VFD vs VSD: Are They The Same?


By Gary Patterson, Municipal Market Manager To answer that question simply: yes and no. Though, that’s not quite so simple, is it? As with most explanations, there’s a short answer and a long answer when we compare Variable Frequency Drives (VFDs) with Variable Speed Drives (VSDs).  Variable frequency drives are variable speed drives but there are other types of variable speed drives. The most common is Eddy Current. There are two significant differences, however, and this is the short answer:  Eddy current drives change the speed of the coupling while leaving the motor speed to run at full speed.  VFD’s change [...]

VFD vs VSD: Are They The Same?2020-08-11T16:08:48-05:00

Mechanical Advantages of Eddy Current Drives


By Jennifer Ludlum, Regional Sales Engineer People most often talk about efficiency and harmonics when discussing variable speed, but there is a mechanical side to variable speed drives and the benefits are significant with an eddy current drive. Let’s take a look. In an eddy current drive, the motor and driven equipment are not physically connected. The input and output shafts turn independently.  The motor end is within the frame of the drive unit, and an open-ended cylinder is coupled to the motor shaft. (Figure 1) Attached to the driven equipment is the output rotor (Figure 2).  This rotor has the [...]

Mechanical Advantages of Eddy Current Drives2020-07-08T13:03:26-05:00

Our (Humble) History


By Rebecca Hart, Marketing Manager 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. 1885-1913 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 [...]

Our (Humble) History2020-07-07T12:49:45-05:00

Why Upgrade from Mark-III to EC-2000?


by DJ Smith, Industrial Market Manager The Mark-III family of eddy current controls has been the mainstay control for Dynamatic® variable speed clutches since 1970. Many of these controls are still in operation today. Did you know that DSI-Dynamatic® still produces the Mark-III controls? Direct, drop-in replacements are still manufactured in southeast Wisconsin and are typically available within a week or less. The EC-2000 family of controls is our newest digital drive, which has all the features of the Mark-III, as well as additional newer features. The EC-2000, in most cases, will have the same footprint as the Mark-III for easy [...]

Why Upgrade from Mark-III to EC-2000?2020-06-15T13:57:14-05:00