We have limited inventory of our fractional horsepower units IN STOCK now!

  • 1/4HP to 1.5HP units available
  • Easy, drop-in replacements
  • Meets demanding overload requirements
  • Permanently lubricated bearings for minimal maintenance
  • Available in single phase or three phase
  • Compatible with existing machinery wiring and plant power
  • Flexible modifications after drive is in service

Drop-In Replacements Ready!

Fractional HP drives can be swapped easily

  • Eliminates downtime
  • No special training needed
  • Expedited shipping
  • Available in single phase or three phase

DSI/Dynamatic is here to help!

Contact us today to get expedited service!

Fractional Horsepower Drive

Fractional Horsepower Variable Speed Drive

What happens after mechanical failure?

Your variable speed drive is mechanical and it will fail.
Will you be prepared?

  • How will this failure affect your business?
  • What would it mean to your company financially?
  • How long could you be without your variable speed drive?
  • How long would it take to get a replacement?

DSI/Dynamatic can provide you with a spare unit to eliminate down time.

AS Drives provide the Best Performance in the 1-40 HP variable speed drive class

Smooth, responsive and highly reliable, the AS Drive with tachometer feedback lets you control speed within 1/2 percent for load changes from no load to full load. You also get a full 34 to 1 speed range and 250 percent of rated motor torque — great for starting and momentary overload conditions.

Dynamatic® AS/FAS Drives

Cutaway illustration reveals the simplicity of our Eddy Current design

What makes the AS great?

  • Control, motor, and clutch in one

  • 200% rated torque on start up

  • Easy installation

  • Tachometer feedback

  • Permanently lubricated bearings

  • Available in single phase or 3-phase

  • Easily add gears or brakes

  • Flexible modifications

PLC compatible

Interfacing the Dynamatic AS drive with a computer control system is a snap. The controller interfaces easily with PLC systems.

Designed for reliable adjustable speed performance

A look inside the Dynamatic AS drive tells you why it’s the leader in adjustable speed drive applications.

  • Simple design
  • High performance & reliability
  • Only 4 bearings to maintain
  • Few points of friction for long-lasting equipment
  • Quick turnaround time from order to delivery
  • 2:1 longevity vs. VFD
  • Approx. 250% starting motor torque
  • No expensive spares
  • One simple controller


  • Spindle
  • Turn table
  • Take-ups/Rewinds

Small, simple controller

The entire SCR controller consists of one printed circuit board. It’s interchangeable among a wide horsepower range of drives to reduce your inventory and save money. We test every controller for 100% usability before it leaves our factory.

AS Drives – Dynamatic Eddy Current, Friction & Spring Set Brakes

There are three brakes options, that can be mounted as an additional optional part, on either the clutch end or motor end of a standard horizontal AS Drive.

  1. Eddy Current Brake is an adjustable torque brake used to decelerate the drive.
  2. Friction Brake is an electromagnetic brake that uses friction to decelerate and stop the drive.
  3. Spring Set Brake is a failsafe/emergency brake to decelerate, stop and hold the drive.

Contact one of our engineers to learn if the addition brake options are right for your application.

World’s Leading Manufacturer