Our beginning is humble but lends to the reason our eddy current products have stood the test of time. The following research comes from many sources, including our own archives, Wikipedia pages, The Wisconsin Historical Society, and The Kenosha News.


Let’s start with eddy current, the reason we exist. Eddy current, also known as Foucault current, was discovered by French physicist Jean Bernard Leon Foucault in 1885. He discovered that eddy currents were electrical currents induced within conductors by a changing magnetic field and he initially used it in his telescopes. Right around the same year, a Dutch family was coming through Ellis Island in New York with a young son. They were settled briefly in Manitowoc, Neenah and eventually settled in Kenosha, Wisconsin, eventually having another son and a daughter. Little did they know, eddy current would be what makes the brothers famous.


The brothers, Martin and Anthony Winther, grew up working in the early automobile industry. Martin, the oldest of the three, spent time working as an apprentice and machine hand for many years. He made chassis for fire trucks and was instrumental in the engineering of a four-wheel drive truck for the Thomas B. Jeffrey Company in Kenosha, which debuted in 1913. Three years later, and six years after Thomas Jeffrey died while on a trip to Italy, Jeffrey’s son Charles, sold the company to Charles Nash (former General Motors president), who renamed it after himself, Nash Motors. This business change allowed Martin an opportunity to start something on his own.


Martin and Anthony founded the Winther Motor and Truck Company in Kenosha in 1916. They manufactured trucks during World War I that were shipped to Australia, and when the war ended, military trucks were abundant, so they shifted manufacturing to a newer Winther automobile, a sportier truck, in 1922. Four years later, work shifted once again to fire trucks, but the market was fading, as was their passion for the company. They sold it to H.P. Olsen. Not much is known about the years under H.P. Olsen, but the Winther brothers continued to work on an invention on their own using eddy current technology, and in 1936, developed the eddy current dynamometer and patented it in 1944. The dynamometer eventually was used to measure aircraft engine performance during World War II. They also developed the variable speed clutch using eddy current technology in 1939 and soon after, the Ajusto-Spede, which was a self-contained drive consisting of a motor and an adjustable-speed clutch. They named their company The Dynamatic Corporation and used “Dynamatic” as the brand name for their products. This name was derived from “dynamo” and “automatic.”


Once World War II ended, the Winther brothers were in their 60s and having been in the business most of their lives, they were on the verge of retirement. In March 1946, the Eaton Manufacturing Company acquired the Dynamatic Corporation, and it remained a wholly owned subsidiary until December 1953, when it became the Dynamatic Division of Eaton Corporation. Eaton continued to manufacture parts for the automobile industry and kept the Dynamatic brand name. It wasn’t until the 1960s that Eaton started manufacturing AC drives and motors with the eddy current technology.


In 1995, Eaton Corporation sold the Dynamatic Division to a group of private investors, who restored the name to Dynamatic Corporation and continued to manufacture the complete line of eddy current drives and controls. Seven years later, those private investors left the business and sold the rights to manufacture to Drive Source International (DSI). The Dynamatic brand is still in wide, global use with its original technology and simple maintenance or available OEM replacements.

Today, we at DSI/Dynamatic focuses much of our attention on the water/wastewater industry.  Having pioneered the concept and advantages of variable speed pumping from the 1950s, Dynamatic is now the world’s leading resource for eddy current drive technology in this application.  We continue to offer a full spectrum of ratings, sizes, and configurations extending to as high as 5,000 hp. We can also upgrade controllers or renew mechanical drives of any brand and vintage, completely refurbish any brand of eddy current drive to factory specifications, and in some instances, we can offer complete replacements for our own or other brands.

Dynamatic services the water/wastewater industry, metal forming and press stamping, wire and cable, chemical manufacturing, dynamometer test stands, chain conveyors,  plastic and rubber, pulp and paper, textile production, high-torque applications, tension control and winders, and asphalt and aggregate industries.

Recent clients have included:

  • NASA
  • The Boeing Company
  • General Motors
  • Dow Chemical Company

and individual municipalities such as Columbus, Ohio, St. Joseph, Missouri and St. Louis, Missouri.