLLING REGULATING
  • Information Patent Grant

    Mercury switch
    • Patent number 4,572,934
    • Issue date Feb 25, 1986
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS
  • Information Patent Grant

    Mercury switch
    • Patent number 4,529,854
    • Issue date Jul 16, 1985
    • S. J. Electro Systems Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS
  • Information Patent Grant

    Float switches with wide differential
    • Patent number 4,302,641
    • Issue date Nov 24, 1981
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS
  • Information Patent Grant

    Electrical load control circuit useful in liquid level control systems
    • Patent number 4,291,261
    • Issue date Sep 22, 1981
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • G05 - CONTROLLING REGULATING
  • Information Patent Grant

    Float switch
    • Patent number 4,262,216
    • Issue date Apr 14, 1981
    • S.J. Electro Systems, Inc.
    • Stephen P. Johnston
    • H01 - BASIC ELECTRIC ELEMENTS