Company History


A Timeline of SJE’s History

Over 40 years of excellence

  • 1970s

  • 1975
    Stephen P. Johnston registers Electro Systems as a business and begins production of the Tank Alert alarm system in his garage.

    steve johnson booth 1976
    Steve Johnson showing off his products at a tradeshow in 1976.
  • 1977
    The business is incorporated and renamed S.J. Electro Systems, Inc.
  • 197
    SJE’s first employee is hired.

    sj electro building 1980
    The old SJ Electro headquarters building outside Detroit Lakes, MN, in 1980.
  • 1980s

  • 1980
    An addition is built that doubles the size of the facility.
  • 1981
    Five employees are active at S.J. Electro Systems, Inc. An addition of 44′ x 74′ is added to the existing building.

    tank alert alarm 1983.
    The original version of our Tank Alert® Alarm circa 1983.
  • 1984-1986
    S.J. Electro Systems, Inc. makes INC magazine’s list of the “500 fastest growing privately held companies in the nation” three years running.
  • 1987
    S.J. Electro Systems Board of Directors adopts an Employee Stock Ownership Plan (ESOP).

    new building 1988
    Construction on the new building, which is located adjacent to the old one, began in 1988.
  • 1988
    A new building! S.J. Electro Systems, Inc. completes and occupies a new 30,000 square foot pre-cast concrete manufacturing building.

    rhombus technoloy 1992
    SJ Electro added a new product line and acquired Rhombus Technology in 1992.
  • 1990s

  • 1992
    S.J. Electro Systems, Inc. adds a new product line and establishes expertise in designing and manufacturing control panels (Rhombus Technology).
  • 1994
    Founder Stephen P. Johnston retires as CEO of SJE. Lois Solheim is named the new CEO.
  • 1997
    S.J. Electro Systems, Inc. begins doing business as SJE Rhombus.

    sje rhombus 1998
    In 1998 SJE becomes 100% employee owned and expands the headquarters building.
  • 1998
    SJE Rhombus becomes 100% employee-owned and 33,000 sq. ft. was added to the existing manufacturing building. Lois Solheim retires as CEO. Laurie Lewandowski is named the new CEO.
  • 2000s

  • 2002
    SJE Rhombus acquires Tamarack Engineering, an embedded controls engineering firm located near Minneapolis, MN.

    embedded controls 2004
    The embedded controls team began manufacturing in 2004.
  • 2004
    Printed Circuit Board production moves from C&D Electronics to SJE Rhombus in Detroit Lakes, MN. Surface mount PCB equipment is installed and production for the Embedded Controls Group begins.
  • 2005
    SJE Rhombus acquires Control Works, Inc., a custom control panel facility located in Milford, Ohio.

    suzhou facility 2007
    The Suzhou, China, facility was added in 2007.
  • 2007
    SJE Rhombus increases engineering and PCB capabilities with the addition of Compucon Co., located in New Hope, MN.
    SJE Rhombus opens a facility in Suzhou, China to better serve pump OEMs currently producing products in China.
    SJE Rhombus is named one of the ’50 Best Small to Medium Companies to Work for in America’.
  • 2008
    SJE Rhombus acquires CSI Controls in Ashland, Ohio – a manufacturer of custom panels and on-site controls.
    SJE Rhombus acquires Best Controls Co. in Clearwater, FL – a manufacturer of custom panels and pump controllers.
  • 2010s

  • 2010
    SJE Rhombus develops new line of innovative products using “floatless” technology.
    SJE Rhombus Suzhou receives TUV certification on the SJE Quest™ pump switch.
    SJE Rhombus creates facebook page.
  • 2011
    SJE Rhombus is recognized by American Heart Association for employee wellness initiatives.
    Compucon Co. begins doing business as SJE Rhombus.
    Corporate website is redesigned.
    Dave Thomas is named President.
  • 2012
    Laurie Lewandowski retires as CEO.
    Dave Thomas is named CEO.
  • 2013
    SJE Rhombus unifies the Engineered Control Solutions businesses (Best Controls, Co., CSI Controls, Control Works, Inc.) under the new master brand PRIMEX™.
    PRIMEX™ website developed.
  • 2014
    SJE Rhombus expands from a three-year to a five-year limited warranty on most wholesale catalog products.

    40th anniversary 2015
    The theme for the 40th anniversary in 2015 was “Soaring to new heights.”
  • 2015
    SJE Rhombus acquires ICS Healy-Ruff™ in Plymouth, MN – a manufacturer and integrator of municipal control systems – and positions them within the PRIMEX engineered brand.
    SJE Rhombus celebrates 40th Anniversary (1975-2015) with a company picnic.

    vacaville ca 2016
    SJE Rhombus acquired the Vacaville, CA., location in 2016.
  • 2016
    SJE Rhombus acquires MCC Control Systems in Vacaville, CA – a systems integrator and automation solutions provider for municipal water, wastewater and industrial applications – and positions them within the PRIMEX engineered brand.

    esop award 2017
    Members of the EOAC got to attend the national ESOP conference in Washington, DC, when SJE won the ESOP of the year award in 2017.
  • 2017
    SJE Rhombus is named 2017 ESOP Company of the Year by the National ESOP (Employee Stock Ownership Plan) Association. Company name becomes SJE to separate SJE Rhombus as a separate brand, along with CSI Controls and Primex. SJE Rhombus gets a new logo and rebranding for the first time in nearly 20 year

    new ashland facility 2018
    The new facility in Ashland, OH, should be finished in December 2018.
  • 2018
    Construction begins on a new facility in Ashland, OH, with more space than the old facility in the same city. CSI Controls gets a new logo and rebranding.