About Simplex

Simplex is a high technology company that designs and manufactures electrical test systems (load banks) and fuel supply systems for the standby power generation industry. Simplex is certified to ISO 9001:2015.

Simplex products are installed in some of the most demanding, mission critical environments in companies like Cummins, Caterpillar, General Electric, Microsoft, Apple, Google, Boeing and all branches of the United States military. Many hospitals, schools and public utilities throughout the country also rely on Simplex products to provide emergency backup electrical power. Simplex equipment is used for the servicing of McDonnell-Douglas MD-11, MD-80 and Boeing 777 jetliners, the Space Shuttle, and all destroyers, cruisers and nuclear submarines and locomotives produced in the United States.

Simplex engineers are experts at building products to meet our customers' exact requirements. We are engineering with a heavy emphasis on creative design and product development. As a light manufacturer, our production processes center around sheet metal fabrication, plumbing assembly and assembly of electrical equipment.

Simplex has been in business since 1934 as a family owned private enterprise. Simplex headquarters is located in Springfield, Illinois. We have manufacturing facilities at our headquarters. Simplex employs over one hundred and fifty people and returns millions of dollars annually to the local economy. Please read about our history, our facility, and our Simplex Onsite Load Bank Rental and Technical Services affiliate.