Dynamatic® Drive Source USA International, Inc.

Dynamatic® Drive Source International, Inc.
Dynamatic® – Adjustable speed drives, brakes and controls OEM

World's leading manufacturer of Eddy Current adjustable speed drives, brakes and controls.

About DSI


Drive Source International (DSI) is the world’s leading provider of Eddy Current adjustable speed solutions

Dynamatic® is a brand built upon 80+ years of reliable performance. Drive Source International, Inc. is the corporation that owns the Dynamatic® brand of Eddy Current adjustable speed drives, brakes and controls.

As an application engineering manufacturer, we offer the most complete line of electromagnetic drives, brakes, and digital controls, centered on the world-renowned Dynamatic® brand. Our broad offering consists of Eddy Current variable speed drives up to 4000HP, Eddy Current air and liquid cooled brakes, CES Constant Energy Digital press drives, Eddy Current controls, custom control systems, high speed AC motors, inverter packages, and Dynamatic® Specialty & AC Dynamometer Motors.

Dynamatic® supports complete factory rebuilds on all products, backed by a factory warranty. We can rebuild, test and repair all control circuit boards back to factory original specifications insuring minimal downtime.

Dynamatic® understands the value of engineering products based on their specific and unique applications. We utilize the vast knowledge and experience of our mechanical and electrical engineering teams to fully engage the natural advantages of the Eddy Current technology.

In addition, Dynamatic® is the North American agents/distributors and factory repair specialist for TECO Eddy Current drives and controls. We also specialize in a complete line of AC Variable Frequency Drive packages (VFDs).

World’s leader in Eddy Current adjustable speed solutions


  • Dynamatic® OEM
  • Eddy Current expertise
  • Adjustable speed solutions
  • Drives, brakes and controls
  • Application engineering
  • Parts and repair services

The history of the Dynamatic® brand

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 were first introduced in 1936. During the years, 1941 to 1946, the entire production was dedicated to the war effort, primarily in the form of dynamometers for aircraft engine testing.

The idea of a variable speed regulated clutch was introduced in 1939, and soon thereafter, the self-contained drive with a motor and variable speed clutch dubbed “Ajusto-Spede” made its appearance.

March 1946 – the Eaton Manufacturing Company acquired Dynamatic®. The Dynamatic® Corporation remained a wholly owned subsidiary until December 1953, when it became the Dynamatic Division of Eaton Corporation. In the middle 1960’s, Eaton also developed and started manufacturing adjustable frequency and DC drives. In 1995, 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 Dynamatic® Eddy Current drives and controls.

February 2002 – Drive Source International, Inc. acquired the assets of the Dynamatic® Corporation with the purpose of re-energizing its applications knowledge and engineering know-how, and to re-establish Eddy Current electromagnetic technology as the reliable and most cost-effective solution for adjustable speed control.

November 2007 – Drive Source International, Inc. added to its Eddy Current dominance with the purchase of Tasc® Eddy Current, Heenan® Eddy Current and Neco® Geared motor products lines from ATB Laurence Scott Ltd. of Norwich, England.

Dynamatic® – Adjustable speed drives, brakes and controls OEM

7900 Durand Avenue, Bldg. 3 | Sturtevant, Wisconsin 53177 USA

Phone: 262-554-7977 | Toll Free: 800-548-2169 US/Canada

Outside the US/Canada: +1-262-554-7977

Fax: 262-554-7041

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