Electromagnetic Eddy Current engineering is simply better by design
The Dynamatic® adjustable speed drive system consists of a constant speed AC induction motor and an electromagnetic clutch, governed by a small digital controller.
Dynamatic® allows the AC motor to run at its optimum rated speed. A simple electromagnetic coupling (clutch) is used to vary the output speed.
The only wear parts are bearings and brushes, since the motor and drive are separated by an air gap. By regulating voltage to the clutch coil, a magnetic flux field is generated in the gap and distortion of the flux field creates torque. Output speed is governed by the digital control. The greater the power is to the clutch coil, the greater the strength of the magnetic flux field, and the greater the output torque/speed.
The feedback signal from the tachometer is compared to a reference signal within the controller to maintain accurate speed within 0.5%. This closed-loop speed system typically uses less than 1% of the total AC input current to the motor.