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Company History

The SJE-Rhombus Story

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

The business is incorporated and renamed S.J. Electro Systems, Inc.

SJE's first employee is hired.  

An addition is built that doubles the size of the facility.

Five employees are active at S.J. Electro Systems, Inc.  An addition of  44' x 74' is added to the existing building.

S.J. Electro Systems, Inc. makes INC magazine's list of the "500 fastest growing privately held companies in the nation" three years running.

S.J. Electro Systems Board of Directors adopts an Employee Stock Ownership Plan (ESOP).

A new building!  S.J. Electro Systems, Inc. completes and occupies a new 30,000 square foot pre-cast concrete manufacturing building.

S.J. Electro Systems, Inc. adds a new product line and establishes expertise in designing and manufacturing control panels (Rhombus Technology).

Founder Stephen P. Johnston retires as CEO of SJE.
Lois Solheim is named the new CEO.

S.J. Electro Systems, Inc. begins doing business as SJE-Rhombus.

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.

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

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.

SJE-Rhombus acquires
Control Works, Inc., a custom control panel facility located in Milford, Ohio. 

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'.

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.

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.

SJE-Rhombus is recognized by American Heart Association for employee wellness initiatives.
Compucon Co. begins doing business as SJE-Rhombus.
Dave Thomas is named President.
Corporate website is redesigned.

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.
Laurie Lewandowski retires as CEO.
Dave Thomas is named CEO.

SJE-Rhombus expands from a three-year to a five-year limited warranty on most wholesale catalog products.

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. 


Steve Johnston, SJE founder, displays the Tank Alert® alarm at trade show.

Steve Johnston 1976

S.J. Electro Systems Building in 1980

SJ Electro Building 1980

Tank Alert® alarm in 1983.

Tank Alert® Alarm 1983

SJE begins building a new 30,000 sq. ft. concrete manufacturing facility in 1988.

New Building Started 1988

Rhombus Technology, a division of SJE, begins control panel production in 1992.

Rhombus Technology 1992

SJE-Rhombus adds 33,000 sq. ft. onto manufacturing facility in Detroit Lakes, MN.

SJE-Rhombus 1998

SJE-Rhombus adds printed circuit board production.

Embedded Controls 2004

SJE-Rhombus facility in Suzhou, China.

Suzhou Facility 2007

SJE-Rhombus facility in Suzhou, China.

40th Anniversary 2015

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