History of Dynamatic™ Corporation

Dyne Systems, Inc. is a combination of three independent companies. These include Dyne Systems Co, Midwest® Dynamometer and Engineering Company and Eaton Dynamatic™ Dynamometer.

September 12, 1931

Dynamatic™ Corporation was founded in Kenosha, Wisconsin, by Martin and Anthony Winther, in order to manufacture the Winther brother’s invention, the “eddy current clutch”, originally intended for automobiles. The first major application was for air conditioning compressors installed on Pullman railroad cars; this application was the reverse of the usual speed control in that it took the varying speed of the car axle and regulated it to a constant speed output for the compressor. Approximately 6,900 of these clutches were manufactured.

The name “Dynamatic” was derived from the words “Dynamo” and “Automatic”, and has become, over the years, a highly recognized and respected trade name in both the US and abroad.


Eddy-Current Dynamometers are introduced.


The idea of a variable speed regulated clutch is introduced and soon thereafter, the self-contained drive with a motor and variable speed clutch dubbed “Adjusto-Spede”, made its appearance.

1941 – 1946

Production is dedicated to the war effort, primarily in the form of dynamometers for aircraft engine testing.

March 1946

The Eaton Manufacturing Company acquired Dynamatic™ Corporation remained a wholly owned subsidiary until December 1953, when it became the Dynamatic Division of Eaton Corporation.


Eaton also develops and manufactures adjustable frequency and DC drives.


Eaton completed a consolidation of AF drive manufacture at its Oldsmar, Florida location and sold the remaining Eddy-Current business to a group of private investors. These investors restored the original name to the business, “Dynamatic™ Corporation”, and continued the manufacture of the full line of EC drives and controls.

February 28, 2002

Drive Source International, Inc. acquired the assets of Dynamatic™.

March 2002

Dyne Systems LLC, owned by Jerry & Diana Jonen purchases the Dynamatic™ Dynamometer division from Drive Source International, Inc.